Increase maximum length of sqlite3_log() messages to 700 bytes. Mark log messages as v=10.

FossilOrigin-Name: 35aa893d4537d0b3605084a1f2f5529794e82af59b8893053815d3fcb4719a27

Makefile.in

@@ -420,6 +420,7 @@ TESTSRC = \
   $(TOP)/ext/fts3/fts3_term.c \
   $(TOP)/ext/fts3/fts3_test.c  \
   $(TOP)/ext/session/test_session.c \
+  $(TOP)/ext/session/sqlite3changebatch.c \
   $(TOP)/ext/recover/sqlite3recover.c \
   $(TOP)/ext/recover/dbdata.c \
   $(TOP)/ext/recover/test_recover.c \
@@ -433,6 +434,7 @@ TESTSRC += \
   $(TOP)/ext/expert/sqlite3expert.c \
   $(TOP)/ext/expert/test_expert.c \
   $(TOP)/ext/misc/amatch.c \
+  $(TOP)/ext/misc/bgckpt.c \
   $(TOP)/ext/misc/appendvfs.c \
   $(TOP)/ext/misc/basexx.c \
   $(TOP)/ext/misc/carray.c \

Makefile.msc

@@ -1581,6 +1581,7 @@ TESTEXT = \
   $(TOP)\ext\misc\amatch.c \
   $(TOP)\ext\misc\appendvfs.c \
   $(TOP)\ext\misc\basexx.c \
+  $(TOP)\ext\misc\bgckpt.c \
   $(TOP)\ext\misc\carray.c \
   $(TOP)\ext\misc\cksumvfs.c \
   $(TOP)\ext\misc\closure.c \

doc/begin_concurrent.md

@@ -0,0 +1,107 @@
+
+Begin Concurrent
+================
+
+## Overview
+
+Usually, SQLite allows at most one writer to proceed concurrently. The
+BEGIN CONCURRENT enhancement allows multiple writers to process write
+transactions simultanously if the database is in "wal" or "wal2" mode,
+although the system still serializes COMMIT commands.
+
+When a write-transaction is opened with "BEGIN CONCURRENT", actually 
+locking the database is deferred until a COMMIT is executed. This means
+that any number of transactions started with BEGIN CONCURRENT may proceed
+concurrently. The system uses optimistic page-level-locking to prevent
+conflicting concurrent transactions from being committed.
+
+When a BEGIN CONCURRENT transaction is committed, the system checks whether 
+or not any of the database pages that the transaction has read have been
+modified since the BEGIN CONCURRENT was opened. In other words - it asks 
+if the transaction being committed operates on a different set of data than
+all other concurrently executing transactions. If the answer is "yes, this
+transaction did not read or modify any data modified by any concurrent
+transaction", then the transaction is committed as normal. Otherwise, if the
+transaction does conflict, it cannot be committed and an SQLITE_BUSY_SNAPSHOT
+error is returned. At this point, all the client can do is ROLLBACK the
+transaction.
+
+If SQLITE_BUSY_SNAPSHOT is returned, messages are output via the sqlite3_log
+mechanism indicating the page and table or index on which the conflict
+occurred. This can be useful when optimizing concurrency.
+
+## Application Programming Notes
+
+In order to serialize COMMIT processing, SQLite takes a lock on the database
+as part of each COMMIT command and releases it before returning. At most one
+writer may hold this lock at any one time. If a writer cannot obtain the lock,
+it uses SQLite's busy-handler to pause and retry for a while:
+
+  <a href=https://www.sqlite.org/c3ref/busy_handler.html>
+      https://www.sqlite.org/c3ref/busy_handler.html
+  </a>
+
+If there is significant contention for the writer lock, this mechanism can be
+inefficient. In this case it is better for the application to use a mutex or
+some other mechanism that supports blocking to ensure that at most one writer
+is attempting to COMMIT a BEGIN CONCURRENT transaction at a time. This is
+usually easier if all writers are part of the same operating system process.
+
+If all database clients (readers and writers) are located in the same OS
+process, and if that OS is a Unix variant, then it can be more efficient to
+the built-in VFS "unix-excl" instead of the default "unix". This is because it
+uses more efficient locking primitives.
+
+The key to maximizing concurrency using BEGIN CONCURRENT is to ensure that
+there are a large number of non-conflicting transactions. In SQLite, each
+table and each index is stored as a separate b-tree, each of which is
+distributed over a discrete set of database pages. This means that:
+
+  * Two transactions that write to different sets of tables never 
+    conflict, and that
+
+  * Two transactions that write to the same tables or indexes only 
+    conflict if the values of the keys (either primary keys or indexed 
+    rows) are fairly close together. For example, given a large 
+    table with the schema:
+
+      <pre>     CREATE TABLE t1(a INTEGER PRIMARY KEY, b BLOB);</pre>
+
+    writing two rows with adjacent values for "a" probably will cause a
+    conflict (as the two keys are stored on the same page), but writing two
+    rows with vastly different values for "a" will not (as the keys will likly
+    be stored on different pages).
+
+Note that, in SQLite, if values are not explicitly supplied for an INTEGER
+PRIMARY KEY, as for example in:
+
+>
+     INSERT INTO t1(b) VALUES(&lt;blob-value>);
+
+then monotonically increasing values are assigned automatically. This is
+terrible for concurrency, as it all but ensures that all new rows are 
+added to the same database page. In such situations, it is better to
+explicitly assign random values to INTEGER PRIMARY KEY fields.
+
+This problem also comes up for non-WITHOUT ROWID tables that do not have an
+explicit INTEGER PRIMARY KEY column. In these cases each table has an implicit
+INTEGER PRIMARY KEY column that is assigned increasing values, leading to the
+same problem as omitting to assign a value to an explicit INTEGER PRIMARY KEY
+column.
+
+For both explicit and implicit INTEGER PRIMARY KEYs, it is possible to have
+SQLite assign values at random (instead of the monotonically increasing
+values) by writing a row with a rowid equal to the largest possible signed
+64-bit integer to the table. For example:
+
+     INSERT INTO t1(a) VALUES(9223372036854775807);
+
+Applications should take care not to malfunction due to the presence of such
+rows.
+
+The nature of some types of indexes, for example indexes on timestamp fields,
+can also cause problems (as concurrent transactions may assign similar
+timestamps that will be stored on the same db page to new records). In these
+cases the database schema may need to be rethought to increase the concurrency
+provided by page-level-locking.
+

doc/wal2.md

@@ -0,0 +1,98 @@
+
+Wal2 Mode Notes
+===============
+
+## Activating/Deactivating Wal2 Mode
+
+"Wal2" mode is very similar to "wal" mode. To change a database to wal2 mode,
+use the command:
+
+>
+     PRAGMA journal_mode = wal2;
+
+It is not possible to change a database directly from "wal" mode to "wal2"
+mode. Instead, it must first be changed to rollback mode. So, to change a wal
+mode database to wal2 mode, the following two commands may be used:
+
+>
+     PRAGMA journal_mode = delete;
+     PRAGMA journal_mode = wal2;
+
+A database in wal2 mode may only be accessed by versions of SQLite compiled
+from this branch. Attempting to use any other version of SQLite results in an
+SQLITE_NOTADB error. A wal2 mode database may be changed back to rollback mode
+(making it accessible by all versions of SQLite) using:
+
+>
+     PRAGMA journal_mode = delete;
+
+## The Advantage of Wal2 Mode
+
+In legacy wal mode, when a writer writes data to the database, it doesn't
+modify the database file directly. Instead, it appends new data to the
+"<database>-wal" file. Readers read data from both the original database
+file and the "<database>-wal" file. At some point, data is copied from the
+"<database>-wal" file into the database file, after which the wal file can
+be deleted or overwritten. Copying data from the wal file into the database
+file is called a "checkpoint", and may be done explictly (either by "PRAGMA
+wal_checkpoint" or sqlite3_wal_checkpoint_v2()), or
+automatically (by configuring "PRAGMA wal_autocheckpoint" - this is the
+default).
+
+Checkpointers do not block writers, and writers do not block checkpointers.
+However, if a writer writes to the database while a checkpoint is ongoing,
+then the new data is appended to the end of the wal file. This means that,
+even following the checkpoint, the wal file cannot be overwritten or deleted,
+and so all subsequent transactions must also be appended to the wal file. The
+work of the checkpointer is not wasted - SQLite remembers which parts of the
+wal file have already been copied into the db file so that the next checkpoint
+does not have to do so again - but it does mean that the wal file may grow
+indefinitely if the checkpointer never gets a chance to finish without a
+writer appending to the wal file. There are also circumstances in which
+long-running readers may prevent a checkpointer from checkpointing the entire
+wal file - also causing the wal file to grow indefinitely in a busy system.
+
+Wal2 mode does not have this problem. In wal2 mode, wal files do not grow
+indefinitely even if the checkpointer never has a chance to finish
+uninterrupted.
+
+In wal2 mode, the system uses two wal files instead of one. The files are named
+"<database>-wal" and "<database>-wal2", where "<database>" is of
+course the name of the database file. When data is written to the database, the
+writer begins by appending the new data to the first wal file. Once the first
+wal file has grown large enough, writers switch to appending data to the second
+wal file. At this point the first wal file can be checkpointed (after which it
+can be overwritten). Then, once the second wal file has grown large enough and
+the first wal file has been checkpointed, writers switch back to the first wal
+file. And so on.
+
+## Application Programming
+
+From the point of view of the user, the main differences between wal and 
+wal2 mode are to do with checkpointing:
+
+  * In wal mode, a checkpoint may be attempted at any time. In wal2 
+    mode, the checkpointer has to wait until writers have switched 
+    to the "other" wal file before a checkpoint can take place.
+
+  * In wal mode, the wal-hook (callback registered using
+    sqlite3_wal_hook()) is invoked after a transaction is committed
+    with the total number of pages in the wal file as an argument. In wal2
+    mode, the argument is either the total number of uncheckpointed pages in
+    both wal files, or - if the "other" wal file is empty or already
+    checkpointed - 0.
+
+Clients are recommended to use the same strategies for checkpointing wal2 mode
+databases as for wal databases - by registering a wal-hook using
+sqlite3_wal_hook() and attempting a checkpoint when the parameter
+exceeds a certain threshold.
+
+However, it should be noted that although the wal-hook is invoked after each
+transaction is committed to disk and database locks released, it is still
+invoked from within the sqlite3_step() call used to execute the "COMMIT"
+command. In BEGIN CONCURRENT systems, where the "COMMIT" is often protected by
+an application mutex, this may reduce concurrency. In such systems, instead of
+executing a checkpoint from within the wal-hook, a thread might defer this
+action until after the application mutex has been released.
+
+

ext/fts5/fts5_main.c

@@ -2046,6 +2046,7 @@ static int fts5UpdateMethod(
   }
 
  update_out:
+  sqlite3Fts5IndexCloseReader(pTab->p.pIndex);
   pTab->p.pConfig->pzErrmsg = 0;
   return rc;
 }

ext/fts5/test/fts5concurrent.test

@@ -0,0 +1,55 @@
+# 2022 May 09
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#*************************************************************************
+# This file implements regression tests for SQLite library.  The
+# focus of this script is testing the FTS5 module.
+#
+
+source [file join [file dirname [info script]] fts5_common.tcl]
+set testprefix fts5concurrent
+
+# If SQLITE_ENABLE_FTS5 is not defined, omit this file.
+ifcapable !fts5 {
+  finish_test
+  return
+}
+
+do_execsql_test 1.0 {
+  CREATE VIRTUAL TABLE ft USING fts5(line, tokenize=trigram);
+}
+
+do_execsql_test 1.1 {
+  BEGIN CONCURRENT;
+    INSERT INTO ft VALUES( hex(randomblob(50)) );
+  COMMIT
+} {}
+
+do_execsql_test 1.2 {
+  BEGIN CONCURRENT;
+    WITH s(i) AS (
+      SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<50
+    )
+    INSERT INTO ft SELECT hex(randomblob(50)) FROM s;
+
+    WITH s(i) AS (
+      SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<50
+    )
+    INSERT INTO ft SELECT hex(randomblob(50)) FROM s;
+
+    WITH s(i) AS (
+      SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<50
+    )
+    INSERT INTO ft SELECT hex(randomblob(50)) FROM s;
+  COMMIT;
+}
+
+
+finish_test
+

ext/fts5/test/fts5secure3.test

@@ -85,7 +85,6 @@ do_execsql_test 2.8 {
 #-------------------------------------------------------------------------
 # Tests with large/small rowid values.
 #
-
 foreach {tn cfg} {
   1 ""
   2 "INSERT INTO fff(fff, rank) VALUES('secure-delete', 1)"
@@ -111,6 +110,13 @@ foreach {tn cfg} {
     set ret
   }
   db func newdoc newdoc
+
+  proc random {} {
+    set res [expr { int(rand() * 0x7FFFFFFFFFFFFFFF) }]
+    if { int(rand() * 2) } { set res [expr $res*-1] }
+    return $res
+  }
+  db func random random
   
   do_execsql_test 3.$tn.0 {
     CREATE VIRTUAL TABLE fff USING fts5(y);
@@ -168,4 +174,3 @@ foreach {tn cfg} {
 
 
 finish_test
-

ext/misc/bgckpt.c

@@ -0,0 +1,228 @@
+/*
+** 2017-10-11
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+*/
+
+#if !defined(SQLITE_TEST) || defined(SQLITE_OS_UNIX)
+
+#include "sqlite3.h"
+#include <string.h>
+#include <pthread.h>
+
+/*
+** API declarations.
+*/
+typedef struct Checkpointer Checkpointer;
+int sqlite3_bgckpt_create(const char *zFilename, Checkpointer **pp);
+int sqlite3_bgckpt_checkpoint(Checkpointer *p, int bBlock);
+void sqlite3_bgckpt_destroy(Checkpointer *p);
+
+
+struct Checkpointer {
+  sqlite3 *db;                    /* Database handle */
+
+  pthread_t thread;               /* Background thread */
+  pthread_mutex_t mutex;
+  pthread_cond_t cond;
+
+  int rc;                         /* Error from "PRAGMA wal_checkpoint" */
+  int bCkpt;                      /* True if checkpoint requested */
+  int bExit;                      /* True if exit requested */
+};
+
+static void *bgckptThreadMain(void *pCtx){
+  int rc = SQLITE_OK;
+  Checkpointer *p = (Checkpointer*)pCtx;
+
+  while( rc==SQLITE_OK ){
+    int bExit;
+
+    pthread_mutex_lock(&p->mutex);
+    if( p->bCkpt==0 && p->bExit==0 ){
+      pthread_cond_wait(&p->cond, &p->mutex);
+    }
+    p->bCkpt = 0;
+    bExit = p->bExit;
+    pthread_mutex_unlock(&p->mutex);
+
+    if( bExit ) break;
+    rc = sqlite3_exec(p->db, "PRAGMA wal_checkpoint", 0, 0, 0);
+    if( rc==SQLITE_BUSY ){
+      rc = SQLITE_OK;
+    }
+  }
+
+  pthread_mutex_lock(&p->mutex);
+  p->rc = rc;
+  pthread_mutex_unlock(&p->mutex);
+  return 0;
+}
+
+void sqlite3_bgckpt_destroy(Checkpointer *p){
+  if( p ){
+    void *ret = 0;
+
+    /* Signal the background thread to exit */
+    pthread_mutex_lock(&p->mutex);
+    p->bExit = 1;
+    pthread_cond_broadcast(&p->cond);
+    pthread_mutex_unlock(&p->mutex);
+
+    pthread_join(p->thread, &ret);
+    sqlite3_close(p->db);
+    sqlite3_free(p);
+  }
+}
+
+
+int sqlite3_bgckpt_create(const char *zFilename, Checkpointer **pp){
+  Checkpointer *pNew = 0;
+  int rc;
+
+  pNew = (Checkpointer*)sqlite3_malloc(sizeof(Checkpointer));
+  if( pNew==0 ){
+    rc = SQLITE_NOMEM;
+  }else{
+    memset(pNew, 0, sizeof(Checkpointer));
+    rc = sqlite3_open(zFilename, &pNew->db);
+  }
+
+  if( rc==SQLITE_OK ){
+    pthread_mutex_init(&pNew->mutex, 0);
+    pthread_cond_init(&pNew->cond, 0);
+    pthread_create(&pNew->thread, 0, bgckptThreadMain, (void*)pNew);
+  }
+
+  if( rc!=SQLITE_OK ){
+    sqlite3_bgckpt_destroy(pNew);
+    pNew = 0;
+  }
+  *pp = pNew;
+  return rc;
+}
+
+int sqlite3_bgckpt_checkpoint(Checkpointer *p, int bBlock){
+  int rc;
+  pthread_mutex_lock(&p->mutex);
+  rc = p->rc;
+  if( rc==SQLITE_OK ){
+    p->bCkpt = 1;
+    pthread_cond_broadcast(&p->cond);
+  }
+  pthread_mutex_unlock(&p->mutex);
+  return rc;
+}
+
+#ifdef SQLITE_TEST
+#include "tclsqlite.h"
+
+const char *sqlite3ErrName(int rc);
+
+static void SQLITE_TCLAPI bgckpt_del(void * clientData){
+  Checkpointer *pCkpt = (Checkpointer*)clientData;
+  sqlite3_bgckpt_destroy(pCkpt);
+}
+
+/*
+** Tclcmd: $ckpt SUBCMD ...
+*/
+static int SQLITE_TCLAPI bgckpt_obj_cmd(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  Checkpointer *pCkpt = (Checkpointer*)clientData;
+  const char *aCmd[] = { "checkpoint", "destroy", 0 };
+  int iCmd;
+
+  if( objc<2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "SUBCMD ...");
+    return TCL_ERROR;
+  }
+
+  if( Tcl_GetIndexFromObj(interp, objv[1], aCmd, "sub-command", 0, &iCmd) ){
+    return TCL_ERROR;
+  }
+
+  switch( iCmd ){
+    case 0: {
+      int rc;
+      int bBlock = 0;
+
+      if( objc>3 ){
+        Tcl_WrongNumArgs(interp, 2, objv, "?BLOCKING?");
+        return TCL_ERROR;
+      }
+      if( objc==3 && Tcl_GetBooleanFromObj(interp, objv[2], &bBlock) ){
+        return TCL_ERROR;
+      }
+
+      rc = sqlite3_bgckpt_checkpoint(pCkpt, bBlock);
+      if( rc!=SQLITE_OK ){
+        Tcl_SetObjResult(interp, Tcl_NewStringObj(sqlite3ErrName(rc), -1));
+        return TCL_ERROR;
+      }
+      break;
+    }
+
+    case 1: {
+      Tcl_DeleteCommand(interp, Tcl_GetString(objv[0]));
+      break;
+    }
+  }
+
+  return TCL_OK;
+}
+
+/*
+** Tclcmd: bgckpt CMDNAME FILENAME
+*/
+static int SQLITE_TCLAPI bgckpt_cmd(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  const char *zCmd;
+  const char *zFilename;
+  int rc;
+  Checkpointer *pCkpt;
+
+  if( objc!=3 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "CMDNAME FILENAME");
+    return TCL_ERROR;
+  }
+  zCmd = Tcl_GetString(objv[1]);
+  zFilename = Tcl_GetString(objv[2]);
+
+  rc = sqlite3_bgckpt_create(zFilename, &pCkpt);
+  if( rc!=SQLITE_OK ){
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(sqlite3ErrName(rc), -1));
+    return TCL_ERROR;
+  }
+
+  Tcl_CreateObjCommand(interp, zCmd, bgckpt_obj_cmd, (void*)pCkpt, bgckpt_del);
+  Tcl_SetObjResult(interp, objv[1]);
+  return TCL_OK;
+}
+
+int Bgckpt_Init(Tcl_Interp *interp){
+  Tcl_CreateObjCommand(interp, "bgckpt", bgckpt_cmd, 0, 0);
+  return TCL_OK;
+}
+#endif   /* SQLITE_TEST */
+
+#else
+# include "tclsqlite.h"
+int Bgckpt_Init(Tcl_Interp *interp){ return TCL_OK; }
+#endif

ext/session/changebatch1.test

@@ -0,0 +1,223 @@
+# 2016 August 23
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library.
+#
+
+if {![info exists testdir]} {
+  set testdir [file join [file dirname [info script]] .. .. test]
+} 
+source $testdir/tester.tcl
+ifcapable !session {finish_test; return}
+
+set testprefix changebatch1
+
+
+proc sql_to_changeset {method sql} {
+  sqlite3session S db main
+  S attach *
+  execsql $sql
+  set ret [S $method]
+  S delete
+  return $ret
+}
+
+proc do_changebatch_test {tn method args} {
+  set C [list]
+  foreach a $args {
+    lappend C [sql_to_changeset $method $a]
+  }
+
+  sqlite3changebatch cb db
+  set i 1
+  foreach ::cs [lrange $C 0 end-1] {
+    set rc [cb add $::cs]
+    if {$rc!="SQLITE_OK"} { error "expected SQLITE_OK, got $rc (i=$i)" }
+    incr i
+  }
+
+  set ::cs [lindex $C end]
+  do_test $tn { cb add [set ::cs] } SQLITE_CONSTRAINT
+  cb delete
+}
+
+proc do_changebatch_test1 {tn args} {
+  uplevel do_changebatch_test $tn changeset $args
+}
+proc do_changebatch_test2 {tn args} {
+  uplevel do_changebatch_test $tn fullchangeset $args
+}
+
+#-------------------------------------------------------------------------
+# The body of the following loop contains tests for database schemas
+# that do not feature multi-column UNIQUE constraints. In this case
+# it doesn't matter if the changesets are generated using
+# sqlite3session_changeset() or sqlite3session_fullchangeset().
+#
+foreach {tn testfunction} {
+  1 do_changebatch_test1
+  2 do_changebatch_test2
+} {
+  reset_db
+
+  #-------------------------------------------------------------------------
+  #
+  do_execsql_test $tn.1.0 {
+    CREATE TABLE t1(a PRIMARY KEY, b);
+  }
+  
+  $testfunction $tn.1.1 {
+    INSERT INTO t1 VALUES(1, 1);
+  } {
+    DELETE FROM t1 WHERE a=1;
+  }
+  
+  do_execsql_test $tn.1.2.0 {
+    INSERT INTO t1 VALUES(1, 1);
+    INSERT INTO t1 VALUES(2, 2);
+    INSERT INTO t1 VALUES(3, 3);
+  }
+  $testfunction $tn.1.2.1 {
+    DELETE FROM t1 WHERE a=2;
+  } {
+    INSERT INTO t1 VALUES(2, 2);
+  }
+  
+  #-------------------------------------------------------------------------
+  #
+  do_execsql_test $tn.2.0 {
+    CREATE TABLE x1(a, b PRIMARY KEY, c UNIQUE);
+    CREATE TABLE x2(a PRIMARY KEY, b UNIQUE, c UNIQUE);
+    CREATE INDEX x1a ON x1(a);
+  
+    INSERT INTO x1 VALUES(1, 1, 'a');
+    INSERT INTO x1 VALUES(1, 2, 'b');
+    INSERT INTO x1 VALUES(1, 3, 'c');
+  }
+  
+  $testfunction $tn.2.1 {
+    DELETE FROM x1 WHERE b=2;
+  } {
+    UPDATE x1 SET c='b' WHERE b=3;
+  }
+  
+  $testfunction $tn.2.2 {
+    DELETE FROM x1 WHERE b=1;
+  } {
+    INSERT INTO x1 VALUES(1, 5, 'a');
+  }
+
+  set L [list]
+  for {set i 1000} {$i < 10000} {incr i} {
+    lappend L "INSERT INTO x2 VALUES($i, $i, 'x' || $i)"
+  }
+  lappend L "DELETE FROM x2 WHERE b=1005"
+  $testfunction $tn.2.3 {*}$L
+
+  execsql { INSERT INTO x1 VALUES('f', 'f', 'f') }
+  $testfunction $tn.2.4 {
+    INSERT INTO x2 VALUES('f', 'f', 'f');
+  } {
+    INSERT INTO x1 VALUES('g', 'g', 'g');
+  } {
+    DELETE FROM x1 WHERE b='f';
+  } {
+    INSERT INTO x2 VALUES('g', 'g', 'g');
+  } {
+    INSERT INTO x1 VALUES('f', 'f', 'f');
+  }
+
+  execsql {
+    DELETE FROM x1;
+    INSERT INTO x1 VALUES(1.5, 1.5, 1.5);
+  }
+  $testfunction $tn.2.5 {
+    DELETE FROM x1 WHERE b BETWEEN 1 AND 2;
+  } {
+    INSERT INTO x1 VALUES(2.5, 2.5, 2.5);
+  } {
+    INSERT INTO x1 VALUES(1.5, 1.5, 1.5);
+  }
+
+  execsql {
+    DELETE FROM x2;
+    INSERT INTO x2 VALUES(X'abcd', X'1234', X'7890');
+    INSERT INTO x2 VALUES(X'0000', X'0000', X'0000');
+  }
+  $testfunction $tn.2.6 {
+    UPDATE x2 SET c = X'1234' WHERE a=X'abcd';
+    INSERT INTO x2 VALUES(X'1234', X'abcd', X'7890');
+  } {
+    DELETE FROM x2 WHERE b=X'0000';
+  } {
+    INSERT INTO x2 VALUES(1, X'0000', NULL);
+  }
+}
+
+#-------------------------------------------------------------------------
+# Test some multi-column UNIQUE constraints. First Using _changeset() to
+# demonstrate the problem, then using _fullchangeset() to show that it has
+# been fixed.
+#
+reset_db
+do_execsql_test 3.0 {
+  CREATE TABLE y1(a PRIMARY KEY, b, c, UNIQUE(b, c));
+  INSERT INTO y1 VALUES(1, 1, 1);
+  INSERT INTO y1 VALUES(2, 2, 2);
+  INSERT INTO y1 VALUES(3, 3, 3);
+  INSERT INTO y1 VALUES(4, 3, 4);
+  BEGIN;
+}
+
+do_test 3.1.1 {
+  set c1 [sql_to_changeset changeset { DELETE FROM y1 WHERE a=4    }]
+  set c2 [sql_to_changeset changeset { UPDATE y1 SET c=4 WHERE a=3 }]
+  sqlite3changebatch cb db
+  cb add $c1
+  cb add $c2
+} {SQLITE_OK}
+do_test 3.1.2 {
+  cb delete
+  execsql ROLLBACK
+} {}
+
+do_test 3.1.1 {
+  set c1 [sql_to_changeset fullchangeset { DELETE FROM y1 WHERE a=4    }]
+  set c2 [sql_to_changeset fullchangeset { UPDATE y1 SET c=4 WHERE a=3 }]
+  sqlite3changebatch cb db
+  cb add $c1
+  cb add $c2
+} {SQLITE_CONSTRAINT}
+do_test 3.1.2 {
+  cb delete
+} {}
+
+#-------------------------------------------------------------------------
+#
+reset_db
+do_execsql_test 4.0 {
+  CREATE TABLE t1(x, y, z, PRIMARY KEY(x, y), UNIQUE(z));
+}
+
+do_test 4.1 {
+  set c1 [sql_to_changeset fullchangeset { INSERT INTO t1 VALUES(1, 2, 3) }]
+  execsql {
+    DROP TABLE t1;
+    CREATE TABLE t1(w, x, y, z, PRIMARY KEY(x, y), UNIQUE(z));
+  }
+  sqlite3changebatch cb db
+  list [catch { cb add $c1 } msg] $msg
+} {1 SQLITE_RANGE}
+
+cb delete
+
+
+
+finish_test

ext/session/changebatchfault.test

@@ -0,0 +1,42 @@
+# 2011 Mar 21
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+# The focus of this file is testing the session module.
+#
+
+if {![info exists testdir]} {
+  set testdir [file join [file dirname [info script]] .. .. test]
+} 
+source [file join [file dirname [info script]] session_common.tcl]
+source $testdir/tester.tcl
+ifcapable !session {finish_test; return}
+set testprefix changebatchfault
+
+do_execsql_test 1.0 {
+  CREATE TABLE t1(a, b, c PRIMARY KEY, UNIQUE(a, b));
+  INSERT INTO t1 VALUES('a', 'a', 'a');
+  INSERT INTO t1 VALUES('b', 'b', 'b');
+}
+
+set ::c1 [changeset_from_sql { delete from t1 where c='a' }]
+set ::c2 [changeset_from_sql { insert into t1 values('c', 'c', 'c') }]
+
+do_faultsim_test 1 -faults oom-* -body {
+  sqlite3changebatch cb db
+  cb add $::c1
+  cb add $::c2
+} -test {
+  faultsim_test_result {0 SQLITE_OK} {1 SQLITE_NOMEM}
+  catch { cb delete }
+}
+
+
+finish_test

ext/session/sessionH.test

@@ -29,7 +29,7 @@ do_test 1.0 {
     WITH s(i) AS (
       VALUES(1) UNION ALL SELECT i+1 FROM s WHERe i<10000
     )
-    INSERT INTO t1 SELECT 'abcde', randomblob(16), i FROM s;
+    INSERT INTO t1 SELECT 'abcde', randomblob(18), i FROM s;
   }
   compare_db db db2
 } {}

ext/session/sqlite3changebatch.c

@@ -0,0 +1,485 @@
+
+#if !defined(SQLITE_TEST) || (defined(SQLITE_ENABLE_SESSION) && defined(SQLITE_ENABLE_PREUPDATE_HOOK))
+
+#include "sqlite3session.h"
+#include "sqlite3changebatch.h"
+
+#include <assert.h>
+#include <string.h>
+
+typedef struct BatchTable BatchTable;
+typedef struct BatchIndex BatchIndex;
+typedef struct BatchIndexEntry BatchIndexEntry;
+typedef struct BatchHash BatchHash;
+
+struct sqlite3_changebatch {
+  sqlite3 *db;                    /* Database handle used to read schema */
+  BatchTable *pTab;               /* First in linked list of tables */
+  int iChangesetId;               /* Current changeset id */
+  int iNextIdxId;                 /* Next available index id */
+  int nEntry;                     /* Number of entries in hash table */
+  int nHash;                      /* Number of hash buckets */
+  BatchIndexEntry **apHash;       /* Array of hash buckets */
+};
+
+struct BatchTable {
+  BatchIndex *pIdx;               /* First in linked list of UNIQUE indexes */
+  BatchTable *pNext;              /* Next table */
+  char zTab[1];                   /* Table name */
+};
+
+struct BatchIndex {
+  BatchIndex *pNext;              /* Next index on same table */
+  int iId;                        /* Index id (assigned internally) */
+  int bPk;                        /* True for PK index */
+  int nCol;                       /* Size of aiCol[] array */
+  int *aiCol;                     /* Array of columns that make up index */
+};
+
+struct BatchIndexEntry {
+  BatchIndexEntry *pNext;         /* Next colliding hash table entry */
+  int iChangesetId;               /* Id of associated changeset */
+  int iIdxId;                     /* Id of index this key is from */
+  int szRecord;
+  char aRecord[1];
+};
+
+/*
+** Allocate and zero a block of nByte bytes. Must be freed using cbFree().
+*/
+static void *cbMalloc(int *pRc, int nByte){
+  void *pRet;
+
+  if( *pRc ){
+    pRet = 0;
+  }else{
+    pRet = sqlite3_malloc(nByte);
+    if( pRet ){
+      memset(pRet, 0, nByte);
+    }else{
+      *pRc = SQLITE_NOMEM;
+    }
+  }
+
+  return pRet;
+}
+
+/*
+** Free an allocation made by cbMalloc().
+*/
+static void cbFree(void *p){
+  sqlite3_free(p);
+}
+
+/*
+** Return the hash bucket that pEntry belongs in.
+*/
+static int cbHash(sqlite3_changebatch *p, BatchIndexEntry *pEntry){
+  unsigned int iHash = (unsigned int)pEntry->iIdxId;
+  unsigned char *pEnd = (unsigned char*)&pEntry->aRecord[pEntry->szRecord];
+  unsigned char *pIter;
+
+  for(pIter=(unsigned char*)pEntry->aRecord; pIter<pEnd; pIter++){
+    iHash += (iHash << 7) + *pIter;
+  }
+
+  return (int)(iHash % p->nHash);
+}
+
+/*
+** Resize the hash table.
+*/
+static int cbHashResize(sqlite3_changebatch *p){
+  int rc = SQLITE_OK;
+  BatchIndexEntry **apNew;
+  int nNew = (p->nHash ? p->nHash*2 : 512);
+  int i;
+
+  apNew = cbMalloc(&rc, sizeof(BatchIndexEntry*) * nNew);
+  if( rc==SQLITE_OK ){
+    int nHash = p->nHash;
+    p->nHash = nNew;
+    for(i=0; i<nHash; i++){
+      BatchIndexEntry *pEntry;
+      while( (pEntry=p->apHash[i])!=0 ){
+        int iHash = cbHash(p, pEntry);
+        p->apHash[i] = pEntry->pNext;
+        pEntry->pNext = apNew[iHash];
+        apNew[iHash] = pEntry;
+      }
+    }
+
+    cbFree(p->apHash);
+    p->apHash = apNew;
+  }
+
+  return rc;
+}
+
+
+/*
+** Allocate a new sqlite3_changebatch object.
+*/
+int sqlite3changebatch_new(sqlite3 *db, sqlite3_changebatch **pp){
+  sqlite3_changebatch *pRet;
+  int rc = SQLITE_OK;
+  *pp = pRet = (sqlite3_changebatch*)cbMalloc(&rc, sizeof(sqlite3_changebatch));
+  if( pRet ){
+    pRet->db = db;
+  }
+  return rc;
+}
+
+/*
+** Add a BatchIndex entry for index zIdx to table pTab.
+*/
+static int cbAddIndex(
+  sqlite3_changebatch *p, 
+  BatchTable *pTab, 
+  const char *zIdx, 
+  int bPk
+){
+  int nCol = 0;
+  sqlite3_stmt *pIndexInfo = 0;
+  BatchIndex *pNew = 0;
+  int rc;
+  char *zIndexInfo;
+
+  zIndexInfo = (char*)sqlite3_mprintf("PRAGMA main.index_info = %Q", zIdx);
+  if( zIndexInfo ){
+    rc = sqlite3_prepare_v2(p->db, zIndexInfo, -1, &pIndexInfo, 0);
+    sqlite3_free(zIndexInfo);
+  }else{
+    rc = SQLITE_NOMEM;
+  }
+
+  if( rc==SQLITE_OK ){
+    while( SQLITE_ROW==sqlite3_step(pIndexInfo) ){ nCol++; }
+    rc = sqlite3_reset(pIndexInfo);
+  }
+
+  pNew = (BatchIndex*)cbMalloc(&rc, sizeof(BatchIndex) + sizeof(int) * nCol);
+  if( rc==SQLITE_OK ){
+    pNew->nCol = nCol;
+    pNew->bPk = bPk;
+    pNew->aiCol = (int*)&pNew[1];
+    pNew->iId = p->iNextIdxId++;
+    while( SQLITE_ROW==sqlite3_step(pIndexInfo) ){ 
+      int i = sqlite3_column_int(pIndexInfo, 0);
+      int j = sqlite3_column_int(pIndexInfo, 1);
+      pNew->aiCol[i] = j;
+    }
+    rc = sqlite3_reset(pIndexInfo);
+  }
+
+  if( rc==SQLITE_OK ){
+    pNew->pNext = pTab->pIdx;
+    pTab->pIdx = pNew;
+  }else{
+    cbFree(pNew);
+  }
+  sqlite3_finalize(pIndexInfo);
+
+  return rc;
+}
+
+/*
+** Free the object passed as the first argument.
+*/
+static void cbFreeTable(BatchTable *pTab){
+  BatchIndex *pIdx;
+  BatchIndex *pIdxNext;
+  for(pIdx=pTab->pIdx; pIdx; pIdx=pIdxNext){
+    pIdxNext = pIdx->pNext;
+    cbFree(pIdx);
+  }
+  cbFree(pTab);
+}
+
+/*
+** Find or create the BatchTable object named zTab.
+*/
+static int cbFindTable(
+  sqlite3_changebatch *p, 
+  const char *zTab, 
+  BatchTable **ppTab
+){
+  BatchTable *pRet = 0;
+  int rc = SQLITE_OK;
+
+  for(pRet=p->pTab; pRet; pRet=pRet->pNext){
+    if( 0==sqlite3_stricmp(zTab, pRet->zTab) ) break;
+  }
+
+  if( pRet==0 ){
+    int nTab = strlen(zTab);
+    pRet = (BatchTable*)cbMalloc(&rc, nTab + sizeof(BatchTable));
+    if( pRet ){
+      sqlite3_stmt *pIndexList = 0;
+      char *zIndexList = 0;
+      int rc2;
+      memcpy(pRet->zTab, zTab, nTab);
+
+      zIndexList = sqlite3_mprintf("PRAGMA main.index_list = %Q", zTab);
+      if( zIndexList==0 ){
+        rc = SQLITE_NOMEM;
+      }else{
+        rc = sqlite3_prepare_v2(p->db, zIndexList, -1, &pIndexList, 0);
+        sqlite3_free(zIndexList);
+      }
+
+      while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pIndexList) ){
+        if( sqlite3_column_int(pIndexList, 2) ){
+          const char *zIdx = (const char*)sqlite3_column_text(pIndexList, 1);
+          const char *zTyp = (const char*)sqlite3_column_text(pIndexList, 3);
+          rc = cbAddIndex(p, pRet, zIdx, (zTyp[0]=='p'));
+        }
+      }
+      rc2 = sqlite3_finalize(pIndexList);
+      if( rc==SQLITE_OK ) rc = rc2;
+
+      if( rc==SQLITE_OK ){
+        pRet->pNext = p->pTab;
+        p->pTab = pRet;
+      }else{
+        cbFreeTable(pRet);
+        pRet = 0;
+      }
+    }
+  }
+
+  *ppTab = pRet;
+  return rc;
+}
+
+/*
+** Extract value iVal from the changeset iterator passed as the first
+** argument. Set *ppVal to point to the value before returning.
+**
+** This function attempts to extract the value using function xVal
+** (which is always either sqlite3changeset_new or sqlite3changeset_old).
+** If the call returns SQLITE_OK but does not supply an sqlite3_value*
+** pointer, an attempt to extract the value is made using the xFallback 
+** function.
+*/
+static int cbGetChangesetValue(
+  sqlite3_changeset_iter *pIter, 
+  int (*xVal)(sqlite3_changeset_iter*,int,sqlite3_value**),
+  int (*xFallback)(sqlite3_changeset_iter*,int,sqlite3_value**),
+  int iVal,
+  sqlite3_value **ppVal
+){
+  int rc = xVal(pIter, iVal, ppVal);
+  if( rc==SQLITE_OK && *ppVal==0 && xFallback ){
+    rc = xFallback(pIter, iVal, ppVal);
+  }
+  return rc;
+}
+
+static int cbAddToHash(
+  sqlite3_changebatch *p, 
+  sqlite3_changeset_iter *pIter, 
+  BatchIndex *pIdx, 
+  int (*xVal)(sqlite3_changeset_iter*,int,sqlite3_value**),
+  int (*xFallback)(sqlite3_changeset_iter*,int,sqlite3_value**),
+  int *pbConf
+){
+  BatchIndexEntry *pNew;
+  int sz = pIdx->nCol;
+  int i;
+  int iOut = 0;
+  int rc = SQLITE_OK;
+
+  for(i=0; rc==SQLITE_OK && i<pIdx->nCol; i++){
+    sqlite3_value *pVal;
+    rc = cbGetChangesetValue(pIter, xVal, xFallback, pIdx->aiCol[i], &pVal);
+    if( rc==SQLITE_OK ){
+      int eType = 0;
+      if( pVal ) eType = sqlite3_value_type(pVal);
+      switch( eType ){
+        case 0:
+        case SQLITE_NULL:
+          return SQLITE_OK;
+
+        case SQLITE_INTEGER:
+          sz += 8;
+          break;
+        case SQLITE_FLOAT:
+          sz += 8;
+          break;
+
+        default:
+          assert( eType==SQLITE_TEXT || eType==SQLITE_BLOB );
+          sz += sqlite3_value_bytes(pVal);
+          break;
+      }
+    }
+  }
+
+  pNew = cbMalloc(&rc, sizeof(BatchIndexEntry) + sz);
+  if( pNew ){
+    pNew->iChangesetId = p->iChangesetId;
+    pNew->iIdxId = pIdx->iId;
+    pNew->szRecord = sz;
+
+    for(i=0; i<pIdx->nCol; i++){
+      int eType;
+      sqlite3_value *pVal;
+      rc = cbGetChangesetValue(pIter, xVal, xFallback, pIdx->aiCol[i], &pVal);
+      if( rc!=SQLITE_OK ) break;  /* coverage: condition is never true */
+      eType = sqlite3_value_type(pVal);
+      pNew->aRecord[iOut++] = eType;
+      switch( eType ){
+        case SQLITE_INTEGER: {
+          sqlite3_int64 i64 = sqlite3_value_int64(pVal);
+          memcpy(&pNew->aRecord[iOut], &i64, 8);
+          iOut += 8;
+          break;
+        }
+        case SQLITE_FLOAT: {
+          double d64 = sqlite3_value_double(pVal);
+          memcpy(&pNew->aRecord[iOut], &d64, sizeof(double));
+          iOut += sizeof(double);
+          break;
+        }
+
+        default: {
+          int nByte = sqlite3_value_bytes(pVal);
+          const char *z = (const char*)sqlite3_value_blob(pVal);
+          memcpy(&pNew->aRecord[iOut], z, nByte);
+          iOut += nByte;
+          break;
+        }
+      }
+    }
+  }
+
+  if( rc==SQLITE_OK && p->nEntry>=(p->nHash/2) ){
+    rc = cbHashResize(p);
+  }
+
+  if( rc==SQLITE_OK ){
+    BatchIndexEntry *pIter;
+    int iHash = cbHash(p, pNew);
+
+    assert( iHash>=0 && iHash<p->nHash );
+    for(pIter=p->apHash[iHash]; pIter; pIter=pIter->pNext){
+      if( pNew->szRecord==pIter->szRecord 
+       && 0==memcmp(pNew->aRecord, pIter->aRecord, pNew->szRecord)
+      ){
+        if( pNew->iChangesetId!=pIter->iChangesetId ){
+          *pbConf = 1;
+        }
+        cbFree(pNew);
+        pNew = 0;
+        break;
+      }
+    }
+
+    if( pNew ){
+      pNew->pNext = p->apHash[iHash];
+      p->apHash[iHash] = pNew;
+      p->nEntry++;
+    }
+  }else{
+    cbFree(pNew);
+  }
+
+  return rc;
+}
+
+
+/*
+** Add a changeset to the current batch.
+*/
+int sqlite3changebatch_add(sqlite3_changebatch *p, void *pBuf, int nBuf){
+  sqlite3_changeset_iter *pIter;  /* Iterator opened on pBuf/nBuf */
+  int rc;                         /* Return code */
+  int bConf = 0;                  /* Conflict was detected */
+
+  rc = sqlite3changeset_start_v2(&pIter, nBuf, pBuf,SQLITE_CHANGESETSTART_FULL);
+  if( rc==SQLITE_OK ){
+    int rc2;
+    for(rc2 = sqlite3changeset_next(pIter);
+        rc2==SQLITE_ROW;
+        rc2 = sqlite3changeset_next(pIter)
+    ){
+      BatchTable *pTab;
+      BatchIndex *pIdx;
+      const char *zTab;           /* Table this change applies to */
+      int nCol;                   /* Number of columns in table */
+      int op;                     /* UPDATE, INSERT or DELETE */
+
+      sqlite3changeset_op(pIter, &zTab, &nCol, &op, 0);
+      assert( op==SQLITE_INSERT || op==SQLITE_UPDATE || op==SQLITE_DELETE );
+
+      rc = cbFindTable(p, zTab, &pTab);
+      assert( pTab || rc!=SQLITE_OK );
+      if( pTab ){
+        for(pIdx=pTab->pIdx; pIdx && rc==SQLITE_OK; pIdx=pIdx->pNext){
+          if( op==SQLITE_UPDATE && pIdx->bPk ) continue;
+          if( op==SQLITE_UPDATE || op==SQLITE_DELETE ){
+            rc = cbAddToHash(p, pIter, pIdx, sqlite3changeset_old, 0, &bConf);
+          }
+          if( op==SQLITE_UPDATE || op==SQLITE_INSERT ){
+            rc = cbAddToHash(p, pIter, pIdx, 
+                sqlite3changeset_new, sqlite3changeset_old, &bConf
+            );
+          }
+        }
+      }
+      if( rc!=SQLITE_OK ) break;
+    }
+
+    rc2 = sqlite3changeset_finalize(pIter);
+    if( rc==SQLITE_OK ) rc = rc2;
+  }
+
+  if( rc==SQLITE_OK && bConf ){
+    rc = SQLITE_CONSTRAINT;
+  }
+  p->iChangesetId++;
+  return rc;
+}
+
+/*
+** Zero an existing changebatch object.
+*/
+void sqlite3changebatch_zero(sqlite3_changebatch *p){
+  int i;
+  for(i=0; i<p->nHash; i++){
+    BatchIndexEntry *pEntry;
+    BatchIndexEntry *pNext;
+    for(pEntry=p->apHash[i]; pEntry; pEntry=pNext){
+      pNext = pEntry->pNext;
+      cbFree(pEntry);
+    }
+  }
+  cbFree(p->apHash);
+  p->nHash = 0;
+  p->apHash = 0;
+}
+
+/*
+** Delete a changebatch object.
+*/
+void sqlite3changebatch_delete(sqlite3_changebatch *p){
+  BatchTable *pTab;
+  BatchTable *pTabNext;
+
+  sqlite3changebatch_zero(p);
+  for(pTab=p->pTab; pTab; pTab=pTabNext){
+    pTabNext = pTab->pNext;
+    cbFreeTable(pTab);
+  }
+  cbFree(p);
+}
+
+/*
+** Return the db handle.
+*/
+sqlite3 *sqlite3changebatch_db(sqlite3_changebatch *p){
+  return p->db;
+}
+
+#endif /* SQLITE_ENABLE_SESSION && SQLITE_ENABLE_PREUPDATE_HOOK */

ext/session/sqlite3changebatch.h

@@ -0,0 +1,82 @@
+
+#if !defined(SQLITECHANGEBATCH_H_) 
+#define SQLITECHANGEBATCH_H_ 1
+
+typedef struct sqlite3_changebatch sqlite3_changebatch;
+
+/*
+** Create a new changebatch object for detecting conflicts between
+** changesets associated with a schema equivalent to that of the "main"
+** database of the open database handle db passed as the first
+** parameter. It is the responsibility of the caller to ensure that
+** the database handle is not closed until after the changebatch
+** object has been deleted.
+**
+** A changebatch object is used to detect batches of non-conflicting
+** changesets. Changesets that do not conflict may be applied to the 
+** target database in any order without affecting the final state of 
+** the database.
+**
+** The changebatch object only works reliably if PRIMARY KEY and UNIQUE
+** constraints on tables affected by the changesets use collation
+** sequences that are equivalent to built-in collation sequence 
+** BINARY for the == operation.
+**
+** If successful, SQLITE_OK is returned and (*pp) set to point to
+** the new changebatch object. If an error occurs, an SQLite error
+** code is returned and the final value of (*pp) is undefined.
+*/
+int sqlite3changebatch_new(sqlite3 *db, sqlite3_changebatch **pp);
+
+/*
+** Argument p points to a buffer containing a changeset n bytes in
+** size. Assuming no error occurs, this function returns SQLITE_OK
+** if the changeset does not conflict with any changeset passed 
+** to an sqlite3changebatch_add() call made on the same 
+** sqlite3_changebatch* handle since the most recent call to
+** sqlite3changebatch_zero(). If the changeset does conflict with 
+** an earlier such changeset, SQLITE_CONSTRAINT is returned. Or, 
+** if an error occurs, some other SQLite error code may be returned.
+**
+** One changeset is said to conflict with another if
+** either:
+**
+**   * the two changesets contain operations (INSERT, UPDATE or 
+**     DELETE) on the same row, identified by primary key, or
+**
+**   * the two changesets contain operations (INSERT, UPDATE or 
+**     DELETE) on rows with identical values in any combination 
+**     of fields constrained by a UNIQUE constraint.
+**
+** Even if this function returns SQLITE_CONFLICT, the current
+** changeset is added to the internal data structures - so future
+** calls to this function may conflict with it. If this function
+** returns any result code other than SQLITE_OK or SQLITE_CONFLICT,
+** the result of any future call to sqlite3changebatch_add() is
+** undefined.
+**
+** Only changesets may be passed to this function. Passing a 
+** patchset to this function results in an SQLITE_MISUSE error.
+*/
+int sqlite3changebatch_add(sqlite3_changebatch*, void *p, int n);
+
+/*
+** Zero a changebatch object. This causes the records of all earlier 
+** calls to sqlite3changebatch_add() to be discarded.
+*/
+void sqlite3changebatch_zero(sqlite3_changebatch*);
+
+/*
+** Return a copy of the first argument passed to the sqlite3changebatch_new()
+** call used to create the changebatch object passed as the only argument
+** to this function.
+*/
+sqlite3 *sqlite3changebatch_db(sqlite3_changebatch*);
+
+/*
+** Delete a changebatch object.
+*/
+void sqlite3changebatch_delete(sqlite3_changebatch*);
+
+#endif /* !defined(SQLITECHANGEBATCH_H_) */
+

ext/session/sqlite3session.c

@@ -27,6 +27,13 @@ typedef struct SessionInput SessionInput;
 
 #define SESSIONS_ROWID "_rowid_"
 
+/*
+** The three different types of changesets generated.
+*/
+#define SESSIONS_PATCHSET      0
+#define SESSIONS_CHANGESET     1
+#define SESSIONS_FULLCHANGESET 2
+
 static int sessions_strm_chunk_size = SESSIONS_STRM_CHUNK_SIZE;
 
 typedef struct SessionHook SessionHook;
@@ -94,6 +101,7 @@ struct SessionInput {
 struct sqlite3_changeset_iter {
   SessionInput in;                /* Input buffer or stream */
   SessionBuffer tblhdr;           /* Buffer to hold apValue/zTab/abPK/ */
+  int bChangebatch;               /* True for changebatch_add() */
   int bPatchset;                  /* True if this is a patchset */
   int bInvert;                    /* True to invert changeset */
   int bSkipEmpty;                 /* Skip noop UPDATE changes */
@@ -2604,7 +2612,7 @@ static void sessionAppendCol(
 */ 
 static int sessionAppendUpdate(
   SessionBuffer *pBuf,            /* Buffer to append to */
-  int bPatchset,                  /* True for "patchset", 0 for "changeset" */
+  int ePatchset,                  /* True for "patchset", 0 for "changeset" */
   sqlite3_stmt *pStmt,            /* Statement handle pointing at new row */
   SessionChange *p,               /* Object containing old values */
   u8 *abPK                        /* Boolean array - true for PK columns */
@@ -2668,8 +2676,8 @@ static int sessionAppendUpdate(
 
     /* Add a field to the old.* record. This is omitted if this module is
     ** currently generating a patchset. */
-    if( bPatchset==0 ){
-      if( bChanged || abPK[i] ){
+    if( ePatchset!=SESSIONS_PATCHSET ){
+      if( ePatchset==SESSIONS_FULLCHANGESET || bChanged || abPK[i] ){
         sessionAppendBlob(pBuf, pCsr, nAdvance, &rc);
       }else{
         sessionAppendByte(pBuf, 0, &rc);
@@ -2678,7 +2686,7 @@ static int sessionAppendUpdate(
 
     /* Add a field to the new.* record. Or the only record if currently
     ** generating a patchset.  */
-    if( bChanged || (bPatchset && abPK[i]) ){
+    if( bChanged || (ePatchset==SESSIONS_PATCHSET && abPK[i]) ){
       sessionAppendCol(&buf2, pStmt, i, &rc);
     }else{
       sessionAppendByte(&buf2, 0, &rc);
@@ -2704,7 +2712,7 @@ static int sessionAppendUpdate(
 */
 static int sessionAppendDelete(
   SessionBuffer *pBuf,            /* Buffer to append to */
-  int bPatchset,                  /* True for "patchset", 0 for "changeset" */
+  int eChangeset,                 /* One of SESSIONS_CHANGESET etc. */
   SessionChange *p,               /* Object containing old values */
   int nCol,                       /* Number of columns in table */
   u8 *abPK                        /* Boolean array - true for PK columns */
@@ -2714,7 +2722,7 @@ static int sessionAppendDelete(
   sessionAppendByte(pBuf, SQLITE_DELETE, &rc);
   sessionAppendByte(pBuf, p->bIndirect, &rc);
 
-  if( bPatchset==0 ){
+  if( eChangeset!=SESSIONS_PATCHSET ){
     sessionAppendBlob(pBuf, p->aRecord, p->nRecord, &rc);
   }else{
     int i;
@@ -2940,12 +2948,12 @@ static int sessionSelectBind(
 */
 static void sessionAppendTableHdr(
   SessionBuffer *pBuf,            /* Append header to this buffer */
-  int bPatchset,                  /* Use the patchset format if true */
+  int ePatchset,                  /* Use the patchset format if true */
   SessionTable *pTab,             /* Table object to append header for */
   int *pRc                        /* IN/OUT: Error code */
 ){
   /* Write a table header */
-  sessionAppendByte(pBuf, (bPatchset ? 'P' : 'T'), pRc);
+  sessionAppendByte(pBuf, (ePatchset==SESSIONS_PATCHSET) ? 'P' : 'T', pRc);
   sessionAppendVarint(pBuf, pTab->nCol, pRc);
   sessionAppendBlob(pBuf, pTab->abPK, pTab->nCol, pRc);
   sessionAppendBlob(pBuf, (u8 *)pTab->zName, (int)strlen(pTab->zName)+1, pRc);
@@ -2963,7 +2971,7 @@ static void sessionAppendTableHdr(
 */
 static int sessionGenerateChangeset(
   sqlite3_session *pSession,      /* Session object */
-  int bPatchset,                  /* True for patchset, false for changeset */
+  int ePatchset,                  /* One of SESSIONS_CHANGESET etc. */
   int (*xOutput)(void *pOut, const void *pData, int nData),
   void *pOut,                     /* First argument for xOutput */
   int *pnChangeset,               /* OUT: Size of buffer at *ppChangeset */
@@ -3008,7 +3016,7 @@ static int sessionGenerateChangeset(
       }
 
       /* Write a table header */
-      sessionAppendTableHdr(&buf, bPatchset, pTab, &rc);
+      sessionAppendTableHdr(&buf, ePatchset, pTab, &rc);
 
       /* Build and compile a statement to execute: */
       if( rc==SQLITE_OK ){
@@ -3034,10 +3042,10 @@ static int sessionGenerateChangeset(
               }
             }else{
               assert( pTab->abPK!=0 );
-              rc = sessionAppendUpdate(&buf, bPatchset, pSel, p, pTab->abPK);
+              rc = sessionAppendUpdate(&buf, ePatchset, pSel, p, pTab->abPK);
             }
           }else if( p->op!=SQLITE_INSERT ){
-            rc = sessionAppendDelete(&buf, bPatchset, p, pTab->nCol,pTab->abPK);
+            rc = sessionAppendDelete(&buf, ePatchset, p, pTab->nCol,pTab->abPK);
           }
           if( rc==SQLITE_OK ){
             rc = sqlite3_reset(pSel);
@@ -3096,7 +3104,8 @@ int sqlite3session_changeset(
   int rc;
 
   if( pnChangeset==0 || ppChangeset==0 ) return SQLITE_MISUSE;
-  rc = sessionGenerateChangeset(pSession, 0, 0, 0, pnChangeset, ppChangeset);
+  rc = sessionGenerateChangeset(
+      pSession, SESSIONS_CHANGESET, 0, 0, pnChangeset, ppChangeset);
   assert( rc || pnChangeset==0 
        || pSession->bEnableSize==0 || *pnChangeset<=pSession->nMaxChangesetSize 
   );
@@ -3112,7 +3121,8 @@ int sqlite3session_changeset_strm(
   void *pOut
 ){
   if( xOutput==0 ) return SQLITE_MISUSE;
-  return sessionGenerateChangeset(pSession, 0, xOutput, pOut, 0, 0);
+  return sessionGenerateChangeset(
+      pSession, SESSIONS_CHANGESET, xOutput, pOut, 0, 0);
 }
 
 /*
@@ -3124,7 +3134,8 @@ int sqlite3session_patchset_strm(
   void *pOut
 ){
   if( xOutput==0 ) return SQLITE_MISUSE;
-  return sessionGenerateChangeset(pSession, 1, xOutput, pOut, 0, 0);
+  return sessionGenerateChangeset(
+      pSession, SESSIONS_PATCHSET, xOutput, pOut, 0, 0);
 }
 
 /*
@@ -3140,9 +3151,20 @@ int sqlite3session_patchset(
   void **ppPatchset               /* OUT: Buffer containing changeset */
 ){
   if( pnPatchset==0 || ppPatchset==0 ) return SQLITE_MISUSE;
-  return sessionGenerateChangeset(pSession, 1, 0, 0, pnPatchset, ppPatchset);
+  return sessionGenerateChangeset(
+      pSession, SESSIONS_PATCHSET, 0, 0, pnPatchset, ppPatchset);
 }
 
+int sqlite3session_fullchangeset(
+  sqlite3_session *pSession,      /* Session object */
+  int *pnChangeset,               /* OUT: Size of buffer at *ppChangeset */
+  void **ppChangeset              /* OUT: Buffer containing changeset */
+){
+  return sessionGenerateChangeset(
+      pSession, SESSIONS_FULLCHANGESET, 0, 0, pnChangeset, ppChangeset);
+}
+
+
 /*
 ** Enable or disable the session object passed as the first argument.
 */
@@ -3295,8 +3317,13 @@ int sqlite3changeset_start_v2(
   void *pChangeset,               /* Pointer to buffer containing changeset */
   int flags
 ){
+  int rc;
+  sqlite3_changeset_iter *pIter = 0;
   int bInvert = !!(flags & SQLITE_CHANGESETSTART_INVERT);
-  return sessionChangesetStart(pp, 0, 0, nChangeset, pChangeset, bInvert, 0);
+  rc = sessionChangesetStart(&pIter, 0, 0, nChangeset, pChangeset, bInvert, 0);
+  if( pIter && (flags & SQLITE_CHANGESETSTART_FULL) ) pIter->bChangebatch = 1;
+  *pp = pIter;
+  return rc;
 }
 
 /*
@@ -3773,8 +3800,12 @@ static int sessionChangesetNextOne(
     **
     ** Such records are technically corrupt, but the rebaser was at one
     ** point generating them. Under most circumstances this is benign, but
-    ** can cause spurious SQLITE_RANGE errors when applying the changeset. */
-    if( p->bPatchset==0 && p->op==SQLITE_UPDATE){
+    ** can cause spurious SQLITE_RANGE errors when applying the changeset. 
+    **
+    ** Update for bedrock branch: Do not do this for changebatch_add() on 
+    ** this branch, as changesets generated by sqlite3sessions_fullchangeset()
+    ** also have this property.  */
+    if( p->bChangebatch==0 && p->bPatchset==0 && p->op==SQLITE_UPDATE){
       for(i=0; i<p->nCol; i++){
         if( p->abPK[i]==0 && p->apValue[i+p->nCol]==0 ){
           sqlite3ValueFree(p->apValue[i]);
@@ -5935,10 +5966,11 @@ static int sessionChangegroupOutput(
   ** hash tables attached to the SessionTable objects in list p->pList. 
   */
   for(pTab=pGrp->pList; rc==SQLITE_OK && pTab; pTab=pTab->pNext){
+    int eChangeset = pGrp->bPatch ? SESSIONS_PATCHSET : SESSIONS_CHANGESET;
     int i;
     if( pTab->nEntry==0 ) continue;
 
-    sessionAppendTableHdr(&buf, pGrp->bPatch, pTab, &rc);
+    sessionAppendTableHdr(&buf, eChangeset, pTab, &rc);
     for(i=0; i<pTab->nChange; i++){
       SessionChange *p;
       for(p=pTab->apChange[i]; p; p=p->pNext){

ext/session/sqlite3session.h

@@ -368,6 +368,32 @@ int sqlite3session_changeset(
   void **ppChangeset              /* OUT: Buffer containing changeset */
 );
 
+/*
+** CAPI3REF: Generate A Full Changeset From A Session Object
+**
+** This function is similar to sqlite3session_changeset(), except that for
+** each row affected by an UPDATE statement, all old.* values are recorded
+** as part of the changeset, not just those modified.
+*/
+int sqlite3session_fullchangeset(
+  sqlite3_session *pSession,      /* Session object */
+  int *pnChangeset,               /* OUT: Size of buffer at *ppChangeset */
+  void **ppChangeset              /* OUT: Buffer containing changeset */
+);
+
+/*
+** CAPI3REF: Generate A Full Changeset From A Session Object
+**
+** This function is similar to sqlite3session_changeset(), except that for
+** each row affected by an UPDATE statement, all old.* values are recorded
+** as part of the changeset, not just those modified.
+*/
+int sqlite3session_fullchangeset(
+  sqlite3_session *pSession,      /* Session object */
+  int *pnChangeset,               /* OUT: Size of buffer at *ppChangeset */
+  void **ppChangeset              /* OUT: Buffer containing changeset */
+);
+
 /*
 ** CAPI3REF: Return An Upper-limit For The Size Of The Changeset
 ** METHOD: sqlite3_session
@@ -568,12 +594,16 @@ int sqlite3changeset_start_v2(
 ** The following flags may passed via the 4th parameter to
 ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
 **
-** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
+** <dt>SQLITE_CHANGESETSTART_INVERT <dd>
 **   Invert the changeset while iterating through it. This is equivalent to
 **   inverting a changeset using sqlite3changeset_invert() before applying it.
 **   It is an error to specify this flag with a patchset.
+**
+** <dt>SQLITE_CHANGESETSTART_FULL <dd>
+**   Do not trim extra fields added to fullchangeset changesets.
 */
 #define SQLITE_CHANGESETSTART_INVERT        0x0002
+#define SQLITE_CHANGESETSTART_FULL          0x0004
 
 
 /*

ext/session/test_session.c

@@ -229,6 +229,7 @@ static int testStreamOutput(
 **          $session indirect INTEGER
 **          $session patchset
 **          $session table_filter SCRIPT
+**          $session fullchangeset
 */
 static int SQLITE_TCLAPI test_session_cmd(
   void *clientData,
@@ -242,20 +243,20 @@ static int SQLITE_TCLAPI test_session_cmd(
     const char *zSub;
     int nArg;
     const char *zMsg;
-    int iSub;
   } aSub[] = {
-    { "attach",       1, "TABLE",      }, /* 0 */
-    { "changeset",    0, "",           }, /* 1 */
-    { "delete",       0, "",           }, /* 2 */
-    { "enable",       1, "BOOL",       }, /* 3 */
-    { "indirect",     1, "BOOL",       }, /* 4 */
-    { "isempty",      0, "",           }, /* 5 */
-    { "table_filter", 1, "SCRIPT",     }, /* 6 */
+    { "attach",       1, "TABLE"       }, /* 0 */
+    { "changeset",    0, ""            }, /* 1 */
+    { "delete",       0, ""            }, /* 2 */
+    { "enable",       1, "BOOL"        }, /* 3 */
+    { "indirect",     1, "BOOL"        }, /* 4 */
+    { "isempty",      0, ""            }, /* 5 */
+    { "table_filter", 1, "SCRIPT"      }, /* 6 */
     { "patchset",     0, "",           }, /* 7 */
-    { "diff",         2, "FROMDB TBL", }, /* 8 */
-    { "memory_used",  0, "",           }, /* 9 */
-    { "changeset_size", 0, "",         }, /* 10 */
-    { "object_config", 2, "OPTION INTEGER", }, /* 11 */
+    { "diff",         2, "FROMDB TBL"  }, /* 8 */
+    { "fullchangeset",0, ""            }, /* 9 */
+    { "memory_used",  0, "",           }, /* 10 */
+    { "changeset_size", 0, "",         }, /* 11 */
+    { "object_config", 2, "OPTION INTEGER", }, /* 12 */
     { 0 }
   };
   int iSub;
@@ -285,10 +286,11 @@ static int SQLITE_TCLAPI test_session_cmd(
       break;
     }
 
+    case 9:        /* fullchangeset */
     case 7:        /* patchset */
     case 1: {      /* changeset */
       TestSessionsBlob o = {0, 0};
-      if( test_tcl_integer(interp, SESSION_STREAM_TCL_VAR) ){
+      if( iSub!=9 && test_tcl_integer(interp, SESSION_STREAM_TCL_VAR) ){
         void *pCtx = (void*)&o;
         if( iSub==7 ){
           rc = sqlite3session_patchset_strm(pSession, testStreamOutput, pCtx);
@@ -298,12 +300,15 @@ static int SQLITE_TCLAPI test_session_cmd(
       }else{
         if( iSub==7 ){
           rc = sqlite3session_patchset(pSession, &o.n, &o.p);
+          assert_changeset_is_ok(o.n, o.p);
+        }else if( iSub==9 ){
+          rc = sqlite3session_fullchangeset(pSession, &o.n, &o.p);
         }else{
           rc = sqlite3session_changeset(pSession, &o.n, &o.p);
+          assert_changeset_is_ok(o.n, o.p);
         }
       }
       if( rc==SQLITE_OK ){
-        assert_changeset_is_ok(o.n, o.p);
         Tcl_SetObjResult(interp, Tcl_NewByteArrayObj(o.p, o.n)); 
       }
       sqlite3_free(o.p);
@@ -313,6 +318,7 @@ static int SQLITE_TCLAPI test_session_cmd(
       break;
     }
 
+
     case 2:        /* delete */
       Tcl_DeleteCommand(interp, Tcl_GetString(objv[0]));
       break;
@@ -363,18 +369,18 @@ static int SQLITE_TCLAPI test_session_cmd(
       break;
     }
 
-    case 9: {      /* memory_used */
+    case 10: {      /* memory_used */
       sqlite3_int64 nMalloc = sqlite3session_memory_used(pSession);
       Tcl_SetObjResult(interp, Tcl_NewWideIntObj(nMalloc));
       break;
     }
 
-    case 10: {
+    case 11: {
       sqlite3_int64 nSize = sqlite3session_changeset_size(pSession);
       Tcl_SetObjResult(interp, Tcl_NewWideIntObj(nSize));
       break;
     }
-    case 11: {    /* object_config */
+    case 12: {    /* object_config */
       struct ObjConfOpt {
         const char *zName;
         int opt;
@@ -384,7 +390,6 @@ static int SQLITE_TCLAPI test_session_cmd(
         { 0, 0 }
       };
       size_t sz = sizeof(aOpt[0]);
-
       int iArg;
       int iOpt;
       if( Tcl_GetIndexFromObjStruct(interp,objv[2],aOpt,sz,"option",0,&iOpt) ){
@@ -541,7 +546,7 @@ static int test_filter_handler(
 
   Tcl_DecrRefCount(pEval);
   return res;
-}  
+}
 
 static int test_conflict_handler(
   void *pCtx,                     /* Pointer to TestConflictHandler structure */
@@ -1192,6 +1197,127 @@ static int SQLITE_TCLAPI test_sqlite3session_foreach(
   return TCL_OK;
 }
 
+#include "sqlite3changebatch.h"
+
+typedef struct TestChangebatch TestChangebatch;
+struct TestChangebatch {
+  sqlite3_changebatch *pChangebatch;
+};
+
+/*
+** Tclcmd:  $changebatch add BLOB
+**          $changebatch zero
+**          $changebatch delete
+*/
+static int SQLITE_TCLAPI test_changebatch_cmd(
+  void *clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  TestChangebatch *p = (TestChangebatch*)clientData;
+  sqlite3_changebatch *pChangebatch = p->pChangebatch;
+  struct SessionSubcmd {
+    const char *zSub;
+    int nArg;
+    const char *zMsg;
+    int iSub;
+  } aSub[] = {
+    { "add",          1, "CHANGESET",  }, /* 0 */
+    { "zero",         0, "",           }, /* 1 */
+    { "delete",       0, "",           }, /* 2 */
+    { 0 }
+  };
+  int iSub;
+  int rc;
+
+  if( objc<2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "SUBCOMMAND ...");
+    return TCL_ERROR;
+  }
+  rc = Tcl_GetIndexFromObjStruct(interp, 
+      objv[1], aSub, sizeof(aSub[0]), "sub-command", 0, &iSub
+  );
+  if( rc!=TCL_OK ) return rc;
+  if( objc!=2+aSub[iSub].nArg ){
+    Tcl_WrongNumArgs(interp, 2, objv, aSub[iSub].zMsg);
+    return TCL_ERROR;
+  }
+
+  switch( iSub ){
+    case 0: {      /* add */
+      int nArg;
+      unsigned char *pArg = Tcl_GetByteArrayFromObj(objv[2], &nArg);
+      rc = sqlite3changebatch_add(pChangebatch, pArg, nArg);
+      if( rc!=SQLITE_OK && rc!=SQLITE_CONSTRAINT ){
+        return test_session_error(interp, rc, 0);
+      }else{
+        extern const char *sqlite3ErrName(int);
+        Tcl_SetObjResult(interp, Tcl_NewStringObj(sqlite3ErrName(rc), -1));
+      }
+      break;
+    }
+
+    case 1: {      /* zero */
+      sqlite3changebatch_zero(pChangebatch);
+      break;
+    }
+
+    case 2:        /* delete */
+      Tcl_DeleteCommand(interp, Tcl_GetString(objv[0]));
+      break;
+  }
+
+  return TCL_OK;
+}
+
+static void SQLITE_TCLAPI test_changebatch_del(void *clientData){
+  TestChangebatch *p = (TestChangebatch*)clientData;
+  sqlite3changebatch_delete(p->pChangebatch);
+  ckfree((char*)p);
+}
+
+/*
+** Tclcmd:  sqlite3changebatch CMD DB-HANDLE
+*/
+static int SQLITE_TCLAPI test_sqlite3changebatch(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3 *db;
+  Tcl_CmdInfo info;
+  int rc;                         /* sqlite3session_create() return code */
+  TestChangebatch *p;             /* New wrapper object */
+
+  if( objc!=3 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "CMD DB-HANDLE");
+    return TCL_ERROR;
+  }
+
+  if( 0==Tcl_GetCommandInfo(interp, Tcl_GetString(objv[2]), &info) ){
+    Tcl_AppendResult(interp, "no such handle: ", Tcl_GetString(objv[2]), 0);
+    return TCL_ERROR;
+  }
+  db = *(sqlite3 **)info.objClientData;
+
+  p = (TestChangebatch*)ckalloc(sizeof(TestChangebatch));
+  memset(p, 0, sizeof(TestChangebatch));
+  rc = sqlite3changebatch_new(db, &p->pChangebatch);
+  if( rc!=SQLITE_OK ){
+    ckfree((char*)p);
+    return test_session_error(interp, rc, 0);
+  }
+
+  Tcl_CreateObjCommand(
+      interp, Tcl_GetString(objv[1]), test_changebatch_cmd, (ClientData)p,
+      test_changebatch_del
+  );
+  Tcl_SetObjResult(interp, objv[1]);
+  return TCL_OK;
+}
+
 /*
 ** tclcmd: CMD configure REBASE-BLOB
 ** tclcmd: CMD rebase CHANGESET
@@ -1746,6 +1872,10 @@ int TestSession_Init(Tcl_Interp *interp){
     Tcl_CreateObjCommand(interp, p->zCmd, p->xProc, 0, 0);
   }
 
+
+  Tcl_CreateObjCommand(
+      interp, "sqlite3changebatch", test_sqlite3changebatch, 0, 0
+  );
   return TCL_OK;
 }
 

ext/wasm/EXPORTED_FUNCTIONS.fiddle

@@ -1,10 +1,7 @@
+_fiddle_exec
+_fiddle_interrupt
+_fiddle_experiment
+_fiddle_the_db
 _fiddle_db_arg
 _fiddle_db_filename
-_fiddle_exec
-_fiddle_experiment
-_fiddle_interrupt
-_fiddle_main
 _fiddle_reset_db
-_fiddle_db_handle
-_fiddle_db_vfs
-_fiddle_export_db

ext/wasm/api/EXPORTED_FUNCTIONS.sqlite3-api

@@ -0,0 +1,72 @@
+_sqlite3_bind_blob
+_sqlite3_bind_double
+_sqlite3_bind_int
+_sqlite3_bind_int64
+_sqlite3_bind_null
+_sqlite3_bind_parameter_count
+_sqlite3_bind_parameter_index
+_sqlite3_bind_text
+_sqlite3_changes
+_sqlite3_changes64
+_sqlite3_clear_bindings
+_sqlite3_close_v2
+_sqlite3_column_blob
+_sqlite3_column_bytes
+_sqlite3_column_count
+_sqlite3_column_count
+_sqlite3_column_double
+_sqlite3_column_int
+_sqlite3_column_int64
+_sqlite3_column_name
+_sqlite3_column_text
+_sqlite3_column_type
+_sqlite3_compileoption_get
+_sqlite3_compileoption_used
+_sqlite3_create_function_v2
+_sqlite3_data_count
+_sqlite3_db_filename
+_sqlite3_db_name
+_sqlite3_errmsg
+_sqlite3_error_offset
+_sqlite3_errstr
+_sqlite3_exec
+_sqlite3_expanded_sql
+_sqlite3_extended_errcode
+_sqlite3_extended_result_codes
+_sqlite3_finalize
+_sqlite3_initialize
+_sqlite3_interrupt
+_sqlite3_libversion
+_sqlite3_libversion_number
+_sqlite3_open
+_sqlite3_open_v2
+_sqlite3_prepare_v2
+_sqlite3_prepare_v3
+_sqlite3_reset
+_sqlite3_result_blob
+_sqlite3_result_double
+_sqlite3_result_error
+_sqlite3_result_error_code
+_sqlite3_result_error_nomem
+_sqlite3_result_error_toobig
+_sqlite3_result_int
+_sqlite3_result_null
+_sqlite3_result_text
+_sqlite3_sourceid
+_sqlite3_sql
+_sqlite3_step
+_sqlite3_strglob
+_sqlite3_strlike
+_sqlite3_total_changes
+_sqlite3_total_changes64
+_sqlite3_value_blob
+_sqlite3_value_bytes
+_sqlite3_value_double
+_sqlite3_value_text
+_sqlite3_value_type
+_sqlite3_vfs_find
+_sqlite3_vfs_register
+_sqlite3_wasm_db_error
+_sqlite3_wasm_enum_json
+_malloc
+_free

ext/wasm/api/EXPORTED_FUNCTIONS.sqlite3-core

@@ -1,158 +0,0 @@
-_malloc
-_free
-_realloc
-_sqlite3_aggregate_context
-_sqlite3_auto_extension
-_sqlite3_bind_blob
-_sqlite3_bind_double
-_sqlite3_bind_int
-_sqlite3_bind_int64
-_sqlite3_bind_null
-_sqlite3_bind_parameter_count
-_sqlite3_bind_parameter_index
-_sqlite3_bind_parameter_name
-_sqlite3_bind_pointer
-_sqlite3_bind_text
-_sqlite3_busy_handler
-_sqlite3_busy_timeout
-_sqlite3_cancel_auto_extension
-_sqlite3_changes
-_sqlite3_changes64
-_sqlite3_clear_bindings
-_sqlite3_close_v2
-_sqlite3_collation_needed
-_sqlite3_column_blob
-_sqlite3_column_bytes
-_sqlite3_column_count
-_sqlite3_column_decltype
-_sqlite3_column_double
-_sqlite3_column_int
-_sqlite3_column_int64
-_sqlite3_column_name
-_sqlite3_column_text
-_sqlite3_column_type
-_sqlite3_column_value
-_sqlite3_commit_hook
-_sqlite3_compileoption_get
-_sqlite3_compileoption_used
-_sqlite3_complete
-_sqlite3_context_db_handle
-_sqlite3_create_collation
-_sqlite3_create_collation_v2
-_sqlite3_create_function
-_sqlite3_create_function_v2
-_sqlite3_create_window_function
-_sqlite3_data_count
-_sqlite3_db_filename
-_sqlite3_db_handle
-_sqlite3_db_name
-_sqlite3_db_readonly
-_sqlite3_db_status
-_sqlite3_deserialize
-_sqlite3_drop_modules
-_sqlite3_errcode
-_sqlite3_errmsg
-_sqlite3_error_offset
-_sqlite3_errstr
-_sqlite3_exec
-_sqlite3_expanded_sql
-_sqlite3_extended_errcode
-_sqlite3_extended_result_codes
-_sqlite3_file_control
-_sqlite3_finalize
-_sqlite3_free
-_sqlite3_get_auxdata
-_sqlite3_get_autocommit
-_sqlite3_initialize
-_sqlite3_interrupt
-_sqlite3_is_interrupted
-_sqlite3_keyword_count
-_sqlite3_keyword_name
-_sqlite3_keyword_check
-_sqlite3_last_insert_rowid
-_sqlite3_libversion
-_sqlite3_libversion_number
-_sqlite3_limit
-_sqlite3_malloc
-_sqlite3_malloc64
-_sqlite3_msize
-_sqlite3_open
-_sqlite3_open_v2
-_sqlite3_overload_function
-_sqlite3_prepare_v2
-_sqlite3_prepare_v3
-_sqlite3_progress_handler
-_sqlite3_randomness
-_sqlite3_realloc
-_sqlite3_realloc64
-_sqlite3_reset
-_sqlite3_reset_auto_extension
-_sqlite3_result_blob
-_sqlite3_result_double
-_sqlite3_result_error
-_sqlite3_result_error_code
-_sqlite3_result_error_nomem
-_sqlite3_result_error_toobig
-_sqlite3_result_int
-_sqlite3_result_int64
-_sqlite3_result_null
-_sqlite3_result_pointer
-_sqlite3_result_subtype
-_sqlite3_result_text
-_sqlite3_result_zeroblob
-_sqlite3_result_zeroblob64
-_sqlite3_rollback_hook
-_sqlite3_serialize
-_sqlite3_set_auxdata
-_sqlite3_set_last_insert_rowid
-_sqlite3_shutdown
-_sqlite3_sourceid
-_sqlite3_sql
-_sqlite3_status
-_sqlite3_status64
-_sqlite3_step
-_sqlite3_stmt_busy
-_sqlite3_stmt_explain
-_sqlite3_stmt_isexplain
-_sqlite3_stmt_readonly
-_sqlite3_stmt_status
-_sqlite3_strglob
-_sqlite3_stricmp
-_sqlite3_strlike
-_sqlite3_strnicmp
-_sqlite3_table_column_metadata
-_sqlite3_total_changes
-_sqlite3_total_changes64
-_sqlite3_trace_v2
-_sqlite3_txn_state
-_sqlite3_update_hook
-_sqlite3_uri_boolean
-_sqlite3_uri_int64
-_sqlite3_uri_key
-_sqlite3_uri_parameter
-_sqlite3_user_data
-_sqlite3_value_blob
-_sqlite3_value_bytes
-_sqlite3_value_double
-_sqlite3_value_dup
-_sqlite3_value_free
-_sqlite3_value_frombind
-_sqlite3_value_int
-_sqlite3_value_int64
-_sqlite3_value_nochange
-_sqlite3_value_numeric_type
-_sqlite3_value_pointer
-_sqlite3_value_subtype
-_sqlite3_value_text
-_sqlite3_value_type
-_sqlite3_vfs_find
-_sqlite3_vfs_register
-_sqlite3_vfs_unregister
-_sqlite3_vtab_collation
-_sqlite3_vtab_distinct
-_sqlite3_vtab_in
-_sqlite3_vtab_in_first
-_sqlite3_vtab_in_next
-_sqlite3_vtab_nochange
-_sqlite3_vtab_on_conflict
-_sqlite3_vtab_rhs_value

ext/wasm/api/sqlite3-worker1-promiser.c-pp.js

@@ -1,4 +1,3 @@
-//#ifnot omit-oo1
 /*
   2022-08-24
 
@@ -42,13 +41,9 @@
    - `onready` (optional, but...): this callback is called with no
    arguments when the worker fires its initial
    'sqlite3-api'/'worker1-ready' message, which it does when
-   sqlite3.initWorker1API() completes its initialization. This is the
-   simplest way to tell the worker to kick off work at the earliest
-   opportunity, and the only way to know when the worker module has
-   completed loading. The irony of using a callback for this, instead
-   of returning a promise from sqlite3Worker1Promiser() is not lost on
-   the developers: see sqlite3Worker1Promiser.v2() which uses a
-   Promise instead.
+   sqlite3.initWorker1API() completes its initialization. This is
+   the simplest way to tell the worker to kick off work at the
+   earliest opportunity.
 
    - `onunhandled` (optional): a callback which gets passed the
    message event object for any worker.onmessage() events which
@@ -119,7 +114,7 @@
    by all client code except that which tests this API. The `row`
    property contains the row result in the form implied by the
    `rowMode` option (defaulting to `'array'`). The `rowNumber` is a
-   1-based integer value incremented by 1 on each call into the
+   1-based integer value incremented by 1 on each call into th 
    callback.
 
    At the end of the result set, the same event is fired with
@@ -127,17 +122,8 @@
    the end of the result set has been reached. Note that the rows
    arrive via worker-posted messages, with all the implications
    of that.
-
-   Notable shortcomings:
-
-   - This API was not designed with ES6 modules in mind. Neither Firefox
-     nor Safari support, as of March 2023, the {type:"module"} flag to the
-     Worker constructor, so that particular usage is not something we're going
-     to target for the time being:
-
-     https://developer.mozilla.org/en-US/docs/Web/API/Worker/Worker
 */
-globalThis.sqlite3Worker1Promiser = function callee(config = callee.defaultConfig){
+self.sqlite3Worker1Promiser = function callee(config = callee.defaultConfig){
   // Inspired by: https://stackoverflow.com/a/52439530
   if(1===arguments.length && 'function'===typeof arguments[0]){
     const f = config;
@@ -160,7 +146,6 @@ globalThis.sqlite3Worker1Promiser = function callee(config = callee.defaultConfi
   if(!config.worker) config.worker = callee.defaultConfig.worker;
   if('function'===typeof config.worker) config.worker = config.worker();
   let dbId;
-  let promiserFunc;
   config.worker.onmessage = function(ev){
     ev = ev.data;
     debug('worker1.onmessage',ev);
@@ -168,14 +153,14 @@ globalThis.sqlite3Worker1Promiser = function callee(config = callee.defaultConfi
     if(!msgHandler){
       if(ev && 'sqlite3-api'===ev.type && 'worker1-ready'===ev.result) {
         /*fired one time when the Worker1 API initializes*/
-        if(config.onready) config.onready(promiserFunc);
+        if(config.onready) config.onready();
         return;
       }
       msgHandler = handlerMap[ev.type] /* check for exec per-row callback */;
       if(msgHandler && msgHandler.onrow){
         msgHandler.onrow(ev);
         return;
-      }
+      }        
       if(config.onunhandled) config.onunhandled(arguments[0]);
       else err("sqlite3Worker1Promiser() unhandled worker message:",ev);
       return;
@@ -197,19 +182,19 @@ globalThis.sqlite3Worker1Promiser = function callee(config = callee.defaultConfi
     try {msgHandler.resolve(ev)}
     catch(e){msgHandler.reject(e)}
   }/*worker.onmessage()*/;
-  return promiserFunc = function(/*(msgType, msgArgs) || (msgEnvelope)*/){
+  return function(/*(msgType, msgArgs) || (msgEnvelope)*/){
     let msg;
     if(1===arguments.length){
       msg = arguments[0];
     }else if(2===arguments.length){
-      msg = Object.create(null);
-      msg.type = arguments[0];
-      msg.args = arguments[1];
-      msg.dbId = msg.args.dbId;
+      msg = {
+        type: arguments[0],
+        args: arguments[1]
+      };
     }else{
-      toss("Invalid arguments for sqlite3Worker1Promiser()-created factory.");
+      toss("Invalid arugments for sqlite3Worker1Promiser()-created factory.");
     }
-    if(!msg.dbId && msg.type!=='open') msg.dbId = dbId;
+    if(!msg.dbId) msg.dbId = dbId;
     msg.messageId = genMsgId(msg);
     msg.departureTime = performance.now();
     const proxy = Object.create(null);
@@ -251,96 +236,28 @@ globalThis.sqlite3Worker1Promiser = function callee(config = callee.defaultConfi
     return p;
   };
 }/*sqlite3Worker1Promiser()*/;
-
-globalThis.sqlite3Worker1Promiser.defaultConfig = {
+self.sqlite3Worker1Promiser.defaultConfig = {
   worker: function(){
-//#if target=es6-module
-    return new Worker(new URL("sqlite3-worker1-bundler-friendly.mjs", import.meta.url),{
-      type: 'module'
-    });
+//#if target=es6-bundler-friendly
+    return new Worker("sqlite3-worker1.js");
 //#else
     let theJs = "sqlite3-worker1.js";
     if(this.currentScript){
       const src = this.currentScript.src.split('/');
       src.pop();
       theJs = src.join('/')+'/' + theJs;
-      //sqlite3.config.warn("promiser currentScript, theJs =",this.currentScript,theJs);
-    }else if(globalThis.location){
-      //sqlite3.config.warn("promiser globalThis.location =",globalThis.location);
-      const urlParams = new URL(globalThis.location.href).searchParams;
+      //console.warn("promiser currentScript, theJs =",this.currentScript,theJs);
+    }else{
+      //console.warn("promiser self.location =",self.location);
+      const urlParams = new URL(self.location.href).searchParams;
       if(urlParams.has('sqlite3.dir')){
         theJs = urlParams.get('sqlite3.dir') + '/' + theJs;
       }
     }
-    return new Worker(theJs + globalThis.location.search);
+    return new Worker(theJs + self.location.search);
 //#endif
-  }
-//#ifnot target=es6-module
-  .bind({
-    currentScript: globalThis?.document?.currentScript
-  })
-//#endif
-  ,
+  }.bind({
+    currentScript: self?.document?.currentScript
+  }),
   onerror: (...args)=>console.error('worker1 promiser error',...args)
-}/*defaultConfig*/;
-
-/**
-   sqlite3Worker1Promiser.v2(), added in 3.46, works identically to
-   sqlite3Worker1Promiser() except that it returns a Promise instead
-   of relying an an onready callback in the config object. The Promise
-   resolves to the same factory function which
-   sqlite3Worker1Promiser() returns.
-
-   If config is-a function or is an object which contains an onready
-   function, that function is replaced by a proxy which will resolve
-   after calling the original function and will reject if that
-   function throws.
-*/
-sqlite3Worker1Promiser.v2 = function(config){
-  let oldFunc;
-  if( 'function' == typeof config ){
-    oldFunc = config;
-    config = {};
-  }else if('function'===typeof config?.onready){
-    oldFunc = config.onready;
-    delete config.onready;
-  }
-  const promiseProxy = Object.create(null);
-  config = Object.assign((config || Object.create(null)),{
-    onready: async function(func){
-      try {
-        if( oldFunc ) await oldFunc(func);
-        promiseProxy.resolve(func);
-      }
-      catch(e){promiseProxy.reject(e)}
-    }
-  });
-  const p = new Promise(function(resolve,reject){
-    promiseProxy.resolve = resolve;
-    promiseProxy.reject = reject;
-  });
-  try{
-    this.original(config);
-  }catch(e){
-    promiseProxy.reject(e);
-  }
-  return p;
-}.bind({
-   /* We do this because clients are
-      recommended to delete globalThis.sqlite3Worker1Promiser. */
-  original: sqlite3Worker1Promiser
-});
-
-//#if target=es6-module
-/**
-  When built as a module, we export sqlite3Worker1Promiser.v2()
-  instead of sqlite3Worker1Promise() because (A) its interface is more
-  conventional for ESM usage and (B) the ESM option export option for
-  this API did not exist until v2 was created, so there's no backwards
-  incompatibility.
-*/
-export default sqlite3Worker1Promiser.v2;
-//#endif /* target=es6-module */
-//#else
-/* Built with the omit-oo1 flag. */
-//#endif ifnot omit-oo1
+};

ext/wasm/fiddle/fiddle.html

@@ -171,31 +171,6 @@
           display: flex;
           flex-direction: column-reverse;
       }
-
-      /* emcscript-related styling, used during the module load/intialization processes... */
-      .emscripten { padding-right: 0; margin-left: auto; margin-right: auto; display: block; }
-      div.emscripten { text-align: center; }
-      div.emscripten_border { border: 1px solid black; }
-      #module-spinner { overflow: visible; }
-      #module-spinner > * {
-          margin-top: 1em;
-      }
-      .spinner {
-          height: 50px;
-          width: 50px;
-          margin: 0px auto;
-          animation: rotation 0.8s linear infinite;
-          border-left: 10px solid rgb(0,150,240);
-          border-right: 10px solid rgb(0,150,240);
-          border-bottom: 10px solid rgb(0,150,240);
-          border-top: 10px solid rgb(100,0,200);
-          border-radius: 100%;
-          background-color: rgb(200,100,250);
-      }
-      @keyframes rotation {
-          from {transform: rotate(0deg);}
-          to {transform: rotate(360deg);}
-      }
     </style>
   </head>
   <body>
@@ -298,6 +273,11 @@
         </fieldset>
       </div>
     </div> <!-- #view-split -->
+    <!-- Maintenance notes:
+
+        ... TODO... currently being refactored...
+
+    -->
     <script src="fiddle.js"></script>
   </body>
 </html>

main.mk

@@ -347,6 +347,7 @@ TESTSRC += \
   $(TOP)/ext/misc/amatch.c \
   $(TOP)/ext/misc/appendvfs.c \
   $(TOP)/ext/misc/basexx.c \
+  $(TOP)/ext/misc/bgckpt.c \
   $(TOP)/ext/misc/carray.c \
   $(TOP)/ext/misc/cksumvfs.c \
   $(TOP)/ext/misc/closure.c \
@@ -435,6 +436,7 @@ TESTSRC2 = \
   $(TOP)/ext/async/sqlite3async.c \
   $(TOP)/ext/misc/stmt.c \
   $(TOP)/ext/session/sqlite3session.c \
+  $(TOP)/ext/session/sqlite3changebatch.c \
   $(TOP)/ext/session/test_session.c \
   fts5.c
 
@@ -1022,11 +1024,15 @@ THREADTEST3_SRC = $(TOP)/test/threadtest3.c    \
                   $(TOP)/test/tt3_index.c      \
                   $(TOP)/test/tt3_vacuum.c      \
                   $(TOP)/test/tt3_stress.c      \
+                  $(TOP)/test/tt3_bcwal2.c      \
                   $(TOP)/test/tt3_lookaside1.c
 
 threadtest3$(EXE): sqlite3.o $(THREADTEST3_SRC) $(TOP)/src/test_multiplex.c
 	$(TCCX) $(TOP)/test/threadtest3.c $(TOP)/src/test_multiplex.c sqlite3.o -o $@ $(THREADLIB)
 
+bc_test1$(EXE): sqlite3.o $(TOP)/test/bc_test1.c $(TOP)/test/tt3_core.c
+	$(TCCX) $(TOP)/test/bc_test1.c sqlite3.o -o $@ $(THREADLIB)
+
 threadtest: threadtest3$(EXE)
 	./threadtest3$(EXE)
 

manifest

@@ -1,11 +1,11 @@
-C Fix\sa\sbug\sin\sthe\sparsing\sof\ssome\scorner-case\sJSON\sPATH\sstrings\sthat\scontain\nescaped\sdouble-quotes.
-D 2024-09-04T16:01:44.145
+C Increase\smaximum\slength\sof\ssqlite3_log()\smessages\sto\s700\sbytes.\sMark\slog\smessages\sas\sv=10.
+D 2024-11-13T14:42:32.861
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
-F Makefile.in af5fbc3453b745daa68c7aa5dfdb945c09cb724971db3b783d6b5e1a62279e28
+F Makefile.in 3cd3e81b3558a4ff391104b4ecba6966246cd226485841a666105740d0cab95f
 F Makefile.linux-gcc f3842a0b1efbfbb74ac0ef60e56b301836d05b4d867d014f714fa750048f1ab6
-F Makefile.msc 2c905f4c795a628d7fd892294e8fdec6d5f719fa5b252cb839fed147e64435a0
+F Makefile.msc 9f54b105b2ceeab4cf397b9f4a119b22933acf90f0a199acb11a464a2efe6c93
 F README.md 5b678e264236788390d11991f2c0052bd73f19790173883fc56d638bcb849154
 F VERSION 0db40f92c04378404eb45bff93e9e42c148c7e54fd3da99469ed21e22411f5a6
 F aclocal.m4 a5c22d164aff7ed549d53a90fa56d56955281f50
@@ -39,6 +39,7 @@ F configure 49523f0a070b583cea040d26eff53a65fb0893eca4663b1343a4d5a9a964da53 x
 F configure.ac a100ebf7a07f5dedd319ef547dd467d1676ed059b85a7877aa9c44ac309f7000
 F contrib/sqlitecon.tcl 210a913ad63f9f991070821e599d600bd913e0ad
 F doc/F2FS.txt c1d4a0ae9711cfe0e1d8b019d154f1c29e0d3abfe820787ba1e9ed7691160fcd
+F doc/begin_concurrent.md 4bee2c3990d1eb800f1ce3726a911292a8e4b889300b2ffd4b08d357370db299
 F doc/compile-for-windows.md e8635eea9153dcd6a51fd2740666ebc4492b3813cb1ac31cd8e99150df91762d
 F doc/json-enhancements.md e356fc834781f1f1aa22ee300027a270b2c960122468499bf347bb123ce1ea4f
 F doc/jsonb.md 5fab4b8613aa9153fbeb6259297bd4697988af8b3d23900deba588fa7841456b
@@ -49,6 +50,7 @@ F doc/trusted-schema.md 33625008620e879c7bcfbbfa079587612c434fa094d338b08242288d
 F doc/vdbesort-memory.md 4da2639c14cd24a31e0af694b1a8dd37eaf277aff3867e9a8cc14046bc49df56
 F doc/vfs-shm.txt e101f27ea02a8387ce46a05be2b1a902a021d37a
 F doc/wal-lock.md 781726aaba20bafeceb7ba9f91d5c98c6731691b30c954e37cf0b49a053d461d
+F doc/wal2.md a807405a05e19a4945c5905a9ffa0fe45b8560dd7572461192501f565c19cdb5
 F ext/README.md fd5f78013b0a2bc6f0067afb19e6ad040e89a10179b4f6f03eee58fac5f169bd
 F ext/async/README.txt e12275968f6fde133a80e04387d0e839b0c51f91
 F ext/async/sqlite3async.c 6f247666b495c477628dd19364d279c78ea48cd90c72d9f9b98ad1aff3294f94
@@ -100,7 +102,7 @@ F ext/fts5/fts5_config.c 353d2a0d12678cae6ab5b9ce54aed8dac0825667b69248b5a4ed81c
 F ext/fts5/fts5_expr.c 9a56f53700d1860f0ee2f373c2b9074eaf2a7aa0637d0e27a6476de26a3fee33
 F ext/fts5/fts5_hash.c adda4272be401566a6e0ba1acbe70ee5cb97fce944bc2e04dc707152a0ec91b1
 F ext/fts5/fts5_index.c 571483823193f09439356741669aa8c81da838ae6f5e1bfa7517f7ee2fb3addd
-F ext/fts5/fts5_main.c 1fddb53f495425d9314c74b30c5848a9dd254be0e5f445bfe38292d5ab21c288
+F ext/fts5/fts5_main.c 43990841e0221e0da1bf7ec687196683692b9e8783c372b8d58dea3e9866a5e4
 F ext/fts5/fts5_storage.c 9a9b880be12901f1962ae2a5a7e1b74348b3099a1e728764e419f75d98e3e612
 F ext/fts5/fts5_tcl.c 4db9258a7882c5eac0da4433042132aaf15b87dd1e1636c7a6ca203abd2c8bfe
 F ext/fts5/fts5_test_mi.c 08c11ec968148d4cb4119d96d819f8c1f329812c568bac3684f5464be177d3ee
@@ -137,6 +139,7 @@ F ext/fts5/test/fts5cat.test bf67dd335f964482ee658287521b81e2b88697b45eb7f73933e
 F ext/fts5/test/fts5circref.test f880dfd0d99f6fb73b88ccacb0927d18e833672fd906cc47d6b4e529419eaa62
 F ext/fts5/test/fts5colset.test 544f4998cdbfe06a3123887fc0221612e8aa8192cdaff152872f1aadb10e6897
 F ext/fts5/test/fts5columnsize.test 0af91d63985afdf663455d4b572b935238380140d74079eac362760866d3297b
+F ext/fts5/test/fts5concurrent.test eaaba0037090138bc86d581ca95f3be7ef8eff60155b5b8fa3014acee4a595c2
 F ext/fts5/test/fts5config.test 017daf10d2642496e97402baa0134de8b5b46b9c37e53c229cd9ab711d21522c
 F ext/fts5/test/fts5conflict.test bf6030a77dbb1bedfcc42e589ed7980846c995765d77460551e448b56d741244
 F ext/fts5/test/fts5connect.test 08030168fc96fc278fa81f28654fb7e90566f33aff269c073e19b3ae9126b2f4
@@ -220,7 +223,7 @@ F ext/fts5/test/fts5rowid.test 8632829fec04996832a4cfb4f0bd89721ba65b7e398c17317
 F ext/fts5/test/fts5savepoint.test 7f373184cf2d6c1c472d2bc732e1fce62211ffe023f13e381db0f5e4fd06e41d
 F ext/fts5/test/fts5secure.test a02f771742fb2b1b9bdcb4bf523bcf2d0aa1ff597831d40fe3e72aaa6d0ec40f
 F ext/fts5/test/fts5secure2.test 2e961d7eef939f294c56b5d895cac7f1c3a60b934ee2cfd5e5e620bdf1ba6bbc
-F ext/fts5/test/fts5secure3.test 6d066828d225b0dbe5db818d4d6165df7bb70210e68a577e858e8762400d5a23
+F ext/fts5/test/fts5secure3.test e29f7e92af78a35e1c0f7461dd598f910036d588437db50242d5823576f3d6ee
 F ext/fts5/test/fts5secure4.test 0d10a80590c07891478700af7793b232962042677432b9846cf7fc8337b67c97
 F ext/fts5/test/fts5secure5.test c07a68ced5951567ac116c22f2d2aafae497e47fe9fcb6a335c22f9c7a4f2c3a
 F ext/fts5/test/fts5secure6.test 74bf04733cc523bccca519bb03d3b4e2ed6f6e3db7c59bf6be82c88a0ac857fd
@@ -386,6 +389,7 @@ F ext/misc/appendvfs.c 9642c7a194a2a25dca7ad3e36af24a0a46d7702168c4ad7e59c9f9b0e
 F ext/misc/base64.c a71b131e50300c654a66c469a25b62874481f3d1cb3beb56aca9a68edd812e0d
 F ext/misc/base85.c 073054111988db593ef5fdb87ab8c459df1ea0c3aaaddf0f5bfa3d72b7e6280a
 F ext/misc/basexx.c 89ad6b76558efbceb627afd5e2ef1d84b2e96d9aaf9b7ecb20e3d00b51be6fcf
+F ext/misc/bgckpt.c 18cfc9c39ffab3299f730f86ae2991c8574c0bd9ec80efd2f89196798a7b7181
 F ext/misc/blobio.c a867c4c4617f6ec223a307ebfe0eabb45e0992f74dd47722b96f3e631c0edb2a
 F ext/misc/btreeinfo.c cb952620eedf5c0b7625b678f0f08e54d2ec0011d4e50efda5ebdc97f3df7d04
 F ext/misc/carray.c 34fac63770971611c5285de0a9f0ac67d504eaf66be891f637add9290f1c76a5
@@ -553,6 +557,8 @@ F ext/rtree/tkt3363.test 142ab96eded44a3615ec79fba98c7bde7d0f96de
 F ext/rtree/util/randomshape.tcl 54ee03d0d4a1c621806f7f44d5b78d2db8fac26e0e8687c36c4bd0203b27dbff
 F ext/rtree/viewrtree.tcl eea6224b3553599ae665b239bd827e182b466024
 F ext/rtree/visual01.txt e9c2564083bcd30ec51b07f881bffbf0e12b50a3f6fced0c222c5c1d2f94ac66
+F ext/session/changebatch1.test 51694900ccbdf144c2e403f99358b7a3f137354e2ba8d1033ef88a53f1a494f2
+F ext/session/changebatchfault.test be49c793219bf387ad692a60856b921f0854ad6d
 F ext/session/changeset.c 7a1e6a14c7e92d36ca177e92e88b5281acd709f3b726298dc34ec0fb58869cb5
 F ext/session/changesetfuzz.c 227076ab0ae4447d742c01ee88a564da6478bbf26b65108bf8fac9cd8b0b24aa
 F ext/session/changesetfuzz1.test 15b629004e58d5ffcc852e6842a603775bb64b1ce51254831f3d12b113b616cd
@@ -571,7 +577,7 @@ F ext/session/sessionD.test f5c6a762d00bc6ca9d561695c322ba8ecca2bed370486707ef37
 F ext/session/sessionE.test b2010949c9d7415306f64e3c2072ddabc4b8250c98478d3c0c4d064bce83111d
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 F ext/session/sessionG.test 3efe388282d641b65485b5462e67851002cd91a282dc95b685d085eb8efdad0a
-F ext/session/sessionH.test 71bbff6b1abb2c4ac62b84dee53273c37e0b21e5fde3aed80929403e091ef859
+F ext/session/sessionH.test 29a5441c3dc0a63fa596d745e64bc6c636e062ae04cd89bc84e32c7d98b1fa9b
 F ext/session/session_common.tcl e5598096425486b363718e2cda48ee85d660c96b4f8ea9d9d7a4c3ef514769da
 F ext/session/session_speed_test.c dcf0ef58d76b70c8fbd9eab3be77cf9deb8bc1638fed8be518b62d6cbdef88b3
 F ext/session/sessionalter.test 460bdac2832a550519f6bc32e5db2c0cee94f335870aaf25a3a403a81ab20e17
@@ -593,13 +599,15 @@ F ext/session/sessionrowid.test 85187c2f1b38861a5844868126f69f9ec62223a03449a98a
 F ext/session/sessionsize.test 8fcf4685993c3dbaa46a24183940ab9f5aa9ed0d23e5fb63bfffbdb56134b795
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 F ext/session/sessionwor.test 6fd9a2256442cebde5b2284936ae9e0d54bde692d0f5fd009ecef8511f4cf3fc
-F ext/session/sqlite3session.c c7473aafbd88f796391a8c25aa90975a8f3729ab7f4f8cf74ab9d3b014e10abe
-F ext/session/sqlite3session.h 683ccbf16e2c2521661fc4c1cf918ce57002039efbcabcd8097fa4bca569104b
-F ext/session/test_session.c 6acbe67db80ab0806147eb62a12f9e3a44930f4a740b68b0a4340dddda2c10d7
+F ext/session/sqlite3changebatch.c d488b42d8fd49fb013a1e9c4535232680dabeb28ae8f9421b65ea0ccc3b430f7
+F ext/session/sqlite3changebatch.h e72016998c9a22d439ddfd547b69e1ebac810c24
+F ext/session/sqlite3session.c 2190541e6870ceb6609e6cee35d2554c1843e5c556a93657e879c08deba6d124
+F ext/session/sqlite3session.h 3376dbf372cb00cc0f4e960ca0a0125418638da8c55aad749c9fe7a58a770506
+F ext/session/test_session.c 1f0cfe31fdcc11565f4a4220382bff807448d7b82cb908d67c5506b1fd2d6f82
 F ext/userauth/sqlite3userauth.h 7f3ea8c4686db8e40b0a0e7a8e0b00fac13aa7a3
 F ext/userauth/user-auth.txt ca7e9ee82ca4e1c1744295f8184dd70edfae1992865d26c64303f539eb6c084c
 F ext/userauth/userauth.c 7f00cded7dcaa5d47f54539b290a43d2e59f4b1eb5f447545fa865f002fc80cb
-F ext/wasm/EXPORTED_FUNCTIONS.fiddle.in 27450c8b8c70875a260aca55435ec927068b34cef801a96205adb81bdcefc65c
+F ext/wasm/EXPORTED_FUNCTIONS.fiddle 7fb73f7150ab79d83bb45a67d257553c905c78cd3d693101699243f36c5ae6c3
 F ext/wasm/GNUmakefile d4f6586d9a36ee2869a8c7f77227a8b7f42b6c4623f3be594beafb1554ab20d9
 F ext/wasm/README-dist.txt 6382cb9548076fca472fb3330bbdba3a55c1ea0b180ff9253f084f07ff383576
 F ext/wasm/README.md a8a2962c3aebdf8d2104a9102e336c5554e78fc6072746e5daf9c61514e7d193
@@ -608,8 +616,8 @@ F ext/wasm/SQLTester/SQLTester.mjs ce765c0ad7d57f93553d12ef4dca574deb00300134a26
 F ext/wasm/SQLTester/SQLTester.run.mjs c72b7fe2072d05992f7a3d8c6a1d34e95712513ceabe40849784e24e41c84638
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 F ext/wasm/SQLTester/touint8array.c 2d5ece04ec1393a6a60c4bf96385bda5e1a10ad49f3038b96460fc5e5aa7e536
+F ext/wasm/api/EXPORTED_FUNCTIONS.sqlite3-api c5eaceabb9e759aaae7d3101a4a3e542f96ab2c99d89a80ce20ec18c23115f33
 F ext/wasm/api/EXPORTED_FUNCTIONS.sqlite3-auth 7ac80cc3b6a6d52e041bb295e85555ce797be78c15ef2008a64ae58815014080
-F ext/wasm/api/EXPORTED_FUNCTIONS.sqlite3-core 400213eb52a7e5ad5f448053d375cacf4dac2cf45d134f3edfe485ae4a49a183
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 F ext/wasm/api/EXPORTED_FUNCTIONS.sqlite3-session 213b6c04267cb9bd760172db011eb1650732805fb3d01f9395478a8ceec18eb0
@@ -633,7 +641,7 @@ F ext/wasm/api/sqlite3-vfs-opfs-sahpool.c-pp.js e529a99b7d5a088284821e2902b20d34
 F ext/wasm/api/sqlite3-vfs-opfs.c-pp.js e99e3d99f736937914527070f00ab13e9391d3f1cef884ab99a64cbcbee8d675
 F ext/wasm/api/sqlite3-vtab-helper.c-pp.js e809739d71e8b35dfe1b55d24d91f02d04239e6aef7ca1ea92a15a29e704f616
 F ext/wasm/api/sqlite3-wasm.c 09a938fc570f282e602acd111147c7b74b5332da72540c512a79b916ab57882a
-F ext/wasm/api/sqlite3-worker1-promiser.c-pp.js 46f303ba8ddd1b2f0a391798837beddfa72e8c897038c8047eda49ce7d5ed46b
+F ext/wasm/api/sqlite3-worker1-promiser.c-pp.js f10c3ecd9df06f6320073c2ce230a7ed7c56034d8b88c1e57095f2a97faf423a
 F ext/wasm/api/sqlite3-worker1.c-pp.js 5e8706c2c4af2a57fbcdc02f4e7ef79869971bc21bb8ede777687786ce1c92d5
 F ext/wasm/batch-runner-sahpool.html e9a38fdeb36a13eac7b50241dfe7ae066fe3f51f5c0b0151e7baee5fce0d07a7
 F ext/wasm/batch-runner-sahpool.js 54a3ac228e6c4703fe72fb65c897e19156263a51fe9b7e21d2834a45e876aabd
@@ -657,8 +665,8 @@ F ext/wasm/dist.make 653e212c1e84aa3be168d62a10616ccea45ee9585b0192745d2706707a5
 F ext/wasm/example_extra_init.c 2347cd69d19d839ef4e5e77b7855103a7fe3ef2af86f2e8c95839afd8b05862f
 F ext/wasm/fiddle.make 2406b02473878a99fb6a2eaff0923277017adc45eb041b2afb2d7707bf7b375c
 F ext/wasm/fiddle/fiddle-worker.js 850e66fce39b89d59e161d1abac43a181a4caa89ddeea162765d660277cd84ce
+F ext/wasm/fiddle/fiddle.html 550c5aafce40bd218de9bf26192749f69f9b10bc379423ecd2e162bcef885c08
 F ext/wasm/fiddle/fiddle.js b444a5646a9aac9f3fc06c53d78af5e1912eb235d69a8e6010723e4eb0e9d4a1
-F ext/wasm/fiddle/index.html 739e0b75bc592679665d25e2f7649d2b8b2db678f3b41a772a8720b609b8482d
 F ext/wasm/index-dist.html 564b5ec5669676482c5a25dea9e721d8eafed426ecb155f93d29aeff8507511f
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 F ext/wasm/jaccwabyt/jaccwabyt.js 1264710db3cfbcb6887d95665b7aeba60c1126eaef789ca4cf1a4a17d5bc7f54
@@ -686,7 +694,7 @@ F ext/wasm/wasmfs.make 8a4955882aaa0783b3f60a9484a1f0f3d8b6f775c0fcd17c082f31966
 F install-sh 9d4de14ab9fb0facae2f48780b874848cbf2f895 x
 F ltmain.sh 3ff0879076df340d2e23ae905484d8c15d5fdea8
 F magic.txt 5ade0bc977aa135e79e3faaea894d5671b26107cc91e70783aa7dc83f22f3ba0
-F main.mk 5a2e7d4a852c058373efc78407816de41595d06975148c766092b3cf0fea4298
+F main.mk b656a84515801f1bda32776e4e8ff75bdba5021b9fec5dd0fee9f84be3f5df7a
 F mptest/config01.test 3c6adcbc50b991866855f1977ff172eb6d901271
 F mptest/config02.test 4415dfe36c48785f751e16e32c20b077c28ae504
 F mptest/crash01.test 61e61469e257df0850df4293d7d4d6c2af301421
@@ -703,15 +711,15 @@ F src/analyze.c 30bf40ec4208ead9e977bec017bccc8a9681820936e38ca5a4a7443100a6d5c5
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 F src/backup.c 5c97e8023aab1ce14a42387eb3ae00ba5a0644569e3476f38661fa6f824c3523
-F src/bitvec.c 9eac5f42c11914d5ef00a75605bb205e934f435c579687f985f1f8b0995c8645
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 F src/btmutex.c 79a43670447eacc651519a429f6ece9fd638563cf95b469d6891185ddae2b522
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-F src/build.c 3a1840d9d171ce2d24f4c1f7acda7266ab796c664290c1acba65ff98ce2bd01e
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 F src/callback.c db3a45e376deff6a16c0058163fe0ae2b73a2945f3f408ca32cf74960b28d490
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-F src/ctime.c b224d3db0f28c4a5f1407c50107a0a8133bd244ff3c7f6f8cedeb896a8cf1b64
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 F src/date.c 89ce1ff20512a7fa5070ba6e7dd5c171148ca7d580955795bf97c79c2456144a
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 F src/dbstat.c 73362c0df0f40ad5523a6f5501224959d0976757b511299bf892313e79d14f5c
@@ -719,7 +727,7 @@ F src/delete.c 444c4d1eaac40103461e3b6f0881846dd3aafc1cec1dd169d3482fa331667da7
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-F src/func.c df400a1d3f4625997d4dd8a81951c303e066277c29b861d37e03cd152d7858dd
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 F src/global.c 61a419dd9e993b9be0f91de4c4ccf322b053eb829868e089f0321dd669be3b90
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 F src/hash.h 3340ab6e1d13e725571d7cee6d3e3135f0779a7d8e76a9ce0a85971fa3953c51
@@ -727,9 +735,9 @@ F src/hwtime.h f9c2dfb84dce7acf95ce6d289e46f5f9d3d1afd328e53da8f8e9008e3b3caae6
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 F src/loadext.c 7432c944ff197046d67a1207790a1b13eec4548c85a9457eb0896bb3641dfb36
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 F src/mem1.c 3bb59158c38e05f6270e761a9f435bf19827a264c13d1631c58b84bdc96d73b2
@@ -750,34 +758,34 @@ F src/os.h 1ff5ae51d339d0e30d8a9d814f4b8f8e448169304d83a7ed9db66a65732f3e63
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-F src/os_unix.c 6e3e4fc75904ff85184091dbab996e6e35c1799e771788961cc3b4fcbe8f852c
+F src/os_unix.c e33663c5a819e2c8532eedcefb1ea1ad7c1f0c9ac42e2149f632a642c2f9e621
 F src/os_win.c 6ff43bac175bd9ed79e7c0f96840b139f2f51d01689a638fd05128becf94908a
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 F src/resolve.c 2c127880c0634962837f16f2f48a295e514357af959330cc038de73015d5b5e8
 F src/rowset.c 8432130e6c344b3401a8874c3cb49fefe6873fec593294de077afea2dce5ec97
-F src/select.c 4b14337a2742f0c0beeba490e9a05507e9b4b12184b9cd12773501d08d48e3fe
+F src/select.c 108baa344f34a17a0723067d28b5b4b7da937d02ddc2d7c1a39a4a4815628ca4
 F src/shell.c.in 40de636c1d90fb8a9ca7f49dc8f50d930f1b60736e73aca5eb37c4c7d0e47f9d
-F src/sqlite.h.in 77f55bd1978a04a14db211732f0a609077cf60ba4ccf9baf39988f508945419c
+F src/sqlite.h.in b7ff496637807ae88b2557039fc940518db328bf5d5621e2f7c048dfba32a52b
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h 3f046c04ea3595d6bfda99b781926b17e672fd6d27da2ba6d8d8fc39981dcb54
-F src/sqliteInt.h 889cd632f4386bbd8619b166abb7d25f1c8ce6514e90cb7f22f63bd530fc6107
+F src/sqliteInt.h 55838cada3b79d88a891e557759f444f2a007c77f61f7a731d00d1df6d95e555
 F src/sqliteLimit.h 6878ab64bdeb8c24a1d762d45635e34b96da21132179023338c93f820eee6728
 F src/status.c cb11f8589a6912af2da3bb1ec509a94dd8ef27df4d4c1a97e0bcf2309ece972b
 F src/table.c 0f141b58a16de7e2fbe81c308379e7279f4c6b50eb08efeec5892794a0ba30d1
 F src/tclsqlite.c c6888598f08dee3d9112a38ef42c8f5c89ca7f3190f4694744d0b84250f4bf8c
 F src/tclsqlite.h c6af51f31a2b2172d674608763a4b98fdf5cd587e4025053e546fb8077757262
-F src/test1.c 3f18399557d954bc85f4564aec8ea1777d2161a81d98a3ff6c9e9046bf3554c1
+F src/test1.c ecbd27140e63d6d70e221ac7e2aa565a13359c126f432b4469ad80f5d66d62ee
 F src/test2.c 7ebc518e6735939d8979273a6f7b1d9b5702babf059f6ad62499f7f60a9eb9a3
 F src/test3.c e7573aa0f78ee4e070a4bc8c3493941c1aa64d5c66d4825c74c0f055451f432b
 F src/test4.c 13e57ae7ec7a959ee180970aef09deed141252fe9bb07c61054f0dfa4f1dfd5d
@@ -791,13 +799,13 @@ F src/test_backup.c bd901e3c116c7f3b3bbbd4aae4ce87d99b400c9cbb0a9e7b4610af451d97
 F src/test_bestindex.c 3401bee51665cbf7f9ed2552b5795452a8b86365e4c9ece745b54155a55670c6
 F src/test_blob.c bcdf6a6c22d0bcc13c41479d63692ef413add2a4d30e1e26b9f74ab85b9fb4d5
 F src/test_btree.c 28283787d32b8fa953eb77412ad0de2c9895260e4e5bd5a94b3c7411664f90d5
-F src/test_config.c 345b8e383f71cecc36d0fa05f2f06639c254b188f98101c3c97749df43037086
+F src/test_config.c 72fcae7f6dbe72975654a018922dbf1accc5ec6ed957010d82edc26ba978cd4f
 F src/test_delete.c e2fe07646dff6300b48d49b2fee2fe192ed389e834dd635e3b3bac0ce0bf9f8f
 F src/test_demovfs.c 3efa2adf4f21e10d95521721687d5ca047aea91fa62dd8cc22ac9e5a9c942383
 F src/test_devsym.c 649434ed34d0b03fbd5a6b42df80f0f9a7e53f94dd1710aad5dd8831e91c4e86
 F src/test_fs.c c411c40baba679536fc34e2679349f59d8225570aed3488b5b3ef1908525a3d5
 F src/test_func.c 8c0e89192f70fac307822d1ac2911ee51751288780b3db0c5ab5ca75fa0fe851
-F src/test_hexio.c 0f777bf9fbb2684bb4978372bacc90ef7337d5d9e3cebe067a9409941e88bacf
+F src/test_hexio.c 35704e7db83fe1a0e1a014bacb17de97d7d1e89af3356a9da04e37cdaa087c09
 F src/test_init.c 17313332d58e90defc527129d5eda4a08bd6b6e8de7207a231523c8d98fb445e
 F src/test_intarray.c e4216aadee9df2de7d1aee7e70f6b22c80ee79ece72a63d57105db74217639e5
 F src/test_intarray.h 6c3534641108cd1bea517a8e117dcba237081310a29a4c35bd2190caa8972293
@@ -816,9 +824,9 @@ F src/test_quota.h 2a8ad1952d1d2ca9af0ce0465e56e6c023b5e15d
 F src/test_rtree.c d844d746a3cc027247318b970025a927f14772339c991f40e7911583ea5ed0d9
 F src/test_schema.c b06d3ddc3edc173c143878f3edb869dd200d57d918ae2f38820534f9a5e3d7d9
 F src/test_sqllog.c 540feaea7280cd5f926168aee9deb1065ae136d0bbbe7361e2ef3541783e187a
-F src/test_superlock.c 18355ca274746aa6909e3744163e5deb1196a85d5bc64b9cd377273cef626da7
+F src/test_superlock.c 388f4741997beb395b6731fd0c4c8e525940bc6cdcbabead0136783450da40d0
 F src/test_syscall.c 9ad7ab39910c16d29411678d91b0d27a7a996a718df5ee93dcd635e846d0275c
-F src/test_tclsh.c 6077f2bdc6b4ea2bace2a0cd6ea48e0a4651007ae7382c13efc0c495eb0c6956
+F src/test_tclsh.c efa390787ecfbae22e0a0a05d9ee771a9db78ffd84e2eea092899c2d80d57b0e
 F src/test_tclvar.c ae873248a0188459b1c16ca7cc431265dacce524399e8b46725c2b3b7e048424
 F src/test_thread.c d7a8bcea7445f37cc2a1f7f81dd6059634f45e0c61bfe80182b02872fb0328bb
 F src/test_vdbecov.c 5c426d9cd2b351f5f9ceb30cabf8c64a63bfcad644c507e0bd9ce2f6ae1a3bf3
@@ -832,16 +840,16 @@ F src/threads.c 4ae07fa022a3dc7c5beb373cf744a85d3c5c6c3c
 F src/tokenize.c 3f703cacdab728d7741e5a6ac242006d74fe1c2754d4f03ed889d7253259bd68
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-F src/update.c 0e01aa6a3edf9ec112b33eb714b9016a81241497b1fb7c3e74332f4f71756508
+F src/update.c 2dd1b745acc9253df1b210ac69137c7a6b290e561d3f42da24418c4e807e889b
 F src/upsert.c 215328c3f91623c520ec8672c44323553f12caeb4f01b1090ebdca99fdf7b4f1
 F src/utf.c f23165685a67b4caf8ec08fb274cb3f319103decfb2a980b7cfd55d18dfa855e
 F src/util.c 5d1a0134cf4240648d1c6bb5cc8efaca0ea2b5d5c840985aec7e947271f04375
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-F src/vdbeInt.h 949669dfd8a41550d27dcb905b494f2ccde9a2e6c1b0b04daa1227e2e74c2b2c
+F src/vacuum.c 25e407a6dc8b288fa4295b3d92fa9ce9318503e84df53cdf403a50fccbc1ba31
+F src/vdbe.c fea60cfe46d8839a08e4680d90a96898d542d3f6d7954e2e99cd92596f1a01f8
+F src/vdbe.h e439c7b44191828413f461eac23360ffbf0513fe57d129853f690c4ea4d46746
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 F src/vdbeapi.c 80235ac380e9467fec1cb0883354d841f2a771976e766995f7e0c77f845406df
-F src/vdbeaux.c 25d685cafe119ff890c94345e884ea558a6b5d823bfa52ba708eb8ff3c70aa71
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 F src/vdbeblob.c 255be187436da38b01f276c02e6a08103489bbe2a7c6c21537b7aecbe0e1f797
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 F src/vdbesort.c d0a3c7056c081703c8b6d91ad60f17da5e062a5c64bf568ed0fa1b5f4cae311f
@@ -849,8 +857,8 @@ F src/vdbetrace.c fe0bc29ebd4e02c8bc5c1945f1d2e6be5927ec12c06d89b03ef2a4def34bf8
 F src/vdbevtab.c fc46b9cbd759dc013f0b3724549cc0d71379183c667df3a5988f7e2f1bd485f3
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 F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
-F src/wal.c 887fc4ca3f020ebb2e376f222069570834ac63bf50111ef0cbf3ae417048ed89
-F src/wal.h ba252daaa94f889f4b2c17c027e823d9be47ce39da1d3799886bbd51f0490452
+F src/wal.c c5c772a50621548398bff23df38cc338c8b874188d1fa7bf975f3381f6071126
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 F src/walker.c d5006d6b005e4ea7302ad390957a8d41ed83faa177e412f89bc5600a7462a014
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 F src/whereInt.h a5d079c346a658b7a6e9e47bb943d021e02fa1e6aed3b964ca112112a4892192
@@ -941,6 +949,7 @@ F test/badutf.test d5360fc31f643d37a973ab0d8b4fb85799c3169f
 F test/badutf2.test f310fd3b24a491b6b77bccdf14923b85d6ebcce751068c180d93a6b8ff854399
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 F test/bc_common.tcl b5e42d80305be95697e6370e015af571e5333a1c
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 F test/bestindex1.test 856a453dff8c68b4568601eed5a8b5e20b4763af9229f3947c215729ed878db0
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 F test/bestindex3.test 34bea272b0e0f835651b16a3931dbe7ac927039be6b2e1cb617bbe1d584b492b
@@ -1014,6 +1023,18 @@ F test/collateB.test 1e68906951b846570f29f20102ed91d29e634854ee47454d725f2151eca
 F test/colmeta.test 2c765ea61ee37bc43bbe6d6047f89004e6508eb1
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 F test/columncount.test 6fe99c2f35738b0129357a1cf3fa483f76140f4cd8a89014c88c33c876d2638f
+F test/commitstatus.test d5a871506ce5944a29afb7e65ce47ca7f76cadc1d09775022830258fdd6168a1
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+F test/concfault2.test 34b3fd258836aa305475d00e804c7450ade92f0de0bf9fa620e701446669bb12
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+F test/concurrent3.test 82923fc2ea7321144b4448f98ea38aa316ddceef9020a392c5f6dea536506434
+F test/concurrent4.test e0b12cd467137e50259df3b4f837507e82aaa07c35941c88664dc8ed1d089c44
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+F test/concurrent6.test a7860e9ca13bb5fb76bcf41c5524fbfa9c37e6e258ecf84ffb5748a272488c67
+F test/concurrent7.test b96fa5c4cfdf8d5c0bc66b6934214500bad0260884a736f054ccc76e81aae85d
+F test/concurrent8.test b93937e74a8efb8b84f2fea7595b53418c5f29777bbe9cbdb5dc219b3dd72a7d
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 F test/conflict.test b705cddf025a675d3c13d62fa78ab1e2696fb8e07a3d7cccce1596ff8b301492
 F test/conflict2.test 5557909ce683b1073982f5d1b61dfb1d41e369533bfdaf003180c5bc87282dd1
 F test/conflict3.test 81865d9599609aca394fb3b9cd5f561d4729ea5b176bece3644f6ecb540f88ac
@@ -1027,7 +1048,7 @@ F test/corrupt6.test fc6a891716139665dae0073b6945e3670bf92568
 F test/corrupt7.test ffa86896fe63a3d00b0a131e1e64f402e4da9f7e5d89609d6501c851e511d73a
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 F test/corrupt9.test 730a3db08d4ab9aa43392ea30d9c2b4879cbff85
-F test/corruptA.test 112f4b2ae0b95ebf3ea63718642fb969a93acea557ace3a307234d19c245989b
+F test/corruptA.test 56e8f321adaf3411960e9d2c7136669d8e1a91cbde6cf401ea84e6d6c7ccbe10
 F test/corruptB.test 73a8d6c0b9833697ecf16b63e3c5c05c945b5dec
 F test/corruptC.test 7d6d9e907334ea3ccb7111a0656cafa30a28f8a5f2aaf1c45ad712236302856a
 F test/corruptD.test 614320aa519f6bf6c7dd2f581f9513ff7b6826954180cca1a606d0e25ea084a3
@@ -1040,7 +1061,7 @@ F test/corruptJ.test 4d5ccc4bf959464229a836d60142831ef76a5aa4
 F test/corruptK.test ac13504593d89d69690d45479547616ed12644d42b5cb7eeb2e759a76fc23dcb
 F test/corruptL.test 652fc8ac0763a6fd3eb28b951d481924167b2d9936083bcc68253b2274a0c8fe
 F test/corruptM.test 7d574320e08c1b36caa3e47262061f186367d593a7e305d35f15289cc2c3e067
-F test/corruptN.test 7c099d153a554001b4fb829c799b01f2ea6276cbc32479131e0db0da4efd9cc4
+F test/corruptN.test 57985a0737f5e008283a91c24630cd3c7003d3c7b62824edaa21258e46da9455
 F test/cost.test cc434a026b1e9d0d98137a147e24e5daf1b1ad09e9ff7da63b34c83ddd136d92
 F test/count.test cd4bd531066e8d77ef8fe1e3fc8253d042072e117ccab214b290cf83f1602249
 F test/countofview.test 4088e461a10ee33e69803c177a69aa1d7bba81a9ffc2df66d76465a22ca7fdfc
@@ -1184,7 +1205,7 @@ F test/fts3conf.test c9cd45433b6787d48a43e84949aa2eb8b3b3d242bac7276731c1476290d
 F test/fts3corrupt.test 6732477c5ace050c5758a40a8b5706c8c0cccd416b9c558e0e15224805a40e57
 F test/fts3corrupt2.test e318f0676e5e78d5a4b702637e2bb25265954c08a1b1e4aaf93c7880bb0c67d0
 F test/fts3corrupt3.test 0d5b69a0998b4adf868cc301fc78f3d0707745f1d984ce044c205cdb764b491f
-F test/fts3corrupt4.test 48bd57baed9654e511709a02dbef2d22ee54c012ad466e8648f0f825233faa08
+F test/fts3corrupt4.test ab870772191b9e1d4f145eac340bc724e107d419bcfee0b197dc2026a2120c17
 F test/fts3corrupt5.test 0549f85ec4bd22e992f645f13c59b99d652f2f5e643dac75568bfd23a6db7ed5
 F test/fts3corrupt6.test f417c910254f32c0bc9ead7affa991a1d5aec35b3b32a183ffb05eea78289525
 F test/fts3cov.test 7eacdbefd756cfa4dc2241974e3db2834e9b372ca215880e00032222f32194cf
@@ -1514,12 +1535,11 @@ F test/pagerfault2.test caf4c7facb914fd3b03a17b31ae2b180c8d6ca1f
 F test/pagerfault3.test 1003fcda009bf48a8e22a516e193b6ef0dd1bbd8
 F test/pageropt.test 84e4cc5cbca285357f7906e99b21be4f2bf5abc0
 F test/pagesize.test 5769fc62d8c890a83a503f67d47508dfdc543305
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 F test/pcache.test c8acbedd3b6fd0f9a7ca887a83b11d24a007972b
 F test/pcache2.test af7f3deb1a819f77a6d0d81534e97d1cf62cd442
 F test/pendingrace.test e99efc5ab3584da3dfc8cd6a0ec4e5a42214820574f5ea24ee93f1d84655f463
 F test/percentile.test 52ba89d6ee6b65f770972b67dace358bab7cdbd532803d3db157845268e789cd
-F test/permutations.test 405542f1d659942994a6b38a9e024cf5cfd23eaa68c806aeb24a72d7c9186e80
+F test/permutations.test 3ed69d571619ab452d06f995c7c1d3f100588b20c1d47595819d9289adedabfb
 F test/pg_common.tcl 3b27542224db1e713ae387459b5d117c836a5f6e328846922993b6d2b7640d9f
 F test/pragma.test 11cb9310c42f921918f7f563e3c0b6e70f9f9c3a6a1cf12af8fccb6c574f3882
 F test/pragma2.test e5d5c176360c321344249354c0c16aec46214c9f
@@ -1544,7 +1564,7 @@ F test/quote.test 7b01b2a261bc26d9821aea9f4941ce1e08191d62fc55ba8862440fb3a59197
 F test/randexpr1.tcl 40dec52119ed3a2b8b2a773bce24b63a3a746459
 F test/randexpr1.test eda062a97e60f9c38ae8d806b03b0ddf23d796df
 F test/rbu.test 168573d353cd0fd10196b87b0caa322c144ef736
-F test/rdonly.test 64e2696c322e3538df0b1ed624e21f9a23ed9ff8
+F test/rdonly.test 21e99ee237265d0cf95a0c84b50c784e834acaa4ef05d92a27b262626a656682
 F test/readonly.test 69a7ccec846cad2e000b3539d56360d02f327061dc5e41f7f9a3e01f19719952
 F test/recover.test a163a156ea9f2beea63fa83c4dcd8dea6e57b8a569fc647155e3d2754eaac1b5
 F test/regexp1.test 8f2a8bc1569666e29a4cee6c1a666cd224eb6d50e2470d1dc1df995170f3e0f1
@@ -1575,11 +1595,11 @@ F test/rowvaluefault.test 963ae9cdaed30a85a29668dd514e639f3556cae903ee9f172ea972
 F test/rowvaluevtab.test cd9747bb3f308086944c07968f547ad6b05022e698d80b9ffbdfe09ce0b8da6f
 F test/rtree.test 0c8d9dd458d6824e59683c19ab2ffa9ef946f798
 F test/run-wordcount.sh 891e89c4c2d16e629cd45951d4ed899ad12afc09
-F test/savepoint.test 6e9804a17767f08432c7a5e738b9a8f4b891d243110b63d3a41d270d3d1378ec
+F test/savepoint.test 63a120ec4fbbd5025b238c259d12ed0516fbf4bca6384041cb995ade9a5f00d2
 F test/savepoint2.test 9b8543940572a2f01a18298c3135ad0c9f4f67d7
 F test/savepoint4.test c8f8159ade6d2acd9128be61e1230f1c1edc6cc0
 F test/savepoint5.test 0735db177e0ebbaedc39812c8d065075d563c4fd
-F test/savepoint6.test f41279c5e137139fa5c21485773332c7adb98cd7
+F test/savepoint6.test 48a645a7bb3a59a6fcf06a7364cfe5b655c336760de39068f7c241b0fc80d963
 F test/savepoint7.test cde525ea3075283eb950cdcdefe23ead4f700daa
 F test/savepointfault.test f044eac64b59f09746c7020ee261734de82bf9b2
 F test/scanstatus.test b249328caf4d317e71058006872b8012598a5fa045b30bf24a81eeff650ab49e
@@ -1714,7 +1734,7 @@ F test/temptable.test d2c9b87a54147161bcd1822e30c1d1cd891e5b30
 F test/temptable2.test 76821347810ecc88203e6ef0dd6897b6036ac788e9dd3e6b04fd4d1631311a16
 F test/temptable3.test d11a0974e52b347e45ee54ef1923c91ed91e4637
 F test/temptrigger.test 38f0ca479b1822d3117069e014daabcaacefffcc
-F test/tester.tcl 2c203a2dd664298f239f0ec3ce22fbc65b5f021c1e09edbae8452af8a694e052
+F test/tester.tcl b4b9cc1520542d34ee061f9f12df0944d6ad1c438feba9db4078f6214e0a8111
 F test/testrunner.tcl 982939f0f1835007298b92e52694c207d16ef79143993b35e5cbc9f0c585938b x
 F test/testrunner_data.tcl dbc0bb1c5b912dfd1e32b25d544318e412edd6085bd5fc9e6619cb93a739b786
 F test/thread001.test a0985c117eab62c0c65526e9fa5d1360dd1cac5b03bde223902763274ce21899
@@ -1728,7 +1748,7 @@ F test/thread3.test a12656a56cdf67acb6a2ff7638826c6d6a645f79909d86df521045ad31cf
 F test/thread_common.tcl 334639cadcb9f912bf82aa73f49efd5282e6cadd
 F test/threadtest1.c 6029d9c5567db28e6dc908a0c63099c3ba6c383b
 F test/threadtest2.c a70a8e94bef23339d34226eb9521015ef99f4df8
-F test/threadtest3.c 655bff6c0895ec03f014126aa65e808fac9aae8c5a7a7da58a510cbe8b43b781
+F test/threadtest3.c e947b396444f7992a942cd8db0f01589ede90dd250ec802fe800cc90bbee21e3
 F test/threadtest4.c c1e67136ceb6c7ec8184e56ac61db28f96bd2925
 F test/threadtest5.c 9b4d782c58d8915d7e955ff8051f3d03628bda0d33b82971ea8c0f2f2808c421
 F test/time-wordcount.sh 8e0b0f8109367827ad5d58f5cc849705731e4b90
@@ -1904,7 +1924,9 @@ F test/triggerF.test 5d76f0a8c428ff87a4d5ed52da06f6096a2c787a1e21b846111dfac4123
 F test/triggerG.test 2b816093c91ba73c733cfa8aedcc210ad819d72a98b1da30768a3c56505233e9
 F test/triggerupfrom.test d1f9e56090408115c522bee626cc33a2f3370f627a5e341d832589d72e3aa271
 F test/trustschema1.test d2996bb284859c99956ac706160eab9f086919da738d19bfef3ac431cce8fd47
+F test/tt3_bcwal2.c 8351577477ce58c3b21a1772c28e73ec58538c44be4a183ff7485d6814bd5385
 F test/tt3_checkpoint.c ac7ca661d739280c89d9c253897df64a59a49369bd1247207ac0f655b622579d
+F test/tt3_core.c 8cd89ead95410f70e7fb02c79f1e040f9c5ad5cf
 F test/tt3_index.c 39eec10a35f57672225be4d182862152896dee4a
 F test/tt3_lookaside1.c 0377e202c3c2a50d688cb65ba203afeda6fafeb9
 F test/tt3_shared.c b37d22defc944a2ac4c91c927fd06c1d48cd51e2ce9d004fe868625bd2399f93
@@ -1937,7 +1959,7 @@ F test/upsert3.test 88d7d590a1948a9cb6eac1b54b0642f67a9f35a1fc0f19b200e97d5d39e3
 F test/upsert4.test 25d2a1da92f149331ae0c51ca6e3eee78189577585eab92de149900d62994fa5
 F test/upsert5.test 9953b180d02d1369cdbb6c73c900834e5fef8cb78e98e07511c8762ec21cc176
 F test/upsertfault.test f21ca47740841fdb4d61acfa7b17646d773e67724fe8c185b71c018db8a94b35
-F test/uri.test c1abaaaa28e9422d61e5f3f9cbc8ef993ec49fe802f581520731708561d49384
+F test/uri.test 8f27eaa41804099fca15101e30fd1b29aebbebf32d4e3c24614fa6319216936d
 F test/uri2.test 9d3ba7a53ee167572d53a298ee4a5d38ec4a8fb7
 F test/userauth01.test e740a2697a7b40d7c5003a7d7edaee16acd349a9
 F test/utf16align.test 9fde0bb5d3a821594aa68c6829ab9c5453a084384137ebb9f6153e2d678039da
@@ -1983,8 +2005,21 @@ F test/vtab_shared.test 5253bff2355a9a3f014c15337da7e177ab0ef8ad
 F test/vtabdistinct.test 7688f0889358f849fd60bbfde1ded38b014b18066076d4bfbb75395804dfe072
 F test/vtabdrop.test 65d4cf6722972e5499bdaf0c0d70ee3b8133944a4e4bc31862563f32a7edca12
 F test/vtabrhs1.test 9b5ecbc74a689500c33a4b2b36761f9bcc22fcc4e3f9d21066ee0c9c74cf5f6c
-F test/wal.test 519c550255c78f55959e9159b93ebbfad2b4e9f36f5b76284da41f572f9d27da
-F test/wal2.test 44fe1cb4935dbbddfa0a34c2c4fd90f0ba8654d59b83c4136eb90fb327fd264f
+F test/wal.test a5d6c7f4bd79251ed344229d96d44ecdfb896bdbd32b7e65f118756699c7e473
+F test/wal2.test e89ca97593b5e92849039f6b68ce1719a853ef20fa22c669ec1ac452fbc31cab
+F test/wal2big.test 829141cbecdda4329db8fa38705424c4a73db72a06b9540b06811a825d330409
+F test/wal2concurrent.test 7fc3e570073683a2a28f42bda46ecf516f5bc82afd703c1fbf4aa38e18fb3361
+F test/wal2fault.test 2e8e60cacd5bcd451618aeffd05f676894d17202d3e2986e288d36e2c5993249
+F test/wal2lock.test 0ef98d72dc6bcf7711dedd684760488400d9a9a6eec0dc5d3822060437793552
+F test/wal2openclose.test 2b26be723ea7f4263c8d5d70b37efd1c359561a0526e39466c45fe8e6478daee
+F test/wal2recover.test 348a3f2a4c79359790f70fd692dcd0c8f04e42a85365e688778c945e10bae02b
+F test/wal2recover2.test a7eece9892b125ef92343bba9e06edd5f6ad20c548dcbf79e3f2ab759f31ef84
+F test/wal2recover3.test 4a91689e165a38bc401736e6518188c2b0ff4fa1566d1810b8867536db128177
+F test/wal2rewrite.test 6ca6f631ffcf871240beab5f02608913fd075c6d0d31310b026c8383c65c9f9c
+F test/wal2rollback.test 23adc4a099b23f6aaea8b04fdca1c35861d887dd80f8be7da2d5273eb777e428
+F test/wal2savepoint.test 3793a0ae97011fca358f79775f5d7d9f85da75c8e67686e2e19713da0cb0d99c
+F test/wal2simple.test 320a08927f307d0ead26fa3fcef4e3f64279f49be9504f918cb33294f75aeec8
+F test/wal2snapshot.test f6c3945bea572fd8745774e95b8dca1e5832c696e2251bb0db33391ee567fe60
 F test/wal3.test 5de023bb862fd1eb9d2ad26fa8d9c43abb5370582e5b08b2ae0d6f93661bc310
 F test/wal4.test 4744e155cd6299c6bd99d3eab1c82f77db9cdb3c
 F test/wal5.test 9c11da7aeccd83a46d79a556ad11a18d3cb15aa9
@@ -1993,7 +2028,7 @@ F test/wal64k.test 2a525c0f45d709bae3765c71045ccec5df7d100ccbd3a7860fdba46c9addb
 F test/wal7.test 2ae8f427d240099cc4b2dfef63cff44e2a68a1bd
 F test/wal8.test d9df3fba4caad5854ed69ed673c68482514203c8
 F test/wal9.test 378e76a9ad09cd9bee06c172ad3547b0129a6750
-F test/wal_common.tcl 4589f701d5527ace2eba43823c96c2177e1f9dd2a6098256ee2203a0a313c13a
+F test/wal_common.tcl 204d1721ac13c5e0c7fae6380315b5ab7f4e8423f580d826c5e9df1995cb018d
 F test/walbak.test 018d4e5a3d45c6298d11b99f09a8ef6876527946
 F test/walbig.test f437473a16cfb314867c6b5d1dbcd519e73e3434
 F test/walblock.test be48f3a75eff0b4456209f26b3ce186c2015497d
@@ -2010,10 +2045,10 @@ F test/walnoshm.test 84ca10c544632a756467336b7c3b864d493ee496
 F test/waloverwrite.test dad2f26567f1b45174e54fbf9a8dc1cb876a7f03
 F test/walpersist.test 8d78a1ec91299163451417b451a2bac3481f8eb9f455b1ca507a6625c927ca6e
 F test/walprotocol.test 1b3f922125e341703f6e946d77fdc564d38fb3e07a9385cfdc6c99cac1ecf878
-F test/walprotocol2.test 7d3b6b4bf0b12f8007121b1e6ef714bc99101fb3b48e46371df1db868eebc131
+F test/walprotocol2.test 7e4bedd5ee83607e2928ac438bf7332a396b980d3e02aa0746509ce11ad1f13c
 F test/walro.test cb438d05ba0d191f10b688e39c4f0cd5b71569a1d1f4440e5bdf3c6880e08c20
 F test/walro2.test 33955a6fd874dd9724005e17f77fef89d334b3171454a1256fe4941a96766cdc
-F test/walrofault.test c70cb6e308c443867701856cce92ad8288cd99488fa52afab77cca6cfd51af68
+F test/walrofault.test 5a25f91c16a68bae65edec7cdef4495e5c6494c8408743fe9b29045fa6665cd0
 F test/walseh1.test bae700eb99519b6d5cd3f893c04759accc5a59c391d4189fe4dd6995a533442b
 F test/walsetlk.test 34c901443b31ab720afc463f5b236c86ca5c4134402573dce91aa0761de8db5a
 F test/walshared.test 42e3808582504878af237ea02c42ca793e8a0efaa19df7df26ac573370dbc7a3
@@ -2132,13 +2167,13 @@ F tool/max-limits.c cbb635fbb37ae4d05f240bfb5b5270bb63c54439
 F tool/merge-test.tcl de76b62f2de2a92d4c1ca4f976bce0aea6899e0229e250479b229b2a1914b176
 F tool/mkautoconfamal.sh cbdcf993fa83dccbef7fb77b39cdeb31ef9f77d9d88c9e343b58d35ca3898a6a
 F tool/mkccode.tcl 86463e68ce9c15d3041610fedd285ce32a5cf7a58fc88b3202b8b76837650dbe x
-F tool/mkctimec.tcl e3af51acc2ef92062fe6d622de010a27a34b497258a248dada04388b916c61c6 x
+F tool/mkctimec.tcl 24074f287208f82f6dfbbe81f9e911849171a9c633961901f2c056cddb8d1663 x
 F tool/mkkeywordhash.c 6b0be901c47f9ad42215fc995eb2f4384ac49213b1fba395102ec3e999acf559
 F tool/mkmsvcmin.tcl d76c45efda1cce2d4005bcea7b8a22bb752e3256009f331120fb4fecb14ebb7a
 F tool/mkopcodec.tcl 33d20791e191df43209b77d37f0ff0904620b28465cca6990cf8d60da61a07ef
 F tool/mkopcodeh.tcl 2b4e6967a670ef21bf53a164964c35c6163277d002a4c6f56fa231d68c88d023
 F tool/mkopts.tcl 680f785fdb09729fd9ac50632413da4eadbdf9071535e3f26d03795828ab07fa
-F tool/mkpragmatab.tcl 32e359ccb21011958a821955254bd7a5fa7915d01a8c16fed91ffc8b40cb4adf
+F tool/mkpragmatab.tcl d03737ad2ac48928d8225d1c571e487b9b7e73e8c1bdcabd61d69b244614408b
 F tool/mkshellc.tcl b7adf08b82de60811d2cb6af05ff59fc17e5cd6f3e98743c14eaaa3f8971fed0
 F tool/mksourceid.c 36aa8020014aed0836fd13c51d6dc9219b0df1761d6b5f58ff5b616211b079b9
 F tool/mkspeedsql.tcl a1a334d288f7adfe6e996f2e712becf076745c97
@@ -2184,6 +2219,8 @@ F tool/stack_usage.tcl f8e71b92cdb099a147dad572375595eae55eca43
 F tool/stripccomments.c 20b8aabc4694d0d4af5566e42da1f1a03aff057689370326e9269a9ddcffdc37
 F tool/symbols-mingw.sh 4dbcea7e74768305384c9fd2ed2b41bbf9f0414d
 F tool/symbols.sh 1612bd947750e21e7b47befad5f6b3825b06cce0705441f903bf35ced65ae9b9
+F tool/tserver.c 17b7f0b06f4e776e26220889941a86936b3c56ad18608baadc8faa00b7bd46ee
+F tool/tserver_test.tcl 64415a134749ac3f38c9abd2bb95c7387a9b44e5116419487fd008cff8a459db
 F tool/varint.c 5d94cb5003db9dbbcbcc5df08d66f16071aee003
 F tool/vdbe-compress.tcl 1dcb7632e57cf57105248029e6e162fddaf6c0fccb3bb9e6215603752c5a2d4a
 F tool/vdbe_profile.tcl 3ac5a4a9449f4baf77059358ea050db3e34395ccf59c5464d29b91746d5b961e
@@ -2212,8 +2249,8 @@ F vsixtest/vsixtest.tcl 6195aba1f12a5e10efc2b8c0009532167be5e301abe5b31385638080
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P c0c6e9abebf76358625f30a179658319b260baba6eded2a4c5ad356143e36f97
-R c9ec90e0d0ba3db3bca78a08a6c286b8
-U drh
-Z c8dd2f7c1df9f10ff01ca20270187b6f
+P e0c0176793d41bef30e093975a87170981277dac20cde08e0fd3e0b6f40dca2f
+R 40d5d8e3822854d0b02030b6b7d7027f
+U dan
+Z 1f420b344bc232a0c739cabd514cf0b5
 # Remove this line to create a well-formed Fossil manifest.

manifest.uuid

@@ -1 +1 @@
-60ac55c4b76355aaf7cbde38bf1f6082ff5612bf4ffc49ab69d00fd4e3d64e64
+35aa893d4537d0b3605084a1f2f5529794e82af59b8893053815d3fcb4719a27

src/bitvec.c

@@ -171,6 +171,12 @@ int sqlite3BitvecSet(Bitvec *p, u32 i){
   if( p==0 ) return SQLITE_OK;
   assert( i>0 );
   assert( i<=p->iSize );
+  if( i>p->iSize || i==0 ){
+    sqlite3_log(SQLITE_ERROR, 
+        "Bitvec: setting bit %d of bitvec size %d\n", (int)i, (int)p->iSize
+    );
+    abort();
+  }
   i--;
   while((p->iSize > BITVEC_NBIT) && p->iDivisor) {
     u32 bin = i/p->iDivisor;

src/btree.h

@@ -357,6 +357,8 @@ sqlite3_uint64 sqlite3BtreeSeekCount(Btree*);
 # define sqlite3BtreeSeekCount(X) 0
 #endif
 
+int sqlite3BtreeExclusiveLock(Btree *pBt);
+
 #ifndef NDEBUG
 int sqlite3BtreeCursorIsValid(BtCursor*);
 #endif
@@ -417,5 +419,4 @@ void sqlite3BtreeClearCache(Btree*);
 # define sqlite3SchemaMutexHeld(X,Y,Z) 1
 #endif
 
-
 #endif /* SQLITE_BTREE_H */

src/btreeInt.h

@@ -232,6 +232,7 @@
 typedef struct MemPage MemPage;
 typedef struct BtLock BtLock;
 typedef struct CellInfo CellInfo;
+typedef struct BtreePtrmap BtreePtrmap;
 
 /*
 ** This is a magic string that appears at the beginning of every
@@ -275,6 +276,9 @@ struct MemPage {
   u8 intKey;           /* True if table b-trees.  False for index b-trees */
   u8 intKeyLeaf;       /* True if the leaf of an intKey table */
   Pgno pgno;           /* Page number for this page */
+#ifndef SQLITE_OMIT_CONCURRENT
+  Pgno pgnoRoot;       /* Root page of b-tree that this page belongs to */
+#endif
   /* Only the first 8 bytes (above) are zeroed by pager.c when a new page
   ** is allocated. All fields that follow must be initialized before use */
   u8 leaf;             /* True if a leaf page */
@@ -360,6 +364,12 @@ struct Btree {
 #ifndef SQLITE_OMIT_SHARED_CACHE
   BtLock lock;       /* Object used to lock page 1 */
 #endif
+#ifndef SQLITE_OMIT_CONCURRENT
+  /* Return values for sqlite3_commit_status() requests:
+  ** SQLITE_COMMIT_FIRSTFRAME, COMMIT_NFRAME.
+  */
+  u32 aCommit[2];
+#endif
 };
 
 /*
@@ -456,7 +466,12 @@ struct BtShared {
   Btree *pWriter;       /* Btree with currently open write transaction */
 #endif
   u8 *pTmpSpace;        /* Temp space sufficient to hold a single cell */
+#ifndef SQLITE_OMIT_CONCURRENT
+  BtreePtrmap *pMap;
+#endif
   int nPreformatSize;   /* Size of last cell written by TransferRow() */
+
+  u64 *aCommitTime;
 };
 
 /*
@@ -673,12 +688,19 @@ struct BtCursor {
 ** (sqliteMallocRaw), it is not possible to use conditional compilation.
 ** So, this macro is defined instead.
 */
-#ifndef SQLITE_OMIT_AUTOVACUUM
-#define ISAUTOVACUUM(pBt) (pBt->autoVacuum)
-#else
+#ifdef SQLITE_OMIT_AUTOVACUUM
 #define ISAUTOVACUUM(pBt) 0
+#else
+#define ISAUTOVACUUM(pBt) (pBt->autoVacuum)
 #endif
 
+#ifdef SQLITE_OMIT_CONCURRENT
+# define ISCONCURRENT 0
+#else
+# define ISCONCURRENT (pBt->pMap!=0)
+#endif
+
+#define REQUIRE_PTRMAP (ISAUTOVACUUM(pBt) || ISCONCURRENT)
 
 /*
 ** This structure is passed around through all the PRAGMA integrity_check

src/build.c

@@ -5236,7 +5236,7 @@ void sqlite3BeginTransaction(Parse *pParse, int type){
   }
   v = sqlite3GetVdbe(pParse);
   if( !v ) return;
-  if( type!=TK_DEFERRED ){
+  if( type==TK_IMMEDIATE || type==TK_EXCLUSIVE ){
     for(i=0; i<db->nDb; i++){
       int eTxnType;
       Btree *pBt = db->aDb[i].pBt;
@@ -5251,7 +5251,7 @@ void sqlite3BeginTransaction(Parse *pParse, int type){
       sqlite3VdbeUsesBtree(v, i);
     }
   }
-  sqlite3VdbeAddOp0(v, OP_AutoCommit);
+  sqlite3VdbeAddOp3(v, OP_AutoCommit, 0, 0, (type==TK_CONCURRENT));
 }
 
 /*

src/ctime.c

@@ -782,6 +782,7 @@ static const char * const sqlite3azCompileOpt[] = {
 #ifdef SQLITE_VDBE_COVERAGE
   "VDBE_COVERAGE",
 #endif
+"WAL2",
 #ifdef SQLITE_WIN32_MALLOC
   "WIN32_MALLOC",
 #endif

src/func.c

@@ -559,8 +559,9 @@ static void randomFunc(
   sqlite3_value **NotUsed2
 ){
   sqlite_int64 r;
+  sqlite3 *db = sqlite3_context_db_handle(context);
   UNUSED_PARAMETER2(NotUsed, NotUsed2);
-  sqlite3_randomness(sizeof(r), &r);
+  sqlite3FastRandomness(&db->sPrng, sizeof(r), &r);
   if( r<0 ){
     /* We need to prevent a random number of 0x8000000000000000
     ** (or -9223372036854775808) since when you do abs() of that
@@ -586,6 +587,7 @@ static void randomBlob(
 ){
   sqlite3_int64 n;
   unsigned char *p;
+  sqlite3 *db = sqlite3_context_db_handle(context);
   assert( argc==1 );
   UNUSED_PARAMETER(argc);
   n = sqlite3_value_int64(argv[0]);
@@ -594,7 +596,7 @@ static void randomBlob(
   }
   p = contextMalloc(context, n);
   if( p ){
-    sqlite3_randomness(n, p);
+    sqlite3FastRandomness(&db->sPrng, n, p);
     sqlite3_result_blob(context, (char*)p, n, sqlite3_free);
   }
 }

src/legacy.c

@@ -49,6 +49,7 @@ int sqlite3_exec(
     int nCol = 0;
     char **azVals = 0;
 
+    sqlite3PrepareTimeSet(db->aSchemaTime, SCHEMA_TIME_BEFORE_PREPARE);
     pStmt = 0;
     rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, &zLeftover);
     assert( rc==SQLITE_OK || pStmt==0 );
@@ -62,6 +63,7 @@ int sqlite3_exec(
     }
     callbackIsInit = 0;
 
+    sqlite3PrepareTimeSet(db->aSchemaTime, SCHEMA_TIME_BEFORE_STEP);
     while( 1 ){
       int i;
       rc = sqlite3_step(pStmt);
@@ -107,6 +109,7 @@ int sqlite3_exec(
         }
       }
 
+      sqlite3PrepareTimeSet(db->aSchemaTime, SCHEMA_TIME_BEFORE_FINALIZE);
       if( rc!=SQLITE_ROW ){
         rc = sqlite3VdbeFinalize((Vdbe *)pStmt);
         pStmt = 0;

src/main.c

@@ -3337,7 +3337,7 @@ static int openDatabase(
   db->aDb = db->aDbStatic;
   db->lookaside.bDisable = 1;
   db->lookaside.sz = 0;
-
+  sqlite3FastPrngInit(&db->sPrng);
   assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
   memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
   db->aLimit[SQLITE_LIMIT_WORKER_THREADS] = SQLITE_DEFAULT_WORKER_THREADS;
@@ -5070,6 +5070,35 @@ void sqlite3_snapshot_free(sqlite3_snapshot *pSnapshot){
 }
 #endif /* SQLITE_ENABLE_SNAPSHOT */
 
+SQLITE_EXPERIMENTAL int sqlite3_wal_info(
+  sqlite3 *db, const char *zDb, 
+  unsigned int *pnPrior, unsigned int *pnFrame
+){
+  int rc = SQLITE_OK;
+
+#ifndef SQLITE_OMIT_WAL
+  Btree *pBt;
+  int iDb;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
+
+  sqlite3_mutex_enter(db->mutex);
+  iDb = sqlite3FindDbName(db, zDb);
+  if( iDb<0 ){
+    return SQLITE_ERROR;
+  }
+  pBt = db->aDb[iDb].pBt;
+  rc = sqlite3PagerWalInfo(sqlite3BtreePager(pBt), pnPrior, pnFrame);
+  sqlite3_mutex_leave(db->mutex);
+#endif   /* SQLITE_OMIT_WAL */
+
+  return rc;
+}
+
 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
 /*
 ** Given the name of a compile-time option, return true if that option

src/os_unix.c

@@ -46,6 +46,16 @@
 #include "sqliteInt.h"
 #if SQLITE_OS_UNIX              /* This file is used on unix only */
 
+/* Turn this feature on in all builds for now */
+#define SQLITE_MUTEXFREE_SHMLOCK 1
+#define SQLITE_MFS_EXCLUSIVE     255
+#ifndef SQLITE_MFS_NSHARD
+# define SQLITE_MFS_NSHARD       8
+#endif
+#if SQLITE_MFS_NSHARD<1
+# error "SQLITE_MFS_NSHARD must be greater than 0"
+#endif
+
 /*
 ** There are various methods for file locking used for concurrency
 ** control:
@@ -1224,6 +1234,10 @@ struct unixInodeInfo {
   sem_t *pSem;                    /* Named POSIX semaphore */
   char aSemName[MAX_PATHNAME+2];  /* Name of that semaphore */
 #endif
+#ifdef SQLITE_SHARED_MAPPING
+  sqlite3_int64 nSharedMapping;   /* Size of mapped region in bytes */
+  void *pSharedMapping;           /* Memory mapped region */
+#endif
 };
 
 /*
@@ -1380,6 +1394,13 @@ static void releaseInodeInfo(unixFile *pFile){
     pInode->nRef--;
     if( pInode->nRef==0 ){
       assert( pInode->pShmNode==0 );
+#ifdef SQLITE_SHARED_MAPPING
+      if( pInode->pSharedMapping ){
+        osMunmap(pInode->pSharedMapping, pInode->nSharedMapping);
+        pInode->pSharedMapping = 0;
+        pInode->nSharedMapping = 0;
+      }
+#endif
       sqlite3_mutex_enter(pInode->pLockMutex);
       closePendingFds(pFile);
       sqlite3_mutex_leave(pInode->pLockMutex);
@@ -2243,6 +2264,14 @@ static int nolockUnlock(sqlite3_file *NotUsed, int NotUsed2){
 ** Close the file.
 */
 static int nolockClose(sqlite3_file *id) {
+#ifdef SQLITE_SHARED_MAPPING
+  unixFile *pFd = (unixFile*)id;
+  if( pFd->pInode ){
+    unixEnterMutex();
+    releaseInodeInfo(pFd);
+    unixLeaveMutex();
+  }
+#endif
   return closeUnixFile(id);
 }
 
@@ -4083,6 +4112,9 @@ static int unixFileControl(sqlite3_file *id, int op, void *pArg){
       *(i64*)pArg = pFile->mmapSizeMax;
       if( newLimit>=0 && newLimit!=pFile->mmapSizeMax && pFile->nFetchOut==0 ){
         pFile->mmapSizeMax = newLimit;
+#ifdef SQLITE_SHARED_MAPPING
+        if( pFile->pInode==0 )
+#endif
         if( pFile->mmapSize>0 ){
           unixUnmapfile(pFile);
           rc = unixMapfile(pFile, -1);
@@ -4352,8 +4384,41 @@ struct unixShmNode {
 #ifdef SQLITE_DEBUG
   u8 nextShmId;              /* Next available unixShm.id value */
 #endif
+
+#ifdef SQLITE_MUTEXFREE_SHMLOCK
+  /* In unix-excl mode, if SQLITE_MUTEXFREE_SHMLOCK is defined, all locks
+  ** are stored in the following 64-bit value. There are in total 8 
+  ** shm-locking slots, each of which are assigned 8-bits from the 64-bit
+  ** value. The least-significant 8 bits correspond to shm-locking slot
+  ** 0, and so on.
+  **
+  ** If the 8-bits corresponding to a shm-locking locking slot are set to
+  ** 0xFF, then a write-lock is held on the slot. Or, if they are set to
+  ** a non-zero value smaller than 0xFF, then they represent the total 
+  ** number of read-locks held on the slot. There is no way to distinguish
+  ** between a write-lock and 255 read-locks.  */
+  struct LockingSlot {
+    u32 nLock;
+    u64 aPadding[7];
+  } aMFSlot[3 + SQLITE_MFS_NSHARD*5];
+#endif
 };
 
+/*
+** Atomic CAS primitive used in multi-process mode. Equivalent to:
+** 
+**   int unixCompareAndSwap(u32 *ptr, u32 oldval, u32 newval){
+**     if( *ptr==oldval ){
+**       *ptr = newval;
+**       return 1;
+**     }
+**     return 0;
+**   }
+*/
+#define unixCompareAndSwap(ptr,oldval,newval) \
+    __sync_bool_compare_and_swap(ptr,oldval,newval)
+
+
 /*
 ** Structure used internally by this VFS to record the state of an
 ** open shared memory connection.
@@ -4374,6 +4439,9 @@ struct unixShm {
   u8 id;                     /* Id of this connection within its unixShmNode */
   u16 sharedMask;            /* Mask of shared locks held */
   u16 exclMask;              /* Mask of exclusive locks held */
+#ifdef SQLITE_MUTEXFREE_SHMLOCK
+  u8 aMFCurrent[8];          /* Current slot used for each shared lock */
+#endif
 };
 
 /*
@@ -4959,6 +5027,87 @@ shmpage_out:
   return rc;
 }
 
+#ifdef SQLITE_MUTEXFREE_SHMLOCK
+static int unixMutexFreeShmlock(
+  unixFile *pFd,             /* Database file holding the shared memory */
+  int ofst,                  /* First lock to acquire or release */
+  int n,                     /* Number of locks to acquire or release */
+  int flags                  /* What to do with the lock */
+){
+  struct LockMapEntry {
+    int iFirst;
+    int nSlot;
+  } aMap[9] = {
+    { 0, 1 },
+    { 1, 1 },
+    { 2, 1 },
+    { 3+0*SQLITE_MFS_NSHARD, SQLITE_MFS_NSHARD },
+    { 3+1*SQLITE_MFS_NSHARD, SQLITE_MFS_NSHARD },
+    { 3+2*SQLITE_MFS_NSHARD, SQLITE_MFS_NSHARD },
+    { 3+3*SQLITE_MFS_NSHARD, SQLITE_MFS_NSHARD },
+    { 3+4*SQLITE_MFS_NSHARD, SQLITE_MFS_NSHARD },
+    { 3+5*SQLITE_MFS_NSHARD, 0 },
+  };
+
+  unixShm *p = pFd->pShm;               /* The shared memory being locked */
+  unixShmNode *pShmNode = p->pShmNode;  /* The underlying file iNode */
+
+  if( flags & SQLITE_SHM_SHARED ){
+    /* SHARED locks */
+    u32 iOld, iNew, *ptr;
+    int iIncr = -1;
+    if( (flags & SQLITE_SHM_UNLOCK)==0 ){
+      p->aMFCurrent[ofst] = (p->aMFCurrent[ofst] + 1) % aMap[ofst].nSlot;
+      iIncr = 1;
+    }
+    ptr = &pShmNode->aMFSlot[aMap[ofst].iFirst + p->aMFCurrent[ofst]].nLock;
+    do {
+      iOld = *ptr;
+      iNew = iOld + iIncr;
+      if( iNew>SQLITE_MFS_EXCLUSIVE ){
+        return SQLITE_BUSY;
+      }
+    }while( 0==unixCompareAndSwap(ptr, iOld, iNew) );
+  }else{
+    /* EXCLUSIVE locks */
+    u16 mask = (1<<(ofst+n)) - (1<<ofst);
+    if( (flags & SQLITE_SHM_LOCK) || (mask & p->exclMask) ){
+      int iFirst = aMap[ofst].iFirst;
+      int iLast = aMap[ofst+n].iFirst;
+      int i;
+      for(i=iFirst; i<iLast; i++){
+        u32 *ptr = &pShmNode->aMFSlot[i].nLock;
+        if( flags & SQLITE_SHM_UNLOCK ){
+          assert( (*ptr)==SQLITE_MFS_EXCLUSIVE );
+          *ptr = 0;
+        }else{
+          u32 iOld;
+          do {
+            iOld = *ptr;
+            if( iOld>0 ){
+              while( i>iFirst ){
+                i--;
+                pShmNode->aMFSlot[i].nLock = 0;
+              }
+              return SQLITE_BUSY;
+            }
+          }while( 0==unixCompareAndSwap(ptr, iOld, SQLITE_MFS_EXCLUSIVE) );
+        }
+      }
+      if( flags & SQLITE_SHM_UNLOCK ){
+        p->exclMask &= ~mask;
+      }else{
+        p->exclMask |= mask;
+      }
+    }
+  }
+
+  return SQLITE_OK;
+}
+#else
+# define unixMutexFreeShmlock(a,b,c,d) SQLITE_OK
+#endif
+
 /*
 ** Check that the pShmNode->aLock[] array comports with the locking bitmasks
 ** held by each client. Return true if it does, or false otherwise. This
@@ -5033,6 +5182,11 @@ static int unixShmLock(
   assert( pShmNode->hShm>=0 || pDbFd->pInode->bProcessLock==1 );
   assert( pShmNode->hShm<0 || pDbFd->pInode->bProcessLock==0 );
 
+  if( pDbFd->pInode->bProcessLock ){
+    return unixMutexFreeShmlock(pDbFd, ofst, n, flags);
+  }
+
+
   /* Check that, if this to be a blocking lock, no locks that occur later
   ** in the following list than the lock being obtained are already held:
   **
@@ -5207,12 +5361,16 @@ static void unixShmBarrier(
   sqlite3_file *fd                /* Database file holding the shared memory */
 ){
   UNUSED_PARAMETER(fd);
+#ifdef SQLITE_MUTEXFREE_SHMLOCK
+  __sync_synchronize();
+#else
   sqlite3MemoryBarrier();         /* compiler-defined memory barrier */
   assert( fd->pMethods->xLock==nolockLock
        || unixFileMutexNotheld((unixFile*)fd)
   );
   unixEnterMutex();               /* Also mutex, for redundancy */
   unixLeaveMutex();
+#endif
 }
 
 /*
@@ -5281,6 +5439,9 @@ static int unixShmUnmap(
 */
 static void unixUnmapfile(unixFile *pFd){
   assert( pFd->nFetchOut==0 );
+#ifdef SQLITE_SHARED_MAPPING
+  if( pFd->pInode ) return;
+#endif
   if( pFd->pMapRegion ){
     osMunmap(pFd->pMapRegion, pFd->mmapSizeActual);
     pFd->pMapRegion = 0;
@@ -5412,6 +5573,28 @@ static int unixMapfile(unixFile *pFd, i64 nMap){
     nMap = pFd->mmapSizeMax;
   }
 
+#ifdef SQLITE_SHARED_MAPPING
+  if( pFd->pInode ){
+    unixInodeInfo *pInode = pFd->pInode;
+    if( pFd->pMapRegion ) return SQLITE_OK;
+    unixEnterMutex();
+    if( pInode->pSharedMapping==0 ){
+      u8 *pNew = osMmap(0, nMap, PROT_READ, MAP_SHARED, pFd->h, 0);
+      if( pNew==MAP_FAILED ){
+        unixLogError(SQLITE_OK, "mmap", pFd->zPath);
+        pFd->mmapSizeMax = 0;
+      }else{
+        pInode->pSharedMapping = pNew;
+        pInode->nSharedMapping = nMap;
+      }
+    }
+    pFd->pMapRegion = pInode->pSharedMapping;
+    pFd->mmapSizeActual = pFd->mmapSize = pInode->nSharedMapping;
+    unixLeaveMutex();
+    return SQLITE_OK;
+  }
+#endif
+
   assert( nMap>0 || (pFd->mmapSize==0 && pFd->pMapRegion==0) );
   if( nMap!=pFd->mmapSize ){
     unixRemapfile(pFd, nMap);
@@ -5854,6 +6037,9 @@ static int fillInUnixFile(
   if( pLockingStyle == &posixIoMethods
 #if defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE
     || pLockingStyle == &nfsIoMethods
+#endif
+#ifdef SQLITE_SHARED_MAPPING
+    || pLockingStyle == &nolockIoMethods
 #endif
   ){
     unixEnterMutex();

src/pager.c

@@ -658,6 +658,9 @@ struct Pager {
   u32 cksumInit;              /* Quasi-random value added to every checksum */
   u32 nSubRec;                /* Number of records written to sub-journal */
   Bitvec *pInJournal;         /* One bit for each page in the database file */
+#ifndef SQLITE_OMIT_CONCURRENT
+  Bitvec *pAllRead;           /* Pages read within current CONCURRENT trans. */
+#endif
   sqlite3_file *fd;           /* File descriptor for database */
   sqlite3_file *jfd;          /* File descriptor for main journal */
   sqlite3_file *sjfd;         /* File descriptor for sub-journal */
@@ -700,6 +703,7 @@ struct Pager {
   Wal *pWal;                  /* Write-ahead log used by "journal_mode=wal" */
   char *zWal;                 /* File name for write-ahead log */
 #endif
+  u64 *aCommitTime;
 };
 
 /*
@@ -789,20 +793,6 @@ static const unsigned char aJournalMagic[] = {
 # define USEFETCH(x) 0
 #endif
 
-/*
-** The argument to this macro is a file descriptor (type sqlite3_file*).
-** Return 0 if it is not open, or non-zero (but not 1) if it is.
-**
-** This is so that expressions can be written as:
-**
-**   if( isOpen(pPager->jfd) ){ ...
-**
-** instead of
-**
-**   if( pPager->jfd->pMethods ){ ...
-*/
-#define isOpen(pFd) ((pFd)->pMethods!=0)
-
 #ifdef SQLITE_DIRECT_OVERFLOW_READ
 /*
 ** Return true if page pgno can be read directly from the database file
@@ -914,7 +904,9 @@ static int assert_pager_state(Pager *p){
       if( !pagerUseWal(pPager) ){
         assert( p->eLock>=RESERVED_LOCK );
       }
-      assert( pPager->dbSize==pPager->dbOrigSize );
+#ifndef SQLITE_OMIT_CONCURRENT
+      assert( pPager->dbSize==pPager->dbOrigSize || pPager->pAllRead );
+#endif
       assert( pPager->dbOrigSize==pPager->dbFileSize );
       assert( pPager->dbOrigSize==pPager->dbHintSize );
       assert( pPager->setSuper==0 );
@@ -933,6 +925,7 @@ static int assert_pager_state(Pager *p){
         assert( isOpen(p->jfd)
              || p->journalMode==PAGER_JOURNALMODE_OFF
              || p->journalMode==PAGER_JOURNALMODE_WAL
+             || p->journalMode==PAGER_JOURNALMODE_WAL2
         );
       }
       assert( pPager->dbOrigSize==pPager->dbFileSize );
@@ -947,6 +940,7 @@ static int assert_pager_state(Pager *p){
       assert( isOpen(p->jfd)
            || p->journalMode==PAGER_JOURNALMODE_OFF
            || p->journalMode==PAGER_JOURNALMODE_WAL
+           || p->journalMode==PAGER_JOURNALMODE_WAL2
            || (sqlite3OsDeviceCharacteristics(p->fd)&SQLITE_IOCAP_BATCH_ATOMIC)
       );
       assert( pPager->dbOrigSize<=pPager->dbHintSize );
@@ -959,6 +953,7 @@ static int assert_pager_state(Pager *p){
       assert( isOpen(p->jfd)
            || p->journalMode==PAGER_JOURNALMODE_OFF
            || p->journalMode==PAGER_JOURNALMODE_WAL
+           || p->journalMode==PAGER_JOURNALMODE_WAL2
            || (sqlite3OsDeviceCharacteristics(p->fd)&SQLITE_IOCAP_BATCH_ATOMIC)
       );
       break;
@@ -1822,6 +1817,53 @@ static int addToSavepointBitvecs(Pager *pPager, Pgno pgno){
   return rc;
 }
 
+#ifndef SQLITE_OMIT_CONCURRENT
+/*
+** If they are not already, begin recording all pages read from the pager layer
+** by the b-tree layer This is used by concurrent transactions. Return
+** SQLITE_OK if successful, or an SQLite error code (SQLITE_NOMEM) if an error
+** occurs.
+*/
+int sqlite3PagerBeginConcurrent(Pager *pPager){
+  int rc = SQLITE_OK;
+  if( pPager->pAllRead==0 ){
+    pPager->pAllRead = sqlite3BitvecCreate(pPager->dbSize);
+    pPager->dbOrigSize = pPager->dbSize;
+    if( pPager->pAllRead==0 ){
+      rc = SQLITE_NOMEM;
+    }
+  }
+  return rc;
+}
+
+/* !defined(SQLITE_OMIT_CONCURRENT)
+**
+** Stop recording all pages read from the pager layer by the b-tree layer
+** and discard any current records.
+*/
+void sqlite3PagerEndConcurrent(Pager *pPager){
+  sqlite3BitvecDestroy(pPager->pAllRead);
+  pPager->pAllRead = 0;
+}
+
+/* !defined(SQLITE_OMIT_CONCURRENT)
+**
+** Return true if the database is in wal mode. False otherwise.
+*/
+int sqlite3PagerIsWal(Pager *pPager){
+  return pPager->pWal!=0;
+}
+#endif /* SQLITE_OMIT_CONCURRENT */
+
+/*
+** Free the Pager.pInJournal and Pager.pAllRead bitvec objects.
+*/
+static void pagerFreeBitvecs(Pager *pPager){
+  sqlite3BitvecDestroy(pPager->pInJournal);
+  pPager->pInJournal = 0;
+  sqlite3PagerEndConcurrent(pPager);
+}
+
 /*
 ** This function is a no-op if the pager is in exclusive mode and not
 ** in the ERROR state. Otherwise, it switches the pager to PAGER_OPEN
@@ -1846,8 +1888,7 @@ static void pager_unlock(Pager *pPager){
        || pPager->eState==PAGER_ERROR
   );
 
-  sqlite3BitvecDestroy(pPager->pInJournal);
-  pPager->pInJournal = 0;
+  pagerFreeBitvecs(pPager);
   releaseAllSavepoints(pPager);
 
   if( pagerUseWal(pPager) ){
@@ -2080,7 +2121,7 @@ static int pager_end_transaction(Pager *pPager, int hasSuper, int bCommit){
       }
       pPager->journalOff = 0;
     }else if( pPager->journalMode==PAGER_JOURNALMODE_PERSIST
-      || (pPager->exclusiveMode && pPager->journalMode!=PAGER_JOURNALMODE_WAL)
+      || (pPager->exclusiveMode && pPager->journalMode<PAGER_JOURNALMODE_WAL)
     ){
       rc = zeroJournalHdr(pPager, hasSuper||pPager->tempFile);
       pPager->journalOff = 0;
@@ -2095,6 +2136,7 @@ static int pager_end_transaction(Pager *pPager, int hasSuper, int bCommit){
       assert( pPager->journalMode==PAGER_JOURNALMODE_DELETE
            || pPager->journalMode==PAGER_JOURNALMODE_MEMORY
            || pPager->journalMode==PAGER_JOURNALMODE_WAL
+           || pPager->journalMode==PAGER_JOURNALMODE_WAL2
       );
       sqlite3OsClose(pPager->jfd);
       if( bDelete ){
@@ -2114,8 +2156,7 @@ static int pager_end_transaction(Pager *pPager, int hasSuper, int bCommit){
   }
 #endif
 
-  sqlite3BitvecDestroy(pPager->pInJournal);
-  pPager->pInJournal = 0;
+  pagerFreeBitvecs(pPager);
   pPager->nRec = 0;
   if( rc==SQLITE_OK ){
     if( MEMDB || pagerFlushOnCommit(pPager, bCommit) ){
@@ -3010,6 +3051,7 @@ end_playback:
 static int readDbPage(PgHdr *pPg){
   Pager *pPager = pPg->pPager; /* Pager object associated with page pPg */
   int rc = SQLITE_OK;          /* Return code */
+  u64 t1 = 0;
 
 #ifndef SQLITE_OMIT_WAL
   u32 iFrame = 0;              /* Frame of WAL containing pgno */
@@ -3021,6 +3063,9 @@ static int readDbPage(PgHdr *pPg){
     rc = sqlite3WalFindFrame(pPager->pWal, pPg->pgno, &iFrame);
     if( rc ) return rc;
   }
+  if( pPager->aCommitTime ){
+    t1 = sqlite3STimeNow();
+  }
   if( iFrame ){
     rc = sqlite3WalReadFrame(pPager->pWal, iFrame,pPager->pageSize,pPg->pData);
   }else
@@ -3032,6 +3077,10 @@ static int readDbPage(PgHdr *pPg){
       rc = SQLITE_OK;
     }
   }
+  if( pPager->aCommitTime ){
+    pPager->aCommitTime[COMMIT_TIME_RELOCATE2_READUS] += (sqlite3STimeNow() - t1);
+    pPager->aCommitTime[COMMIT_TIME_RELOCATE2_READCOUNT]++;
+  }
 
   if( pPg->pgno==1 ){
     if( rc ){
@@ -3145,8 +3194,24 @@ static int pagerRollbackWal(Pager *pPager){
   **   + Reload page content from the database (if refcount>0).
   */
   pPager->dbSize = pPager->dbOrigSize;
-  rc = sqlite3WalUndo(pPager->pWal, pagerUndoCallback, (void *)pPager);
+  rc = sqlite3WalUndo(pPager->pWal, pagerUndoCallback, (void *)pPager, 
+#ifdef SQLITE_OMIT_CONCURRENT
+      0
+#else
+      pPager->pAllRead!=0
+#endif
+  );
   pList = sqlite3PcacheDirtyList(pPager->pPCache);
+
+#ifndef SQLITE_OMIT_CONCURRENT
+  /* If this is an CONCURRENT transaction, then page 1 must be reread from 
+  ** the db file, even if it is not dirty. This is because the b-tree layer 
+  ** may have already zeroed the nFree and iTrunk header fields.  */
+  if( rc==SQLITE_OK && (pList==0 || pList->pgno!=1) && pPager->pAllRead ){
+    rc = pagerUndoCallback((void*)pPager, 1);
+  }
+#endif
+
   while( pList && rc==SQLITE_OK ){
     PgHdr *pNext = pList->pDirty;
     rc = pagerUndoCallback((void *)pPager, pList->pgno);
@@ -3196,6 +3261,8 @@ static int pagerWalFrames(
       if( p->pgno<=nTruncate ){
         ppNext = &p->pDirty;
         nList++;
+        PAGERTRACE(("TO-WAL %d page %d hash(%08x)\n",
+                     PAGERID(pPager), p->pgno, pager_pagehash(p)));
       }
     }
     assert( pList );
@@ -3205,6 +3272,7 @@ static int pagerWalFrames(
   pPager->aStat[PAGER_STAT_WRITE] += nList;
 
   if( pList->pgno==1 ) pager_write_changecounter(pList);
+  sqlite3CommitTimeSet(pPager->aCommitTime, COMMIT_TIME_AFTER_CHANGECOUNTER);
   rc = sqlite3WalFrames(pPager->pWal,
       pPager->pageSize, pList, nTruncate, isCommit, pPager->walSyncFlags
   );
@@ -3250,6 +3318,10 @@ static int pagerBeginReadTransaction(Pager *pPager){
   if( rc!=SQLITE_OK || changed ){
     pager_reset(pPager);
     if( USEFETCH(pPager) ) sqlite3OsUnfetch(pPager->fd, 0, 0);
+    assert( pPager->journalMode==PAGER_JOURNALMODE_WAL
+         || pPager->journalMode==PAGER_JOURNALMODE_WAL2
+    );
+    pPager->journalMode = sqlite3WalJournalMode(pPager->pWal);
   }
 
   return rc;
@@ -3345,9 +3417,9 @@ static int pagerOpenWalIfPresent(Pager *pPager){
           rc = sqlite3OsDelete(pPager->pVfs, pPager->zWal, 0);
         }else{
           testcase( sqlite3PcachePagecount(pPager->pPCache)==0 );
-          rc = sqlite3PagerOpenWal(pPager, 0);
+          rc = sqlite3PagerOpenWal(pPager, 0, 0);
         }
-      }else if( pPager->journalMode==PAGER_JOURNALMODE_WAL ){
+      }else if( pPager->journalMode>=PAGER_JOURNALMODE_WAL ){
         pPager->journalMode = PAGER_JOURNALMODE_DELETE;
       }
     }
@@ -4266,7 +4338,7 @@ static int syncJournal(Pager *pPager, int newHdr){
   assert( assert_pager_state(pPager) );
   assert( !pagerUseWal(pPager) );
 
-  rc = sqlite3PagerExclusiveLock(pPager);
+  rc = sqlite3PagerExclusiveLock(pPager, 0, 0);
   if( rc!=SQLITE_OK ) return rc;
 
   if( !pPager->noSync ){
@@ -4617,6 +4689,12 @@ static int pagerStress(void *p, PgHdr *pPg){
   pPager->aStat[PAGER_STAT_SPILL]++;
   pPg->pDirty = 0;
   if( pagerUseWal(pPager) ){
+#ifndef SQLITE_OMIT_CONCURRENT
+    /* If the transaction is a "BEGIN CONCURRENT" transaction, the page 
+    ** cannot be flushed to disk. Return early in this case. */
+    if( pPager->pAllRead ) return SQLITE_OK;
+#endif
+
     /* Write a single frame for this page to the log. */
     rc = subjournalPageIfRequired(pPg);
     if( rc==SQLITE_OK ){
@@ -4852,6 +4930,7 @@ int sqlite3PagerOpen(
     nPathname + 8 + 1 +                  /* Journal filename */
 #ifndef SQLITE_OMIT_WAL
     nPathname + 4 + 1 +                  /* WAL filename */
+    nPathname + 5 + 1 +                  /* Second WAL filename */
 #endif
     3                                    /* Terminator */
   );
@@ -4904,6 +4983,8 @@ int sqlite3PagerOpen(
     sqlite3FileSuffix3(zFilename, pPager->zWal);
     pPtr = (u8*)(pPager->zWal + sqlite3Strlen30(pPager->zWal)+1);
 #endif
+    memcpy(pPtr, zPathname, nPathname);   pPtr += nPathname;
+    memcpy(pPtr, "-wal2", 5);             pPtr += 5 + 1;
   }else{
     pPager->zWal = 0;
   }
@@ -5448,6 +5529,23 @@ static void pagerUnlockIfUnused(Pager *pPager){
   }
 }
 
+#ifndef SQLITE_OMIT_CONCURRENT
+/*
+** If this pager is currently in a concurrent transaction (pAllRead!=0),
+** then set the bit in the pAllRead vector to indicate that the transaction
+** read from page pgno. Return SQLITE_OK if successful, or an SQLite error
+** code (i.e. SQLITE_NOMEM) if an error occurs.
+*/
+int sqlite3PagerUsePage(Pager *pPager, Pgno pgno){
+  int rc = SQLITE_OK;
+  if( pPager->pAllRead && pgno<=pPager->dbOrigSize ){
+    PAGERTRACE(("USING page %d\n", pgno));
+    rc = sqlite3BitvecSet(pPager->pAllRead, pgno);
+  }
+  return rc;
+}
+#endif
+
 /*
 ** The page getter methods each try to acquire a reference to a
 ** page with page number pgno. If the requested reference is
@@ -5521,6 +5619,14 @@ static int getPageNormal(
   assert( assert_pager_state(pPager) );
   assert( pPager->hasHeldSharedLock==1 );
 
+  /* If this is an CONCURRENT transaction and the page being read was
+  ** present in the database file when the transaction was opened,
+  ** mark it as read in the pAllRead vector.  */
+  if( (rc = sqlite3PagerUsePage(pPager, pgno))!=SQLITE_OK ){
+    pPg = 0;
+    goto pager_acquire_err;
+  }
+
   if( pgno==0 ) return SQLITE_CORRUPT_BKPT;
   pBase = sqlite3PcacheFetch(pPager->pPCache, pgno, 3);
   if( pBase==0 ){
@@ -5879,11 +5985,14 @@ static int pager_open_journal(Pager *pPager){
 ** Begin a write-transaction on the specified pager object. If a
 ** write-transaction has already been opened, this function is a no-op.
 **
-** If the exFlag argument is false, then acquire at least a RESERVED
-** lock on the database file. If exFlag is true, then acquire at least
+** If the exFlag argument is 0, then acquire at least a RESERVED
+** lock on the database file. If exFlag is >0, then acquire at least
 ** an EXCLUSIVE lock. If such a lock is already held, no locking
 ** functions need be called.
 **
+** If (exFlag<0) and the database is in WAL mode, do not take any locks.
+** The transaction will run in CONCURRENT mode instead.
+**
 ** If the subjInMemory argument is non-zero, then any sub-journal opened
 ** within this transaction will be opened as an in-memory file. This
 ** has no effect if the sub-journal is already opened (as it may be when
@@ -5901,7 +6010,6 @@ int sqlite3PagerBegin(Pager *pPager, int exFlag, int subjInMemory){
 
   if( pPager->eState==PAGER_READER ){
     assert( pPager->pInJournal==0 );
-
     if( pagerUseWal(pPager) ){
       /* If the pager is configured to use locking_mode=exclusive, and an
       ** exclusive lock on the database is not already held, obtain it now.
@@ -5917,9 +6025,10 @@ int sqlite3PagerBegin(Pager *pPager, int exFlag, int subjInMemory){
       /* Grab the write lock on the log file. If successful, upgrade to
       ** PAGER_RESERVED state. Otherwise, return an error code to the caller.
       ** The busy-handler is not invoked if another connection already
-      ** holds the write-lock. If possible, the upper layer will call it.
-      */
-      rc = sqlite3WalBeginWriteTransaction(pPager->pWal);
+      ** holds the write-lock. If possible, the upper layer will call it.  */
+      if( exFlag>=0 ){
+        rc = sqlite3WalBeginWriteTransaction(pPager->pWal);
+      }
     }else{
       /* Obtain a RESERVED lock on the database file. If the exFlag parameter
       ** is true, then immediately upgrade this to an EXCLUSIVE lock. The
@@ -5927,7 +6036,7 @@ int sqlite3PagerBegin(Pager *pPager, int exFlag, int subjInMemory){
       ** lock, but not when obtaining the RESERVED lock.
       */
       rc = pagerLockDb(pPager, RESERVED_LOCK);
-      if( rc==SQLITE_OK && exFlag ){
+      if( rc==SQLITE_OK && exFlag>0 ){
         rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK);
       }
     }
@@ -6227,7 +6336,7 @@ int sqlite3PagerWrite(PgHdr *pPg){
 ** to sqlite3PagerWrite().  In other words, return TRUE if it is ok
 ** to change the content of the page.
 */
-#ifndef NDEBUG
+#if !defined(SQLITE_OMIT_CONCURRENT) || !defined(NDEBUG)
 int sqlite3PagerIswriteable(DbPage *pPg){
   return pPg->flags & PGHDR_WRITEABLE;
 }
@@ -6383,17 +6492,26 @@ int sqlite3PagerSync(Pager *pPager, const char *zSuper){
 }
 
 /*
-** This function may only be called while a write-transaction is active in
-** rollback. If the connection is in WAL mode, this call is a no-op.
-** Otherwise, if the connection does not already have an EXCLUSIVE lock on
-** the database file, an attempt is made to obtain one.
+** This function is called to ensure that all locks required to commit the
+** current write-transaction to the database file are held. If the db is
+** in rollback mode, this means the EXCLUSIVE lock on the database file.
 **
-** If the EXCLUSIVE lock is already held or the attempt to obtain it is
-** successful, or the connection is in WAL mode, SQLITE_OK is returned.
-** Otherwise, either SQLITE_BUSY or an SQLITE_IOERR_XXX error code is
-** returned.
+** Or, if this is a non-CONCURRENT transaction on a wal-mode database, this
+** function is a no-op.
+**
+** If this is an CONCURRENT transaction on a wal-mode database, this function
+** attempts to obtain the WRITER lock on the wal file and also checks to
+** see that the transaction can be safely committed (does not commit with 
+** any other transaction committed since it was opened).
+**
+** If the required locks are already held or successfully obtained and
+** the transaction can be committed, SQLITE_OK is returned. If a required lock
+** cannot be obtained, SQLITE_BUSY is returned. Or, if the current transaction
+** is CONCURRENT and cannot be committed due to a conflict, SQLITE_BUSY_SNAPSHOT
+** is returned. Otherwise, if some other error occurs (IO error, OOM etc.),
+** and SQLite error code is returned.
 */
-int sqlite3PagerExclusiveLock(Pager *pPager){
+int sqlite3PagerExclusiveLock(Pager *pPager, PgHdr *pPage1, u32 *aConflict){
   int rc = pPager->errCode;
   assert( assert_pager_state(pPager) );
   if( rc==SQLITE_OK ){
@@ -6405,10 +6523,73 @@ int sqlite3PagerExclusiveLock(Pager *pPager){
     if( 0==pagerUseWal(pPager) ){
       rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK);
     }
+#ifndef SQLITE_OMIT_CONCURRENT
+    else{
+      if( pPager->pAllRead ){
+        /* This is an CONCURRENT transaction. Attempt to lock the wal database
+        ** here. If SQLITE_BUSY (but not SQLITE_BUSY_SNAPSHOT) is returned,
+        ** invoke the busy-handler and try again for as long as it returns
+        ** non-zero.  */
+        do {
+          rc = sqlite3WalLockForCommit(
+              pPager->pWal, pPage1, pPager->pAllRead, aConflict
+          );
+        }while( rc==SQLITE_BUSY 
+             && pPager->xBusyHandler(pPager->pBusyHandlerArg) 
+        );
+      }
+    }
+#endif /* SQLITE_OMIT_CONCURRENT */
   }
   return rc;
 }
 
+#ifndef SQLITE_OMIT_CONCURRENT
+/*
+** This function is called as part of committing an CONCURRENT transaction.
+** At this point the wal WRITER lock is held, and all pages in the cache 
+** except for page 1 are compatible with the snapshot at the head of the
+** wal file. 
+**
+** This function updates the in-memory data structures and reloads the
+** contents of page 1 so that the client is operating on the snapshot 
+** at the head of the wal file.
+**
+** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
+*/
+int sqlite3PagerUpgradeSnapshot(Pager *pPager, DbPage *pPage1){
+  int rc;
+
+  assert( pPager->pWal && pPager->pAllRead );
+  rc = sqlite3WalUpgradeSnapshot(pPager->pWal);
+  if( rc==SQLITE_OK ){
+    rc = readDbPage(pPage1);
+  }
+
+  return rc;
+}
+
+/* !defined(SQLITE_OMIT_CONCURRENT)
+**
+** Set the in-memory cache of the database file size to nSz pages.
+*/
+void sqlite3PagerSetDbsize(Pager *pPager, Pgno nSz){
+  pPager->dbSize = nSz;
+}
+
+/* !defined(SQLITE_OMIT_CONCURRENT)
+**
+** If this is a WAL mode connection and the WRITER lock is currently held,
+** relinquish it.
+*/
+void sqlite3PagerDropExclusiveLock(Pager *pPager){
+  if( pagerUseWal(pPager) ){
+    sqlite3WalEndWriteTransaction(pPager->pWal);
+  }
+}
+#endif  /* SQLITE_OMIT_CONCURRENT */
+
+
 /*
 ** Sync the database file for the pager pPager. zSuper points to the name
 ** of a super-journal file that should be written into the individual
@@ -6482,7 +6663,9 @@ int sqlite3PagerCommitPhaseOne(
       }
       assert( rc==SQLITE_OK );
       if( ALWAYS(pList) ){
+        sqlite3CommitTimeSet(pPager->aCommitTime, COMMIT_TIME_BEFORE_WALFRAMES);
         rc = pagerWalFrames(pPager, pList, pPager->dbSize, 1);
+        sqlite3CommitTimeSet(pPager->aCommitTime, COMMIT_TIME_AFTER_WALFRAMES);
       }
       sqlite3PagerUnref(pPageOne);
       if( rc==SQLITE_OK ){
@@ -6656,6 +6839,10 @@ commit_phase_one_exit:
   return rc;
 }
 
+void sqlite3PagerSetCommitTime(Pager *pPager, u64 *aCommitTime){
+  pPager->aCommitTime = aCommitTime;
+  sqlite3WalSetCommitTime(pPager->pWal, aCommitTime);
+}
 
 /*
 ** When this function is called, the database file has been completely
@@ -7340,7 +7527,8 @@ int sqlite3PagerSetJournalMode(Pager *pPager, int eMode){
             || eMode==PAGER_JOURNALMODE_OFF       /* 2 */
             || eMode==PAGER_JOURNALMODE_TRUNCATE  /* 3 */
             || eMode==PAGER_JOURNALMODE_MEMORY    /* 4 */
-            || eMode==PAGER_JOURNALMODE_WAL       /* 5 */ );
+            || eMode==PAGER_JOURNALMODE_WAL       /* 5 */
+            || eMode==PAGER_JOURNALMODE_WAL2      /* 6 */ );
 
   /* This routine is only called from the OP_JournalMode opcode, and
   ** the logic there will never allow a temporary file to be changed
@@ -7374,9 +7562,12 @@ int sqlite3PagerSetJournalMode(Pager *pPager, int eMode){
     assert( (PAGER_JOURNALMODE_MEMORY & 5)==4 );
     assert( (PAGER_JOURNALMODE_OFF & 5)==0 );
     assert( (PAGER_JOURNALMODE_WAL & 5)==5 );
+    assert( (PAGER_JOURNALMODE_WAL2 & 5)==4 );
 
     assert( isOpen(pPager->fd) || pPager->exclusiveMode );
-    if( !pPager->exclusiveMode && (eOld & 5)==1 && (eMode & 1)==0 ){
+    if( !pPager->exclusiveMode && (eOld & 5)==1 && (eMode & 1)==0 
+     && eMode!=PAGER_JOURNALMODE_WAL2       /* TODO: fix this if possible */
+    ){
       /* In this case we would like to delete the journal file. If it is
       ** not possible, then that is not a problem. Deleting the journal file
       ** here is an optimization only.
@@ -7551,7 +7742,7 @@ static int pagerExclusiveLock(Pager *pPager){
 ** lock on the database file and use heap-memory to store the wal-index
 ** in. Otherwise, use the normal shared-memory.
 */
-static int pagerOpenWal(Pager *pPager){
+static int pagerOpenWal(Pager *pPager, int bWal2){
   int rc = SQLITE_OK;
 
   assert( pPager->pWal==0 && pPager->tempFile==0 );
@@ -7572,7 +7763,7 @@ static int pagerOpenWal(Pager *pPager){
   if( rc==SQLITE_OK ){
     rc = sqlite3WalOpen(pPager->pVfs,
         pPager->fd, pPager->zWal, pPager->exclusiveMode,
-        pPager->journalSizeLimit, &pPager->pWal
+        pPager->journalSizeLimit, bWal2, &pPager->pWal
     );
   }
   pagerFixMaplimit(pPager);
@@ -7598,6 +7789,7 @@ static int pagerOpenWal(Pager *pPager){
 */
 int sqlite3PagerOpenWal(
   Pager *pPager,                  /* Pager object */
+  int bWal2,                      /* Open in wal2 mode if not already open */
   int *pbOpen                     /* OUT: Set to true if call is a no-op */
 ){
   int rc = SQLITE_OK;             /* Return code */
@@ -7614,9 +7806,9 @@ int sqlite3PagerOpenWal(
     /* Close any rollback journal previously open */
     sqlite3OsClose(pPager->jfd);
 
-    rc = pagerOpenWal(pPager);
+    rc = pagerOpenWal(pPager, bWal2);
     if( rc==SQLITE_OK ){
-      pPager->journalMode = PAGER_JOURNALMODE_WAL;
+      pPager->journalMode = bWal2?PAGER_JOURNALMODE_WAL2:PAGER_JOURNALMODE_WAL;
       pPager->eState = PAGER_OPEN;
     }
   }else{
@@ -7638,7 +7830,9 @@ int sqlite3PagerOpenWal(
 int sqlite3PagerCloseWal(Pager *pPager, sqlite3 *db){
   int rc = SQLITE_OK;
 
-  assert( pPager->journalMode==PAGER_JOURNALMODE_WAL );
+  assert( pPager->journalMode==PAGER_JOURNALMODE_WAL 
+       || pPager->journalMode==PAGER_JOURNALMODE_WAL2
+  );
 
   /* If the log file is not already open, but does exist in the file-system,
   ** it may need to be checkpointed before the connection can switch to
@@ -7653,7 +7847,7 @@ int sqlite3PagerCloseWal(Pager *pPager, sqlite3 *db){
       );
     }
     if( rc==SQLITE_OK && logexists ){
-      rc = pagerOpenWal(pPager);
+      rc = pagerOpenWal(pPager, 0);
     }
   }
    
@@ -7776,6 +7970,11 @@ void sqlite3PagerSnapshotUnlock(Pager *pPager){
 }
 
 #endif /* SQLITE_ENABLE_SNAPSHOT */
+
+int sqlite3PagerWalInfo(Pager *pPager, u32 *pnPrior, u32 *pnFrame){
+  return sqlite3WalInfo(pPager->pWal, pnPrior, pnFrame);
+}
+
 #endif /* !SQLITE_OMIT_WAL */
 
 #ifdef SQLITE_ENABLE_ZIPVFS

src/pager.h

@@ -82,6 +82,23 @@ typedef struct PgHdr DbPage;
 #define PAGER_JOURNALMODE_TRUNCATE    3   /* Commit by truncating journal */
 #define PAGER_JOURNALMODE_MEMORY      4   /* In-memory journal file */
 #define PAGER_JOURNALMODE_WAL         5   /* Use write-ahead logging */
+#define PAGER_JOURNALMODE_WAL2        6   /* Use write-ahead logging mode 2 */
+
+#define isWalMode(x) ((x)==PAGER_JOURNALMODE_WAL || (x)==PAGER_JOURNALMODE_WAL2)
+
+/*
+** The argument to this macro is a file descriptor (type sqlite3_file*).
+** Return 0 if it is not open, or non-zero (but not 1) if it is.
+**
+** This is so that expressions can be written as:
+**
+**   if( isOpen(pPager->jfd) ){ ...
+**
+** instead of
+**
+**   if( pPager->jfd->pMethods ){ ...
+*/
+#define isOpen(pFd) ((pFd)->pMethods!=0)
 
 /*
 ** Flags that make up the mask passed to sqlite3PagerGet().
@@ -163,7 +180,7 @@ void *sqlite3PagerGetExtra(DbPage *);
 void sqlite3PagerPagecount(Pager*, int*);
 int sqlite3PagerBegin(Pager*, int exFlag, int);
 int sqlite3PagerCommitPhaseOne(Pager*,const char *zSuper, int);
-int sqlite3PagerExclusiveLock(Pager*);
+int sqlite3PagerExclusiveLock(Pager*, DbPage *pPage1, u32*);
 int sqlite3PagerSync(Pager *pPager, const char *zSuper);
 int sqlite3PagerCommitPhaseTwo(Pager*);
 int sqlite3PagerRollback(Pager*);
@@ -171,11 +188,12 @@ int sqlite3PagerOpenSavepoint(Pager *pPager, int n);
 int sqlite3PagerSavepoint(Pager *pPager, int op, int iSavepoint);
 int sqlite3PagerSharedLock(Pager *pPager);
 
+
 #ifndef SQLITE_OMIT_WAL
   int sqlite3PagerCheckpoint(Pager *pPager, sqlite3*, int, int*, int*);
   int sqlite3PagerWalSupported(Pager *pPager);
   int sqlite3PagerWalCallback(Pager *pPager);
-  int sqlite3PagerOpenWal(Pager *pPager, int *pisOpen);
+  int sqlite3PagerOpenWal(Pager *pPager, int, int *pisOpen);
   int sqlite3PagerCloseWal(Pager *pPager, sqlite3*);
 # ifdef SQLITE_ENABLE_SNAPSHOT
   int sqlite3PagerSnapshotGet(Pager*, sqlite3_snapshot **ppSnapshot);
@@ -225,10 +243,28 @@ void sqlite3PagerTruncateImage(Pager*,Pgno);
 
 void sqlite3PagerRekey(DbPage*, Pgno, u16);
 
+#ifndef SQLITE_OMIT_CONCURRENT
+int sqlite3PagerUsePage(Pager*, Pgno);
+void sqlite3PagerEndConcurrent(Pager*);
+int sqlite3PagerBeginConcurrent(Pager*);
+void sqlite3PagerDropExclusiveLock(Pager*);
+int sqlite3PagerUpgradeSnapshot(Pager *pPager, DbPage*);
+void sqlite3PagerSetDbsize(Pager *pPager, Pgno);
+int sqlite3PagerIsWal(Pager*);
+#else
+# define sqlite3PagerEndConcurrent(x)
+# define sqlite3PagerUsePage(x, y) SQLITE_OK
+#endif
+
+#if defined(SQLITE_DEBUG) || !defined(SQLITE_OMIT_CONCURRENT)
+int sqlite3PagerIswriteable(DbPage*);
+#endif
+
+int sqlite3PagerWalInfo(Pager*, u32 *pnPrior, u32 *pnFrame);
+
 /* Functions to support testing and debugging. */
 #if !defined(NDEBUG) || defined(SQLITE_TEST)
   Pgno sqlite3PagerPagenumber(DbPage*);
-  int sqlite3PagerIswriteable(DbPage*);
 #endif
 #ifdef SQLITE_TEST
   int *sqlite3PagerStats(Pager*);
@@ -244,4 +280,6 @@ void sqlite3PagerRekey(DbPage*, Pgno, u16);
 int sqlite3PagerWalSystemErrno(Pager*);
 #endif
 
+void sqlite3PagerSetCommitTime(Pager *pPager, u64 *aCommitTime);
+
 #endif /* SQLITE_PAGER_H */

src/parse.y

@@ -109,6 +109,13 @@
 */
 struct TrigEvent { int a; IdList * b; };
 
+/*
+** Generate a syntax error
+*/
+static void parserSyntaxError(Parse *pParse, Token *p){
+  sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", p);
+}
+
 struct FrameBound     { int eType; Expr *pExpr; };
 
 /*
@@ -168,7 +175,16 @@ trans_opt ::= TRANSACTION nm.
 transtype(A) ::= .             {A = TK_DEFERRED;}
 transtype(A) ::= DEFERRED(X).  {A = @X; /*A-overwrites-X*/}
 transtype(A) ::= IMMEDIATE(X). {A = @X; /*A-overwrites-X*/}
-transtype(A) ::= EXCLUSIVE(X). {A = @X; /*A-overwrites-X*/}
+transtype(A) ::= ID(X). {
+   Token *p = &X;
+   if( p->n==9 && sqlite3_strnicmp(p->z,"exclusive",9)==0 ){
+     A = TK_EXCLUSIVE;
+   }else if( p->n==10 && sqlite3_strnicmp(p->z,"concurrent",10)==0 ){
+     A = TK_CONCURRENT;  /*A-overwrites-X*/
+   }else{
+     parserSyntaxError(pParse, p);
+   }
+}
 cmd ::= COMMIT|END(X) trans_opt.   {sqlite3EndTransaction(pParse,@X);}
 cmd ::= ROLLBACK(X) trans_opt.     {sqlite3EndTransaction(pParse,@X);}
 
@@ -304,7 +320,6 @@ columnname(A) ::= nm(A) typetoken(Y). {sqlite3AddColumn(pParse,A,Y);}
 // keywords.  Any non-standard keyword can also be an identifier.
 //
 %token_class id  ID|INDEXED.
-
 // And "ids" is an identifer-or-string.
 //
 %token_class ids  ID|STRING.
@@ -1152,7 +1167,7 @@ expr(A) ::= VARIABLE(X).     {
     Token t = X; /*A-overwrites-X*/
     assert( t.n>=2 );
     if( pParse->nested==0 ){
-      sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", &t);
+      parserSyntaxError(pParse, &t);
       A = 0;
     }else{
       A = sqlite3PExpr(pParse, TK_REGISTER, 0, 0);
@@ -2023,6 +2038,7 @@ filter_clause(A) ::= FILTER LP WHERE expr(X) RP.  { A = X; }
   UMINUS          /* Unary minus */
   TRUTH           /* IS TRUE or IS FALSE or IS NOT TRUE or IS NOT FALSE */
   REGISTER        /* Reference to a VDBE register */
+  CONCURRENT      /* BEGIN CONCURRENT */
   VECTOR          /* Vector */
   SELECT_COLUMN   /* Choose a single column from a multi-column SELECT */
   IF_NULL_ROW     /* the if-null-row operator */

src/pcache1.c

@@ -633,6 +633,14 @@ static void pcache1EnforceMaxPage(PCache1 *pCache){
     pcache1RemoveFromHash(p, 1);
   }
   if( pCache->nPage==0 && pCache->pBulk ){
+    if( pcache1.separateCache ){
+      PgHdr1 *p1 = pCache->pFree;
+      while( p1 ){
+        PgHdr1 *pNext = p1->pNext;
+        if( p1->isBulkLocal==0 ) pcache1Free(p1->page.pBuf);
+        p1 = pNext;
+      }
+    }
     sqlite3_free(pCache->pBulk);
     pCache->pBulk = pCache->pFree = 0;
   }
@@ -678,7 +686,13 @@ static void pcache1TruncateUnsafe(
         pCache->nPage--;
         *pp = pPage->pNext;
         if( PAGE_IS_UNPINNED(pPage) ) pcache1PinPage(pPage);
-        pcache1FreePage(pPage);
+        if( pcache1.separateCache ){
+          pPage->pNext = pCache->pFree;
+          pCache->pFree = pPage;
+          (*pCache->pnPurgeable)--;
+        }else{
+          pcache1FreePage(pPage);
+        }
       }else{
         pp = &pPage->pNext;
         TESTONLY( if( nPage>=0 ) nPage++; )
@@ -1096,7 +1110,13 @@ static void pcache1Unpin(
   assert( PAGE_IS_PINNED(pPage) );
 
   if( reuseUnlikely || pGroup->nPurgeable>pGroup->nMaxPage ){
+    /* If pcache1.separateCache is set, temporarily set the isBulkLocal flag 
+    ** so that pcache1RemoveFromHash() moves the page buffer to the pFree
+    ** list instead of sqlite3_free()ing it. */
+    u16 isBulkLocal = pPage->isBulkLocal;
+    pPage->isBulkLocal = (u16)pcache1.separateCache;
     pcache1RemoveFromHash(pPage, 1);
+    pPage->isBulkLocal = isBulkLocal;
   }else{
     /* Add the page to the PGroup LRU list. */
     PgHdr1 **ppFirst = &pGroup->lru.pLruNext;
@@ -1176,6 +1196,15 @@ static void pcache1Destroy(sqlite3_pcache *p){
   assert( pCache->bPurgeable || (pCache->nMax==0 && pCache->nMin==0) );
   pcache1EnterMutex(pGroup);
   if( pCache->nPage ) pcache1TruncateUnsafe(pCache, 0);
+  if( pcache1.separateCache ){
+    PgHdr1 *p1 = pCache->pFree;
+    while( p1 ){
+      PgHdr1 *pNext = p1->pNext;
+      if( p1->isBulkLocal==0 ) pcache1Free(p1->page.pBuf);
+      p1 = pNext;
+    }
+    pCache->pFree = 0;
+  }
   assert( pGroup->nMaxPage >= pCache->nMax );
   pGroup->nMaxPage -= pCache->nMax;
   assert( pGroup->nMinPage >= pCache->nMin );

src/pragma.c

@@ -290,7 +290,7 @@ const char *sqlite3JournalModename(int eMode){
   static char * const azModeName[] = {
     "delete", "persist", "off", "truncate", "memory"
 #ifndef SQLITE_OMIT_WAL
-     , "wal"
+     , "wal", "wal2"
 #endif
   };
   assert( PAGER_JOURNALMODE_DELETE==0 );
@@ -299,6 +299,7 @@ const char *sqlite3JournalModename(int eMode){
   assert( PAGER_JOURNALMODE_TRUNCATE==3 );
   assert( PAGER_JOURNALMODE_MEMORY==4 );
   assert( PAGER_JOURNALMODE_WAL==5 );
+  assert( PAGER_JOURNALMODE_WAL2==6 );
   assert( eMode>=0 && eMode<=ArraySize(azModeName) );
 
   if( eMode==ArraySize(azModeName) ) return 0;
@@ -425,6 +426,7 @@ void sqlite3Pragma(
   Vdbe *v = sqlite3GetVdbe(pParse);  /* Prepared statement */
   const PragmaName *pPragma;   /* The pragma */
 
+  sqlite3PrepareTimeSet(db->aPrepareTime, PREPARE_TIME_BEGINPRAGMA);
   if( v==0 ) return;
   sqlite3VdbeRunOnlyOnce(v);
   pParse->nMem = 2;
@@ -450,11 +452,13 @@ void sqlite3Pragma(
     zRight = sqlite3NameFromToken(db, pValue);
   }
 
+  sqlite3PrepareTimeSet(db->aPrepareTime, PREPARE_TIME_BEGINAUTHCHECK);
   assert( pId2 );
   zDb = pId2->n>0 ? pDb->zDbSName : 0;
   if( sqlite3AuthCheck(pParse, SQLITE_PRAGMA, zLeft, zRight, zDb) ){
     goto pragma_out;
   }
+  sqlite3PrepareTimeSet(db->aPrepareTime, PREPARE_TIME_ENDAUTHCHECK);
 
   /* Send an SQLITE_FCNTL_PRAGMA file-control to the underlying VFS
   ** connection.  If it returns SQLITE_OK, then assume that the VFS
@@ -502,10 +506,12 @@ void sqlite3Pragma(
     goto pragma_out;
   }
 
+  sqlite3PrepareTimeSet(db->aPrepareTime, PREPARE_TIME_BEGINLOADSCHEMA);
   /* Make sure the database schema is loaded if the pragma requires that */
   if( (pPragma->mPragFlg & PragFlg_NeedSchema)!=0 ){
     if( sqlite3ReadSchema(pParse) ) goto pragma_out;
   }
+  sqlite3PrepareTimeSet(db->aPrepareTime, PREPARE_TIME_ENDLOADSCHEMA);
 
   /* Register the result column names for pragmas that return results */
   if( (pPragma->mPragFlg & PragFlg_NoColumns)==0
@@ -865,6 +871,7 @@ void sqlite3Pragma(
   */
   case PragTyp_CACHE_SIZE: {
     assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
+    sqlite3PrepareTimeSet(db->aPrepareTime, PREPARE_TIME_BEGINCACHESIZE);
     if( !zRight ){
       returnSingleInt(v, pDb->pSchema->cache_size);
     }else{
@@ -872,6 +879,7 @@ void sqlite3Pragma(
       pDb->pSchema->cache_size = size;
       sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
     }
+    sqlite3PrepareTimeSet(db->aPrepareTime, PREPARE_TIME_ENDCACHESIZE);
     break;
   }
 
@@ -2758,6 +2766,7 @@ void sqlite3Pragma(
 pragma_out:
   sqlite3DbFree(db, zLeft);
   sqlite3DbFree(db, zRight);
+  sqlite3PrepareTimeSet(db->aPrepareTime, PREPARE_TIME_ENDPRAGMA);
 }
 #ifndef SQLITE_OMIT_VIRTUALTABLE
 /*****************************************************************************

src/pragma.h

@@ -441,6 +441,15 @@ static const PragmaName aPragmaName[] = {
   /* iArg:      */ 0 },
 #endif
 #endif
+#endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
+#if defined(SQLITE_ENABLE_NOOP_UPDATE)
+ {/* zName:     */ "noop_update",
+  /* ePragTyp:  */ PragTyp_FLAG,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ SQLITE_NoopUpdate },
+#endif
 #endif
  {/* zName:     */ "optimize",
   /* ePragTyp:  */ PragTyp_OPTIMIZE,
@@ -657,4 +666,4 @@ static const PragmaName aPragmaName[] = {
   /* iArg:      */ SQLITE_WriteSchema|SQLITE_NoSchemaError },
 #endif
 };
-/* Number of pragmas: 68 on by default, 78 total. */
+/* Number of pragmas: 68 on by default, 79 total. */

src/prepare.c

@@ -209,6 +209,11 @@ int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg, u32 mFlags){
   int openedTransaction = 0;
   int mask = ((db->mDbFlags & DBFLAG_EncodingFixed) | ~DBFLAG_EncodingFixed);
 
+  u64 aSchemaTime[SCHEMA_TIME_N];
+  memset(aSchemaTime, 0, sizeof(aSchemaTime));
+  db->aSchemaTime = aSchemaTime;
+  sqlite3PrepareTimeSet(aSchemaTime, SCHEMA_TIME_START);
+
   assert( (db->mDbFlags & DBFLAG_SchemaKnownOk)==0 );
   assert( iDb>=0 && iDb<db->nDb );
   assert( db->aDb[iDb].pSchema );
@@ -243,6 +248,8 @@ int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg, u32 mFlags){
     goto error_out;
   }
 
+  sqlite3PrepareTimeSet(aSchemaTime, SCHEMA_TIME_AFTER_CREATE_1);
+
   /* Create a cursor to hold the database open
   */
   pDb = &db->aDb[iDb];
@@ -266,6 +273,8 @@ int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg, u32 mFlags){
     openedTransaction = 1;
   }
 
+  sqlite3PrepareTimeSet(aSchemaTime, SCHEMA_TIME_AFTER_OPEN_TRANS);
+
   /* Get the database meta information.
   **
   ** Meta values are as follows:
@@ -291,6 +300,8 @@ int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg, u32 mFlags){
   }
   pDb->pSchema->schema_cookie = meta[BTREE_SCHEMA_VERSION-1];
 
+  sqlite3PrepareTimeSet(aSchemaTime, SCHEMA_TIME_AFTER_GET_META);
+
   /* If opening a non-empty database, check the text encoding. For the
   ** main database, set sqlite3.enc to the encoding of the main database.
   ** For an attached db, it is an error if the encoding is not the same
@@ -326,6 +337,8 @@ int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg, u32 mFlags){
   }
   pDb->pSchema->enc = ENC(db);
 
+  sqlite3PrepareTimeSet(aSchemaTime, SCHEMA_TIME_AFTER_FIX_ENCODING);
+
   if( pDb->pSchema->cache_size==0 ){
 #ifndef SQLITE_OMIT_DEPRECATED
     size = sqlite3AbsInt32(meta[BTREE_DEFAULT_CACHE_SIZE-1]);
@@ -337,6 +350,8 @@ int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg, u32 mFlags){
     sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
   }
 
+  sqlite3PrepareTimeSet(aSchemaTime, SCHEMA_TIME_AFTER_SETCACHESIZE);
+
   /*
   ** file_format==1    Version 3.0.0.
   ** file_format==2    Version 3.1.3.  // ALTER TABLE ADD COLUMN
@@ -377,6 +392,7 @@ int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg, u32 mFlags){
       xAuth = db->xAuth;
       db->xAuth = 0;
 #endif
+      sqlite3PrepareTimeSet(aSchemaTime, SCHEMA_TIME_BEGIN_EXEC);
       rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
 #ifndef SQLITE_OMIT_AUTHORIZATION
       db->xAuth = xAuth;
@@ -384,11 +400,13 @@ int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg, u32 mFlags){
 #endif
     if( rc==SQLITE_OK ) rc = initData.rc;
     sqlite3DbFree(db, zSql);
+    sqlite3PrepareTimeSet(aSchemaTime, SCHEMA_TIME_BEGIN_ANALYZE_LOAD);
 #ifndef SQLITE_OMIT_ANALYZE
     if( rc==SQLITE_OK ){
       sqlite3AnalysisLoad(db, iDb);
     }
 #endif
+    sqlite3PrepareTimeSet(aSchemaTime, SCHEMA_TIME_END_ANALYZE_LOAD);
   }
   assert( pDb == &(db->aDb[iDb]) );
   if( db->mallocFailed ){
@@ -422,6 +440,9 @@ initone_error_out:
   sqlite3BtreeLeave(pDb->pBt);
 
 error_out:
+  db->aSchemaTime = 0;
+  sqlite3PrepareTimeSet(aSchemaTime, SCHEMA_TIME_FINISH);
+  sqlite3SchemaTimeLog(aSchemaTime);
   if( rc ){
     if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
       sqlite3OomFault(db);
@@ -782,14 +803,18 @@ static int sqlite3Prepare(
     }
     zSqlCopy = sqlite3DbStrNDup(db, zSql, nBytes);
     if( zSqlCopy ){
+      sqlite3PrepareTimeSet(db->aPrepareTime, PREPARE_TIME_BEGINPARSE);
       sqlite3RunParser(&sParse, zSqlCopy);
+      sqlite3PrepareTimeSet(db->aPrepareTime, PREPARE_TIME_ENDPARSE);
       sParse.zTail = &zSql[sParse.zTail-zSqlCopy];
       sqlite3DbFree(db, zSqlCopy);
     }else{
       sParse.zTail = &zSql[nBytes];
     }
   }else{
+    sqlite3PrepareTimeSet(db->aPrepareTime, PREPARE_TIME_BEGINPARSE);
     sqlite3RunParser(&sParse, zSql);
+    sqlite3PrepareTimeSet(db->aPrepareTime, PREPARE_TIME_ENDPARSE);
   }
   assert( 0==sParse.nQueryLoop );
 
@@ -850,6 +875,12 @@ static int sqlite3LockAndPrepare(
 ){
   int rc;
   int cnt = 0;
+  u64 *aPrepareSave = db->aPrepareTime;
+
+  u64 aPrepareTime[PREPARE_TIME_N];
+  memset(aPrepareTime, 0, sizeof(aPrepareTime));
+  sqlite3PrepareTimeSet(aPrepareTime, PREPARE_TIME_START);
+  db->aPrepareTime = aPrepareTime;
 
 #ifdef SQLITE_ENABLE_API_ARMOR
   if( ppStmt==0 ) return SQLITE_MISUSE_BKPT;
@@ -875,6 +906,11 @@ static int sqlite3LockAndPrepare(
   db->busyHandler.nBusy = 0;
   sqlite3_mutex_leave(db->mutex);
   assert( rc==SQLITE_OK || (*ppStmt)==0 );
+
+  db->aPrepareTime = aPrepareSave;
+  sqlite3PrepareTimeSet(aPrepareTime, PREPARE_TIME_FINISH);
+  sqlite3PrepareTimeLog(zSql, nBytes, aPrepareTime);
+
   return rc;
 }
 

src/printf.c

@@ -1317,7 +1317,7 @@ char *sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){
 */
 static void renderLogMsg(int iErrCode, const char *zFormat, va_list ap){
   StrAccum acc;                          /* String accumulator */
-  char zMsg[SQLITE_PRINT_BUF_SIZE*3];    /* Complete log message */
+  char zMsg[SQLITE_PRINT_BUF_SIZE*10];   /* Complete log message */
 
   sqlite3StrAccumInit(&acc, 0, zMsg, sizeof(zMsg), 0);
   sqlite3_str_vappendf(&acc, zFormat, ap);

src/random.c

@@ -129,6 +129,28 @@ void sqlite3_randomness(int N, void *pBuf){
   sqlite3_mutex_leave(mutex);
 }
 
+/*
+** Initialize a fast PRNG.  A Fast PRNG is called "fast" because it does
+** not need a mutex to operate, though it does use a mutex to initialize.
+** The quality of the randomness is not as good as the global PRNG.
+*/
+void sqlite3FastPrngInit(FastPrng *pPrng){
+  sqlite3_randomness(sizeof(*pPrng), pPrng);
+  pPrng->x |= 1;
+}
+
+/*
+** Generate N bytes of pseudo-randomness using a FastPrng
+*/
+void sqlite3FastRandomness(FastPrng *pPrng, int N, void *P){
+  unsigned char *pOut = (unsigned char*)P;
+  while( N-->0 ){
+    pPrng->x = ((pPrng->x)>>1) ^ ((1+~((pPrng->x)&1)) & 0xd0000001);
+    pPrng->y = (pPrng->y)*1103515245 + 12345;
+    *(pOut++) = (pPrng->x ^ pPrng->y) & 0xff;
+  }
+}
+
 #ifndef SQLITE_UNTESTABLE
 /*
 ** For testing purposes, we sometimes want to preserve the state of

src/select.c

@@ -2284,7 +2284,7 @@ int sqlite3ColumnsFromExprList(
       zName = sqlite3MPrintf(db, "%.*z:%u", nName, zName, ++cnt);
       sqlite3ProgressCheck(pParse);
       if( cnt>3 ){
-        sqlite3_randomness(sizeof(cnt), &cnt);
+        sqlite3FastRandomness(&db->sPrng, sizeof(cnt), &cnt);
       }
     }
     pCol->zCnName = zName;

src/sqlite.h.in

@@ -10693,6 +10693,31 @@ SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
 */
 SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
 
+/*
+** CAPI3REF: Wal related information regarding the most recent COMMIT
+** EXPERIMENTAL
+**
+** This function reports on the state of the wal file (if any) for database 
+** zDb, which should be "main", "temp", or the name of the attached database.
+** Its results - the values written to the output parameters - are only
+** defined if the most recent SQL command on the connection was a successful 
+** COMMIT that wrote data to wal-mode database zDb.
+**
+** Assuming the above conditions are met, output parameter (*pnFrame) is set
+** to the total number of frames in the wal file. Parameter (*pnPrior) is
+** set to the number of frames that were present in the wal file before the
+** most recent transaction was committed. So that the number of frames written
+** by the most recent transaction is (*pnFrame)-(*pnPrior).
+**
+** If successful, SQLITE_OK is returned. Otherwise, an SQLite error code. It
+** is not an error if this function is called at a time when the results
+** are undefined.
+*/
+SQLITE_EXPERIMENTAL int sqlite3_wal_info(
+  sqlite3 *db, const char *zDb, 
+  unsigned int *pnPrior, unsigned int *pnFrame
+);
+
 /*
 ** CAPI3REF: Serialize a database
 **
@@ -10836,6 +10861,98 @@ int sqlite3_deserialize(
 #define SQLITE_DESERIALIZE_RESIZEABLE  2 /* Resize using sqlite3_realloc64() */
 #define SQLITE_DESERIALIZE_READONLY    4 /* Database is read-only */
 
+/*
+** Access details of recent COMMIT commands. This function allows various
+** details related to the most recent COMMIT command to be accessed. 
+** The requested value is always returned via output parameter (*piVal).
+** The specific value requested is identified by parameter op (see
+** below).
+**
+** SQLITE_OK is returned if successful, or SQLITE_ERROR if the "op" or
+** "zDb" paramters are unrecognized.
+*/
+int sqlite3_commit_status(
+  sqlite3 *db,                    /* Database handle */
+  const char *zDb,                /* Name of database - "main" etc. */
+  int op,                         /* SQLITE_COMMIT_XXX constant */
+  unsigned int *piVal             /* OUT: Write requested value here */
+);
+
+/*
+** The following describes the five requests supported by
+** sqlite3_commit_status(), each identified by an SQLITE_COMMIT_XXX 
+** constant:
+** 
+** SQLITE_COMMIT_FIRSTFRAME:
+**   In this case argument zDb must be "main", or "temp", or else the name of
+**   an attached database. If zDb does not correspond to any attached database, 
+**   SQLITE_ERROR is returned.
+**
+**   The final value of (*piVal) for this request is only defined if (a) the
+**   most recent attempt to write to the database connection was successful,
+**   (b) the most recent attempt to write to the database did write to database 
+**   zDb, and (c) zDb is a wal mode database.
+**
+**   If the above conditions are true, then output parameter (*piVal) is
+**   set to the frame number of the first frame written by the recent 
+**   transaction. In wal mode, or in wal2 mode when a transaction is
+**   written into the *-wal file, the frame number indicates the frame's 
+**   position in the wal file - frames are numbered starting from 1. In 
+**   wal2 mode, when a transaction is written to the *-wal2 file, the frame
+**   number is the frame's position in the *-wal2 file, plus (1 << 31).
+**
+**   Note: Although the a database may have up to (1<<32) pages, each wal
+**   file may contain at most (1<<31) frames.
+**
+** SQLITE_COMMIT_NFRAME:
+**   zDb is interpreted in the same way as, and the final value of (*piVal)
+**   is undefined, for SQLITE_COMMIT_FIRSTFRAME.
+**
+**   Otherwise, (*piVal) is set to the number of frames written by the 
+**   recent transaction.
+**
+** SQLITE_COMMIT_CONFLICT_DB:
+**   Parameter zDb is ignored for this request. The results of this
+**   request are only defined if the most recent attempt to write to
+**   the database handle was a BEGIN CONCURRENT transaction that 
+**   failed with an SQLITE_BUSY_SNAPSHOT error.
+**
+**   In other cases, (*piVal) is set to the index of the database
+**   on which the SQLITE_BUSY_SNAPSHOT error occurred (0 for main,
+**   a value of 2 or greater for an attached database). This value
+**   may be used with the sqlite3_db_name() API to find the name
+**   of the conflicting database.
+**
+** SQLITE_COMMIT_CONFLICT_FRAME:
+**   Parameter zDb is ignored for this request. The results of this
+**   request are only defined if the most recent attempt to write to
+**   the database handle was a BEGIN CONCURRENT transaction that 
+**   failed with an SQLITE_BUSY_SNAPSHOT error.
+**
+**   (*piVal) is set to the frame number of the conflicting frame for 
+**   the recent SQLITE_BUSY_SNAPSHOT error. The conflicting transaction may
+**   be found by comparing this value with the FIRSTFRAME and
+**   NFRAME values for recent succesfully committed transactions on
+**   the same db. If the CONFLICT_FRAME value is F, then the conflicting 
+**   transaction is the most recent successful commit for which 
+**   (FIRSTFRAME <= F <= FIRSTFRAME+NFRAME) is true.
+**
+** SQLITE_COMMIT_CONFLICT_PGNO:
+**   Parameter zDb is ignored for this request. The results of this
+**   request are only defined if the previous attempt to write to
+**   the database using database handle db failed with 
+**   SQLITE_BUSY_SNAPSHOT.
+**
+**   Return the page number of the conflicting page for the most
+**   recent SQLITE_BUSY_SNAPSHOT error.
+*/
+#define SQLITE_COMMIT_FIRSTFRAME     0
+#define SQLITE_COMMIT_NFRAME         1
+#define SQLITE_COMMIT_CONFLICT_DB    2
+#define SQLITE_COMMIT_CONFLICT_FRAME 3
+#define SQLITE_COMMIT_CONFLICT_PGNO  4
+
+
 /*
 ** Undo the hack that converts floating point types to integer for
 ** builds on processors without floating point support.

src/sqliteInt.h

@@ -1309,6 +1309,7 @@ typedef struct DbFixer DbFixer;
 typedef struct Schema Schema;
 typedef struct Expr Expr;
 typedef struct ExprList ExprList;
+typedef struct FastPrng FastPrng;
 typedef struct FKey FKey;
 typedef struct FpDecode FpDecode;
 typedef struct FuncDestructor FuncDestructor;
@@ -1437,6 +1438,14 @@ typedef int VList;
 # define SQLITE_DEFAULT_WAL_SYNCHRONOUS SQLITE_DEFAULT_SYNCHRONOUS
 #endif
 
+/*
+** State of a simple PRNG used for the per-connection and per-pager
+** pseudo-random number generators.
+*/
+struct FastPrng {
+  unsigned int x, y;
+};
+
 /*
 ** Each database file to be accessed by the system is an instance
 ** of the following structure.  There are normally two of these structures
@@ -1688,6 +1697,7 @@ struct sqlite3 {
   u32 dbOptFlags;               /* Flags to enable/disable optimizations */
   u8 enc;                       /* Text encoding */
   u8 autoCommit;                /* The auto-commit flag. */
+  u8 eConcurrent;               /* CONCURRENT_* value */
   u8 temp_store;                /* 1: file 2: memory 0: default */
   u8 mallocFailed;              /* True if we have seen a malloc failure */
   u8 bBenignMalloc;             /* Do not require OOMs if true */
@@ -1701,6 +1711,7 @@ struct sqlite3 {
   u8 nSqlExec;                  /* Number of pending OP_SqlExec opcodes */
   u8 eOpenState;                /* Current condition of the connection */
   int nextPagesize;             /* Pagesize after VACUUM if >0 */
+  FastPrng sPrng;               /* State of the per-connection PRNG */
   i64 nChange;                  /* Value returned by sqlite3_changes() */
   i64 nTotalChange;             /* Value returned by sqlite3_total_changes() */
   int aLimit[SQLITE_N_LIMIT];   /* Limits */
@@ -1809,8 +1820,72 @@ struct sqlite3 {
 #ifdef SQLITE_USER_AUTHENTICATION
   sqlite3_userauth auth;        /* User authentication information */
 #endif
+#ifndef SQLITE_OMIT_CONCURRENT
+  /* Return values for sqlite3_commit_status() requests:
+  ** SQLITE_COMMIT_CONFLICT_DB, CONFLICT_FRAME and CONFLICT_PGNO.  
+  */
+  u32 aCommit[5];
+#endif
+
+  u64 *aPrepareTime;
+  u64 *aSchemaTime;
 };
 
+#define PREPARE_TIME_START 0
+#define PREPARE_TIME_BEGINPARSE 1
+#define PREPARE_TIME_BEGINPRAGMA 2
+
+#define PREPARE_TIME_BEGINAUTHCHECK 3
+#define PREPARE_TIME_ENDAUTHCHECK 4
+#define PREPARE_TIME_BEGINLOADSCHEMA 5
+#define PREPARE_TIME_ENDLOADSCHEMA 6
+
+
+#define PREPARE_TIME_BEGINCACHESIZE 7
+#define PREPARE_TIME_BEGINSETCACHESIZE 8
+#define PREPARE_TIME_ENDSETCACHESIZE 9
+#define PREPARE_TIME_ENDCACHESIZE 10
+#define PREPARE_TIME_ENDPRAGMA 11
+#define PREPARE_TIME_ENDPARSE 12
+#define PREPARE_TIME_FINISH 13
+
+#define PREPARE_TIME_N 14
+
+
+
+#define SCHEMA_TIME_START 0
+#define SCHEMA_TIME_AFTER_CREATE_1 1
+#define SCHEMA_TIME_AFTER_OPEN_TRANS 2
+#define SCHEMA_TIME_AFTER_GET_META 3
+#define SCHEMA_TIME_AFTER_FIX_ENCODING 4
+#define SCHEMA_TIME_AFTER_SETCACHESIZE 5
+#define SCHEMA_TIME_BEGIN_EXEC 6
+#define SCHEMA_TIME_BEFORE_STEP 7
+#define SCHEMA_TIME_BEFORE_PREPARE 8
+#define SCHEMA_TIME_BEFORE_FINALIZE 9
+#define SCHEMA_TIME_BEGIN_ANALYZE_LOAD 10
+#define SCHEMA_TIME_END_ANALYZE_LOAD 11
+#define SCHEMA_TIME_FINISH 12
+
+#define SCHEMA_TIME_N 13
+#define SCHEMA_TIME_TIMEOUT (2 * 1000 * 1000)
+
+
+
+#define sqlite3PrepareTimeSet(x,y) sqlite3CommitTimeSet(x,y)
+void sqlite3PrepareTimeLog(const char *zSql, int nSql, u64 *aPrepareTime);
+void sqlite3SchemaTimeLog(u64 *aSchemaTime);
+
+#define PREPARE_TIME_TIMEOUT (2 * 1000 * 1000)    /* 2 second timeout */
+
+
+/*
+** Candidate values for sqlite3.eConcurrent
+*/
+#define CONCURRENT_NONE   0
+#define CONCURRENT_OPEN   1
+#define CONCURRENT_SCHEMA 2
+
 /*
 ** A macro to discover the encoding of a database.
 */
@@ -1873,6 +1948,7 @@ struct sqlite3 {
 #define SQLITE_ReadUncommit   HI(0x00004) /* READ UNCOMMITTED in shared-cache */
 #define SQLITE_FkNoAction     HI(0x00008) /* Treat all FK as NO ACTION */
 
+#define SQLITE_NoopUpdate     0x01000000  /* UPDATE operations are no-ops */
 /* Flags used only if debugging */
 #ifdef SQLITE_DEBUG
 #define SQLITE_SqlTrace       HI(0x0100000) /* Debug print SQL as it executes */
@@ -5121,6 +5197,8 @@ Vdbe *sqlite3GetVdbe(Parse*);
 void sqlite3PrngSaveState(void);
 void sqlite3PrngRestoreState(void);
 #endif
+void sqlite3FastPrngInit(FastPrng*);
+void sqlite3FastRandomness(FastPrng*, int N, void *P);
 void sqlite3RollbackAll(sqlite3*,int);
 void sqlite3CodeVerifySchema(Parse*, int);
 void sqlite3CodeVerifyNamedSchema(Parse*, const char *zDb);

src/test1.c

@@ -2565,6 +2565,83 @@ static int SQLITE_TCLAPI test_create_null_module(
 }
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
 
+/*
+** Usage: sqlite3_randomess NBYTE
+*/
+static int SQLITE_TCLAPI test_sqlite3_randomness(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int nByte = 0;
+  u8 *aBuf = 0;
+
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "NBYTE");
+    return TCL_ERROR;
+  }
+  if( Tcl_GetIntFromObj(interp, objv[1], &nByte) ) return TCL_ERROR;
+
+  aBuf = ckalloc(nByte);
+  sqlite3_randomness(nByte, aBuf);
+  Tcl_SetObjResult(interp, Tcl_NewByteArrayObj(aBuf, nByte));
+  ckfree(aBuf);
+
+  return TCL_OK;
+}
+
+/*
+** tclcmd:  sqlite3_commit_status db DBNAME OP
+*/
+static int SQLITE_TCLAPI test_commit_status(
+  ClientData clientData, /* Unused */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  struct Op {
+    const char *zOp;
+    int op;
+  } aOp[] = {
+    { "FIRSTFRAME",     SQLITE_COMMIT_FIRSTFRAME },
+    { "NFRAME",         SQLITE_COMMIT_NFRAME },
+    { "CONFLICT_DB",    SQLITE_COMMIT_CONFLICT_DB },
+    { "CONFLICT_FRAME", SQLITE_COMMIT_CONFLICT_FRAME },
+    { "CONFLICT_PGNO",  SQLITE_COMMIT_CONFLICT_PGNO },
+    { 0, 0 }
+  };
+  sqlite3 *db = 0;
+  const char *zDb = 0;
+  int op = 0;
+  int rc = SQLITE_OK;
+  unsigned int val = 0;
+
+  if( objc!=4 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "DB DBNAME OP");
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ){
+    return TCL_ERROR;
+  }
+  zDb = Tcl_GetString(objv[2]);
+  if( Tcl_GetIndexFromObjStruct(
+        interp, objv[3], aOp, sizeof(aOp[0]), "OP", 0, &op
+  )){
+    return TCL_ERROR;
+  }
+  op = aOp[op].op;
+
+  rc = sqlite3_commit_status(db, zDb, op, &val);
+  if( rc==SQLITE_OK ){
+    Tcl_SetObjResult(interp, Tcl_NewWideIntObj((i64)val));
+    return TCL_OK;
+  }
+
+  Tcl_SetObjResult(interp, Tcl_NewStringObj(sqlite3ErrName(rc), -1));
+  return TCL_ERROR;
+}
+
 #ifdef SQLITE_ENABLE_SNAPSHOT
 /*
 ** Usage: sqlite3_snapshot_get DB DBNAME
@@ -8686,6 +8763,41 @@ static int SQLITE_TCLAPI test_dbconfig_maindbname_icecube(
   }
 }
 
+/*
+** Usage: sqlite3_wal_info DB DBNAME
+*/
+static int SQLITE_TCLAPI test_wal_info(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int rc;
+  sqlite3 *db;
+  char *zName;
+  unsigned int nPrior;
+  unsigned int nFrame;
+
+  if( objc!=3 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "DB DBNAME");
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  zName = Tcl_GetString(objv[2]);
+
+  rc = sqlite3_wal_info(db, zName, &nPrior, &nFrame);
+  if( rc!=SQLITE_OK ){
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(sqlite3ErrName(rc), -1));
+    return TCL_ERROR;
+  }else{
+    Tcl_Obj *pNew = Tcl_NewObj();
+    Tcl_ListObjAppendElement(interp, pNew, Tcl_NewWideIntObj((i64)nPrior));
+    Tcl_ListObjAppendElement(interp, pNew, Tcl_NewWideIntObj((i64)nFrame));
+    Tcl_SetObjResult(interp, pNew);
+  }
+  return TCL_OK;
+}
+
 /*
 ** Usage: sqlite3_mmap_warm DB DBNAME
 */
@@ -9284,8 +9396,9 @@ int Sqlitetest1_Init(Tcl_Interp *interp){
      { "sqlite3_snapshot_open_blob", test_snapshot_open_blob, 0 },
      { "sqlite3_snapshot_cmp_blob", test_snapshot_cmp_blob, 0 },
 #endif
-     { "sqlite3_delete_database", test_delete_database,    0 },
-     { "atomic_batch_write",      test_atomic_batch_write, 0 },
+     { "sqlite3_delete_database", test_delete_database, 0 },
+     { "sqlite3_wal_info", test_wal_info, 0 },
+     { "atomic_batch_write",      test_atomic_batch_write,     0   },
      { "sqlite3_mmap_warm",       test_mmap_warm,          0 },
      { "sqlite3_config_sorterref", test_config_sorterref,   0 },
      { "sqlite3_autovacuum_pages", test_autovacuum_pages,   0 },
@@ -9297,6 +9410,8 @@ int Sqlitetest1_Init(Tcl_Interp *interp){
 #ifndef SQLITE_OMIT_VIRTUALTABLE
      { "create_null_module",       test_create_null_module,     0 },
 #endif
+     { "sqlite3_commit_status",    test_commit_status,     0 },
+     { "sqlite3_randomness",       test_sqlite3_randomness,     0 },
   };
   static int bitmask_size = sizeof(Bitmask)*8;
   static int longdouble_size = sizeof(LONGDOUBLE_TYPE);

src/test_config.c

@@ -689,6 +689,12 @@ Tcl_SetVar2(interp, "sqlite_options", "mergesort", "1", TCL_GLOBAL_ONLY);
   Tcl_SetVar2(interp, "sqlite_options", "truncate_opt", "1", TCL_GLOBAL_ONLY);
 #endif
 
+#ifndef SQLITE_OMIT_CONCURRENT
+  Tcl_SetVar2(interp, "sqlite_options", "concurrent", "1", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "concurrent", "0", TCL_GLOBAL_ONLY);
+#endif
+
 #ifdef SQLITE_OMIT_UTF16
   Tcl_SetVar2(interp, "sqlite_options", "utf16", "0", TCL_GLOBAL_ONLY);
 #else

src/test_hexio.c

@@ -187,7 +187,7 @@ static int SQLITE_TCLAPI hexio_write(
 }
 
 /*
-** USAGE:   hexio_get_int   HEXDATA
+** USAGE:   hexio_get_int [-littleendian] HEXDATA
 **
 ** Interpret the HEXDATA argument as a big-endian integer.  Return
 ** the value of that integer.  HEXDATA can contain between 2 and 8
@@ -205,12 +205,20 @@ static int SQLITE_TCLAPI hexio_get_int(
   const unsigned char *zIn;
   unsigned char *aOut;
   unsigned char aNum[4];
+  int bLittle = 0;
 
-  if( objc!=2 ){
-    Tcl_WrongNumArgs(interp, 1, objv, "HEXDATA");
+  if( objc==3 ){
+    Tcl_Size n;
+    char *z = Tcl_GetStringFromObj(objv[1], &n);
+    if( n>=2 && n<=13 && memcmp(z, "-littleendian", n)==0 ){
+      bLittle = 1;
+    }
+  }
+  if( (objc-bLittle)!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "[-littleendian] HEXDATA");
     return TCL_ERROR;
   }
-  zIn = (const unsigned char *)Tcl_GetStringFromObj(objv[1], &nIn);
+  zIn = (const unsigned char *)Tcl_GetStringFromObj(objv[1+bLittle], &nIn);
   aOut = sqlite3_malloc64( 1 + nIn/2 );
   if( aOut==0 ){
     return TCL_ERROR;
@@ -223,7 +231,11 @@ static int SQLITE_TCLAPI hexio_get_int(
     memcpy(&aNum[4-nOut], aOut, nOut);
   }
   sqlite3_free(aOut);
-  val = (aNum[0]<<24) | (aNum[1]<<16) | (aNum[2]<<8) | aNum[3];
+  if( bLittle ){
+    val = (aNum[3]<<24) | (aNum[2]<<16) | (aNum[1]<<8) | aNum[0];
+  }else{
+    val = (aNum[0]<<24) | (aNum[1]<<16) | (aNum[2]<<8) | aNum[3];
+  }
   Tcl_SetObjResult(interp, Tcl_NewIntObj(val));
   return TCL_OK;
 }

src/test_superlock.c

@@ -41,6 +41,8 @@ typedef struct SuperlockBusy SuperlockBusy;
 struct Superlock {
   sqlite3 *db;                    /* Database handle used to lock db */
   int bWal;                       /* True if db is a WAL database */
+  int bRecoveryLocked;            /* True if WAL RECOVERY lock is held */
+  int bReaderLocked;              /* True if WAL READER locks are held */
 };
 typedef struct Superlock Superlock;
 
@@ -107,12 +109,13 @@ static int superlockShmLock(
 ** Invoke the supplied busy-handler as required.
 */
 static int superlockWalLock(
-  sqlite3 *db,                    /* Database handle open on WAL database */
+  Superlock *pLock,               /* Superlock handle */
   SuperlockBusy *pBusy            /* Busy handler wrapper object */
 ){
   int rc;                         /* Return code */
   sqlite3_file *fd = 0;           /* Main database file handle */
   void volatile *p = 0;           /* Pointer to first page of shared memory */
+  sqlite3 *db = pLock->db;
 
   /* Obtain a pointer to the sqlite3_file object open on the main db file. */
   rc = sqlite3_file_control(db, "main", SQLITE_FCNTL_FILE_POINTER, (void *)&fd);
@@ -121,8 +124,10 @@ static int superlockWalLock(
   /* Obtain the "recovery" lock. Normally, this lock is only obtained by
   ** clients running database recovery.  
   */
+  assert( pLock->bRecoveryLocked==0 );
   rc = superlockShmLock(fd, 2, 1, pBusy);
   if( rc!=SQLITE_OK ) return rc;
+  pLock->bRecoveryLocked = 1;
 
   /* Zero the start of the first shared-memory page. This means that any
   ** clients that open read or write transactions from this point on will
@@ -139,7 +144,9 @@ static int superlockWalLock(
   ** are held, it is guaranteed that there are no active reader, writer or 
   ** checkpointer clients.
   */
+  assert( pLock->bReaderLocked==0 );
   rc = superlockShmLock(fd, 3, SQLITE_SHM_NLOCK-3, pBusy);
+  if( rc==SQLITE_OK ) pLock->bReaderLocked = 1;
   return rc;
 }
 
@@ -156,8 +163,14 @@ void sqlite3demo_superunlock(void *pLock){
     sqlite3_file *fd = 0;
     rc = sqlite3_file_control(p->db, "main", SQLITE_FCNTL_FILE_POINTER, (void *)&fd);
     if( rc==SQLITE_OK ){
-      fd->pMethods->xShmLock(fd, 2, 1, flags);
-      fd->pMethods->xShmLock(fd, 3, SQLITE_SHM_NLOCK-3, flags);
+      if( p->bRecoveryLocked ){
+        fd->pMethods->xShmLock(fd, 2, 1, flags);
+        p->bRecoveryLocked = 0;
+      }
+      if( p->bReaderLocked ){
+        fd->pMethods->xShmLock(fd, 3, SQLITE_SHM_NLOCK-3, flags);
+        p->bReaderLocked = 0;
+      }
     }
   }
   sqlite3_close(p->db);
@@ -232,7 +245,7 @@ int sqlite3demo_superlock(
     if( SQLITE_OK==(rc = superlockIsWal(pLock)) && pLock->bWal ){
       rc = sqlite3_exec(pLock->db, "COMMIT", 0, 0, 0);
       if( rc==SQLITE_OK ){
-        rc = superlockWalLock(pLock->db, &busy);
+        rc = superlockWalLock(pLock, &busy);
       }
     }
   }

src/test_tclsh.c

@@ -91,6 +91,7 @@ const char *sqlite3TestInit(Tcl_Interp *interp){
   extern int Fts5tcl_Init(Tcl_Interp *);
   extern int SqliteRbu_Init(Tcl_Interp*);
   extern int Sqlitetesttcl_Init(Tcl_Interp*);
+  extern int Bgckpt_Init(Tcl_Interp*);
 #if defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4)
   extern int Sqlitetestfts3_Init(Tcl_Interp *interp);
 #endif
@@ -161,6 +162,8 @@ const char *sqlite3TestInit(Tcl_Interp *interp){
   Fts5tcl_Init(interp);
   SqliteRbu_Init(interp);
   Sqlitetesttcl_Init(interp);
+  Bgckpt_Init(interp);
+
 
 #if defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4)
   Sqlitetestfts3_Init(interp);

src/update.c

@@ -465,6 +465,17 @@ void sqlite3Update(
   */
   chngRowid = chngPk = 0;
   for(i=0; i<pChanges->nExpr; i++){
+#if defined(SQLITE_ENABLE_NOOP_UPDATE) && !defined(SQLITE_OMIT_FLAG_PRAGMAS)
+    if( db->flags & SQLITE_NoopUpdate ){
+      Token x;
+      sqlite3ExprDelete(db, pChanges->a[i].pExpr);
+      x.z = pChanges->a[i].zEName;
+      x.n = sqlite3Strlen30(x.z);
+      pChanges->a[i].pExpr =
+         sqlite3PExpr(pParse, TK_UPLUS, sqlite3ExprAlloc(db, TK_ID, &x, 0), 0);
+      if( db->mallocFailed ) goto update_cleanup;
+    }
+#endif
     u8 hCol = sqlite3StrIHash(pChanges->a[i].zEName);
     /* If this is an UPDATE with a FROM clause, do not resolve expressions
     ** here. The call to sqlite3Select() below will do that. */

src/vacuum.c

@@ -401,6 +401,7 @@ end_of_vacuum:
   ** is closed by the DETACH.
   */
   db->autoCommit = 1;
+  assert( db->eConcurrent==0 );
 
   if( pDb ){
     sqlite3BtreeClose(pDb->pBt);

src/vdbe.c

@@ -3839,6 +3839,7 @@ case OP_Savepoint: {
       ** is committed.
       */
       int isTransaction = pSavepoint->pNext==0 && db->isTransactionSavepoint;
+      assert( db->eConcurrent==0 || db->isTransactionSavepoint==0 );
       if( isTransaction && p1==SAVEPOINT_RELEASE ){
         if( (rc = sqlite3VdbeCheckFk(p, 1))!=SQLITE_OK ){
           goto vdbe_return;
@@ -3925,35 +3926,55 @@ case OP_Savepoint: {
   break;
 }
 
-/* Opcode: AutoCommit P1 P2 * * *
+/* Opcode: AutoCommit P1 P2 P3 * *
 **
 ** Set the database auto-commit flag to P1 (1 or 0). If P2 is true, roll
 ** back any currently active btree transactions. If there are any active
 ** VMs (apart from this one), then a ROLLBACK fails.  A COMMIT fails if
 ** there are active writing VMs or active VMs that use shared cache.
 **
+** If P3 is non-zero, then this instruction is being executed as part of
+** a "BEGIN CONCURRENT" command.
+**
 ** This instruction causes the VM to halt.
 */
 case OP_AutoCommit: {
   int desiredAutoCommit;
   int iRollback;
+  int bConcurrent;
+  int hrc;
 
   desiredAutoCommit = pOp->p1;
   iRollback = pOp->p2;
+  bConcurrent = pOp->p3;
   assert( desiredAutoCommit==1 || desiredAutoCommit==0 );
   assert( desiredAutoCommit==1 || iRollback==0 );
+  assert( desiredAutoCommit==0 || bConcurrent==0 );
+  assert( db->autoCommit==0 || db->eConcurrent==CONCURRENT_NONE );
   assert( db->nVdbeActive>0 );  /* At least this one VM is active */
   assert( p->bIsReader );
 
   if( desiredAutoCommit!=db->autoCommit ){
+
+    u64 aCommit[COMMIT_TIME_N];
+    memset(aCommit, 0, sizeof(aCommit));
+    sqlite3CommitTimeSet(aCommit, COMMIT_TIME_START);
+
     if( iRollback ){
       assert( desiredAutoCommit==1 );
       sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
       db->autoCommit = 1;
-    }else if( desiredAutoCommit && db->nVdbeWrite>0 ){
-      /* If this instruction implements a COMMIT and other VMs are writing
-      ** return an error indicating that the other VMs must complete first.
-      */
+      db->eConcurrent = CONCURRENT_NONE;
+    }else if( desiredAutoCommit
+            && (db->nVdbeWrite>0 || (db->eConcurrent && db->nVdbeActive>1)) ){
+      /* A transaction may only be committed if there are no other active
+      ** writer VMs. If the transaction is CONCURRENT, then it may only be
+      ** committed if there are no active VMs at all (readers or writers).
+      **
+      ** If this instruction is a COMMIT and the transaction may not be
+      ** committed due to one of the conditions above, return an error
+      ** indicating that other VMs must complete before the COMMIT can
+      ** be processed.  */
       sqlite3VdbeError(p, "cannot commit transaction - "
                           "SQL statements in progress");
       rc = SQLITE_BUSY;
@@ -3963,18 +3984,28 @@ case OP_AutoCommit: {
     }else{
       db->autoCommit = (u8)desiredAutoCommit;
     }
-    if( sqlite3VdbeHalt(p)==SQLITE_BUSY ){
+    sqlite3CommitTimeSet(aCommit, COMMIT_TIME_BEFORE_HALT);
+    p->aCommitTime = aCommit;
+    hrc = sqlite3VdbeHalt(p);
+    p->aCommitTime = 0;
+    sqlite3CommitTimeSet(aCommit, COMMIT_TIME_AFTER_HALT);
+    if( (hrc & 0xFF)==SQLITE_BUSY ){
       p->pc = (int)(pOp - aOp);
       db->autoCommit = (u8)(1-desiredAutoCommit);
-      p->rc = rc = SQLITE_BUSY;
+      p->rc = hrc;
+      rc = SQLITE_BUSY;
       goto vdbe_return;
     }
+    assert( bConcurrent==CONCURRENT_NONE || bConcurrent==CONCURRENT_OPEN );
+    db->eConcurrent = (u8)bConcurrent;
     sqlite3CloseSavepoints(db);
     if( p->rc==SQLITE_OK ){
       rc = SQLITE_DONE;
     }else{
       rc = SQLITE_ERROR;
     }
+    sqlite3CommitTimeSet(aCommit, COMMIT_TIME_FINISH);
+    if( desiredAutoCommit ) sqlite3CommitTimeLog(aCommit);
     goto vdbe_return;
   }else{
     sqlite3VdbeError(p,
@@ -4181,6 +4212,17 @@ case OP_SetCookie: {
   pDb = &db->aDb[pOp->p1];
   assert( pDb->pBt!=0 );
   assert( sqlite3SchemaMutexHeld(db, pOp->p1, 0) );
+#ifndef SQLITE_OMIT_CONCURRENT
+  if( db->eConcurrent 
+   && (pOp->p2==BTREE_USER_VERSION || pOp->p2==BTREE_APPLICATION_ID)
+  ){
+    rc = SQLITE_ERROR;
+    sqlite3VdbeError(p, "cannot modify %s within CONCURRENT transaction",
+        pOp->p2==BTREE_USER_VERSION ? "user_version" : "application_id"
+    );
+    goto abort_due_to_error;
+  }
+#endif
   /* See note about index shifting on OP_ReadCookie */
   rc = sqlite3BtreeUpdateMeta(pDb->pBt, pOp->p2, pOp->p3);
   if( pOp->p2==BTREE_SCHEMA_VERSION ){
@@ -4330,6 +4372,11 @@ case OP_OpenWrite:
   pX = pDb->pBt;
   assert( pX!=0 );
   if( pOp->opcode==OP_OpenWrite ){
+#ifndef SQLITE_OMIT_CONCURRENT
+    if( db->eConcurrent==CONCURRENT_OPEN && p2==1 && iDb!=1 ){
+      db->eConcurrent = CONCURRENT_SCHEMA;
+    }
+#endif
     assert( OPFLAG_FORDELETE==BTREE_FORDELETE );
     wrFlag = BTREE_WRCSR | (pOp->p5 & OPFLAG_FORDELETE);
     assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
@@ -7900,6 +7947,7 @@ case OP_JournalMode: {    /* out2 */
        || eNew==PAGER_JOURNALMODE_OFF
        || eNew==PAGER_JOURNALMODE_MEMORY
        || eNew==PAGER_JOURNALMODE_WAL
+       || eNew==PAGER_JOURNALMODE_WAL2
        || eNew==PAGER_JOURNALMODE_QUERY
   );
   assert( pOp->p1>=0 && pOp->p1<db->nDb );
@@ -7918,16 +7966,25 @@ case OP_JournalMode: {    /* out2 */
   /* Do not allow a transition to journal_mode=WAL for a database
   ** in temporary storage or if the VFS does not support shared memory
   */
-  if( eNew==PAGER_JOURNALMODE_WAL
+  if( isWalMode(eNew)
    && (sqlite3Strlen30(zFilename)==0           /* Temp file */
        || !sqlite3PagerWalSupported(pPager))   /* No shared-memory support */
   ){
     eNew = eOld;
   }
 
-  if( (eNew!=eOld)
-   && (eOld==PAGER_JOURNALMODE_WAL || eNew==PAGER_JOURNALMODE_WAL)
-  ){
+  if( eNew!=eOld && (isWalMode(eNew) || isWalMode(eOld)) ){
+
+    /* Prevent changing directly to wal2 from wal mode. And vice versa. */
+    if( isWalMode(eNew) && isWalMode(eOld) ){
+      rc = SQLITE_ERROR;
+      sqlite3VdbeError(p, "cannot change from %s to %s mode",
+          sqlite3JournalModename(eOld), sqlite3JournalModename(eNew)
+      );
+      goto abort_due_to_error;
+    }
+
+    /* Prevent switching into or out of wal/wal2 mode mid-transaction */
     if( !db->autoCommit || db->nVdbeRead>1 ){
       rc = SQLITE_ERROR;
       sqlite3VdbeError(p,
@@ -7935,31 +7992,34 @@ case OP_JournalMode: {    /* out2 */
           (eNew==PAGER_JOURNALMODE_WAL ? "into" : "out of")
       );
       goto abort_due_to_error;
-    }else{
-
-      if( eOld==PAGER_JOURNALMODE_WAL ){
-        /* If leaving WAL mode, close the log file. If successful, the call
-        ** to PagerCloseWal() checkpoints and deletes the write-ahead-log
-        ** file. An EXCLUSIVE lock may still be held on the database file
-        ** after a successful return.
-        */
-        rc = sqlite3PagerCloseWal(pPager, db);
-        if( rc==SQLITE_OK ){
-          sqlite3PagerSetJournalMode(pPager, eNew);
-        }
-      }else if( eOld==PAGER_JOURNALMODE_MEMORY ){
-        /* Cannot transition directly from MEMORY to WAL.  Use mode OFF
-        ** as an intermediate */
-        sqlite3PagerSetJournalMode(pPager, PAGER_JOURNALMODE_OFF);
-      }
+    }
  
-      /* Open a transaction on the database file. Regardless of the journal
-      ** mode, this transaction always uses a rollback journal.
+    if( isWalMode(eOld) ){
+      /* If leaving WAL mode, close the log file. If successful, the call
+      ** to PagerCloseWal() checkpoints and deletes the write-ahead-log 
+      ** file. An EXCLUSIVE lock may still be held on the database file 
+      ** after a successful return. 
       */
-      assert( sqlite3BtreeTxnState(pBt)!=SQLITE_TXN_WRITE );
+      rc = sqlite3PagerCloseWal(pPager, db);
       if( rc==SQLITE_OK ){
-        rc = sqlite3BtreeSetVersion(pBt, (eNew==PAGER_JOURNALMODE_WAL ? 2 : 1));
+        sqlite3PagerSetJournalMode(pPager, eNew);
       }
+    }else if( eOld==PAGER_JOURNALMODE_MEMORY ){
+      /* Cannot transition directly from MEMORY to WAL.  Use mode OFF
+      ** as an intermediate */
+      sqlite3PagerSetJournalMode(pPager, PAGER_JOURNALMODE_OFF);
+    }
+
+    /* Open a transaction on the database file. Regardless of the journal
+    ** mode, this transaction always uses a rollback journal.
+    */
+    assert( sqlite3BtreeTxnState(pBt)!=SQLITE_TXN_WRITE );
+    if( rc==SQLITE_OK ){
+      /* 1==rollback, 2==wal, 3==wal2 */
+      rc = sqlite3BtreeSetVersion(pBt, 
+          1 + isWalMode(eNew) + (eNew==PAGER_JOURNALMODE_WAL2)
+      );
+
     }
   }
 #endif /* ifndef SQLITE_OMIT_WAL */
@@ -8095,6 +8155,11 @@ case OP_CursorUnlock: {
 */
 case OP_TableLock: {
   u8 isWriteLock = (u8)pOp->p3;
+#ifndef SQLITE_OMIT_CONCURRENT
+  if( isWriteLock && db->eConcurrent && pOp->p2==1 && pOp->p1!=1 ){
+    db->eConcurrent = CONCURRENT_SCHEMA;
+  }
+#endif
   if( isWriteLock || 0==(db->flags&SQLITE_ReadUncommit) ){
     int p1 = pOp->p1;
     assert( p1>=0 && p1<db->nDb );

src/vdbe.h

@@ -425,4 +425,61 @@ void sqlite3VdbePrintOp(FILE*, int, VdbeOp*);
 int sqlite3CursorRangeHintExprCheck(Walker *pWalker, Expr *pExpr);
 #endif
 
+
+#define COMMIT_TIME_START 0
+#define COMMIT_TIME_BEFORE_HALT 1
+#define COMMIT_TIME_BEFORE_VDBECOMMIT 2
+
+#define COMMIT_TIME_BEFORE_PHASEONE 3
+#define COMMIT_TIME_START_FIXUNLOCKED 4
+#define COMMIT_TIME_START_RELOCATE1 5
+#define COMMIT_TIME_START_RELOCATE2 6
+
+#define COMMIT_TIME_OTHERWRITERS 7
+#define COMMIT_TIME_RELOCATE1COUNT 8
+#define COMMIT_TIME_RELOCATE2COUNT 9
+
+#define COMMIT_TIME_RELOCATE2_READUS     10
+#define COMMIT_TIME_RELOCATE2_READCOUNT  11
+#define COMMIT_TIME_RELOCATE2_ALLOCATEUS 12
+#define COMMIT_TIME_RELOCATE2_RELOCATEUS 13
+
+#define COMMIT_TIME_AFTER_FIXUNLOCKED 14
+
+#define COMMIT_TIME_BEFORE_WALFRAMES 15
+#define COMMIT_TIME_AFTER_CHANGECOUNTER 16
+#define COMMIT_TIME_AFTER_RESTARTLOG 17
+#define COMMIT_TIME_AFTER_WRITEHDR 18
+
+#define COMMIT_TIME_OSWRITE 19
+
+#define COMMIT_TIME_AFTER_WRITEFRAMES 20
+
+#define COMMIT_TIME_NFRAME            21
+#define COMMIT_TIME_HASHMAPUS         22
+
+#define COMMIT_TIME_BEFORE_WALINDEX 23
+#define COMMIT_TIME_AFTER_WALINDEX 24
+#define COMMIT_TIME_AFTER_WALINDEXHDR 25
+
+#define COMMIT_TIME_WALFRAMESFLAGS 26
+
+#define COMMIT_TIME_AFTER_WALFRAMES 27
+
+#define COMMIT_TIME_BEFORE_PHASETWO 28
+#define COMMIT_TIME_AFTER_PHASETWO 29
+
+#define COMMIT_TIME_AFTER_VDBECOMMIT 30
+#define COMMIT_TIME_AFTER_HALT 31
+#define COMMIT_TIME_FINISH 32
+
+#define COMMIT_TIME_N 33
+
+/* #define COMMIT_TIME_TIMEOUT (2*1000*1000) */
+#define COMMIT_TIME_TIMEOUT (10*1000)         /* 10ms threshold */
+
+void sqlite3CommitTimeLog(u64*);
+u64 sqlite3STimeNow();
+void sqlite3CommitTimeSet(u64*, int);
+
 #endif /* SQLITE_VDBE_H */

src/vdbeInt.h

@@ -514,6 +514,7 @@ struct Vdbe {
   int nScan;              /* Entries in aScan[] */
   ScanStatus *aScan;      /* Scan definitions for sqlite3_stmt_scanstatus() */
 #endif
+  u64 *aCommitTime;
 };
 
 /*

src/vdbeaux.c

@@ -15,6 +15,8 @@
 #include "sqliteInt.h"
 #include "vdbeInt.h"
 
+#include "btreeInt.h"
+
 /* Forward references */
 static void freeEphemeralFunction(sqlite3 *db, FuncDef *pDef);
 static void vdbeFreeOpArray(sqlite3 *, Op *, int);
@@ -2941,7 +2943,8 @@ static int vdbeCommit(sqlite3 *db, Vdbe *p){
         /* OFF       */ 0,
         /* TRUNCATE  */ 1,
         /* MEMORY    */ 0,
-        /* WAL       */ 0
+        /* WAL       */ 0,
+        /* WAL2      */ 0
       };
       Pager *pPager;   /* Pager associated with pBt */
       needXcommit = 1;
@@ -2954,10 +2957,27 @@ static int vdbeCommit(sqlite3 *db, Vdbe *p){
         assert( i!=1 );
         nTrans++;
       }
-      rc = sqlite3PagerExclusiveLock(pPager);
+      rc = sqlite3BtreeExclusiveLock(pBt);
       sqlite3BtreeLeave(pBt);
     }
   }
+
+#ifndef SQLITE_OMIT_CONCURRENT
+  if( db->eConcurrent && (rc & 0xFF)==SQLITE_BUSY ){
+    /* An SQLITE_BUSY or SQLITE_BUSY_SNAPSHOT was encountered while 
+    ** attempting to take the WRITER lock on a wal file. Release the
+    ** WRITER locks on all wal files and return early.  */
+    for(i=0; i<db->nDb; i++){
+      Btree *pBt = db->aDb[i].pBt;
+      if( sqlite3BtreeTxnState(pBt)==SQLITE_TXN_WRITE ){
+        sqlite3BtreeEnter(pBt);
+        sqlite3PagerDropExclusiveLock(sqlite3BtreePager(pBt));
+        sqlite3BtreeLeave(pBt);
+      }
+    }
+  }
+#endif
+
   if( rc!=SQLITE_OK ){
     return rc;
   }
@@ -2982,13 +3002,18 @@ static int vdbeCommit(sqlite3 *db, Vdbe *p){
   if( 0==sqlite3Strlen30(sqlite3BtreeGetFilename(db->aDb[0].pBt))
    || nTrans<=1
   ){
+    sqlite3CommitTimeSet(p->aCommitTime, COMMIT_TIME_BEFORE_PHASEONE);
     for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
       Btree *pBt = db->aDb[i].pBt;
       if( pBt ){
+        pBt->pBt->aCommitTime = p->aCommitTime;
         rc = sqlite3BtreeCommitPhaseOne(pBt, 0);
+        pBt->pBt->aCommitTime = 0;
       }
     }
 
+    sqlite3CommitTimeSet(p->aCommitTime, COMMIT_TIME_BEFORE_PHASETWO);
+
     /* Do the commit only if all databases successfully complete phase 1.
     ** If one of the BtreeCommitPhaseOne() calls fails, this indicates an
     ** IO error while deleting or truncating a journal file. It is unlikely,
@@ -2997,9 +3022,13 @@ static int vdbeCommit(sqlite3 *db, Vdbe *p){
     for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
       Btree *pBt = db->aDb[i].pBt;
       if( pBt ){
+        pBt->pBt->aCommitTime = p->aCommitTime;
         rc = sqlite3BtreeCommitPhaseTwo(pBt, 0);
+        pBt->pBt->aCommitTime = 0;
       }
     }
+
+    sqlite3CommitTimeSet(p->aCommitTime, COMMIT_TIME_AFTER_PHASETWO);
     if( rc==SQLITE_OK ){
       sqlite3VtabCommit(db);
     }
@@ -3359,6 +3388,7 @@ int sqlite3VdbeHalt(Vdbe *p){
           sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
           sqlite3CloseSavepoints(db);
           db->autoCommit = 1;
+          db->eConcurrent = CONCURRENT_NONE;
           p->nChange = 0;
         }
       }
@@ -3395,11 +3425,13 @@ int sqlite3VdbeHalt(Vdbe *p){
           ** or hit an 'OR FAIL' constraint and there are no deferred foreign
           ** key constraints to hold up the transaction. This means a commit
           ** is required. */
+          sqlite3CommitTimeSet(p->aCommitTime, COMMIT_TIME_BEFORE_VDBECOMMIT);
           rc = vdbeCommit(db, p);
+          sqlite3CommitTimeSet(p->aCommitTime, COMMIT_TIME_AFTER_VDBECOMMIT);
         }
-        if( rc==SQLITE_BUSY && p->readOnly ){
+        if( (rc & 0xFF)==SQLITE_BUSY && p->readOnly ){
           sqlite3VdbeLeave(p);
-          return SQLITE_BUSY;
+          return rc;
         }else if( rc!=SQLITE_OK ){
           sqlite3SystemError(db, rc);
           p->rc = rc;
@@ -3427,6 +3459,7 @@ int sqlite3VdbeHalt(Vdbe *p){
         sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
         sqlite3CloseSavepoints(db);
         db->autoCommit = 1;
+        db->eConcurrent = CONCURRENT_NONE;
         p->nChange = 0;
       }
     }
@@ -3448,6 +3481,7 @@ int sqlite3VdbeHalt(Vdbe *p){
         sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
         sqlite3CloseSavepoints(db);
         db->autoCommit = 1;
+        db->eConcurrent = CONCURRENT_NONE;
         p->nChange = 0;
       }
     }
@@ -5425,6 +5459,91 @@ int sqlite3CursorRangeHintExprCheck(Walker *pWalker, Expr *pExpr){
 }
 #endif /* SQLITE_ENABLE_CURSOR_HINTS && SQLITE_DEBUG */
 
+#include <sys/time.h>
+void sqlite3CommitTimeLog(u64 *aCommit){
+  u64 i1 = aCommit[COMMIT_TIME_START];
+  assert( COMMIT_TIME_START==0 && COMMIT_TIME_FINISH==COMMIT_TIME_N-1 );
+  if( aCommit[COMMIT_TIME_FINISH]>(i1+COMMIT_TIME_TIMEOUT) ){
+    char *zStr = 0;
+    int ii;
+    for(ii=1; ii<COMMIT_TIME_N; ii++){
+      int iVal;
+      const char *zHash = "";
+      const char *zU = "";
+      if( ii==COMMIT_TIME_RELOCATE1COUNT
+       || ii==COMMIT_TIME_RELOCATE2COUNT
+       || ii==COMMIT_TIME_OTHERWRITERS
+       || ii==COMMIT_TIME_NFRAME
+       || ii==COMMIT_TIME_RELOCATE2_READCOUNT
+      ){
+        iVal = (int)aCommit[ii];
+        zHash = "#";
+      }else if( ii==COMMIT_TIME_OSWRITE 
+             || ii==COMMIT_TIME_RELOCATE2_READUS 
+             || ii==COMMIT_TIME_RELOCATE2_ALLOCATEUS 
+             || ii==COMMIT_TIME_RELOCATE2_RELOCATEUS 
+             || ii==COMMIT_TIME_HASHMAPUS 
+      ){
+        iVal = (int)aCommit[ii];
+        zU = "us";
+      }else if( ii==COMMIT_TIME_WALFRAMESFLAGS ){
+        iVal = (int)aCommit[ii];
+        zHash = "flags=";
+      }else{
+        iVal = (aCommit[ii]==0 ? 0 : (int)(aCommit[ii] - i1));
+      }
+      zStr = sqlite3_mprintf("%z%s%s%d%s", zStr, (zStr?", ":""),zHash,iVal,zU);
+    }
+    sqlite3_log(SQLITE_WARNING, "slow commit (v=10): (%s)", zStr);
+    sqlite3_free(zStr);
+  }
+}
+u64 sqlite3STimeNow(){
+  struct timeval time;
+  gettimeofday(&time, 0);
+  return ((u64)time.tv_sec * 1000000 + (u64)time.tv_usec);
+}
+void sqlite3CommitTimeSet(u64 *aCommit, int iCommit){
+  if( aCommit && aCommit[iCommit]==0 ){
+    aCommit[iCommit] = sqlite3STimeNow();
+  }
+}
+void sqlite3PrepareTimeLog(const char *zSql, int nSql, u64 *aPrepare){
+  u64 i1 = aPrepare[PREPARE_TIME_START];
+  assert( PREPARE_TIME_START==0 && PREPARE_TIME_FINISH==PREPARE_TIME_N-1 );
+  if( aPrepare[PREPARE_TIME_FINISH]>(i1+PREPARE_TIME_TIMEOUT) ){
+    int nByte = nSql;
+    char *zStr = 0;
+    int ii;
+    for(ii=1; ii<PREPARE_TIME_N; ii++){
+      zStr = sqlite3_mprintf("%z%s%d", zStr, (zStr?", ":""), 
+        (aPrepare[ii]==0 ? 0 : (int)(aPrepare[ii] - i1))
+      );
+    }
+    if( nByte<0 ){ nByte = sqlite3Strlen30(zSql); }
+    sqlite3_log(SQLITE_WARNING, 
+        "slow prepare (v=10): (%s) [%.*s]", zStr, nByte, zSql
+    );
+    sqlite3_free(zStr);
+  }
+}
+void sqlite3SchemaTimeLog(u64 *aSchema){
+  u64 i1 = aSchema[SCHEMA_TIME_START];
+  assert( SCHEMA_TIME_START==0 && SCHEMA_TIME_FINISH==SCHEMA_TIME_N-1 );
+  if( aSchema[SCHEMA_TIME_FINISH]>(i1+SCHEMA_TIME_TIMEOUT) ){
+    char *zStr = 0;
+    int ii;
+    for(ii=1; ii<SCHEMA_TIME_N; ii++){
+      zStr = sqlite3_mprintf("%z%s%d", zStr, (zStr?", ":""), 
+        (aSchema[ii]==0 ? 0 : (int)(aSchema[ii] - i1))
+      );
+    }
+    sqlite3_log(SQLITE_WARNING, "slow schema (v=10): (%s)", zStr);
+    sqlite3_free(zStr);
+  }
+}
+
+
 #ifndef SQLITE_OMIT_VIRTUALTABLE
 /*
 ** Transfer error message text from an sqlite3_vtab.zErrMsg (text stored

src/wal.h

@@ -26,7 +26,7 @@
 #define CKPT_SYNC_FLAGS(X)  (((X)>>2)&0x03)
 
 #ifdef SQLITE_OMIT_WAL
-# define sqlite3WalOpen(x,y,z)                   0
+# define sqlite3WalOpen(w,x,y,z)                 0
 # define sqlite3WalLimit(x,y)
 # define sqlite3WalClose(v,w,x,y,z)              0
 # define sqlite3WalBeginReadTransaction(y,z)     0
@@ -34,7 +34,7 @@
 # define sqlite3WalDbsize(y)                     0
 # define sqlite3WalBeginWriteTransaction(y)      0
 # define sqlite3WalEndWriteTransaction(x)        0
-# define sqlite3WalUndo(x,y,z)                   0
+# define sqlite3WalUndo(w,x,y,z)                 0
 # define sqlite3WalSavepoint(y,z)
 # define sqlite3WalSavepointUndo(y,z)            0
 # define sqlite3WalFrames(u,v,w,x,y,z)           0
@@ -45,6 +45,7 @@
 # define sqlite3WalFramesize(z)                  0
 # define sqlite3WalFindFrame(x,y,z)              0
 # define sqlite3WalFile(x)                       0
+# define sqlite3WalJournalMode(x)                0
 # undef SQLITE_USE_SEH
 #else
 
@@ -56,7 +57,7 @@
 typedef struct Wal Wal;
 
 /* Open and close a connection to a write-ahead log. */
-int sqlite3WalOpen(sqlite3_vfs*, sqlite3_file*, const char *, int, i64, Wal**);
+int sqlite3WalOpen(sqlite3_vfs*, sqlite3_file*, const char *,int,i64,int,Wal**);
 int sqlite3WalClose(Wal *pWal, sqlite3*, int sync_flags, int, u8 *);
 
 /* Set the limiting size of a WAL file. */
@@ -84,7 +85,7 @@ int sqlite3WalBeginWriteTransaction(Wal *pWal);
 int sqlite3WalEndWriteTransaction(Wal *pWal);
 
 /* Undo any frames written (but not committed) to the log */
-int sqlite3WalUndo(Wal *pWal, int (*xUndo)(void *, Pgno), void *pUndoCtx);
+int sqlite3WalUndo(Wal *pWal, int (*xUndo)(void *, Pgno), void *pUndoCtx, int);
 
 /* Return an integer that records the current (uncommitted) write
 ** position in the WAL */
@@ -137,6 +138,15 @@ int sqlite3WalSnapshotCheck(Wal *pWal, sqlite3_snapshot *pSnapshot);
 void sqlite3WalSnapshotUnlock(Wal *pWal);
 #endif
 
+#ifndef SQLITE_OMIT_CONCURRENT
+/* Tell the wal layer that we want to commit a concurrent transaction */
+int sqlite3WalLockForCommit(Wal *pWal, PgHdr *pPg, Bitvec *pRead, u32*);
+
+/* Upgrade the state of the client to take into account changes written
+** by other connections */
+int sqlite3WalUpgradeSnapshot(Wal *pWal);
+#endif /* SQLITE_OMIT_CONCURRENT */
+
 #ifdef SQLITE_ENABLE_ZIPVFS
 /* If the WAL file is not empty, return the number of bytes of content
 ** stored in each frame (i.e. the db page-size when the WAL was created).
@@ -147,6 +157,9 @@ int sqlite3WalFramesize(Wal *pWal);
 /* Return the sqlite3_file object for the WAL file */
 sqlite3_file *sqlite3WalFile(Wal *pWal);
 
+/* Return the journal mode (WAL or WAL2) used by this Wal object. */
+int sqlite3WalJournalMode(Wal *pWal);
+
 #ifdef SQLITE_ENABLE_SETLK_TIMEOUT
 int sqlite3WalWriteLock(Wal *pWal, int bLock);
 void sqlite3WalDb(Wal *pWal, sqlite3 *db);
@@ -156,5 +169,13 @@ void sqlite3WalDb(Wal *pWal, sqlite3 *db);
 int sqlite3WalSystemErrno(Wal*);
 #endif
 
+/* sqlite3_wal_info() data */
+int sqlite3WalInfo(Wal *pWal, u32 *pnPrior, u32 *pnFrame);
+
+/* sqlite3_wal_info() data */
+int sqlite3WalInfo(Wal *pWal, u32 *pnPrior, u32 *pnFrame);
+
+void sqlite3WalSetCommitTime(Wal *pWal, u64 *aCommitTime);
+
 #endif /* ifndef SQLITE_OMIT_WAL */
 #endif /* SQLITE_WAL_H */

test/bc_test1.c

@@ -0,0 +1,556 @@
+/*
+** 2016-05-07
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+*/
+
+
+#include <sqlite3.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include "tt3_core.c"
+
+#ifdef USE_OSINST
+# include "../src/test_osinst.c"
+#else
+# define vfslog_time() 0
+#endif
+
+typedef struct Config Config;
+typedef struct ThreadCtx ThreadCtx;
+
+#define THREAD_TIME_INSERT   0
+#define THREAD_TIME_COMMIT   1
+#define THREAD_TIME_ROLLBACK 2
+#define THREAD_TIME_WRITER   3
+#define THREAD_TIME_CKPT     4
+
+struct ThreadCtx {
+  Config *pConfig;
+  Sqlite *pDb;
+  Error *pErr;
+  sqlite3_int64 aTime[5];
+};
+
+struct Config {
+  int nIPT;                       /* --inserts-per-transaction */
+  int nThread;                    /* --threads */
+  int nSecond;                    /* --seconds */
+  int bMutex;                     /* --mutex */
+  int nAutoCkpt;                  /* --autockpt */
+  int bRm;                        /* --rm */
+  int bClearCache;                /* --clear-cache */
+  int nMmap;                      /* mmap limit in MB */
+  char *zFile;
+  int bOsinst;                    /* True to use osinst */
+
+  ThreadCtx *aCtx;                /* Array of size nThread */
+
+  pthread_cond_t cond;
+  pthread_mutex_t mutex;
+  int nCondWait;                  /* Number of threads waiting on hCond */
+  sqlite3_vfs *pVfs;
+};
+
+
+typedef struct VfsWrapperFd VfsWrapperFd;
+struct VfsWrapperFd {
+  sqlite3_file base;              /* Base class */
+  int bWriter;                    /* True if holding shm WRITER lock */
+  int iTid;
+  Config *pConfig;
+  sqlite3_file *pFd;              /* Underlying file descriptor */
+};
+
+/* Methods of the wrapper VFS */
+static int vfsWrapOpen(sqlite3_vfs*, const char*, sqlite3_file*, int, int*);
+static int vfsWrapDelete(sqlite3_vfs*, const char*, int);
+static int vfsWrapAccess(sqlite3_vfs*, const char*, int, int*);
+static int vfsWrapFullPathname(sqlite3_vfs*, const char *, int, char*);
+static void *vfsWrapDlOpen(sqlite3_vfs*, const char*);
+static void vfsWrapDlError(sqlite3_vfs*, int, char*);
+static void (*vfsWrapDlSym(sqlite3_vfs*,void*, const char*))(void);
+static void vfsWrapDlClose(sqlite3_vfs*, void*);
+static int vfsWrapRandomness(sqlite3_vfs*, int, char*);
+static int vfsWrapSleep(sqlite3_vfs*, int);
+static int vfsWrapCurrentTime(sqlite3_vfs*, double*);
+static int vfsWrapGetLastError(sqlite3_vfs*, int, char*);
+static int vfsWrapCurrentTimeInt64(sqlite3_vfs*, sqlite3_int64*);
+static int vfsWrapSetSystemCall(sqlite3_vfs*, const char*, sqlite3_syscall_ptr);
+static sqlite3_syscall_ptr vfsWrapGetSystemCall(sqlite3_vfs*, const char*);
+static const char *vfsWrapNextSystemCall(sqlite3_vfs*, const char*);
+
+/* Methods of wrapper sqlite3_io_methods object (see vfsWrapOpen()) */
+static int vfsWrapClose(sqlite3_file*);
+static int vfsWrapRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
+static int vfsWrapWrite(sqlite3_file*, const void*, int iAmt, sqlite3_int64);
+static int vfsWrapTruncate(sqlite3_file*, sqlite3_int64 size);
+static int vfsWrapSync(sqlite3_file*, int flags);
+static int vfsWrapFileSize(sqlite3_file*, sqlite3_int64 *pSize);
+static int vfsWrapLock(sqlite3_file*, int);
+static int vfsWrapUnlock(sqlite3_file*, int);
+static int vfsWrapCheckReservedLock(sqlite3_file*, int *pResOut);
+static int vfsWrapFileControl(sqlite3_file*, int op, void *pArg);
+static int vfsWrapSectorSize(sqlite3_file*);
+static int vfsWrapDeviceCharacteristics(sqlite3_file*);
+static int vfsWrapShmMap(sqlite3_file*, int iPg, int, int, void volatile**);
+static int vfsWrapShmLock(sqlite3_file*, int offset, int n, int flags);
+static void vfsWrapShmBarrier(sqlite3_file*);
+static int vfsWrapShmUnmap(sqlite3_file*, int deleteFlag);
+static int vfsWrapFetch(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **);
+static int vfsWrapUnfetch(sqlite3_file*, sqlite3_int64 iOfst, void *p);
+
+static int vfsWrapOpen(
+  sqlite3_vfs *pVfs, 
+  const char *zName, 
+  sqlite3_file *pFd, 
+  int flags, 
+  int *fout
+){
+  static sqlite3_io_methods methods = {
+    3,
+    vfsWrapClose, vfsWrapRead, vfsWrapWrite,
+    vfsWrapTruncate, vfsWrapSync, vfsWrapFileSize,
+    vfsWrapLock, vfsWrapUnlock, vfsWrapCheckReservedLock,
+    vfsWrapFileControl, vfsWrapSectorSize, vfsWrapDeviceCharacteristics,
+    vfsWrapShmMap, vfsWrapShmLock, vfsWrapShmBarrier,
+    vfsWrapShmUnmap, vfsWrapFetch, vfsWrapUnfetch
+  };
+
+  Config *pConfig = (Config*)pVfs->pAppData;
+  VfsWrapperFd *pWrapper = (VfsWrapperFd*)pFd;
+  int rc;
+
+  memset(pWrapper, 0, sizeof(VfsWrapperFd));
+  if( flags & SQLITE_OPEN_MAIN_DB ){
+    pWrapper->iTid = (int)sqlite3_uri_int64(zName, "tid", 0);
+  }
+
+  pWrapper->pFd = (sqlite3_file*)&pWrapper[1];
+  pWrapper->pConfig = pConfig;
+  rc = pConfig->pVfs->xOpen(pConfig->pVfs, zName, pWrapper->pFd, flags, fout);
+  if( rc==SQLITE_OK ){
+    pWrapper->base.pMethods = &methods;
+  }
+  return rc;
+}
+
+static int vfsWrapDelete(sqlite3_vfs *pVfs, const char *a, int b){
+  Config *pConfig = (Config*)pVfs->pAppData;
+  return pConfig->pVfs->xDelete(pConfig->pVfs, a, b);
+}
+static int vfsWrapAccess(sqlite3_vfs *pVfs, const char *a, int b, int *c){
+  Config *pConfig = (Config*)pVfs->pAppData;
+  return pConfig->pVfs->xAccess(pConfig->pVfs, a, b, c);
+}
+static int vfsWrapFullPathname(sqlite3_vfs *pVfs, const char *a, int b, char*c){
+  Config *pConfig = (Config*)pVfs->pAppData;
+  return pConfig->pVfs->xFullPathname(pConfig->pVfs, a, b, c);
+}
+static void *vfsWrapDlOpen(sqlite3_vfs *pVfs, const char *a){
+  Config *pConfig = (Config*)pVfs->pAppData;
+  return pConfig->pVfs->xDlOpen(pConfig->pVfs, a);
+}
+static void vfsWrapDlError(sqlite3_vfs *pVfs, int a, char *b){
+  Config *pConfig = (Config*)pVfs->pAppData;
+  return pConfig->pVfs->xDlError(pConfig->pVfs, a, b);
+}
+static void (*vfsWrapDlSym(sqlite3_vfs *pVfs, void *a, const char *b))(void){
+  Config *pConfig = (Config*)pVfs->pAppData;
+  return pConfig->pVfs->xDlSym(pConfig->pVfs, a, b);
+}
+static void vfsWrapDlClose(sqlite3_vfs *pVfs, void *a){
+  Config *pConfig = (Config*)pVfs->pAppData;
+  return pConfig->pVfs->xDlClose(pConfig->pVfs, a);
+}
+static int vfsWrapRandomness(sqlite3_vfs *pVfs, int a, char *b){
+  Config *pConfig = (Config*)pVfs->pAppData;
+  return pConfig->pVfs->xRandomness(pConfig->pVfs, a, b);
+}
+static int vfsWrapSleep(sqlite3_vfs *pVfs, int a){
+  Config *pConfig = (Config*)pVfs->pAppData;
+  return pConfig->pVfs->xSleep(pConfig->pVfs, a);
+}
+static int vfsWrapCurrentTime(sqlite3_vfs *pVfs, double *a){
+  Config *pConfig = (Config*)pVfs->pAppData;
+  return pConfig->pVfs->xCurrentTime(pConfig->pVfs, a);
+}
+static int vfsWrapGetLastError(sqlite3_vfs *pVfs, int a, char *b){
+  Config *pConfig = (Config*)pVfs->pAppData;
+  return pConfig->pVfs->xGetLastError(pConfig->pVfs, a, b);
+}
+static int vfsWrapCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *a){
+  Config *pConfig = (Config*)pVfs->pAppData;
+  return pConfig->pVfs->xCurrentTimeInt64(pConfig->pVfs, a);
+}
+static int vfsWrapSetSystemCall(
+  sqlite3_vfs *pVfs, 
+  const char *a, 
+  sqlite3_syscall_ptr b
+){
+  Config *pConfig = (Config*)pVfs->pAppData;
+  return pConfig->pVfs->xSetSystemCall(pConfig->pVfs, a, b);
+}
+static sqlite3_syscall_ptr vfsWrapGetSystemCall(
+  sqlite3_vfs *pVfs, 
+  const char *a
+){
+  Config *pConfig = (Config*)pVfs->pAppData;
+  return pConfig->pVfs->xGetSystemCall(pConfig->pVfs, a);
+}
+static const char *vfsWrapNextSystemCall(sqlite3_vfs *pVfs, const char *a){
+  Config *pConfig = (Config*)pVfs->pAppData;
+  return pConfig->pVfs->xNextSystemCall(pConfig->pVfs, a);
+}
+
+static int vfsWrapClose(sqlite3_file *pFd){
+  VfsWrapperFd *pWrapper = (VfsWrapperFd*)pFd;
+  pWrapper->pFd->pMethods->xClose(pWrapper->pFd);
+  pWrapper->pFd = 0;
+  return SQLITE_OK;
+}
+static int vfsWrapRead(sqlite3_file *pFd, void *a, int b, sqlite3_int64 c){
+  VfsWrapperFd *pWrapper = (VfsWrapperFd*)pFd;
+  return pWrapper->pFd->pMethods->xRead(pWrapper->pFd, a, b, c);
+}
+static int vfsWrapWrite(
+  sqlite3_file *pFd, 
+  const void *a, int b, 
+  sqlite3_int64 c
+){
+  VfsWrapperFd *pWrapper = (VfsWrapperFd*)pFd;
+  return pWrapper->pFd->pMethods->xWrite(pWrapper->pFd, a, b, c);
+}
+static int vfsWrapTruncate(sqlite3_file *pFd, sqlite3_int64 a){
+  VfsWrapperFd *pWrapper = (VfsWrapperFd*)pFd;
+  return pWrapper->pFd->pMethods->xTruncate(pWrapper->pFd, a);
+}
+static int vfsWrapSync(sqlite3_file *pFd, int a){
+  VfsWrapperFd *pWrapper = (VfsWrapperFd*)pFd;
+  return pWrapper->pFd->pMethods->xSync(pWrapper->pFd, a);
+}
+static int vfsWrapFileSize(sqlite3_file *pFd, sqlite3_int64 *a){
+  VfsWrapperFd *pWrapper = (VfsWrapperFd*)pFd;
+  return pWrapper->pFd->pMethods->xFileSize(pWrapper->pFd, a);
+}
+static int vfsWrapLock(sqlite3_file *pFd, int a){
+  VfsWrapperFd *pWrapper = (VfsWrapperFd*)pFd;
+  return pWrapper->pFd->pMethods->xLock(pWrapper->pFd, a);
+}
+static int vfsWrapUnlock(sqlite3_file *pFd, int a){
+  VfsWrapperFd *pWrapper = (VfsWrapperFd*)pFd;
+  return pWrapper->pFd->pMethods->xUnlock(pWrapper->pFd, a);
+}
+static int vfsWrapCheckReservedLock(sqlite3_file *pFd, int *a){
+  VfsWrapperFd *pWrapper = (VfsWrapperFd*)pFd;
+  return pWrapper->pFd->pMethods->xCheckReservedLock(pWrapper->pFd, a);
+}
+static int vfsWrapFileControl(sqlite3_file *pFd, int a, void *b){
+  VfsWrapperFd *pWrapper = (VfsWrapperFd*)pFd;
+  return pWrapper->pFd->pMethods->xFileControl(pWrapper->pFd, a, b);
+}
+static int vfsWrapSectorSize(sqlite3_file *pFd){
+  VfsWrapperFd *pWrapper = (VfsWrapperFd*)pFd;
+  return pWrapper->pFd->pMethods->xSectorSize(pWrapper->pFd);
+}
+static int vfsWrapDeviceCharacteristics(sqlite3_file *pFd){
+  VfsWrapperFd *pWrapper = (VfsWrapperFd*)pFd;
+  return pWrapper->pFd->pMethods->xDeviceCharacteristics(pWrapper->pFd);
+}
+static int vfsWrapShmMap(
+  sqlite3_file *pFd, 
+  int a, int b, int c, 
+  void volatile **d
+){
+  VfsWrapperFd *pWrapper = (VfsWrapperFd*)pFd;
+  return pWrapper->pFd->pMethods->xShmMap(pWrapper->pFd, a, b, c, d);
+}
+static int vfsWrapShmLock(sqlite3_file *pFd, int offset, int n, int flags){
+  VfsWrapperFd *pWrapper = (VfsWrapperFd*)pFd;
+  Config *pConfig = pWrapper->pConfig;
+  int bMutex = 0;
+  int rc;
+
+  if(  (offset==0 && n==1)
+    && (flags & SQLITE_SHM_LOCK) && (flags & SQLITE_SHM_EXCLUSIVE)
+  ){
+    pthread_mutex_lock(&pConfig->mutex);
+    pWrapper->bWriter = 1;
+    bMutex = 1;
+    if( pWrapper->iTid ){
+      sqlite3_int64 t = vfslog_time();
+      pConfig->aCtx[pWrapper->iTid-1].aTime[THREAD_TIME_WRITER] -= t;
+    }
+  }
+
+  rc = pWrapper->pFd->pMethods->xShmLock(pWrapper->pFd, offset, n, flags);
+
+  if( (rc!=SQLITE_OK && bMutex)
+   || (offset==0 && (flags & SQLITE_SHM_UNLOCK) && pWrapper->bWriter)
+  ){
+    assert( pWrapper->bWriter );
+    pthread_mutex_unlock(&pConfig->mutex);
+    pWrapper->bWriter = 0;
+    if( pWrapper->iTid ){
+      sqlite3_int64 t = vfslog_time();
+      pConfig->aCtx[pWrapper->iTid-1].aTime[THREAD_TIME_WRITER] += t;
+    }
+  }
+
+  return rc;
+}
+static void vfsWrapShmBarrier(sqlite3_file *pFd){
+  VfsWrapperFd *pWrapper = (VfsWrapperFd*)pFd;
+  return pWrapper->pFd->pMethods->xShmBarrier(pWrapper->pFd);
+}
+static int vfsWrapShmUnmap(sqlite3_file *pFd, int a){
+  VfsWrapperFd *pWrapper = (VfsWrapperFd*)pFd;
+  return pWrapper->pFd->pMethods->xShmUnmap(pWrapper->pFd, a);
+}
+static int vfsWrapFetch(sqlite3_file *pFd, sqlite3_int64 a, int b, void **c){
+  VfsWrapperFd *pWrapper = (VfsWrapperFd*)pFd;
+  return pWrapper->pFd->pMethods->xFetch(pWrapper->pFd, a, b, c);
+}
+static int vfsWrapUnfetch(sqlite3_file *pFd, sqlite3_int64 a, void *b){
+  VfsWrapperFd *pWrapper = (VfsWrapperFd*)pFd;
+  return pWrapper->pFd->pMethods->xUnfetch(pWrapper->pFd, a, b);
+}
+
+static void create_vfs(Config *pConfig){
+  static sqlite3_vfs vfs = {
+    3, 0, 0, 0, "wrapper", 0,
+    vfsWrapOpen, vfsWrapDelete, vfsWrapAccess,
+    vfsWrapFullPathname, vfsWrapDlOpen, vfsWrapDlError,
+    vfsWrapDlSym, vfsWrapDlClose, vfsWrapRandomness,
+    vfsWrapSleep, vfsWrapCurrentTime, vfsWrapGetLastError,
+    vfsWrapCurrentTimeInt64, vfsWrapSetSystemCall, vfsWrapGetSystemCall,
+    vfsWrapNextSystemCall
+  };
+  sqlite3_vfs *pVfs;
+
+  pVfs = sqlite3_vfs_find(0);
+  vfs.mxPathname = pVfs->mxPathname;
+  vfs.szOsFile = pVfs->szOsFile + sizeof(VfsWrapperFd);
+  vfs.pAppData = (void*)pConfig;
+  pConfig->pVfs = pVfs;
+
+  sqlite3_vfs_register(&vfs, 1);
+}
+
+
+/*
+** Wal hook used by connections in thread_main().
+*/
+static int thread_wal_hook(
+  void *pArg,                     /* Pointer to ThreadCtx object */
+  sqlite3 *db,
+  const char *zDb, 
+  int nFrame
+){
+  ThreadCtx *pCtx = (ThreadCtx*)pArg;
+  Config *pConfig = pCtx->pConfig;
+
+  if( pConfig->nAutoCkpt && nFrame>=pConfig->nAutoCkpt ){
+    pCtx->aTime[THREAD_TIME_CKPT] -= vfslog_time();
+    pthread_mutex_lock(&pConfig->mutex);
+    if( pConfig->nCondWait>=0 ){
+      pConfig->nCondWait++;
+      if( pConfig->nCondWait==pConfig->nThread ){
+        execsql(pCtx->pErr, pCtx->pDb, "PRAGMA wal_checkpoint");
+        pthread_cond_broadcast(&pConfig->cond);
+      }else{
+        pthread_cond_wait(&pConfig->cond, &pConfig->mutex);
+      }
+      pConfig->nCondWait--;
+    }
+    pthread_mutex_unlock(&pConfig->mutex);
+    pCtx->aTime[THREAD_TIME_CKPT] += vfslog_time();
+  }
+
+  return SQLITE_OK;
+}
+
+
+static char *thread_main(int iTid, void *pArg){
+  Config *pConfig = (Config*)pArg;
+  Error err = {0};                /* Error code and message */
+  Sqlite db = {0};                /* SQLite database connection */
+  int nAttempt = 0;               /* Attempted transactions */
+  int nCommit = 0;                /* Successful transactions */
+  int j;
+  ThreadCtx *pCtx = &pConfig->aCtx[iTid-1];
+  char *zUri = 0;
+
+#ifdef USE_OSINST
+  char *zOsinstName = 0;
+  char *zLogName = 0;
+  if( pConfig->bOsinst ){
+    zOsinstName = sqlite3_mprintf("osinst%d", iTid);
+    zLogName = sqlite3_mprintf("bc_test1.log.%d.%d", (int)getpid(), iTid);
+    zUri = sqlite3_mprintf(
+        "file:%s?vfs=%s&tid=%d", pConfig->zFile, zOsinstName, iTid
+    );
+    sqlite3_vfslog_new(zOsinstName, 0, zLogName);
+    opendb(&err, &db, zUri, 0);
+  }else
+#endif
+  {
+    zUri = sqlite3_mprintf("file:%s?tid=%d", pConfig->zFile, iTid);
+    opendb(&err, &db, zUri, 0);
+  }
+
+  sqlite3_busy_handler(db.db, 0, 0);
+  sql_script_printf(&err, &db, 
+      "PRAGMA wal_autocheckpoint = 0;"
+      "PRAGMA synchronous = 0;"
+      "PRAGMA mmap_size = %lld;",
+      (i64)(pConfig->nMmap) * 1024 * 1024
+  );
+
+  pCtx->pConfig = pConfig;
+  pCtx->pErr = &err;
+  pCtx->pDb = &db;
+  sqlite3_wal_hook(db.db, thread_wal_hook, (void*)pCtx);
+
+  while( !timetostop(&err) ){
+    execsql(&err, &db, "BEGIN CONCURRENT");
+
+    pCtx->aTime[THREAD_TIME_INSERT] -= vfslog_time();
+    for(j=0; j<pConfig->nIPT; j++){
+      execsql(&err, &db, 
+          "INSERT INTO t1 VALUES"
+          "(randomblob(10), randomblob(20), randomblob(30), randomblob(200))"
+      );
+    }
+    pCtx->aTime[THREAD_TIME_INSERT] += vfslog_time();
+
+    pCtx->aTime[THREAD_TIME_COMMIT] -= vfslog_time();
+    execsql(&err, &db, "COMMIT");
+    pCtx->aTime[THREAD_TIME_COMMIT] += vfslog_time();
+
+    pCtx->aTime[THREAD_TIME_ROLLBACK] -= vfslog_time();
+    nAttempt++;
+    if( err.rc==SQLITE_OK ){
+      nCommit++;
+    }else{
+      clear_error(&err, SQLITE_BUSY);
+      execsql(&err, &db, "ROLLBACK");
+    }
+    pCtx->aTime[THREAD_TIME_ROLLBACK] += vfslog_time();
+
+    if( pConfig->bClearCache ){
+      sqlite3_db_release_memory(db.db);
+    }
+  }
+
+  closedb(&err, &db);
+
+#ifdef USE_OSINST
+  if( pConfig->bOsinst ){
+    sqlite3_vfslog_finalize(zOsinstName);
+    sqlite3_free(zOsinstName);
+    sqlite3_free(zLogName);
+  }
+#endif
+  sqlite3_free(zUri);
+
+  pthread_mutex_lock(&pConfig->mutex);
+  pConfig->nCondWait = -1;
+  pthread_cond_broadcast(&pConfig->cond);
+  pthread_mutex_unlock(&pConfig->mutex);
+
+  return sqlite3_mprintf("commits: %d/%d insert: %dms"
+      " commit: %dms"
+      " rollback: %dms" 
+      " writer: %dms"
+      " checkpoint: %dms", 
+      nCommit, nAttempt, 
+      (int)(pCtx->aTime[THREAD_TIME_INSERT]/1000), 
+      (int)(pCtx->aTime[THREAD_TIME_COMMIT]/1000), 
+      (int)(pCtx->aTime[THREAD_TIME_ROLLBACK]/1000),
+      (int)(pCtx->aTime[THREAD_TIME_WRITER]/1000),
+      (int)(pCtx->aTime[THREAD_TIME_CKPT]/1000)
+  );
+}
+
+int main(int argc, const char **argv){
+  Error err = {0};                /* Error code and message */
+  Sqlite db = {0};                /* SQLite database connection */
+  Threadset threads = {0};        /* Test threads */
+  Config conf = {5, 3, 5};
+  int i;
+
+  CmdlineArg apArg[] = {
+    { "-seconds", CMDLINE_INT,  offsetof(Config, nSecond) },
+    { "-inserts", CMDLINE_INT,  offsetof(Config, nIPT) },
+    { "-threads", CMDLINE_INT,  offsetof(Config, nThread) },
+    { "-mutex",   CMDLINE_BOOL, offsetof(Config, bMutex) },
+    { "-rm",      CMDLINE_BOOL, offsetof(Config, bRm) },
+    { "-autockpt",CMDLINE_INT,  offsetof(Config, nAutoCkpt) },
+    { "-mmap",    CMDLINE_INT,  offsetof(Config, nMmap) },
+    { "-clear-cache",    CMDLINE_BOOL,  offsetof(Config, bClearCache) },
+    { "-file",    CMDLINE_STRING,  offsetof(Config, zFile) },
+    { "-osinst",  CMDLINE_BOOL,  offsetof(Config, bOsinst) },
+    { 0, 0, 0 }
+  };
+
+  conf.nAutoCkpt = 1000;
+  cmdline_process(apArg, argc, argv, (void*)&conf);
+  if( err.rc==SQLITE_OK ){
+    char *z = cmdline_construct(apArg, (void*)&conf);
+    printf("With: %s\n", z);
+    sqlite3_free(z);
+  }
+  if( conf.zFile==0 ){
+    conf.zFile = "xyz.db";
+  }
+
+  /* Create the special VFS - "wrapper". And the mutex and condition 
+  ** variable. */
+  create_vfs(&conf);
+  pthread_mutex_init(&conf.mutex, 0);
+  pthread_cond_init(&conf.cond, 0);
+
+  conf.aCtx = sqlite3_malloc(sizeof(ThreadCtx) * conf.nThread);
+  memset(conf.aCtx, 0, sizeof(ThreadCtx) * conf.nThread);
+
+  /* Ensure the schema has been created */
+  opendb(&err, &db, conf.zFile, conf.bRm);
+  sql_script(&err, &db,
+      "PRAGMA journal_mode = wal;"
+      "CREATE TABLE IF NOT EXISTS t1(a PRIMARY KEY, b, c, d) WITHOUT ROWID;"
+      "CREATE INDEX IF NOT EXISTS t1b ON t1(b);"
+      "CREATE INDEX IF NOT EXISTS t1c ON t1(c);"
+  );
+
+  setstoptime(&err, conf.nSecond*1000);
+  if( conf.nThread==1 ){
+    char *z = thread_main(1, (void*)&conf);
+    printf("Thread 0 says: %s\n", (z==0 ? "..." : z));
+    fflush(stdout);
+  }else{
+    for(i=0; i<conf.nThread; i++){
+      launch_thread(&err, &threads, thread_main, (void*)&conf);
+    }
+    join_all_threads(&err, &threads);
+  }
+
+  if( err.rc==SQLITE_OK ){
+    printf("Database is %dK\n", (int)(filesize(&err, conf.zFile) / 1024));
+  }
+  if( err.rc==SQLITE_OK ){
+    char *zWal = sqlite3_mprintf("%s-wal", conf.zFile);
+    printf("Wal file is %dK\n", (int)(filesize(&err, zWal) / 1024));
+  }
+
+  closedb(&err, &db);
+  print_and_free_err(&err);
+  return 0;
+}

test/commitstatus.test

@@ -0,0 +1,297 @@
+# 2015 July 26
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+set ::testprefix commitstatus
+
+ifcapable !concurrent {
+  finish_test
+  return
+}
+
+proc commit_status_frames {db} {
+  list [sqlite3_commit_status $db main FIRSTFRAME] \
+       [sqlite3_commit_status $db main NFRAME]
+}
+
+proc commit_status_conflict {db} {
+  list [sqlite3_commit_status $db main CONFLICT_DB]    \
+       [sqlite3_commit_status $db main CONFLICT_FRAME] \
+       [sqlite3_commit_status $db main CONFLICT_PGNO]
+}
+
+
+do_execsql_test 1.0 {
+  PRAGMA journal_mode = wal;
+} {wal}
+
+do_execsql_test 1.1 {
+  CREATE TABLE t1(k INTEGER PRIMARY KEY, v);
+}
+
+do_test 1.2 { commit_status_frames db } {1 2}
+
+do_execsql_test 1.3 {
+  INSERT INTO t1 VALUES(2, 'two');
+}
+do_test 1.4 { commit_status_frames db } {3 1}
+
+do_execsql_test 1.5 {
+  CREATE INDEX i1 ON t1(v);
+}
+do_test 1.6 { commit_status_frames db } {4 2}
+
+do_execsql_test 1.7 {
+  DROP INDEX i1;
+}
+do_test 1.8 { commit_status_frames db } {6 2}
+
+do_execsql_test 1.9 {
+  PRAGMA wal_checkpoint;
+  INSERT INTO t1 VALUES(3, 'three');
+} {0 7 7}
+do_test 1.10 { commit_status_frames db } {1 1}
+
+do_execsql_test 1.11 {
+  PRAGMA journal_mode = delete;
+  PRAGMA journal_mode = wal2;
+  PRAGMA journal_size_limit = 10000;
+} {delete wal2 10000}
+
+for {set ii 1} {$ii < 30} {incr ii} {
+  do_execsql_test 1.13.$ii.1 {
+    INSERT INTO t1(v) VALUES('value');
+  }
+
+  if {$ii<=10} {
+    set expect [list $ii 1]
+  } elseif {$ii <= 20} {
+    set expect [list [expr {(1+($ii-1)%10)|0x80000000}] 1]
+  } else {
+    set expect [list [expr ($ii%10)] 1]
+  }
+
+  do_test 1.13.$ii.2 { commit_status_frames db } $expect
+
+  if {$ii==15} {
+    execsql { PRAGMA wal_checkpoint }
+  }
+}
+
+#-------------------------------------------------------------------------
+reset_db
+
+do_execsql_test 2.0 {
+  CREATE TABLE t1(a, b);
+  CREATE TABLE t2(a, b);
+  PRAGMA journal_mode = wal;
+} {wal}
+
+sqlite3 db2 test.db
+
+do_execsql_test -db db2 2.1 {
+  BEGIN CONCURRENT;
+    INSERT INTO t1 VALUES(1, 1);
+}
+
+do_execsql_test 2.2 {
+  INSERT INTO t2 VALUES(1, 1);
+  INSERT INTO t2 VALUES(2, 2);
+  INSERT INTO t2 VALUES(3, 3);
+  INSERT INTO t2 VALUES(4, 4);
+}
+
+do_execsql_test -db db2 2.3 {
+  COMMIT
+}
+do_test 2.4 { commit_status_frames db2 } {5 1}
+
+do_execsql_test 2.5 {
+  BEGIN CONCURRENT;
+    INSERT INTO t1 VALUES('yes', 'no');
+    INSERT INTO t2 VALUES('yes', 'no');
+  COMMIT;
+}
+do_test 2.6 { commit_status_frames db } {6 2}
+
+db2 close
+do_execsql_test 2.7 {
+  PRAGMA journal_mode = delete;
+  PRAGMA journal_mode = wal2;
+} {delete wal2}
+sqlite3 db2 test.db
+
+do_execsql_test 2.8 {
+  PRAGMA journal_size_limit = 5000;
+  BEGIN CONCURRENT;
+    INSERT INTO t1 VALUES('x', 'y');
+} {5000}
+
+do_execsql_test -db db2 2.9 {
+  PRAGMA journal_size_limit = 5000;
+  INSERT INTO t2 VALUES(1, 1);
+  INSERT INTO t2 VALUES(2, 2);
+  INSERT INTO t2 VALUES(3, 3);
+  INSERT INTO t2 VALUES(4, 4);
+  INSERT INTO t2 VALUES(5, 5);
+  INSERT INTO t2 VALUES(6, 6);
+  INSERT INTO t2 VALUES(7, 7);
+  INSERT INTO t2 VALUES(8, 8);
+} {5000}
+
+do_execsql_test 2.10 {
+  COMMIT;
+} 
+do_test 2.11 { commit_status_frames db } [list [expr {0x80000000 | 4}] 1]
+
+do_execsql_test 2.12 {
+  PRAGMA wal_checkpoint;
+  BEGIN CONCURRENT;
+    INSERT INTO t1 VALUES('a', 'b');
+} {0 9 5}
+
+do_execsql_test -db db2 2.13 {
+  INSERT INTO t2 VALUES(1, 1);
+  INSERT INTO t2 VALUES(2, 2);
+  INSERT INTO t2 VALUES(3, 3);
+  INSERT INTO t2 VALUES(4, 4);
+  INSERT INTO t2 VALUES(5, 5);
+  INSERT INTO t2 VALUES(6, 6);
+  INSERT INTO t2 VALUES(7, 7);
+  INSERT INTO t2 VALUES(8, 8);
+} {}
+
+do_execsql_test 2.14 {
+  COMMIT;
+} 
+do_test 2.15 { commit_status_frames db } [list 8 1]
+
+#-------------------------------------------------------------------------
+reset_db
+do_execsql_test 3.0 {
+  CREATE TABLE t1(x);
+  CREATE TABLE t2(y);
+  CREATE TABLE t3(z);
+  PRAGMA journal_mode = wal2;
+  PRAGMA journal_size_limit = 8000;
+} {wal2 8000}
+
+sqlite3 db2 test.db
+do_execsql_test -db db2 3.1 {
+  BEGIN CONCURRENT;
+    INSERT INTO t1 VALUES('x');
+}
+
+do_execsql_test 3.2.0 {
+  INSERT INTO t2 VALUES('y');  -- frame 1
+  INSERT INTO t3 VALUES('y');  -- frame 2
+  INSERT INTO t2 VALUES('z');  -- frame 3
+  INSERT INTO t3 VALUES('z');  -- frame 4
+  INSERT INTO t1 VALUES('a');  -- frame 5
+}
+do_test 3.2.1 { commit_status_frames db } {5 1}
+do_execsql_test 3.2.2 {
+  INSERT INTO t3 VALUES('a');  -- frame 6
+}
+
+do_test 3.3 {
+  catchsql { COMMIT } db2
+} {1 {database is locked}}
+execsql ROLLBACK db2
+do_test 3.4 {
+  commit_status_conflict db2 
+} {0 5 2}
+
+do_execsql_test -db db2 3.5 {
+  BEGIN CONCURRENT;
+    INSERT INTO t3 VALUES('x');
+}
+
+do_execsql_test 3.6.0 {
+  INSERT INTO t2 VALUES('y');  -- frame 7
+  INSERT INTO t1 VALUES('y');  -- frame 8
+  INSERT INTO t2 VALUES('z');  -- frame 1b
+  INSERT INTO t1 VALUES('z');  -- frame 2b
+  INSERT INTO t3 VALUES('a');  -- frame 3b
+}
+do_test 3.6.1 { commit_status_frames db } [list [expr {0x80000000 | 3}] 1]
+do_execsql_test 3.6.2 {
+  INSERT INTO t1 VALUES('a');  -- frame 4b
+}
+
+do_test 3.7 {
+  catchsql { COMMIT } db2
+} {1 {database is locked}}
+execsql ROLLBACK db2
+do_test 3.8 {
+  commit_status_conflict db2 
+} [list 0 [expr {0x80000000 | 3}] 4]
+
+#-------------------------------------------------------------------------
+reset_db
+do_execsql_test 4.0 {
+  CREATE TABLE t1(x);
+  CREATE TABLE t2(y);
+
+  PRAGMA journal_mode = wal2;
+  PRAGMA journal_size_limit = 10000000;
+} {wal2 10000000}
+
+sqlite3 db2 test.db
+db2 eval {SELECT * FROM sqlite_schema}
+
+foreach {tn s1 s2} {
+  1 100 100
+  2 1000 1000
+  3 1000 1000
+  4 1000 1000
+  5 1000 1000
+  6 1000 1000
+  7 1000 1000
+  8 1000 1000
+  9 1000 1000
+
+  10 2000 2000
+  11 2000 2000
+  12 2000 2000
+  13 2000 2000
+  14 2000 2000
+  15 2000 2000
+  16 2000 2000
+  17 2000 2000
+} {
+  execsql { 
+    BEGIN CONCURRENT;
+      INSERT INTO t1 VALUES(NULL);
+  } db2
+
+  for {set ii 0} {$ii<$s1} {incr ii} {
+    execsql { INSERT INTO t2 VALUES(randomblob(30)); }
+  }
+
+  execsql { INSERT INTO t1 VALUES(NULL) }
+  set frame [sqlite3_commit_status db main FIRSTFRAME]
+
+  for {set ii 0} {$ii<$s2} {incr ii} {
+    execsql { INSERT INTO t2 VALUES(randomblob(30)); }
+  }
+
+  do_test 4.$tn.1 { catchsql "COMMIT" db2 } {1 {database is locked}}
+  do_test 4.$tn.2 { 
+    commit_status_conflict db2
+  } [list 0 $frame 2]
+  execsql { ROLLBACK } db2
+}
+
+finish_test

test/concfault.test

@@ -0,0 +1,86 @@
+# 2015 Aug 25
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+# This file contains fault injection tests designed to test the concurrent
+# transactions feature.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/malloc_common.tcl
+set testprefix concfault
+
+# This test will not work with an in-memory journal, as the database will
+# become corrupt if an error is injected into a transaction after it starts
+# writing data out to the db file.
+ifcapable !concurrent {
+  finish_test
+  return
+}
+
+do_test 1-pre1 {
+  execsql {
+    PRAGMA journal_mode = wal;
+    CREATE TABLE t1(a PRIMARY KEY, b);
+    INSERT INTO t1 VALUES(randomblob(1000), randomblob(100));
+    INSERT INTO t1 SELECT randomblob(1000), randomblob(1000) FROM t1;
+    INSERT INTO t1 SELECT randomblob(1000), randomblob(1000) FROM t1;
+    INSERT INTO t1 SELECT randomblob(1000), randomblob(1000) FROM t1;
+    INSERT INTO t1 SELECT randomblob(1000), randomblob(1000) FROM t1;
+    DELETE FROM t1 WHERE rowid%2;
+  }
+  faultsim_save_and_close
+} {}
+
+do_faultsim_test 1.1 -prep {
+  faultsim_restore_and_reopen
+} -body {
+  execsql { 
+    BEGIN CONCURRENT;
+      INSERT INTO t1 VALUES(randomblob(1000), randomblob(100));
+    COMMIT;
+  }
+} -test {
+  faultsim_test_result {0 {}} 
+  catchsql { ROLLBACK }
+  faultsim_integrity_check
+}
+
+do_faultsim_test 1.2 -prep {
+  faultsim_restore_and_reopen
+} -body {
+  execsql { 
+    BEGIN CONCURRENT;
+      INSERT INTO t1 VALUES(randomblob(1000), randomblob(100));
+    ROLLBACK;
+  }
+} -test {
+  faultsim_test_result {0 {}} 
+  catchsql { ROLLBACK }
+  faultsim_integrity_check
+}
+
+do_faultsim_test 1.3 -prep {
+  faultsim_restore_and_reopen
+} -body {
+  execsql { 
+    BEGIN CONCURRENT;
+      DELETE FROM t1;
+    COMMIT;
+  }
+} -test {
+  faultsim_test_result {0 {}} 
+  catchsql { ROLLBACK }
+  faultsim_integrity_check
+}
+
+finish_test
+

test/concfault2.test

@@ -0,0 +1,69 @@
+# 2018 Dec 28
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+# This file contains fault injection tests designed to test the concurrent
+# transactions feature.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/malloc_common.tcl
+set testprefix concfault2
+
+ifcapable !concurrent {
+  finish_test
+  return
+}
+
+do_execsql_test 1.0 {
+  PRAGMA auto_vacuum = 0;
+  PRAGMA journal_mode = wal2;
+  CREATE TABLE t1(a PRIMARY KEY, b);
+  CREATE TABLE t2(a PRIMARY KEY, b);
+  INSERT INTO t1 VALUES(randomblob(1000), randomblob(100));
+  INSERT INTO t1 SELECT randomblob(1000), randomblob(1000) FROM t1;
+  INSERT INTO t1 SELECT randomblob(1000), randomblob(1000) FROM t1;
+  INSERT INTO t1 SELECT randomblob(1000), randomblob(1000) FROM t1;
+  INSERT INTO t1 SELECT randomblob(1000), randomblob(1000) FROM t1;
+  DELETE FROM t1 WHERE rowid%2;
+} {wal2}
+
+do_test 1.1 {
+  list [expr [file size test.db-wal]>75000] [file size test.db-shm]
+} {1 32768}
+
+faultsim_save_and_close
+
+do_faultsim_test 1 -prep {
+  faultsim_restore_and_reopen
+  execsql {
+    SELECT * FROM t1;
+    BEGIN CONCURRENT;
+      INSERT INTO t2 VALUES(1, 2);
+  }
+  sqlite3 db2 test.db
+  execsql {
+    PRAGMA journal_size_limit = 10000;
+    INSERT INTO t1 VALUES(randomblob(1000), randomblob(1000));
+  } db2
+  db2 close
+} -body {
+  execsql { COMMIT }
+} -test {
+  faultsim_test_result {0 {}} 
+  catchsql { ROLLBACK }
+  set res [catchsql { SELECT count(*) FROM t1 }]
+  if {$res!="0 9"} { error "expected {0 9} got {$res}" }
+  faultsim_integrity_check
+}
+
+finish_test
+

test/concurrent.test

@@ -0,0 +1,688 @@
+# 2015 July 26
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+set ::testprefix concurrent
+
+ifcapable !concurrent {
+  finish_test
+  return
+}
+
+do_execsql_test 1.0 {
+  PRAGMA journal_mode = wal;
+} {wal}
+
+do_execsql_test 1.1 {
+  CREATE TABLE t1(k INTEGER PRIMARY KEY, v);
+  BEGIN CONCURRENT;
+    INSERT INTO t1 VALUES(1, 'abcd');
+  COMMIT;
+}
+
+do_execsql_test 1.2 {
+  SELECT * FROM t1;
+} {1 abcd}
+
+do_execsql_test 1.3 {
+  BEGIN CONCURRENT;
+    INSERT INTO t1 VALUES(2, 'efgh');
+  ROLLBACK;
+}
+
+do_execsql_test 1.4 {
+  SELECT * FROM t1;
+} {1 abcd}
+
+
+#-------------------------------------------------------------------------
+# CONCURRENT transactions cannot do cache spills.
+#
+foreach {tn trans spill} {
+  1 {BEGIN CONCURRENT}  0
+  2 {BEGIN}           1
+} {
+  do_test 1.5.$tn {
+    sqlite3 db2 test.db
+    set walsz [file size test.db-wal]
+
+    execsql { PRAGMA cache_size = 10 } db2
+    execsql $trans db2
+    execsql {
+      WITH cnt(i) AS (SELECT 1 UNION ALL SELECT i+1 FROM cnt WHERE i<50)
+        INSERT INTO t1(v) SELECT randomblob(900) FROM cnt;
+    } db2
+
+    expr {[file size test.db-wal]==$walsz}
+  } [expr !$spill]
+
+  execsql ROLLBACK db2
+  db2 close
+}
+
+#-------------------------------------------------------------------------
+# CONCURRENT transactions man not be committed while there are active
+# readers.
+do_execsql_test 1.6.setup {
+  DROP TABLE t1;
+  CREATE TABLE t1(a, b);
+  INSERT INTO t1 VALUES(1, 2);
+  INSERT INTO t1 VALUES(3, 4);
+  INSERT INTO t1 VALUES(5, 6);
+}
+foreach {tn trans commit_ok} {
+  1 {BEGIN CONCURRENT}  0
+  2 {BEGIN}           1
+} {
+  do_test 1.6.$tn.1 {
+    set stmt [sqlite3_prepare db "SELECT * FROM t1" -1 dummy]
+    sqlite3_step $stmt
+  } SQLITE_ROW
+  do_test 1.6.$tn.2 {
+    execsql $trans
+    execsql { INSERT INTO t1 VALUES(7, 8) }
+  } {}
+
+  if { $commit_ok } {
+    do_test 1.6.$tn.3 { catchsql COMMIT } {0 {}}
+  } else {
+    do_test 1.6.$tn.4 { catchsql COMMIT } {/1 {cannot commit transaction .*}/}
+  }
+
+  sqlite3_finalize $stmt
+  catchsql ROLLBACK
+}
+
+#-------------------------------------------------------------------------
+# CONCURRENT transactions may not modify the db schema.
+#
+sqlite3 db2 test.db
+foreach {tn sql} {
+  1 { CREATE TABLE xx(a, b) }
+  2 { DROP TABLE t1 }
+  3 { CREATE INDEX i1 ON t1(a) }
+  4 { CREATE VIEW v1 AS SELECT * FROM t1 }
+} {
+  do_catchsql_test 1.7.0.$tn.1 "
+    BEGIN CONCURRENT;
+    $sql
+  " {0 {}}
+
+  db2 eval {INSERT INTO t1 DEFAULT VALUES}
+
+  do_catchsql_test 1.7.0.$tn.2 {
+    COMMIT
+  } {1 {database is locked}}
+
+  do_execsql_test 1.7.0.$tn.2 ROLLBACK
+
+  do_execsql_test 1.7.0.$tn.3 {
+    SELECT sql FROM sqlite_master;
+    SELECT sql FROM sqlite_temp_master;
+  } {{CREATE TABLE t1(a, b)}}
+
+  #do_execsql_test 1.7.0.$tn.3 COMMIT
+}
+
+# Except the temp db schema.
+foreach {tn sql} {
+  1 { CREATE TEMP TABLE xx(a, b) }
+  2 { DROP TABLE xx }
+  3 { CREATE TEMP TABLE yy(a, b) }
+  4 { CREATE VIEW temp.v1 AS SELECT * FROM t1 }
+  5 { CREATE INDEX yyi1 ON yy(a); }
+  6 { CREATE TABLE temp.zz(a, b) }
+} {
+  do_catchsql_test 1.7.1.$tn.1 "
+    BEGIN CONCURRENT;
+    $sql
+  " {0 {}}
+
+  do_execsql_test 1.7.1.$tn.2 COMMIT
+}
+
+
+do_execsql_test 1.7.1.x {
+  SELECT sql FROM sqlite_master;
+  SELECT sql FROM sqlite_temp_master;
+} {
+  {CREATE TABLE t1(a, b)}
+  {CREATE TABLE yy(a, b)} 
+  {CREATE VIEW v1 AS SELECT * FROM t1} 
+  {CREATE INDEX yyi1 ON yy(a)} 
+  {CREATE TABLE zz(a, b)}
+}
+db2 close
+
+#-------------------------------------------------------------------------
+# If an auto-vacuum database is written within an CONCURRENT transaction, it
+# is handled in the same way as for a non-CONCURRENT transaction.
+#
+reset_db
+do_execsql_test 1.8.1 {
+  PRAGMA auto_vacuum = 1;
+  PRAGMA journal_mode = wal;
+  CREATE TABLE t1(x, y);
+  INSERT INTO t1 VALUES('x', 'y');
+} {wal}
+
+do_execsql_test 1.8.2 {
+  BEGIN CONCURRENT;
+    SELECT * FROM t1;
+  COMMIT;
+} {x y}
+
+do_catchsql_test 1.8.3 {
+  BEGIN CONCURRENT;
+    INSERT INTO t1 VALUES('a', 'b');
+} {0 {}}
+
+do_test 1.8.4 {
+  sqlite3 db2 test.db
+  catchsql {
+    BEGIN CONCURRENT;
+      INSERT INTO t1 VALUES('c', 'd');
+  } db2
+} {1 {database is locked}}
+
+do_test 1.8.5 {
+  db eval COMMIT
+  db2 eval COMMIT
+} {}
+db close
+db2 close
+
+do_multiclient_test tn {
+
+  #-----------------------------------------------------------------------
+  # 1. Start an CONCURRENT transaction using [db1].
+  #
+  # 2. Start and then rollback a regular transaction using [db2]. This 
+  #    can be done as the ongoing [db1] transaction is CONCURRENT.
+  #
+  # 3. The [db1] transaction can now be committed, as [db2] has relinquished
+  #    the write lock.
+  #
+  do_test 2.$tn.1.1 {
+    sql1 { 
+      PRAGMA journal_mode = wal;
+      CREATE TABLE t1(k INTEGER PRIMARY KEY, v);
+      INSERT INTO t1 VALUES(1, 'one');
+    }
+    sql1 { 
+      BEGIN CONCURRENT;
+        INSERT INTO t1 VALUES(2, 'two');
+    }
+    code1 { sqlite3_get_autocommit db }
+  } 0
+
+  do_test 2.$tn.1.2 {
+    sql2 {
+      BEGIN;
+        INSERT INTO t1 VALUES(3, 'three');
+      ROLLBACK;
+    }
+  } {}
+
+  do_test 2.$tn.1.3 {
+    sql1 COMMIT
+    sql2 { SELECT * FROM t1 }
+  } {1 one 2 two}
+  
+  #-----------------------------------------------------------------------
+  # 1. Start an CONCURRENT transaction using [db1].
+  #
+  # 2. Commit a transaction using [db2].
+  #
+  # 3. Try to commit with [db1]. Check that SQLITE_BUSY_SNAPSHOT is returned,
+  #    and the transaction is not rolled back.
+  #
+  do_test 2.$tn.2.1 {
+    sql1 {
+      BEGIN CONCURRENT;
+        INSERT INTO t1 VALUES(-1, 'hello world');
+    }
+  } {}
+
+  do_test 2.$tn.2.2 {
+    sql2 {
+      INSERT INTO t1 VALUES(3, 'three');
+    }
+  } {}
+
+  do_test 2.$tn.2.3.1 {
+    set rc [catch { sql1 COMMIT } msg]
+    list $rc $msg
+  } {1 {database is locked}}
+
+  do_test 2.$tn.2.3.2 {
+    code1 { list [sqlite3_extended_errcode db] [sqlite3_get_autocommit db] }
+  } {SQLITE_BUSY_SNAPSHOT 0}
+
+  do_test 2.$tn.2.3.3 {
+    sql1 {
+      SELECT * FROM t1;
+      ROLLBACK;
+    }
+  } {-1 {hello world} 1 one 2 two}
+  
+  #-----------------------------------------------------------------------
+  # 1. Start an CONCURRENT transaction using [db1].
+  #
+  # 2. Open a transaction using [db2].
+  #
+  # 3. Try to commit with [db1]. Check that SQLITE_BUSY is returned,
+  #    and the transaction is not rolled back.
+  #
+  # 4. Have [db2] roll its transaction back. Then check that [db1] can
+  #    commit.
+  #
+  do_test 2.$tn.3.1 {
+    sql1 {
+      BEGIN CONCURRENT;
+        INSERT INTO t1 VALUES(4, 'four');
+    }
+  } {}
+
+  do_test 2.$tn.3.2 {
+    sql2 {
+      BEGIN;
+        INSERT INTO t1 VALUES(-1, 'xyz');
+    }
+  } {}
+
+  do_test 2.$tn.3.3.1 {
+    set rc [catch { sql1 COMMIT } msg]
+    list $rc $msg
+  } {1 {database is locked}}
+
+  do_test 2.$tn.3.3.2 {
+    code1 { list [sqlite3_extended_errcode db] [sqlite3_get_autocommit db] }
+  } {SQLITE_BUSY 0}
+
+  do_test 2.$tn.3.3.3 {
+    sql1 { SELECT * FROM t1; }
+  } {1 one 2 two 3 three 4 four}
+
+  do_test 2.$tn.3.4 {
+    sql2 ROLLBACK
+    sql1 COMMIT
+    sql1 { SELECT * FROM t1; }
+  } {1 one 2 two 3 three 4 four}
+
+  #-----------------------------------------------------------------------
+  # 1. Create a second table - t2.
+  #
+  # 2. Write to t1 with [db] and t2 with [db2].
+  #
+  # 3. See if it worked.
+  #
+  do_test 2.$tn.4.1 {
+    sql1 { CREATE TABLE t2(a, b) }
+  } {}
+  do_test 2.$tn.4.2 {
+    sql2 {
+      BEGIN CONCURRENT;
+        INSERT INTO t2 VALUES('i', 'n');
+    }
+
+    sql1 {
+      BEGIN CONCURRENT;
+        INSERT INTO t1 VALUES(5, 'five');
+      COMMIT;
+    }
+
+    sql2 COMMIT
+  } {}
+
+  do_test 2.$tn.4.3.1 {
+    sql2 {SELECT * FROM t1}
+  } {1 one 2 two 3 three 4 four 5 five}
+  do_test 2.$tn.4.3.2 {
+    sql1 {SELECT * FROM t1}
+  } {1 one 2 two 3 three 4 four 5 five}
+
+  do_test 2.$tn.4.3.3 { sql2 {SELECT * FROM t2} } {i n}
+  do_test 2.$tn.4.3.4 { sql1 {SELECT * FROM t2} } {i n}
+
+  #-----------------------------------------------------------------------
+  # The "schema cookie" issue.
+  #
+  # 1. Begin and CONCURRENT write to "t1" using [db]
+  #
+  # 2. Create an index on t1 using [db2].
+  #
+  # 3. Attempt to commit the CONCURRENT write. This is an SQLITE_BUSY_SNAPSHOT,
+  #    even though there is no page collision.
+  #
+  do_test 2.$tn.5.1 {
+    sql1 {
+      BEGIN CONCURRENT;
+        INSERT INTO t1 VALUES(6, 'six');
+    }
+  } {}
+
+  do_test 2.$tn.5.2 {
+    sql2 { CREATE INDEX i1 ON t1(v); }
+  } {}
+
+  do_test 2.$tn.5.3 {
+    list [catch { sql1 { COMMIT } } msg] $msg [sqlite3_errcode db]
+  } {1 {database is locked} SQLITE_BUSY_SNAPSHOT}
+
+  do_test 2.$tn.5.4 {
+    sql2 { PRAGMA integrity_check }
+  } {ok}
+  catch { sql1 ROLLBACK }
+
+  #-----------------------------------------------------------------------
+  #
+  # 1. Begin an CONCURRENT write to "t1" using [db]
+  #
+  # 2. Lots of inserts into t2. Enough to grow the db file and modify page 1.
+  #
+  # 3. Check that the CONCURRENT transaction can not be committed.
+  #
+  do_test 2.$tn.6.1 {
+    sql1 {
+      BEGIN CONCURRENT;
+        INSERT INTO t1 VALUES(6, 'six');
+    }
+  } {}
+
+  do_test 2.$tn.6.2 {
+    sql2 { 
+      WITH src(a,b) AS (
+        VALUES(1,1) UNION ALL SELECT a+1,b+1 FROM src WHERE a<10000
+      ) INSERT INTO t2 SELECT * FROM src;
+    }
+  } {}
+
+  do_test 2.$tn.6.3 {
+    sql1 { SELECT count(*) FROM t2 }
+    list [catch { sql1 { COMMIT } } msg] $msg [sqlite3_errcode db]
+  } {1 {database is locked} SQLITE_BUSY_SNAPSHOT}
+  sql1 ROLLBACK
+
+  do_test 2.$tn.6.4 {
+    sql1 {
+      SELECT count(*) FROM t1;
+      SELECT count(*) FROM t2;
+    }
+  } {5 10001}
+
+  #-----------------------------------------------------------------------
+  # 
+  # 1. Begin an big CONCURRENT write to "t1" using [db] - large enough to
+  #    grow the db file.
+  #
+  # 2. Lots of inserts into t2. Also enough to grow the db file.
+  #
+  # 3. Check that the CONCURRENT transaction cannot be committed (due to a clash
+  #    on page 1 - the db size field).
+  #
+  do_test 2.$tn.7.1 {
+    sql1 {
+      BEGIN CONCURRENT;
+        WITH src(a,b) AS (
+          VALUES(10000,10000) UNION ALL SELECT a+1,b+1 FROM src WHERE a<20000
+        ) INSERT INTO t1 SELECT * FROM src;
+    }
+  } {}
+
+  do_test 2.$tn.7.2 {
+    sql2 { 
+      WITH src(a,b) AS (
+        VALUES(1,1) UNION ALL SELECT a+1,b+1 FROM src WHERE a<10000
+      ) INSERT INTO t2 SELECT * FROM src;
+    }
+  } {}
+
+  do_test 2.$tn.7.3 {
+    list [catch { sql1 { COMMIT } } msg] $msg [sqlite3_errcode db]
+  } {0 {} SQLITE_OK}
+
+  do_test 2.$tn.7.4 { sql3 { PRAGMA integrity_check } } ok
+}
+
+#-------------------------------------------------------------------------
+# Concurrent transactions may not modify the user_version or application_id.
+#
+reset_db
+do_execsql_test 3.0 {
+  PRAGMA journal_mode = wal;
+  CREATE TABLE t1(x, y);
+  INSERT INTO t1 VALUES('a', 'b');
+  PRAGMA user_version = 10;
+} {wal}
+do_execsql_test 3.1 {
+  BEGIN CONCURRENT;
+    INSERT INTO t1 VALUES('c', 'd');
+    SELECT * FROM t1;
+} {a b c d}
+do_catchsql_test 3.2 {
+  PRAGMA user_version = 11;
+} {1 {cannot modify user_version within CONCURRENT transaction}}
+do_execsql_test 3.3 {
+  PRAGMA user_version;
+  SELECT * FROM t1;
+} {10 a b c d}
+do_catchsql_test 3.4 {
+  PRAGMA application_id = 11;
+} {1 {cannot modify application_id within CONCURRENT transaction}}
+do_execsql_test 3.5 {
+  COMMIT;
+  PRAGMA user_version;
+  PRAGMA application_id;
+  SELECT * FROM t1;
+} {10 0 a b c d}
+
+#-------------------------------------------------------------------------
+# However, another transaction modifying the user_version or application_id
+# should not cause a conflict. And committing a concurrent transaction does not
+# clobber the modification - even if the concurrent transaction allocates or
+# frees database pages.
+#
+do_multiclient_test tn {
+  do_test 4.$tn.1 {
+    sql1 {
+      PRAGMA journal_mode = wal;
+      CREATE TABLE ttt(y UNIQUE, z UNIQUE);
+      PRAGMA user_version = 14;
+      BEGIN CONCURRENT;
+        INSERT INTO ttt VALUES('y', 'z');
+    }
+  } {wal}
+  do_test 4.$tn.2 {
+    sql2 { PRAGMA user_version = 16 }
+    sql1 COMMIT
+    sql1 { PRAGMA user_version }
+  } {16}
+
+  do_test 4.$tn.3 {
+    sql1 {
+      BEGIN CONCURRENT;
+        INSERT INTO ttt VALUES(randomblob(10000), randomblob(4));
+        PRAGMA user_version;
+    }
+  } {16}
+  do_test 4.$tn.4 {
+    sql2 { PRAGMA user_version = 1234 }
+    sql1 {
+        PRAGMA user_version;
+      COMMIT;
+      PRAGMA user_version;
+      PRAGMA integrity_check;
+    }
+  } {16 1234 ok}
+
+  do_test 4.$tn.5 {
+    sql1 {
+      BEGIN CONCURRENT;
+        DELETE FROM ttt;
+        PRAGMA user_version;
+    }
+  } {1234}
+  do_test 4.$tn.4 {
+    sql2 { PRAGMA user_version = 5678 }
+    sql1 {
+        PRAGMA user_version;
+      COMMIT;
+      PRAGMA user_version;
+      PRAGMA integrity_check;
+    }
+  } {1234 5678 ok}
+}
+
+do_multiclient_test tn {
+  do_test 5.$tn.1 {
+    sql1 {
+      PRAGMA journal_mode = wal;
+      CREATE TABLE tt(a INTEGER PRIMARY KEY, b);
+      CREATE TABLE t2(a INTEGER PRIMARY KEY, b);
+      INSERT INTO tt VALUES(1, randomblob(400));
+      BEGIN CONCURRENT;
+    }
+  } {wal}
+
+  do_test 5.$tn.2 {
+    sql1 { UPDATE t2 SET b=5 WHERE a=3 }
+    sql2 { INSERT INTO tt VALUES(2, randomblob(6000)) }
+  } {}
+
+  do_test 5.$tn.3 {
+    sql1 { COMMIT }
+  } {}
+}
+
+do_multiclient_test tn {
+  do_test 6.$tn.1 {
+    sql1 {
+      PRAGMA journal_mode = wal;
+      CREATE TABLE t1(a INTEGER PRIMARY KEY, b);
+      CREATE TABLE t2(a INTEGER PRIMARY KEY, b);
+      INSERT INTO t1 VALUES(1, 'one');
+      INSERT INTO t2 VALUES(2, 'two');
+    }
+  } {wal}
+
+  do_test 6.$tn.2 {
+    sql2 {
+      BEGIN CONCURRENT;
+        SELECT * FROM t2;
+        INSERT INTO t1 VALUES(3, 'three');
+    }
+  } {2 two}
+
+  do_test 6.$tn.3 {
+    sql1 {
+      INSERT INTO t2 VALUES(3, 'three');
+    }
+  } {}
+
+  do_test 6.$tn.2 {
+    list [catch { sql2 { COMMIT } } msg] $msg
+  } {1 {database is locked}}
+}
+
+do_multiclient_test tn {
+  do_test 7.$tn.1 {
+    sql1 {
+      PRAGMA journal_mode = wal;
+      CREATE TABLE t1(a INTEGER PRIMARY KEY, b);
+      WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<100) 
+      INSERT INTO t1 SELECT NULL, randomblob(400) FROM s;
+
+      CREATE TABLE t2(a INTEGER PRIMARY KEY, b);
+      WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<50000) 
+      INSERT INTO t2 SELECT NULL, randomblob(400) FROM s;
+
+      CREATE TABLE t3(a INTEGER PRIMARY KEY, b);
+      WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<100) 
+      INSERT INTO t3 SELECT NULL, randomblob(400) FROM s;
+
+      CREATE TABLE t4(a INTEGER PRIMARY KEY, b);
+
+    }
+    set {} {}
+  } {}
+
+  do_test 7.$tn.2 {
+    sql2 {
+      BEGIN CONCURRENT;
+        SELECT * FROM t1;
+        INSERT INTO t4 VALUES(1, 2);
+    }
+    set {} {}
+  } {}
+
+  do_test 7.$tn.3 {
+    sql3 {
+      BEGIN CONCURRENT;
+        SELECT * FROM t3;
+        INSERT INTO t4 VALUES(1, 2);
+    }
+    set {} {}
+  } {}
+
+  do_test 7.$tn.4 {
+    sql1 {
+      UPDATE t1 SET b=randomblob(400);
+      UPDATE t2 SET b=randomblob(400);
+      UPDATE t3 SET b=randomblob(400);
+    }
+  } {}
+
+  do_test 7.$tn.5 {
+    csql2 { COMMIT } 
+  } {1 {database is locked}}
+
+  do_test 7.$tn.6 {
+    csql3 { COMMIT } 
+  } {1 {database is locked}}
+
+
+  csql2 ROLLBACK
+  csql3 ROLLBACK
+
+  # The following test works with $tn==1 (sql2 and sql3 use separate 
+  # processes), but is quite slow. So only run it with $tn==2 (all
+  # connections in the same process).
+  #
+  if {$tn==2} {
+    do_test 7.$tn.7 {
+      for {set i 1} {$i < 10000} {incr i} {
+        sql3 { 
+          PRAGMA wal_checkpoint;
+          BEGIN CONCURRENT;
+          SELECT * FROM t3;
+          INSERT INTO t4 VALUES(1, 2);
+        }
+
+        sql1 {
+          UPDATE t2 SET b = randomblob(400) WHERE rowid <= $i;
+          UPDATE t3 SET b = randomblob(400) WHERE rowid = 1;
+        }
+
+        if {[csql3 COMMIT]!={1 {database is locked}}} {
+          error "Failed at i=$i"
+        }
+        csql3 ROLLBACK
+      }
+    } {}
+  }
+
+}
+
+finish_test

test/concurrent2.test

@@ -0,0 +1,630 @@
+# 2015 July 26
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+# Miscellaneous tests for transactions started with BEGIN CONCURRENT. 
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+source $testdir/wal_common.tcl
+set ::testprefix concurrent2
+
+ifcapable !concurrent {
+  finish_test
+  return
+}
+
+do_test 0.1 {
+  llength [sqlite3_wal_info db main]
+} {2}
+
+do_multiclient_test tn {
+
+  do_test 1.$tn.1 {
+    sql1 {
+      PRAGMA journal_mode = wal;
+      CREATE TABLE t1(x);
+      CREATE TABLE t2(y);
+    }
+  } {wal}
+  do_test 1.$tn.5 { sql3 { PRAGMA integrity_check } } {ok}
+
+  # Test that an CONCURRENT transaction that allocates/frees no pages does
+  # not conflict with a transaction that does allocate pages.
+  do_test 1.$tn.2  {
+    sql1 { 
+      BEGIN CONCURRENT;
+        INSERT INTO t1 VALUES(4);
+    }
+    sql2 {
+      INSERT INTO t2 VALUES(randomblob(1500));
+    }
+    sql1 {
+      COMMIT;
+    }
+  } {}
+  do_test 1.$tn.5 { sql3 { PRAGMA integrity_check } } {ok}
+  
+  # But that an CONCURRENT transaction does conflict with a transaction
+  # that modifies the db schema.
+  do_test 1.$tn.3  {
+    sql1 {
+      BEGIN CONCURRENT;
+        INSERT INTO t1 VALUES(5);
+    }
+    sql2 {
+      CREATE TABLE t3(z);
+    }
+    list [catch { sql1 COMMIT } msg] $msg
+  } {1 {database is locked}}
+  do_test 1.$tn.5 { sql3 { PRAGMA integrity_check } } {ok}
+  
+  # Test that an CONCURRENT transaction that allocates at least one page 
+  # does not conflict with a transaction that allocates no pages.
+  do_test 1.$tn.4  {
+    sql1 { 
+      ROLLBACK;
+      BEGIN CONCURRENT;
+        INSERT INTO t1 VALUES(randomblob(1500));
+    }
+    sql2 {
+      INSERT INTO t2 VALUES(8);
+    }
+    sql1 {
+      COMMIT;
+    }
+  } {}
+
+  do_test 1.$tn.5 { sql3 { PRAGMA integrity_check } } {ok}
+}
+
+do_multiclient_test tn {
+  do_test 2.$tn.1 {
+    sql1 {
+      PRAGMA journal_mode = wal;
+      CREATE TABLE t1(x UNIQUE);
+      CREATE TABLE t2(y UNIQUE);
+    }
+  } {wal}
+
+  do_test 2.$tn.2  {
+    sql1 { 
+      BEGIN CONCURRENT;
+        INSERT INTO t1 VALUES(randomblob(1500));
+    }
+    sql2 {
+      INSERT INTO t2 VALUES(randomblob(1500));
+    }
+    sql1 COMMIT
+  } {}
+
+  do_test 2.$tn.3 { sql3 { PRAGMA integrity_check } } {ok}
+
+  do_test 2.$tn.4  {
+    sql1 { 
+      BEGIN CONCURRENT;
+        DELETE FROM t1;
+    }
+    sql2 {
+      DELETE FROM t2;
+    }
+    sql1 COMMIT
+  } {}
+
+  do_test 2.$tn.5 { sql3 { PRAGMA integrity_check } } {ok}
+
+  do_test 2.$tn.6 {
+    sql1 {
+      INSERT INTO t1 VALUES(randomblob(1500));
+      INSERT INTO t1 VALUES(randomblob(1500));
+      INSERT INTO t2 VALUES(randomblob(1500));
+      DELETE FROM t1 WHERE rowid=1;
+    }
+
+    sql1 {
+      BEGIN CONCURRENT;
+        DELETE FROM t1 WHERE rowid=2;
+    }
+
+    sql2 {
+      DELETE FROM t2;
+    }
+
+    sql1 COMMIT
+  } {}
+
+  do_test 2.$tn.7 { sql3 { PRAGMA integrity_check } } {ok}
+}
+
+#-------------------------------------------------------------------------
+# When an CONCURRENT transaction is opened on a database, the nFree and 
+# iTrunk header fields of the cached version of page 1 are both set 
+# to 0. This allows an CONCURRENT transaction to use its own private 
+# free-page-list, which is merged with the main database free-list when
+# the transaction is committed.
+#
+# The following tests check that nFree/iTrunk are correctly restored if
+# an CONCURRENT transaction is rolled back, and that savepoint rollbacks
+# that occur within CONCURRENT transactions do not incorrectly restore
+# these fields to their on-disk values.
+#
+reset_db
+do_execsql_test 3.0 {
+  PRAGMA journal_mode = wal;
+  CREATE TABLE t1(x, y);
+  INSERT INTO t1 VALUES(randomblob(1500), randomblob(1500));
+  DELETE FROM t1;
+} {wal}
+
+do_execsql_test 3.1 {
+  BEGIN CONCURRENT;
+    INSERT INTO t1 VALUES(1, 2);
+  ROLLBACK;
+}
+
+do_execsql_test 3.2 { PRAGMA integrity_check } {ok}
+do_execsql_test 3.3 { PRAGMA freelist_count } {2}
+
+do_execsql_test 3.4.1 {
+  BEGIN CONCURRENT;
+    PRAGMA freelist_count;
+} {2}
+do_execsql_test 3.4.2 {
+  SAVEPOINT xyz;
+    INSERT INTO t1 VALUES(randomblob(1500), NULL);
+    PRAGMA freelist_count;
+} {0}
+do_execsql_test 3.4.3 {
+  ROLLBACK TO xyz;
+} {}
+do_execsql_test 3.4.4 { PRAGMA freelist_count } {0}
+do_execsql_test 3.4.5 { COMMIT; PRAGMA freelist_count } {2}
+do_execsql_test 3.4.6 { PRAGMA integrity_check } {ok}
+
+do_execsql_test 3.5.1 {
+  BEGIN CONCURRENT;
+    UPDATE t1 SET x=randomblob(10) WHERE y=555;
+    PRAGMA freelist_count;
+} {0}
+do_execsql_test 3.5.2 {
+  ROLLBACK;
+  PRAGMA freelist_count;
+} {2}
+do_execsql_test 3.5.3 { PRAGMA integrity_check } {ok}
+
+#-------------------------------------------------------------------------
+# Test that nothing goes wrong if an CONCURRENT transaction allocates a
+# page at the end of the file, frees it within the same transaction, and
+# then has to move the same page to avoid a conflict on COMMIT.
+#
+do_multiclient_test tn {
+  do_test 4.$tn.1 {
+    sql1 {
+      PRAGMA journal_mode = wal;
+      CREATE TABLE t1(x);
+      CREATE TABLE t2(x);
+    }
+  } {wal}
+
+  do_test 4.$tn.2 {
+    sql1 {
+      BEGIN CONCURRENT;
+        INSERT INTO t1 VALUES(randomblob(1500));
+        INSERT INTO t1 VALUES(randomblob(1500));
+        DELETE FROM t1 WHERE rowid = 1;
+    }
+
+    sql2 {
+      INSERT INTO t2 VALUES(randomblob(1500));
+      INSERT INTO t2 VALUES(randomblob(1500));
+      INSERT INTO t2 VALUES(randomblob(1500));
+      INSERT INTO t2 VALUES(randomblob(1500));
+      DELETE FROM t2 WHERE rowid IN (1, 2);
+    }
+
+    sql1 COMMIT
+  } {}
+}
+
+#-------------------------------------------------------------------------
+#
+do_multiclient_test tn {
+  do_test 5.$tn.1 {
+    sql1 {
+      PRAGMA journal_mode = wal;
+      CREATE TABLE t1(x);
+      CREATE TABLE t2(x);
+      INSERT INTO t1 VALUES(randomblob(1500));
+      PRAGMA page_count;
+    }
+  } {wal 4}
+
+  do_test 5.$tn.2 {
+    sql1 {
+      BEGIN CONCURRENT;
+        INSERT INTO t2 VALUES(randomblob(1500));
+        PRAGMA page_count;
+    }
+  } {5}
+
+  do_test 5.$tn.3 {
+    sql2 { 
+      DELETE FROM t1;
+      PRAGMA freelist_count;
+      PRAGMA page_count;
+    }
+  } {1 4}
+
+  do_test 5.$tn.4 { sql1 COMMIT } {}
+  do_test 5.$tn.5 { sql3 { PRAGMA integrity_check } } {ok}
+}
+
+#-------------------------------------------------------------------------
+#
+do_multiclient_test tn {
+  do_test 6.$tn.1 {
+    sql1 {
+      PRAGMA journal_mode = wal;
+      CREATE TABLE t1(x);
+      INSERT INTO t1 VALUES(randomblob(1500));
+      PRAGMA wal_checkpoint;
+    }
+  } {wal 0 5 5}
+
+  do_test 6.$tn.2 {
+    sql1 { 
+      BEGIN CONCURRENT;
+        INSERT INTO t1 VALUES(randomblob(1500));
+        INSERT INTO t1 VALUES(randomblob(1500));
+    }
+  } {}
+
+  do_test 6.$tn.3 {
+    sql2 {
+      BEGIN;
+        INSERT INTO t1 VALUES(randomblob(1500));
+        INSERT INTO t1 VALUES(randomblob(1500));
+      COMMIT;
+    }
+  } {}
+
+  do_test 6.$tn.4 { 
+    list [catch { sql1 COMMIT } msg] $msg
+  } {1 {database is locked}}
+  do_test 6.$tn.5 { sql3 { PRAGMA integrity_check } } {ok}
+  do_test 6.$tn.5 { sql3 { SELECT count(*) from t1 } } {3}
+}
+
+#-------------------------------------------------------------------------
+# Test that if a corrupt wal-index-header is encountered when attempting
+# to commit a CONCURRENT transaction, the transaction is not committed
+# (or rolled back) and that SQLITE_BUSY_SNAPSHOT is returned to the user.
+#
+catch { db close }
+forcedelete test.db
+testvfs tvfs
+sqlite3 db test.db -vfs tvfs
+do_execsql_test 7.1 {
+  PRAGMA journal_mode = wal;
+  BEGIN;
+    CREATE TABLE t1(a, b, PRIMARY KEY(a));
+    INSERT INTO t1 VALUES(1, 2);
+    INSERT INTO t1 VALUES(3, 4);
+  COMMIT;
+  BEGIN CONCURRENT;
+    INSERT INTO t1 VALUES(5, 6);
+    INSERT INTO t1 VALUES(7, 8);
+    SELECT * FROM t1;
+} {wal 1 2 3 4 5 6 7 8}
+
+# Corrupt the wal-index header
+incr_tvfs_hdr test.db 11 1
+
+do_catchsql_test 7.2.1 { COMMIT } {1 {database is locked}}
+do_test 7.2.2 { sqlite3_extended_errcode db } SQLITE_BUSY_SNAPSHOT
+
+do_execsql_test 7.3.1 {
+  SELECT * FROM t1;
+  ROLLBACK;
+} {1 2 3 4 5 6 7 8}
+do_execsql_test 7.3.2 {
+  SELECT * FROM t1;
+} {1 2 3 4}
+
+#-------------------------------------------------------------------------
+# Test that "PRAGMA integrity_check" works within a concurrent 
+# transaction. Within a concurrent transaction, "PRAGMA integrity_check"
+# is unable to detect unused database pages, but can detect other types
+# of corruption.
+#
+reset_db
+do_test 8.1 {
+  execsql {
+    PRAGMA journal_mode = wal;
+    CREATE TABLE kv(k INTEGER PRIMARY KEY, v UNIQUE);
+    INSERT INTO kv VALUES(NULL, randomblob(750));
+    INSERT INTO kv SELECT NULL, randomblob(750) FROM kv;
+    INSERT INTO kv SELECT NULL, randomblob(750) FROM kv;
+    INSERT INTO kv SELECT NULL, randomblob(750) FROM kv;
+    INSERT INTO kv SELECT NULL, randomblob(750) FROM kv;
+    INSERT INTO kv SELECT NULL, randomblob(750) FROM kv;
+    DELETE FROM kv WHERE rowid%2;
+  }
+  set v [db one {PRAGMA freelist_count}]
+  expr $v==33 || $v==34
+} {1}
+do_execsql_test 8.2 { PRAGMA integrity_check } ok
+do_execsql_test 8.3 { 
+  BEGIN CONCURRENT;
+    PRAGMA integrity_check;
+} {ok}
+do_execsql_test 8.4 { 
+    INSERT INTO kv VALUES(1100, 1100);
+    PRAGMA integrity_check;
+} {ok}
+do_execsql_test 8.5 { 
+  COMMIT;
+  PRAGMA integrity_check;
+} {ok}
+
+#-------------------------------------------------------------------------
+# Test that concurrent transactions do not allow foreign-key constraints
+# to be bypassed.
+#
+do_multiclient_test tn {
+  do_test 9.$tn.1 {
+    sql1 {
+      PRAGMA journal_mode = wal;
+      CREATE TABLE pp(i INTEGER PRIMARY KEY, j);
+      CREATE TABLE cc(a, b REFERENCES pp);
+
+      WITH seq(i) AS (SELECT 1 UNION ALL SELECT i+1 FROM seq WHERE i<100)
+      INSERT INTO pp SELECT i, randomblob(1000) FROM seq;
+
+      PRAGMA foreign_keys = 1;
+    }
+  } {wal}
+
+
+  do_test 9.$tn.2.1 {
+    sql1 {
+      BEGIN CONCURRENT;
+        INSERT INTO cc VALUES(42, 42);
+    }
+  } {}
+  do_test 9.$tn.2.2 {
+    sql2 { DELETE FROM pp WHERE i=42 }
+    list [catch { sql1 COMMIT } msg] $msg
+  } {1 {database is locked}}
+  do_test 9.$tn.2.3 {
+    sql1 ROLLBACK
+  } {}
+
+  do_test 9.$tn.3.1 {
+    sql1 {
+      PRAGMA foreign_keys = 0;
+      BEGIN CONCURRENT;
+        INSERT INTO cc VALUES(43, 43);
+    }
+  } {}
+  do_test 9.$tn.3.2 {
+    sql2 { DELETE FROM pp WHERE i=43 }
+    list [catch { sql1 COMMIT } msg] $msg
+  } {0 {}}
+
+  do_test 9.$tn.4.1 {
+    sql1 {
+      PRAGMA foreign_keys = on;
+      BEGIN CONCURRENT;
+        INSERT INTO cc VALUES(44, 44);
+    }
+  } {}
+  do_test 9.$tn.4.2 {
+    sql2 { DELETE FROM pp WHERE i=1 }
+    list [catch { sql1 COMMIT } msg] $msg
+  } {0 {}}
+}
+
+#-------------------------------------------------------------------------
+# Test that even if a SELECT statement appears before all writes within
+# a CONCURRENT transaction, the pages it reads are still considered when
+# considering whether or not the transaction may be committed.
+#
+do_multiclient_test tn {
+  do_test 10.$tn.1.1 {
+    sql1 {
+      PRAGMA journal_mode = wal;
+      CREATE TABLE t1(a);
+      CREATE TABLE t2(b);
+      CREATE TABLE t3(c);
+      INSERT INTO t1 VALUES(1), (2), (3);
+      INSERT INTO t2 VALUES(1), (2), (3);
+      INSERT INTO t3 VALUES(1), (2), (3);
+    }
+  } {wal}
+
+  do_test 10.$tn.1.2 {
+    sql1 {
+      BEGIN CONCURRENT;
+        SELECT * FROM t1;
+        INSERT INTO t2 VALUES(4);
+    }
+  } {1 2 3}
+
+  do_test 10.$tn.1.3 {
+    sql2 { INSERT INTO t1 VALUES(4) }
+    list [catch {sql1 COMMIT} msg] $msg
+  } {1 {database is locked}}
+  sql1 ROLLBACK
+
+  # In this case, because the "SELECT * FROM t1" is first stepped before
+  # the "BEGIN CONCURRENT", the pages it reads are not recorded by the
+  # pager object. And so the transaction can be committed. Technically
+  # this behaviour (the effect of an ongoing SELECT on a BEGIN CONCURRENT
+  # transacation) is undefined.
+  #
+  do_test 10.$tn.2.1 {
+    code1 {
+      set ::stmt [sqlite3_prepare db "SELECT * FROM t1" -1 dummy]
+      sqlite3_step $::stmt
+    }
+  } {SQLITE_ROW}
+  do_test 10.$tn.2.2 {
+    sql1 {
+      BEGIN CONCURRENT; 
+        INSERT INTO t2 VALUES(4);
+    }
+    code1 {
+      set res [list]
+      lappend res [sqlite3_column_int $::stmt 0]
+      while {[sqlite3_step $::stmt]=="SQLITE_ROW"} {
+        lappend res [sqlite3_column_int $::stmt 0]
+      }
+      sqlite3_finalize $::stmt
+      set res
+    }
+  } {1 2 3 4}
+  do_test 10.$tn.2.3 {
+    sql2 { INSERT INTO t1 VALUES(5) }
+    sql1 COMMIT
+  } {}
+
+  # More tests surrounding long-lived prepared statements and concurrent
+  # transactions.
+  do_test 10.$tn.3.1 {
+    sql1 {
+      BEGIN CONCURRENT;
+        SELECT * FROM t1;
+      COMMIT;
+    }
+    sql1 {
+      BEGIN CONCURRENT;
+        INSERT INTO t2 VALUES(5);
+    }
+    sql2 {
+      INSERT INTO t1 VALUES(5);
+    }
+    sql1 COMMIT
+    sql3 {
+      SELECT * FROM t2;
+    }
+  } {1 2 3 4 5}
+  do_test 10.$tn.3.2 {
+    sql1 {
+      BEGIN CONCURRENT;
+        SELECT * FROM t1;
+      ROLLBACK;
+    }
+    sql1 {
+      BEGIN CONCURRENT;
+        INSERT INTO t2 VALUES(6);
+    }
+    sql2 {
+      INSERT INTO t1 VALUES(6);
+    }
+    sql1 COMMIT
+    sql3 { SELECT * FROM t2 }
+  } {1 2 3 4 5 6}
+  do_test 10.$tn.3.3 {
+    sql1 { BEGIN CONCURRENT }
+    code1 {
+      set ::stmt [sqlite3_prepare db "SELECT * FROM t1" -1 dummy]
+      sqlite3_step $::stmt
+    }
+    sql1 {
+      INSERT INTO t2 VALUES(7);
+      SELECT * FROM t3;
+      ROLLBACK;
+      BEGIN CONCURRENT;
+    }
+    sql2 { INSERT INTO t3 VALUES(5) }
+    code1 { sqlite3_finalize $::stmt }
+    sql1 {
+      INSERT INTO t2 VALUES(8);
+      COMMIT;
+    }
+  } {}
+}
+
+do_multiclient_test tn {
+  do_test 11.$tn.1 {
+    sql1 {
+      PRAGMA journal_mode = wal;
+      CREATE TABLE t1(a);
+    }
+  } {wal}
+
+  do_test 11.$tn.2 {
+    code1 { sqlite3_wal_info db main }
+  } {0 2}
+
+  do_test 11.$tn.3 {
+    sql1 { INSERT INTO t1 VALUES(1) }
+    code1 { sqlite3_wal_info db main }
+  } {2 3}
+
+  do_test 11.$tn.4 {
+    sql2 { INSERT INTO t1 VALUES(2) }
+    code2 { sqlite3_wal_info db2 main }
+  } {3 4}
+
+  do_test 11.$tn.5 {
+    sql1 { PRAGMA wal_checkpoint }
+    sql2 { INSERT INTO t1 VALUES(3) }
+    code2 { sqlite3_wal_info db2 main }
+  } {0 1}
+}
+
+reset_db
+do_execsql_test 12.0 {
+  PRAGMA journal_mode = wal;
+  CREATE TABLE tx(a INTEGER PRIMARY KEY, b);
+} {wal}
+do_test 12.1 {
+  for {set i 0} {$i < 50} {incr i} {
+    execsql {
+      BEGIN CONCURRENT;
+      INSERT INTO tx(b) VALUES( randomblob( 1200 ) );
+      COMMIT;
+    }
+  }
+  execsql { PRAGMA page_size }
+} {1024}
+do_execsql_test 12.2 {
+  DELETE FROM tx;
+}
+do_test 12.3 {
+  for {set i 0} {$i < 50} {incr i} {
+    execsql {
+      BEGIN CONCURRENT;
+      INSERT INTO tx(b) VALUES( randomblob( 1200 ) );
+      COMMIT;
+    }
+  }
+  execsql { PRAGMA page_size }
+} {1024}
+do_execsql_test 12.4 {
+  DELETE FROM tx;
+}
+do_test 12.5 {
+  execsql { BEGIN CONCURRENT }
+  for {set i 0} {$i < 5000} {incr i} {
+    execsql {
+      INSERT INTO tx(b) VALUES( randomblob( 1200 ) );
+    }
+  }
+  execsql { COMMIT }
+  execsql { PRAGMA page_size }
+} {1024}
+
+
+finish_test

test/concurrent3.test

@@ -0,0 +1,234 @@
+# 2015 July 26
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+# Tests for transactions started with BEGIN CONCURRENT. The tests in this
+# file focus on testing that deferred page allocation works properly.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+set ::testprefix concurrent3
+
+if {$AUTOVACUUM} { finish_test ; return }
+ifcapable !concurrent {
+  finish_test
+  return
+}
+
+db close
+sqlite3_shutdown
+test_sqlite3_log xLog
+proc xLog {error_code msg} {
+  # puts "$error_code: $msg"
+  # Enable the previous for debugging
+}
+reset_db
+
+proc create_schema {} {
+  db eval {
+    PRAGMA journal_mode = wal;
+
+    CREATE TABLE t1(x, y);
+    CREATE TABLE t2(x, y);
+    CREATE TABLE t3(x, y);
+    CREATE TABLE t4(x, y);
+
+    CREATE INDEX i1 ON t1(y, x);
+    CREATE INDEX i2 ON t2(y, x);
+    CREATE INDEX i3 ON t3(y, x);
+    CREATE INDEX i4 ON t4(y, x);
+  }
+}
+
+proc do_sql_op {iTbl iOp} {
+  set db "db$iTbl"
+
+  switch $iOp {
+    "i" {
+      set sql "
+        WITH cnt(i) AS (SELECT 1 UNION ALL SELECT i+1 FROM cnt WHERE i<10)
+        INSERT INTO t$iTbl SELECT randomblob(800), randomblob(800) FROM cnt;
+      "
+    }
+
+    "d" {
+      set sql "
+        DELETE FROM t$iTbl WHERE rowid IN (
+          SELECT rowid FROM t$iTbl ORDER BY 1 ASC LIMIT 10
+        )
+      "
+    }
+
+    "D" {
+      set sql "
+        DELETE FROM t$iTbl WHERE rowid IN (
+          SELECT rowid FROM t$iTbl o WHERE (
+            SELECT count(*) FROM t$iTbl i WHERE i.rowid<o.rowid
+          ) % 2
+        )
+      "
+    }
+
+    "I" {
+      set sql "
+        INSERT INTO t$iTbl SELECT randomblob(800), randomblob(800) FROM t$iTbl;
+      "
+    }
+
+    default {
+      error "bad iOp parameter: $iOp"
+    }
+  }
+
+  $db eval $sql
+}
+
+
+set DBLIST {db1 db2 db3 db4} 
+
+create_schema
+foreach {tn oplist} {
+  1  {1i   2i   3i   4i} 
+  2  {1iii 2iii 3iii 4iii}
+  3  {1d   2d   3d   4d} 
+  .  -----------------------
+  4  {1i}
+  5  {1d 2i}
+  .  -----------------------
+  6  {1iii 2iii 3iii 4iii}
+  7  {1di  2id  3iii 4ddd}
+  8  {1iii 2iii 3iii 4iii}
+  9  {1D  2II}
+  10 {1I  2D  3I  4D}
+  11 {1III 3dddddd 4III}
+} {
+  if {[string range $oplist 0 0]=="-"} {
+    reset_db
+    create_schema
+    continue
+  }
+  foreach db $DBLIST { sqlite3 $db test.db }
+
+  do_test 1.$tn {
+    foreach db $DBLIST { $db eval "BEGIN CONCURRENT" } 
+
+    foreach op $oplist {
+      set iTbl [string range $op 0 0]
+      foreach char [split [string range $op 1 end] {}] {
+        do_sql_op $iTbl $char
+      }
+    }
+
+    foreach db $DBLIST { $db eval "COMMIT" }
+    db eval {PRAGMA integrity_check}
+  } {ok}
+
+  foreach db $DBLIST { 
+    $db close 
+  }
+}
+
+#-------------------------------------------------------------------------
+#
+proc create_schema2 {} {
+  db eval {
+    PRAGMA journal_mode = wal;
+    CREATE TABLE t1(x INTEGER PRIMARY KEY, y);
+    CREATE INDEX i1 ON t1(y);
+  }
+}
+
+proc randint {nMax} {
+  db eval {SELECT abs(random() % $nMax)}
+}
+
+proc do_sql_op2 {db iOp} {
+  switch -- $iOp {
+    i {
+      # Insert 1 rows.
+      set r [randint 1000000000]
+      set ::rows($r) 1
+      #puts "insert row $r"
+      $db eval { INSERT OR IGNORE INTO t1 VALUES($r, randomblob(50)); }
+    }
+
+    d {
+      # Insert 1 row
+      set keys [array names ::rows]
+      set r [randint [llength $keys]]
+      set rowid [lindex $keys $r]
+      $db eval { DELETE FROM t1 WHERE x=$rowid }
+      unset ::rows($rowid)
+    }
+  }
+}
+
+foreach {tn nRepeat oplist} {
+  - - ----------------------------
+  1 100 { 1iiiiiiiiii }
+  2 100 { 1i 2d }
+  3 100 { 1d 2i }
+  4  50 { 1d 2i 3d }
+  5 500 { 1i 2i 3i 4i }
+  6 500 { 1i 2d 3d 4d }
+} {
+  if {[string range $oplist 0 0]=="-"} {
+    array unset rows
+    reset_db
+    create_schema2
+    continue
+  }
+
+  foreach db $DBLIST { 
+    sqlite3 $db test.db 
+    set stats($db,0) 0
+    set stats($db,1) 0
+  }
+  array unset used
+
+  do_test 2.$tn {
+
+    for {set i 0} {$i < $nRepeat} {incr i} {
+      foreach db $DBLIST { $db eval "BEGIN CONCURRENT" } 
+
+      foreach op $oplist {
+        set iDb [string range $op 0 0]
+        set used(db$iDb) 1
+        foreach char [split [string range $op 1 end] {}] {
+          do_sql_op2 "db$iDb" $char
+        }
+      }
+
+      foreach db $DBLIST { 
+        set rc [catch { $db eval COMMIT } msg]
+        if {$rc} { $db eval ROLLBACK }
+        incr stats($db,$rc)
+      }
+      set res [db eval {PRAGMA integrity_check}]
+      if {$res != "ok"} { puts "after $db $rc: $res" ; after 1000000 }
+    }
+  } {}
+
+  foreach db $DBLIST { 
+    $db close 
+  }
+  # foreach k [lsort [array names used]] {
+  #   puts "$k: $stats($k,0) committed, $stats($k,1) rolled back"
+  # }
+}
+
+catch { db close }
+sqlite3_shutdown
+test_sqlite3_log
+
+
+finish_test

test/concurrent4.test

@@ -0,0 +1,194 @@
+# 2017 May 26
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+# Miscellaneous tests for transactions started with BEGIN CONCURRENT. 
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+source $testdir/wal_common.tcl
+set ::testprefix concurrent4
+
+ifcapable !concurrent {
+  finish_test
+  return
+}
+
+do_execsql_test 1.0 {
+  PRAGMA journal_mode = wal;
+  CREATE TABLE t1(x PRIMARY KEY, y UNIQUE);
+  WITH s(i) AS (SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<100)
+  INSERT INTO t1 SELECT randomblob(400), randomblob(400) FROM s;
+  DELETE FROM t1 WHERE rowid<2;
+} {wal}
+
+do_execsql_test 1.1 {
+  BEGIN CONCURRENT;
+    INSERT INTO t1(rowid, x, y) VALUES(1000, randomblob(3000), randomblob(3000));
+    SAVEPOINT abc;
+    DELETE FROM t1 WHERE rowid = 1000;
+}
+
+do_execsql_test 1.2 { ROLLBACK TO abc }
+do_execsql_test 1.3 { COMMIT }
+do_execsql_test 1.4 { PRAGMA integrity_check } {ok}
+
+do_multiclient_test tn {
+  do_test 2.$tn.1 {
+    sql1 {
+      PRAGMA journal_mode = wal;
+      CREATE TABLE t1(a, b);
+      WITH s(i) AS (SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<100)
+        INSERT INTO t1 SELECT randomblob(400), randomblob(400) FROM s;
+
+      CREATE TABLE t2(a, b);
+      WITH s(i) AS (SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<100)
+        INSERT INTO t2 SELECT randomblob(400), randomblob(400) FROM s;
+    }
+
+    sql1 {
+      BEGIN CONCURRENT;
+        INSERT INTO t1 VALUES(randomblob(3000), randomblob(3000));
+    }
+  } {}
+
+  do_test 2.$tn.2 {
+    sql2 {
+      WITH s(i) AS (SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<10)
+        INSERT INTO t2 SELECT randomblob(400), randomblob(400) FROM s;
+    }
+    sql2 {
+      DELETE FROM t2 WHERE rowid<10;
+    }
+  } {}
+
+  do_test 2.$tn.3 {
+    sql1 {
+      COMMIT;
+      PRAGMA integrity_check;
+    }
+  } {ok}
+  do_test 2.$tn.4 {
+    sql2 {
+      PRAGMA integrity_check;
+    }
+  } {ok}
+}
+
+reset_db
+do_execsql_test 3.1 {
+  PRAGMA page_size = 1024;
+  PRAGMA journal_mode = wal;
+  CREATE TABLE t2(x);
+  INSERT INTO t2 VALUES(randomblob(5000));
+  CREATE TABLE t1(a INTEGER PRIMARY KEY, b);
+  INSERT INTO t1 VALUES(25, randomblob(104));
+  DELETE FROM t2;
+} {wal}
+
+do_execsql_test 3.2 {
+  BEGIN CONCURRENT;
+    REPLACE INTO t1 VALUES(25, randomblob(1117));
+  COMMIT;
+} {}
+
+#-------------------------------------------------------------------------
+# Test the effect of BEGIN CONCURRENT transactions that consist entirely
+# of read-only statements.
+#
+reset_db
+do_execsql_test 4.0 {
+  PRAGMA page_size = 1024;
+  PRAGMA journal_mode = wal;
+  
+  CREATE TABLE t4(a, b);
+  INSERT INTO t4 VALUES(1, 2);
+  INSERT INTO t4 VALUES(3, 4);
+} {wal}
+ 
+sqlite3 db2 test.db
+do_test 4.1.1 {
+  db eval {
+    BEGIN CONCURRENT;
+      INSERT INTO t4 VALUES(5, 6);
+  }
+
+  db2 eval {
+    BEGIN CONCURRENT;
+      SELECT * FROM t4;
+    ROLLBACK;
+  }
+} {1 2 3 4}
+
+do_test 4.1.2 {
+  db eval { COMMIT }
+  db2 eval { SELECT * FROM t4 }
+} {1 2 3 4 5 6}
+
+do_test 4.2.1 {
+  db eval {
+    BEGIN CONCURRENT;
+      INSERT INTO t4 VALUES(7, 8);
+  }
+
+  db2 eval {
+    BEGIN CONCURRENT;
+      SELECT * FROM t4;
+    COMMIT;
+  }
+} {1 2 3 4 5 6}
+
+do_test 4.2.2 {
+  db eval { COMMIT }
+  db2 eval { SELECT * FROM t4 }
+} {1 2 3 4 5 6 7 8}
+
+do_test 4.3 {
+  db2 eval {
+    BEGIN CONCURRENT;
+      SELECT * FROM t4;
+  }
+
+  db eval {
+    BEGIN CONCURRENT;
+      INSERT INTO t4 VALUES(9, 10);
+    COMMIT;
+  }
+  db2 eval {
+    SELECT * FROM t4;
+    COMMIT;
+  }
+} {1 2 3 4 5 6 7 8}
+
+set sz [file size test.db-wal]
+do_test 4.4.1 {
+  db eval {
+    BEGIN CONCURRENT;
+      SELECT * FROM t4;
+      SELECT * FROM sqlite_master;
+  }
+
+  db eval COMMIT
+  file size test.db-wal
+} $sz
+do_test 4.4.2 {
+  db eval {
+    BEGIN CONCURRENT;
+      SELECT * FROM t4;
+      SELECT * FROM sqlite_master;
+    ROLLBACK;
+  }
+  file size test.db-wal
+} $sz
+
+finish_test
+

test/concurrent5.test

@@ -0,0 +1,278 @@
+# 2017 May 26
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+source $testdir/wal_common.tcl
+set ::testprefix concurrent5
+
+ifcapable !concurrent {
+  finish_test
+  return
+}
+
+db close
+sqlite3_shutdown
+test_sqlite3_log [list lappend ::log]
+set ::log [list]
+
+sqlite3 db test.db
+
+proc do_test_conflict_msg {tn msg} {
+  set msg "cannot commit CONCURRENT transaction - [string trim $msg]"
+  uplevel [list do_test $tn {lindex $::log end} $msg]
+}
+
+do_execsql_test 1.0 {
+  PRAGMA journal_mode = wal;
+  CREATE TABLE t1(x, y);
+  CREATE TABLE t2(c);
+  WITH s(i) AS (SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<100)
+  INSERT INTO t1 SELECT randomblob(400), randomblob(400) FROM s;
+} {wal}
+
+sqlite3 db2 test.db
+
+do_test 1.1.1 {
+  set ::log [list]
+  db2 eval {
+    BEGIN CONCURRENT;
+      SELECT count(*) FROM t1;
+      INSERT INTO t2 VALUES(10);
+  }
+
+  db eval {
+    INSERT INTO t1 VALUES(randomblob(200), randomblob(200));
+  }
+
+  catchsql COMMIT db2
+} {1 {database is locked}}
+do_test_conflict_msg 1.1.2 {
+  conflict at page 2 (read-only page; part of db table t1; content=0500000063021100...)
+}
+
+do_test 1.2.1 {
+  set ::log [list]
+  db2 eval {
+    ROLLBACK;
+    BEGIN CONCURRENT;
+      INSERT INTO t1 VALUES(11, 12);
+  }
+
+  db eval {
+    INSERT INTO t1 VALUES(12, 11);
+  }
+
+  catchsql COMMIT db2
+} {1 {database is locked}}
+
+do_test_conflict_msg 1.2.2 {
+  conflict at page 105 (read/write page; part of db table t1; content=0D00000002026100...)
+}
+
+do_test 1.3.1 {
+  set ::log [list]
+  db2 eval {
+    ROLLBACK;
+    BEGIN CONCURRENT;
+      INSERT INTO t2 VALUES('x');
+  }
+
+  db eval {
+    INSERT INTO t2 VALUES('y');
+  }
+
+  catchsql COMMIT db2
+} {1 {database is locked}}
+
+do_test_conflict_msg 1.3.2 {
+  conflict at page 3 (read/write page; part of db table t2; content=0D0000000103FB00...)
+}
+
+do_test 1.4.1 {
+  set ::log [list]
+
+  execsql {
+    ROLLBACK;
+    CREATE TABLE t3(a INTEGER PRIMARY KEY, b INTEGER);
+    CREATE INDEX i3 ON t3(b);
+
+    WITH s(i) AS (
+      SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<5000
+    ) INSERT INTO t3 SELECT i, i FROM s;
+
+    BEGIN CONCURRENT;
+      INSERT INTO t3 VALUES(0, 5001);
+  } db2
+
+  execsql { INSERT INTO t3 VALUES(NULL, 5002) } db
+  catchsql COMMIT db2
+} {1 {database is locked}}
+
+do_test_conflict_msg 1.3.2 {
+  conflict at page 211 (read/write page; part of db index t3.i3; content=0A0310006300D800...)
+}
+
+db2 close
+reset_db
+do_execsql_test 1.5.0 {
+  PRAGMA auto_vacuum = 0;
+  PRAGMA journal_mode = wal;
+  CREATE TABLE t1(a, b);
+  CREATE INDEX i1 ON t1(a, b);
+  WITH s(i) AS (
+    SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<1000
+  ) 
+  INSERT INTO t1 SELECT i, randomblob(200) FROM s;
+} {wal}
+do_test 1.5.1 {
+  set ::log [list]
+
+  execsql {
+    BEGIN CONCURRENT;
+      INSERT INTO t1 VALUES(100000, '');
+  } db
+
+  sqlite3 db2 test.db
+  execsql { INSERT INTO t1(rowid, a, b) VALUES(-1, 100001, '') } db2
+  catchsql COMMIT db
+} {1 {database is locked}}
+
+do_test_conflict_msg 1.5.2 {
+  conflict at page 507 (read/write page; part of db index t1.i1; content=0A00000003025000...)
+}
+
+
+#-------------------------------------------------------------------------
+reset_db
+sqlite3 db2 test.db
+
+set big1 [string repeat ab 10000]
+set big2 "[string repeat ab  9999]xy"
+
+do_execsql_test 1.6.0 {
+  CREATE TABLE x1(x, y);
+  INSERT INTO x1 VALUES(1, $big1);
+  PRAGMA journal_mode = wal;
+} {wal}
+
+do_execsql_test -db db2 1.6.1.1 {
+  BEGIN; 
+    UPDATE x1 SET y=$big2;
+} {}
+do_execsql_test 1.6.1.2 {
+  BEGIN CONCURRENT;
+    UPDATE x1 SET y=$big2;
+}
+do_execsql_test -db db2 1.6.1.3 COMMIT
+do_catchsql_test 1.6.1.4 {
+  COMMIT;
+} {1 {database is locked}}
+do_test_conflict_msg 1.6.1.5 {
+  conflict at page 21 (read/write page; part of db table x1; content=0000000061626162...)
+}
+catchsql ROLLBACK
+
+do_test 1.6.2.1 {
+  execsql { BEGIN } db2
+  set fd [db2 incrblob main x1 y 1]
+  seek $fd 19998
+  puts -nonewline $fd 00
+  close $fd
+} {}
+do_test 1.6.2.2 {
+  execsql { BEGIN CONCURRENT } db
+  set fd [db incrblob main x1 y 1]
+  seek $fd 19998
+  puts -nonewline $fd 12
+  close $fd
+} {}
+do_execsql_test -db db2 1.6.2.3 COMMIT
+do_catchsql_test 1.6.2.4 {
+  COMMIT;
+} {1 {database is locked}}
+do_test_conflict_msg 1.6.1.5 {
+  conflict at page 21 (read/write page; part of db table x1; content=0000000061626162...)
+}
+catchsql ROLLBACK
+
+#--------------------------------------------------------------------------
+reset_db
+sqlite3 db2 test.db
+
+set big1 [string repeat ab 10000]
+set big2 "[string repeat ab  9999]xy"
+
+do_execsql_test 1.7.0 {
+  CREATE TABLE ww(a);
+  CREATE TABLE y1(x, y);
+  INSERT INTO y1 VALUES(1, $big1);
+  PRAGMA journal_mode = wal;
+} {wal}
+
+do_execsql_test -db db2 1.7.1 {
+  BEGIN;
+    UPDATE y1 SET y=$big2;
+    SELECT * FROM ww;
+}
+
+do_execsql_test 1.7.2 {
+  BEGIN CONCURRENT;
+    INSERT INTO ww SELECT y FROM y1;
+}
+
+do_execsql_test -db db2 1.7.3 COMMIT
+
+do_catchsql_test 1.7.4 {
+  COMMIT;
+} {1 {database is locked}}
+
+#-------------------------------------------------------------------------
+reset_db
+sqlite3 db2 test.db
+
+set big1 "[string repeat ab 10000]"
+set big2 "[string repeat ab  9999]xy"
+do_execsql_test 2.0 {
+  PRAGMA journal_mode = wal;
+  CREATE TABLE t1(a INTEGER PRIMARY KEY, b TEXT);
+  CREATE TABLE t2(a INTEGER PRIMARY KEY, b TEXT);
+  INSERT INTO t1 VALUES(100, $big1);
+} {wal}
+
+do_execsql_test -db db2 2.1 {
+  BEGIN CONCURRENT;
+    INSERT INTO t2 SELECT * FROM t1;
+}
+
+do_execsql_test 2.2 {
+   UPDATE t1 SET b=$big2
+}
+
+do_test 2.3 {
+  list [catch { db2 eval COMMIT } msg] $msg
+} {1 {database is locked}}
+
+do_test_conflict_msg 2.4 {
+  conflict at page 22 (read-only page; part of db table t1; content=0000000061626162...)
+}
+
+db close
+db2 close
+sqlite3_shutdown
+test_sqlite3_log 
+sqlite3_initialize
+finish_test
+
+

test/concurrent6.test

@@ -0,0 +1,60 @@
+# 2017 May 26
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+source $testdir/wal_common.tcl
+set ::testprefix concurrent6
+
+ifcapable !concurrent {
+  finish_test
+  return
+}
+
+sqlite3 db2 test.db
+
+do_execsql_test 1.0 {
+  PRAGMA page_size = 1024;
+  PRAGMA journal_mode = wal;
+  CREATE TABLE t1(x);
+  CREATE TABLE t2(x);
+  CREATE TABLE t3(x);
+  CREATE TABLE t4(x);
+
+  INSERT INTO t1 VALUES(zeroblob(1500));
+} {wal}
+
+do_execsql_test -db db2 1.1 {
+  BEGIN CONCURRENT;
+    INSERT INTO t3 VALUES(zeroblob(4000));
+    DELETE FROM t1;
+}
+
+do_execsql_test 1.2 {
+  WITH s(i) AS ( SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<100) 
+  INSERT INTO t2 SELECT zeroblob(1000) FROM s;
+
+  WITH s(i) AS ( SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<100) 
+  INSERT INTO t4  SELECT zeroblob(1000) FROM s;
+
+  DELETE FROM t4;
+}
+
+do_execsql_test -db db2 1.3 {
+  COMMIT;
+}
+
+
+finish_test
+

test/concurrent7.test

@@ -0,0 +1,52 @@
+# 2018 Jan 5
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+set ::testprefix concurrent7
+
+sqlite3 db2 test.db
+
+do_execsql_test 1 {
+  PRAGMA journal_mode = wal;
+  CREATE TABLE t1(x);
+  CREATE TABLE t2(x);
+} {wal}
+
+do_execsql_test -db db2 2 {
+  SELECT * FROM t1;
+}
+
+do_execsql_test 3 {
+  BEGIN CONCURRENT;
+    INSERT INTO t1 VALUES(randomblob(1500));
+    INSERT INTO t1 VALUES(randomblob(1500));
+    DELETE FROM t1 WHERE rowid = 1;
+}
+
+do_execsql_test -db db2 4 {
+  INSERT INTO t2 VALUES(randomblob(1500));
+  INSERT INTO t2 VALUES(randomblob(1500));
+  INSERT INTO t2 VALUES(randomblob(1500));
+  INSERT INTO t2 VALUES(randomblob(1500));
+  DELETE FROM t2 WHERE rowid IN (1, 2);
+}
+
+do_execsql_test 5 {
+  COMMIT;
+  PRAGMA integrity_check;
+} {ok}
+
+finish_test
+
+

test/concurrent8.test

@@ -0,0 +1,109 @@
+# 2020 July 17
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+set ::testprefix concurrent8
+
+source $testdir/lock_common.tcl
+
+ifcapable !concurrent {
+  finish_test
+  return
+}
+
+do_multiclient_test tn {
+
+  do_test 1.$tn.0 {
+    sql1 {
+      CREATE TABLE t1(x, y);
+      PRAGMA journal_mode = wal;
+    }
+  } {wal}
+
+  do_test 1.$tn.1 {
+    sql1 {
+      BEGIN CONCURRENT;
+        INSERT INTO t1 VALUES(1, 1);
+    }
+  } {}
+
+  do_test 1.$tn.2 {
+    sql2 {
+      CREATE TABLE t2(a, b);
+    }
+  } {}
+
+  do_test 1.$tn.3 {
+    list [catch { sql1 { COMMIT } } msg] $msg
+  } {1 {database is locked}}
+
+  do_test 1.$tn.4 {
+    code1 { db errorcode }
+  } {517}  ;# SQLITE_BUSY_SNAPSHOT
+
+  do_test 1.$tn.5 {
+    sql1 {
+      ROLLBACK;
+      BEGIN CONCURRENT;
+        CREATE TABLE t3(a, b);
+      COMMIT;
+    }
+  } {}
+
+  do_test 1.$tn.6 {
+    set nPg [sql1 {PRAGMA page_count}]
+    sql1 "BEGIN CONCURRENT"
+    for {set i 0} {$i<250} {incr i} {
+      sql1 "CREATE TABLE z$i (a, b, c)"
+    }
+    sql1 "COMMIT"
+    set nPg2 [sql1 {PRAGMA page_count}]
+    expr $nPg2>$nPg
+  } {1}
+
+  do_test 1.$tn.7 {
+    sql2 { PRAGMA integrity_check }
+  } {ok}
+
+  do_test 1.$tn.8 {
+    sql1 {
+      BEGIN CONCURRENT;
+        CREATE TABLE t4(a, b);
+    }
+    sql2 {
+      INSERT INTO t1 VALUES(2, 2);
+    }
+    list [catch { sql1 COMMIT } msg] $msg
+  } {1 {database is locked}}
+  sql1 ROLLBACK
+
+  do_test 1.$tn.9 {
+    sql1 {
+      BEGIN CONCURRENT;
+        CREATE TEMP TABLE t5(a, b);
+        INSERT INTO t2 VALUES('x', 'x');
+    }
+    sql2 {
+      INSERT INTO t1 VALUES(3, 3);
+      CREATE TEMP TABLE t1(x, y);
+    }
+    sql1 COMMIT 
+  } {}
+}
+
+
+
+finish_test
+
+

test/concurrent9.test

@@ -0,0 +1,120 @@
+# 2023 January 12
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#*************************************************************************
+# This file implements regression tests for SQLite library.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+set testprefix concurrent9
+
+do_execsql_test 1.0 {
+  CREATE TABLE t1(x);
+  INSERT INTO t1 VALUES(1), (2);
+  CREATE TABLE t2(y);
+  INSERT INTO t2 VALUES('a'), ('b');
+  PRAGMA journal_mode = wal;
+} {wal}
+
+db close
+
+#-------------------------------------------------------------------------
+# Fix a problem that may occur if a BEGIN CONCURRENT transaction is 
+# started when the wal file is completely empty and committed after
+# it has been initialized by some other connection.
+#
+sqlite3 db  test.db
+sqlite3 db2 test.db
+
+do_execsql_test -db db  1.1 {
+  BEGIN CONCURRENT;
+    INSERT INTO t2 VALUES('c');
+}
+
+do_execsql_test -db db2  1.2 {
+  INSERT INTO t1 VALUES(3);
+}
+
+do_execsql_test -db db  1.3 {
+  COMMIT;
+}
+
+do_execsql_test -db db2  1.4 {
+  SELECT * FROM t1;
+  SELECT * FROM t2;
+} {1 2 3 a b c}
+
+db2 close
+
+#-------------------------------------------------------------------------
+reset_db
+
+do_execsql_test 2.1 {
+  CREATE TABLE t1(a INTEGER PRIMARY KEY, b);
+  PRAGMA journal_mode = wal;
+  WITH s(i) AS (
+    SELECT 1 UNION SELECT i+1 FROM s WHERE i<500
+  )
+  INSERT INTO t1(b) SELECT hex(randomblob(200)) FROM s;
+  PRAGMA page_count;
+} {wal 255}
+
+sqlite3 db2 test.db
+do_execsql_test -db db2 2.2 {
+  DELETE FROM t1 WHERE a<100;
+  PRAGMA freelist_count;
+} {49}
+
+do_execsql_test 2.3 {
+  BEGIN CONCURRENT;
+    WITH s(i) AS (
+      SELECT 1 UNION SELECT i+1 FROM s WHERE i<100
+    )
+    INSERT INTO t1(b) SELECT hex(randomblob(200)) FROM s;
+}
+
+sqlite3_db_status db CACHE_MISS 1
+do_execsql_test 2.4.1 {
+  COMMIT;
+}
+
+do_test 2.4.2 {
+  lindex [sqlite3_db_status db CACHE_MISS 0] 1
+} {1}
+
+do_execsql_test -db db2 2.5 {
+  DELETE FROM t1 WHERE a<200;
+  PRAGMA freelist_count;
+} {50}
+
+do_execsql_test 2.6 {
+  BEGIN CONCURRENT;
+    WITH s(i) AS (
+      SELECT 1 UNION SELECT i+1 FROM s WHERE i<100
+    )
+    INSERT INTO t1(b) SELECT hex(randomblob(200)) FROM s;
+    DELETE FROM t1 WHERE rowid BETWEEN 600 AND 680;
+}
+
+sqlite3_db_status db CACHE_MISS 1
+do_execsql_test 2.7.1 {
+  COMMIT;
+}
+do_test 2.7.2 {
+  lindex [sqlite3_db_status db CACHE_MISS 0] 1
+} {1}
+
+do_execsql_test 2.8 {
+  PRAGMA integrity_check;
+} {ok}
+
+finish_test
+
+

test/corruptA.test

@@ -47,7 +47,7 @@ db close
 forcecopy test.db test.db-template
 
 set unreadable_version 02
-ifcapable wal { set unreadable_version 03 }
+ifcapable wal { set unreadable_version 04 }
 do_test corruptA-2.1 {
   forcecopy test.db-template test.db
   hexio_write test.db 19 $unreadable_version   ;# the read format number

test/corruptN.test

@@ -141,16 +141,6 @@ do_test 2.0 {
 | end c-b92b.txt.db
 }]} {}
 
-# This test only works with the legacy RC4 PRNG
-if 0 {
-  prng_seed 0 db
-  do_catchsql_test 2.1 {
-  SELECT count(*) FROM sqlite_schema;
-  WITH RECURSIVE c(x) AS (VALUES(1) UNION ALL SELECT x+1 FROM c WHERE x<1000)
-  INSERT INTO t1(a) SELECT randomblob(null) FROM c;
-  } {1 {database disk image is malformed}}
-}
-
 reset_db
 if {![info exists ::G(perm:presql)]} {
   do_execsql_test 3.0 {

test/fts3corrupt4.test

@@ -4376,6 +4376,9 @@ do_test 25.0 {
 | end crash-dde9e76ed8ab2d.db
 }]} {}
 
+proc rndblob {n} { return [sqlite3_randomness $n] }
+db func randomblob rndblob
+
 do_catchsql_test 25.1 {
   PRAGMA writable_schema = 1;
   WITH RECURSIVE c(x) AS (VALUES(1) UNION ALL SELECT x%1 FROM c WHERE x<599237)

test/parser1.test

@@ -1,103 +0,0 @@
-# 2014-08-24
-#
-# The author disclaims copyright to this source code.  In place of
-# a legal notice, here is a blessing:
-#
-#    May you do good and not evil.
-#    May you find forgiveness for yourself and forgive others.
-#    May you share freely, never taking more than you give.
-#
-#***********************************************************************
-# This file implements regression tests for SQLite library.
-# The focus of this script is testing details of the SQL language parser.
-# 
-
-set testdir [file dirname $argv0]
-source $testdir/tester.tcl
-
-do_catchsql_test parser1-1.1 {
-  CREATE TABLE t1(
-    a TEXT PRIMARY KEY,
-    b TEXT,
-    FOREIGN KEY(b COLLATE nocase DESC) REFERENCES t1(a COLLATE binary ASC)
-  );
-} {1 {syntax error after column name "b"}}
-
-
-# Verify that a legacy schema in the sqlite_master file is allowed to have
-# COLLATE, ASC, and DESC keywords on the id list of a FK constraint, and that
-# those keywords are silently ignored.
-#
-sqlite3_db_config db DEFENSIVE 0
-do_execsql_test parser1-1.2 {
-  CREATE TABLE t1(
-    a TEXT PRIMARY KEY,
-    b TEXT,
-    FOREIGN KEY(b) REFERENCES t1(a)
-  );
-  INSERT INTO t1 VALUES('abc',NULL),('xyz','abc');
-  PRAGMA writable_schema=on;
-  UPDATE sqlite_master SET sql='CREATE TABLE t1(
-    a TEXT PRIMARY KEY,
-    b TEXT,
-    FOREIGN KEY(b COLLATE nocase) REFERENCES t1(a)
-  )' WHERE name='t1';
-  SELECT name FROM sqlite_master WHERE sql LIKE '%collate%';
-} {t1}
-sqlite3 db2 test.db
-do_test parser1-1.3 {
-  sqlite3 db2 test.db
-  db2 eval {SELECT * FROM t1 ORDER BY 1}
-} {abc {} xyz abc}
-db2 close
-
-do_execsql_test parser1-1.4 {
-  UPDATE sqlite_master SET sql='CREATE TABLE t1(
-    a TEXT PRIMARY KEY,
-    b TEXT,
-    FOREIGN KEY(b ASC) REFERENCES t1(a)
-  )' WHERE name='t1';
-  SELECT name FROM sqlite_master WHERE sql LIKE '%ASC%';
-} {t1}
-sqlite3 db2 test.db
-do_test parser1-1.5 {
-  sqlite3 db2 test.db
-  db2 eval {SELECT * FROM t1 ORDER BY 1}
-} {abc {} xyz abc}
-db2 close
-
-do_catchsql_test parser1-2.1 {
-  WITH RECURSIVE
-    c(x COLLATE binary) AS (VALUES(1) UNION SELECT x+1 FROM c WHERE x<5)
-  SELECT x FROM c;
-} {1 {syntax error after column name "x"}}
-do_catchsql_test parser1-2.2 {
-  WITH RECURSIVE
-    c(x ASC) AS (VALUES(1) UNION SELECT x+1 FROM c WHERE x<5)
-  SELECT x FROM c;
-} {1 {syntax error after column name "x"}}
-
-# Verify that the comma between multiple table constraints is
-# optional.
-#
-# The missing comma is technically a syntax error.  But we have to support
-# it because there might be legacy databases that omit the commas in their
-# sqlite_master tables.
-#
-do_execsql_test parser1-3.1 {
-  CREATE TABLE t300(id INTEGER PRIMARY KEY);
-  CREATE TABLE t301(
-    id INTEGER PRIMARY KEY,
-    c1 INTEGER NOT NULL,
-    c2 INTEGER NOT NULL,
-    c3 BOOLEAN NOT NULL DEFAULT 0,
-    FOREIGN KEY(c1) REFERENCES t300(id) ON DELETE CASCADE ON UPDATE RESTRICT
-        /* no comma */
-    FOREIGN KEY(c2) REFERENCES t300(id) ON DELETE CASCADE ON UPDATE RESTRICT
-        /* no comma */
-    UNIQUE(c1, c2)
-  );
-  PRAGMA foreign_key_list(t301);
-} {0 0 t300 c2 id RESTRICT CASCADE NONE 1 0 t300 c1 id RESTRICT CASCADE NONE}
-
-finish_test

test/permutations.test

@@ -91,7 +91,6 @@ foreach f [glob $testdir/*.test] { lappend alltests [file tail $f] }
 foreach f [glob -nocomplain            \
     $testdir/../ext/rtree/*.test       \
     $testdir/../ext/fts5/test/*.test   \
-    $testdir/../ext/expert/*.test      \
     $testdir/../ext/lsm1/test/*.test   \
     $testdir/../ext/recover/*.test     \
     $testdir/../ext/rbu/*.test         \
@@ -465,18 +464,28 @@ lappend ::testsuitelist xxx
 test_suite "coverage-wal" -description {
   Coverage tests for file wal.c.
 } -files {
-  wal.test wal2.test wal3.test wal4.test wal5.test
-  wal64k.test wal6.test wal7.test wal8.test wal9.test
-  walbak.test walbig.test walblock.test walcksum.test walcrash2.test
-  walcrash3.test walcrash4.test walcrash.test walfault.test walhook.test
-  walmode.test walnoshm.test waloverwrite.test walpersist.test 
-  walprotocol2.test walprotocol.test walro2.test walrofault.test 
-  walro.test walshared.test walslow.test walvfs.test
-  walfault2.test
-  nockpt.test
+wal2big.test wal2recover.test wal2rewrite.test
+wal2simple.test wal2snapshot.test wal2.test
+wal3.test wal4.test wal5.test
+wal64k.test wal6.test wal7.test wal8.test wal9.test
+walbak.test walbig.test walblock.test walcksum.test 
+walfault.test walhook.test walmode.test walnoshm.test
+waloverwrite.test walpersist.test walprotocol2.test
+walprotocol.test walro2.test walrofault.test walro.test
+walshared.test walslow.test wal.test
+wal2savepoint.test wal2lock.test wal2recover2.test
 
+  wal2concurrent.test
+  concurrent.test concurrent2.test concurrent3.test
+  concurrent4.test concurrent5.test concurrent6.test
+  concurrent7.test
+  concfault.test concfault2.test
+
+  walvfs.test walfault2.test nockpt.test
   snapshot2.test snapshot3.test snapshot4.test
   snapshot_fault.test snapshot.test snapshot_up.test
+  walcrash2.test walcrash3.test walcrash4.test walcrash.test
+  wal2fault.test
 } 
 
 test_suite "coverage-pager" -description {
@@ -650,6 +659,16 @@ test_suite "onefile" -description {
   rollback.test  select1.test  select2.test  select3.test
 }
 
+# Run some tests using the "unix-excl" VFS.
+#
+test_suite "unix-excl" -description {
+  Run some tests using the "unix-excl" VFS
+} -initialize {
+  set ::G(perm:sqlite3_args) [list -vfs unix-excl]
+} -files {
+  shmlock.test
+}
+
 # Run some tests using UTF-16 databases.
 #
 test_suite "utf16" -description {
@@ -1034,6 +1053,23 @@ test_suite "wal" -description {
   fts3c.test   fts3d.test   fts3e.test   fts3query.test 
 }
 
+test_suite "wal2" -description {
+  Run tests with journal_mode=WAL2
+} -initialize {
+  set ::G(savepoint6_iterations) 100
+} -shutdown {
+  unset -nocomplain ::G(savepoint6_iterations)
+} -files {
+  savepoint.test     savepoint2.test     savepoint6.test
+  trans.test         avtrans.test
+
+  fts3aa.test  fts3ab.test  fts3ac.test  fts3ad.test
+  fts3ae.test  fts3af.test  fts3ag.test  fts3ah.test
+  fts3ai.test  fts3aj.test  fts3ak.test  fts3al.test
+  fts3am.test  fts3an.test  fts3ao.test  fts3b.test
+  fts3c.test   fts3d.test   fts3e.test   fts3query.test 
+}
+
 test_suite "rtree" -description {
   All R-tree related tests. Provides coverage of source file rtree.c.
 } -files [glob -nocomplain $::testdir/../ext/rtree/*.test]

test/rdonly.test

@@ -41,7 +41,7 @@ do_test rdonly-1.1.1 {
   sqlite3_db_readonly db main
 } {0}
 
-# Changes the write version from 1 to 3.  Verify that the database
+# Changes the write version from 1 to 4.  Verify that the database
 # can be read but not written.
 #
 do_test rdonly-1.2 {
@@ -49,7 +49,7 @@ do_test rdonly-1.2 {
   hexio_get_int [hexio_read test.db 18 1]
 } 1
 do_test rdonly-1.3 {
-  hexio_write test.db 18 03
+  hexio_write test.db 18 04
   sqlite3 db test.db
   execsql {
     SELECT * FROM t1;
@@ -83,7 +83,7 @@ do_test rdonly-1.5 {
 # the database is read-only until after it is locked.
 #
 set ro_version 02
-ifcapable wal { set ro_version 03 }
+ifcapable wal { set ro_version 04 }
 do_test rdonly-1.6 {
   hexio_write test.db 18 $ro_version     ; # write-version
   hexio_write test.db 24 11223344        ; # change-counter

test/savepoint.test

@@ -30,6 +30,7 @@ do_test savepoint-1.1 {
     RELEASE sp1;
   }
 } {}
+wal_check_journal_mode savepoint-1.1
 do_test savepoint-1.2 {
   execsql {
     SAVEPOINT sp1;
@@ -807,7 +808,8 @@ do_test savepoint-11.6 {
 integrity_check savepoint-11.7
 do_test savepoint-11.8 {
   execsql { ROLLBACK }
-  execsql { PRAGMA wal_checkpoint }
+  db close
+  sqlite3 db test.db
   file size test.db
 } {8192}
 

test/savepoint6.test

@@ -15,6 +15,10 @@ set testdir [file dirname $argv0]
 source $testdir/tester.tcl
 
 proc sql {zSql} {
+  if {0 && $::debug_op} {
+    puts stderr "$zSql ;"
+    flush stderr
+  }
   uplevel db eval [list $zSql]
   #puts stderr "$zSql ;"
 }
@@ -67,11 +71,13 @@ proc x_to_y {x} {
 #   delete_rows XVALUES
 #
 proc savepoint {zName} {
+  if {$::debug_op} { puts stderr "savepoint $zName" ; flush stderr }
   catch { sql "SAVEPOINT $zName" }
   lappend ::lSavepoint [list $zName [array get ::aEntry]]
 }
 
 proc rollback {zName} {
+  if {$::debug_op} { puts stderr "rollback $zName" ; flush stderr }
   catch { sql "ROLLBACK TO $zName" }
   for {set i [expr {[llength $::lSavepoint]-1}]} {$i>=0} {incr i -1} {
     set zSavepoint [lindex $::lSavepoint $i 0]
@@ -89,6 +95,7 @@ proc rollback {zName} {
 }
 
 proc release {zName} {
+  if {$::debug_op} { puts stderr "release $zName" ; flush stderr }
   catch { sql "RELEASE $zName" }
   for {set i [expr {[llength $::lSavepoint]-1}]} {$i>=0} {incr i -1} {
     set zSavepoint [lindex $::lSavepoint $i 0]
@@ -104,6 +111,7 @@ proc release {zName} {
 }
 
 proc insert_rows {lX} {
+  if {$::debug_op} { puts stderr "insert_rows $lX" ; flush stderr }
   foreach x $lX {
     set y [x_to_y $x]
 
@@ -116,6 +124,7 @@ proc insert_rows {lX} {
 }
 
 proc delete_rows {lX} {
+  if {$::debug_op} { puts stderr "delete_rows $lX" ; flush stderr }
   foreach x $lX {
     # Update database [db]
     sql "DELETE FROM t1 WHERE x = $x"
@@ -164,6 +173,11 @@ proc random_integers {nRes nRange} {
 } 
 #-------------------------------------------------------------------------
 
+set ::debug_op 0
+proc debug_ops {} {
+  set ::debug_op 1
+}
+
 proc database_op {} {
   set i [expr int(rand()*2)] 
   if {$i==0} {
@@ -185,9 +199,6 @@ proc savepoint_op {} {
   set C [lindex $cmds [expr int(rand()*6)]]
   set N [lindex $names [expr int(rand()*5)]]
 
-  #puts stderr "   $C $N ;  "
-  #flush stderr
-
   $C $N
   return ok
 }

test/tester.tcl

@@ -553,6 +553,7 @@ proc reset_db {} {
   forcedelete test.db
   forcedelete test.db-journal
   forcedelete test.db-wal
+  forcedelete test.db-wal2
   sqlite3 db ./test.db
   set ::DB [sqlite3_connection_pointer db]
   if {[info exists ::SETUP_SQL]} {
@@ -2292,17 +2293,32 @@ proc drop_all_indexes {{db db}} {
 #     Returns true if this test should be run in WAL mode. False otherwise.
 #
 proc wal_is_wal_mode {} {
-  expr {[permutation] eq "wal"}
+  if {[permutation] eq "wal"} { return 1 }
+  if {[permutation] eq "wal2"} { return 2 }
+  return 0
 }
 proc wal_set_journal_mode {{db db}} {
-  if { [wal_is_wal_mode] } {
-    $db eval "PRAGMA journal_mode = WAL"
+  switch -- [wal_is_wal_mode] {
+    0 {
+    }
+
+    1 {
+      $db eval "PRAGMA journal_mode = WAL"
+    }
+
+    2 {
+      $db eval "PRAGMA journal_mode = WAL2"
+    }
   }
 }
 proc wal_check_journal_mode {testname {db db}} {
   if { [wal_is_wal_mode] } {
     $db eval { SELECT * FROM sqlite_master }
-    do_test $testname [list $db eval "PRAGMA main.journal_mode"] {wal}
+    set expected "wal"
+    if {[wal_is_wal_mode]==2} {
+      set expected "wal2"
+    }
+    do_test $testname [list $db eval "PRAGMA main.journal_mode"] $expected
   }
 }
 

test/threadtest3.c

@@ -1494,6 +1494,8 @@ static void dynamic_triggers(int nMs){
 #include "tt3_stress.c"
 #include "tt3_shared.c"
 
+#include "tt3_bcwal2.c"
+
 int main(int argc, char **argv){
   struct ThreadTest {
     void (*xTest)(int);   /* Routine for running this test */
@@ -1518,6 +1520,8 @@ int main(int argc, char **argv){
     { stress1,             "stress1", 10000 },
     { stress2,             "stress2", 60000 },
     { shared1,             "shared1", 10000 },
+
+    { bcwal2_1,            "bcwal2_1", 100000 },
   };
   static char *substArgv[] = { 0, "*", 0 };
   int i, iArg;

test/tt3_bcwal2.c

@@ -0,0 +1,122 @@
+/*
+** 2011-02-02
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file is part of the test program "threadtest3". Despite being a C
+** file it is not compiled separately, but included by threadtest3.c using
+** the #include directive normally used with header files.
+**
+** This file contains the implementation of test cases:
+**
+**     bcwal2_1
+*/
+
+static char *bcwal2_1_checkpointer(int iTid, void *pArg){
+  Error err = {0};                /* Error code and message */
+  Sqlite db = {0};                /* SQLite database connection */
+  int nIter = 0;
+
+  opendb(&err, &db, "test.db", 0);
+  while( !timetostop(&err) ){
+    sql_script(&err, &db, "PRAGMA wal_checkpoint;");
+    nIter++;
+  }
+  closedb(&err, &db);
+
+  print_and_free_err(&err);
+  return sqlite3_mprintf("%d iterations", nIter);
+}
+
+static char *bcwal2_1_integrity(int iTid, void *pArg){
+  Error err = {0};                /* Error code and message */
+  Sqlite db = {0};                /* SQLite database connection */
+  int nIter = 0;
+
+  opendb(&err, &db, "test.db", 0);
+  while( !timetostop(&err) ){
+    // integrity_check(&err, &db);
+    sql_script(&err, &db, "SELECT * FROM t1;");
+    nIter++;
+  }
+  closedb(&err, &db);
+
+  print_and_free_err(&err);
+  return sqlite3_mprintf("%d integrity-checks", nIter);
+}
+
+static char *bcwal2_1_writer(int iTid, void *pArg){
+  Error err = {0};                /* Error code and message */
+  Sqlite db = {0};                /* SQLite database connection */
+  int nWrite = 0;                 /* Writes so far */
+  int nBusy = 0;                  /* Busy errors so far */
+  sqlite3_mutex *pMutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_APP1);
+
+  opendb(&err, &db, "test.db", 0);
+  while( !timetostop(&err) ){
+
+    sql_script(&err, &db,
+        "PRAGMA wal_autocheckpoint = 0;"
+        "BEGIN CONCURRENT;"
+        "  REPLACE INTO t1 VALUES( abs(random() % 100000), "
+        "     hex(randomblob( abs( random() % 200 ) + 50 ))"
+        "  );"
+    );
+
+    if( err.rc==SQLITE_OK ){
+      sqlite3_mutex_enter(pMutex);
+      sql_script(&err, &db, "COMMIT");
+      sqlite3_mutex_leave(pMutex);
+      if( err.rc==SQLITE_OK ){
+        nWrite++;
+      }else{
+        clear_error(&err, SQLITE_BUSY);
+        sql_script(&err, &db, "ROLLBACK");
+        nBusy++;
+      }
+
+      assert( err.rc!=SQLITE_OK || sqlite3_get_autocommit(db.db)==1 );
+    }
+  }
+  closedb(&err, &db);
+
+  print_and_free_err(&err);
+  return sqlite3_mprintf("%d successful writes, %d busy", nWrite, nBusy);
+}
+
+static void bcwal2_1(int nMs){
+  Error err = {0};
+  Sqlite db = {0};
+  Threadset threads = {0};
+
+  opendb(&err, &db, "test.db", 1);
+  sql_script(&err, &db, 
+      "PRAGMA page_size = 1024;"
+      "PRAGMA journal_mode = wal2;"
+      "CREATE TABLE t1(ii INTEGER PRIMARY KEY, tt TEXT);"
+      "CREATE INDEX t1tt ON t1(tt);"
+  );
+
+  setstoptime(&err, nMs);
+
+  launch_thread(&err, &threads, bcwal2_1_writer, 0);
+  launch_thread(&err, &threads, bcwal2_1_writer, 0);
+  launch_thread(&err, &threads, bcwal2_1_writer, 0);
+  launch_thread(&err, &threads, bcwal2_1_integrity, 0);
+  launch_thread(&err, &threads, bcwal2_1_checkpointer, 0);
+
+  join_all_threads(&err, &threads);
+
+  /* Do a final integrity-check on the db */
+  integrity_check(&err, &db);
+  closedb(&err, &db);
+
+  print_and_free_err(&err);
+}
+

test/uri.test

@@ -282,11 +282,11 @@ ifcapable wal {
       INSERT INTO t2 VALUES('x', 'y');
     }
     lsort [array names ::T1]
-  } {test.db1 test.db1-journal test.db1-wal}
+  } {test.db1 test.db1-journal test.db1-wal test.db1-wal2}
   
   do_test 5.1.2 {
     lsort [array names ::T2]
-  } {test.db2 test.db2-journal test.db2-wal}
+  } {test.db2 test.db2-journal test.db2-wal test.db2-wal2}
   db close
   
   tvfs1 delete

test/wal.test

@@ -1175,7 +1175,7 @@ foreach {tn pgsz works} {
   9  32768    1
  10  65536    1
  11 131072    0
- 11   1016    0
+ 12   1016    0
 } {
 
   if {$::SQLITE_MAX_PAGE_SIZE < $pgsz} {
@@ -1185,14 +1185,14 @@ foreach {tn pgsz works} {
   for {set pg 1} {$pg <= 3} {incr pg} {
     forcecopy testX.db test.db
     forcedelete test.db-wal
-  
+
     # Check that the database now exists and consists of three pages. And
     # that there is no associated wal file.
     #
     do_test wal-18.2.$tn.$pg.1 { file exists test.db-wal } 0
     do_test wal-18.2.$tn.$pg.2 { file exists test.db } 1
     do_test wal-18.2.$tn.$pg.3 { file size test.db } [expr 1024*3]
-  
+
     do_test wal-18.2.$tn.$pg.4 {
 
       # Create a wal file that contains a single frame (database page
@@ -1224,16 +1224,16 @@ foreach {tn pgsz works} {
       puts -nonewline $fd $framehdr
       puts -nonewline $fd $framebody
       close $fd
-  
+
       file size test.db-wal
     } [wal_file_size 1 $pgsz]
-  
+
     do_test wal-18.2.$tn.$pg.5 {
       sqlite3 db test.db
       set rc [catch { db one {PRAGMA integrity_check} } msg]
       expr { $rc!=0 || $msg!="ok" }
     } $works
-  
+ 
     db close
   }
 }

test/wal2.test

@@ -35,43 +35,6 @@ proc cond_incr_sync_count {adj} {
   }
 }
 
-proc set_tvfs_hdr {file args} {
-
-  # Set $nHdr to the number of bytes in the wal-index header:
-  set nHdr 48
-  set nInt [expr {$nHdr/4}]
-
-  if {[llength $args]>2} {
-    error {wrong # args: should be "set_tvfs_hdr fileName ?val1? ?val2?"}
-  }
-
-  set blob [tvfs shm $file]
-  if {$::tcl_platform(byteOrder)=="bigEndian"} {set fmt I} {set fmt i}
-
-  if {[llength $args]} {
-    set ia [lindex $args 0]
-    set ib $ia
-    if {[llength $args]==2} {
-      set ib [lindex $args 1]
-    }
-    binary scan $blob a[expr $nHdr*2]a* dummy tail
-    set blob [binary format ${fmt}${nInt}${fmt}${nInt}a* $ia $ib $tail]
-    tvfs shm $file $blob
-  }
-
-  binary scan $blob ${fmt}${nInt} ints
-  return $ints
-}
-
-proc incr_tvfs_hdr {file idx incrval} {
-  set ints [set_tvfs_hdr $file]
-  set v [lindex $ints $idx]
-  incr v $incrval
-  lset ints $idx $v
-  set_tvfs_hdr $file $ints
-}
-
-
 #-------------------------------------------------------------------------
 # Test case wal2-1.*:
 #

test/wal2big.test

@@ -0,0 +1,73 @@
+# 2017 September 19
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# TESTRUNNER: slow
+#
+# This file implements regression tests for SQLite library.  The
+# focus of this file is testing the operation of the library in
+# "PRAGMA journal_mode=WAL2" mode.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+source $testdir/malloc_common.tcl
+source $testdir/wal_common.tcl
+
+set testprefix wal2big
+ifcapable !wal {finish_test ; return }
+
+do_execsql_test 1.0 {
+  CREATE TABLE t1(a, b, c);
+  CREATE INDEX t1a ON t1(a);
+  CREATE INDEX t1b ON t1(b);
+  CREATE INDEX t1c ON t1(c);
+  PRAGMA journal_mode = wal2;
+  PRAGMA journal_size_limit = 10000000;
+
+  WITH s(i) AS (
+    SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<200000
+  )
+  INSERT INTO t1 SELECT random(), random(), random() FROM s;
+} {wal2 10000000}
+
+do_execsql_test 1.1 {
+  WITH s(i) AS (
+    SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<200000
+  )
+  INSERT INTO t1 SELECT random(), random(), random() FROM s;
+}
+
+do_test 1.2 {
+  list [expr [file size test.db-wal]>10000000] \
+       [expr [file size test.db-wal2]>10000000]
+} {1 1}
+
+do_test 1.3 {
+  sqlite3 db2 test.db
+  execsql {
+    SELECT count(*) FROM t1;
+    PRAGMA integrity_check;
+  } db2
+} {400000 ok}
+
+do_test 1.4 {
+  db2 close
+  forcecopy test.db test.db2
+  forcecopy test.db-wal test.db2-wal
+  forcecopy test.db-wal2 test.db2-wal2
+  sqlite3 db2 test.db2
+  execsql {
+    SELECT count(*) FROM t1;
+    PRAGMA integrity_check;
+  }
+} {400000 ok}
+
+finish_test

test/wal2concurrent.test

@@ -0,0 +1,164 @@
+# 2018 December 6
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+set ::testprefix wal2concurrent
+
+ifcapable !concurrent {
+  finish_test
+  return
+}
+
+
+#-------------------------------------------------------------------------
+# Warm-body test.
+#
+foreach tn {1 2} {
+  reset_db
+  sqlite3 db2 test.db
+  do_execsql_test 1.0 {
+    PRAGMA page_size = 1024;
+    CREATE TABLE t1(x);
+    CREATE TABLE t2(y);
+    PRAGMA journal_size_limit = 5000;
+    PRAGMA journal_mode = wal2;
+  } {5000 wal2}
+  
+  do_execsql_test 1.1 {
+    INSERT INTO t1 VALUES(1);
+    BEGIN CONCURRENT;
+      INSERT INTO t1 VALUES(2);
+  } {}
+  
+  do_test 1.2 {
+    execsql { 
+      PRAGMA journal_size_limit = 5000;
+      INSERT INTO t1 VALUES(3) 
+    } db2
+    catchsql { COMMIT }
+  } {1 {database is locked}}
+  
+  do_catchsql_test 1.3 { COMMIT   } {1 {database is locked}}
+  do_catchsql_test 1.4 { ROLLBACK } {0 {}}
+  
+  do_test 1.5 {
+    list [file size test.db-wal] [file size test.db-wal2]
+  } {2128 0}
+  
+  do_execsql_test 1.6 {
+    BEGIN CONCURRENT;
+      INSERT INTO t1 VALUES(2);
+  } {}
+  
+  do_test 1.7 {
+    execsql { INSERT INTO t2 VALUES(randomblob(4000)) } db2
+    list [file size test.db-wal] [file size test.db-wal2]
+  } {7368 0}
+  
+  if {$tn==1} {
+    do_test 1.8 {
+      execsql { 
+        INSERT INTO t2 VALUES(1);
+        INSERT INTO t1 VALUES(5);
+      } db2
+      list [file size test.db-wal] [file size test.db-wal2]
+    } {7368 2128}
+
+    do_catchsql_test 1.9  { COMMIT   } {1 {database is locked}}
+    do_catchsql_test 1.10 { ROLLBACK } {0 {}}
+    db close
+    sqlite3 db test.db
+    do_execsql_test 1.11 { SELECT * FROM t1 } {1 3 5}
+    do_execsql_test 1.12 { SELECT count(*) FROM t2 } {2}
+  } else {
+    do_test 1.8 {
+      execsql { 
+        INSERT INTO t2 VALUES(1);
+      } db2
+      list [file size test.db-wal] [file size test.db-wal2]
+    } {7368 1080}
+
+    do_catchsql_test 1.9  { COMMIT   } {0 {}}
+    db close
+    sqlite3 db test.db
+    do_execsql_test 1.11 { SELECT * FROM t1 } {1 3 2}
+    do_execsql_test 1.12 { SELECT count(*) FROM t2 } {2}
+
+    do_test 1.13 {
+      list [file size test.db-wal] [file size test.db-wal2]
+    } {7368 2128}
+  }
+}
+
+do_multiclient_test tn {
+  do_test 2.$tn.1 {
+    sql1 {
+      PRAGMA auto_vacuum = OFF;
+      CREATE TABLE t1(x UNIQUE);
+      CREATE TABLE t2(x UNIQUE);
+      PRAGMA journal_mode = wal2;
+      PRAGMA journal_size_limit = 15000;
+    }
+  } {wal2 15000}
+
+  do_test 2.$tn.2 {
+    sql1 {
+      WITH s(i) AS (
+        SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<=10
+      )
+      INSERT INTO t1 SELECT randomblob(800) FROM s;
+    }
+  } {}
+
+  do_test 2.$tn.3 {
+    sql1 { DELETE FROM t1 WHERE (rowid%4)==0 }
+    list [expr [file size test.db-wal]>15000] \
+         [expr [file size test.db-wal2]>15000]
+  } {1 0}
+
+  do_test 2.$tn.4 {
+    sql1 { PRAGMA wal_checkpoint; }
+    sql1 { 
+      BEGIN CONCURRENT;
+        INSERT INTO t1 VALUES(randomblob(800));
+    }
+  } {}
+
+  do_test 2.$tn.5 {
+    sql2 { 
+      PRAGMA journal_size_limit = 15000;
+      INSERT INTO t2 VALUES(randomblob(800));
+      INSERT INTO t2 VALUES(randomblob(800));
+      INSERT INTO t2 VALUES(randomblob(800));
+      INSERT INTO t2 VALUES(randomblob(800));
+      INSERT INTO t2 VALUES(randomblob(800));
+      DELETE FROM t2;
+    }
+    list [expr [file size test.db-wal]>15000] \
+         [expr [file size test.db-wal2]>15000]
+  } {1 1}
+
+  do_test 2.$tn.6 {
+    sql1 { 
+        INSERT INTO t1 VALUES(randomblob(800));
+      COMMIT;
+      PRAGMA integrity_check;
+    }
+  } {ok}
+}
+
+
+
+finish_test
+

test/wal2fault.test

@@ -0,0 +1,52 @@
+# 2010 May 03
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library.  The
+# focus of this file is testing the operation of the library in
+# "PRAGMA journal_mode=WAL" mode.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/malloc_common.tcl
+source $testdir/lock_common.tcl
+
+ifcapable !wal {finish_test ; return }
+set testprefix wal2fault
+
+do_execsql_test 1.0 {
+  CREATE TABLE t1(x,y);
+  PRAGMA journal_mode = wal2;
+  WITH s(i) AS ( SELECT 100 UNION ALL SELECT i-1 FROM s WHERE (i-1)>0 )
+  INSERT INTO t1 SELECT i, randomblob(i) FROM s;
+  WITH s(i) AS ( SELECT 100 UNION ALL SELECT i-1 FROM s WHERE (i-1)>0 )
+  INSERT INTO t1 SELECT i, randomblob(i) FROM s;
+} {wal2}
+
+do_test 1.1 {
+  expr [file size test.db-wal]>10000
+} {1}
+faultsim_save_and_close
+
+do_faultsim_test 1 -prep {
+  faultsim_restore_and_reopen
+  execsql {
+    PRAGMA journal_size_limit = 10000;
+    SELECT count(*) FROM sqlite_master;
+  }
+} -body {
+  execsql {
+    INSERT INTO t1 VALUES(1, 2);
+  }
+} -test {
+  faultsim_test_result {0 {}}
+}
+
+finish_test

test/wal2lock.test

@@ -0,0 +1,106 @@
+# 2018 December 15
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library.  The
+# focus of this file is testing the operation of the library in
+# "PRAGMA journal_mode=WAL2" mode.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+source $testdir/malloc_common.tcl
+source $testdir/wal_common.tcl
+
+set testprefix wal2lock
+ifcapable !wal {finish_test ; return }
+
+db close
+testvfs tvfs 
+sqlite3 db test.db -vfs tvfs
+
+do_execsql_test 1.0 {
+  PRAGMA journal_mode = wal2;
+  CREATE TABLE y1(y, yy);
+  CREATE INDEX y1y ON y1(y);
+  CREATE INDEX y1yy ON y1(yy);
+  INSERT INTO y1 VALUES(1, 2), (3, 4), (5, 6);
+} {wal2}
+
+tvfs script vfs_callback
+tvfs filter xShmLock
+
+set ::lock [list]
+proc vfs_callback {func file name lock} {
+  lappend ::lock $lock
+  return SQLITE_OK
+}
+
+do_execsql_test 1.1.1 {
+  SELECT * FROM y1
+} {1 2 3 4 5 6}
+do_test 1.1.2 {
+  set ::lock
+} {{4 1 lock shared} {4 1 unlock shared}}
+
+set ::bFirst 1
+proc vfs_callback {func file name lock} {
+  if {$::bFirst} {
+    set ::bFirst 0
+    return SQLITE_BUSY
+  }
+  return SQLITE_OK
+}
+do_execsql_test 1.2 {
+  SELECT * FROM y1
+} {1 2 3 4 5 6}
+
+set ::bFirst 1
+proc vfs_callback {func file name lock} {
+  if {$::bFirst} {
+    set ::bFirst 0
+    return SQLITE_IOERR
+  }
+  return SQLITE_OK
+}
+do_catchsql_test 1.3 {
+  SELECT * FROM y1
+} {1 {disk I/O error}}
+
+puts "# Warning: This next test case causes SQLite to call xSleep(1) 100 times."
+puts "# Normally this equates to a delay of roughly 10 seconds, but if SQLite"
+puts "# is built on unix without HAVE_USLEEP defined, it may be much longer."
+proc vfs_callback {func file name lock} { return SQLITE_BUSY }
+do_catchsql_test 1.4 {
+  SELECT * FROM y1
+} {1 {locking protocol}}
+proc vfs_callback {func file name lock} { return SQLITE_OK }
+
+sqlite3 db2 test.db -vfs tvfs
+set ::bFirst 1
+
+proc vfs_callback {func file name lock} {
+  if {$::bFirst} {
+    set ::bFirst 0
+    db2 eval { INSERT INTO y1 VALUES(7, 8) }
+  }
+}
+
+do_execsql_test 1.5.1 {
+  SELECT * FROM y1
+} {1 2 3 4 5 6 7 8}
+do_execsql_test 1.5.2 {
+  SELECT * FROM y1
+} {1 2 3 4 5 6 7 8}
+
+db close
+db2 close
+tvfs delete
+finish_test

test/wal2openclose.test

@@ -0,0 +1,81 @@
+# 2017 September 19
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library.  The
+# focus of this file is testing the operation of the library in
+# "PRAGMA journal_mode=WAL2" mode.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+source $testdir/malloc_common.tcl
+source $testdir/wal_common.tcl
+
+set testprefix wal2openclose
+ifcapable !wal {finish_test ; return }
+
+do_execsql_test 1.0 {
+  CREATE TABLE t1(a, b, c);
+  PRAGMA journal_mode = wal2;
+  PRAGMA wal_autocheckpoint = 0;
+  PRAGMA journal_size_limit = 75000;
+} {wal2 0 75000}
+
+do_test 1.1 {
+  for {set ii 1} {$ii <= 200} {incr ii} {
+    execsql {
+      INSERT INTO t1 VALUES($ii, $ii, $ii);
+    }
+  }
+  expr ([file size test.db-wal2] - 75000) > 30000
+} {1}
+
+do_test 1.2 {
+  db close
+  list [file exists test.db-wal] [file exists test.db-wal2]
+} {0 0}
+
+sqlite3 db test.db
+do_execsql_test 1.3 {
+  SELECT sum(c) FROM t1
+} {20100}
+db close
+
+#-------------------------------------------------------------------------
+reset_db
+do_execsql_test 2.0 {
+  CREATE TABLE t1(a, b, c);
+  PRAGMA journal_mode = wal2;
+  INSERT INTO t1 VALUES(1, 2, 3);
+} {wal2}
+db_save_and_close
+
+db_restore_and_reopen
+do_execsql_test 2.1 {
+  SELECT * FROM t1;
+} {1 2 3}
+
+do_test 2.2 {
+  sqlite3 db2 test.db
+  db2 eval {INSERT INTO t1 VALUES(4, 5, 6)}
+  db2 close
+} {}
+
+breakpoint
+db close
+sqlite3 db test.db
+do_execsql_test 2.2 {
+  SELECT * FROM t1;
+} {1 2 3 4 5 6}
+
+
+
+finish_test

test/wal2recover.test

@@ -0,0 +1,271 @@
+# 2018 December 13
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library.  The
+# focus of this file is testing the operation of the library in
+# "PRAGMA journal_mode=WAL2" mode.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+source $testdir/malloc_common.tcl
+source $testdir/wal_common.tcl
+
+set testprefix wal2recover
+ifcapable !wal {finish_test ; return }
+
+proc db_copy {from to} {
+  forcecopy $from $to
+  forcecopy ${from}-wal ${to}-wal
+  forcecopy ${from}-wal2 ${to}-wal2
+}
+
+do_execsql_test 1.0 {
+  CREATE TABLE t1(a, b, c);
+  CREATE INDEX t1a ON t1(a);
+  CREATE INDEX t1b ON t1(b);
+  CREATE INDEX t1c ON t1(c);
+  PRAGMA journal_mode = wal2;
+  PRAGMA journal_size_limit = 15000;
+  PRAGMA wal_autocheckpoint = 0;
+} {wal2 15000 0}
+
+do_test 1.1 {
+  for {set i 1} {$i <= 1000} {incr i} {
+    execsql { INSERT INTO t1 VALUES(random(), random(), random()) }
+    db_copy test.db test.db2
+    sqlite3 db2 test.db
+    set res [execsql {
+      SELECT count(*) FROM t1;
+      PRAGMA integrity_check;
+    } db2]
+    db2 close
+    if {$res != [list $i ok]} {
+      error "failure on iteration $i"
+    }
+  }
+  set {} {}
+} {}
+
+#--------------------------------------------------------------------------
+reset_db
+do_execsql_test 2.0 {
+  CREATE TABLE t1(x UNIQUE);
+  CREATE TABLE t2(x UNIQUE);
+  PRAGMA journal_mode = wal2;
+  PRAGMA journal_size_limit = 10000;
+  PRAGMA wal_autocheckpoint = 0;
+  BEGIN;
+    INSERT INTO t1 VALUES(randomblob(4000));
+    INSERT INTO t1 VALUES(randomblob(4000));
+    INSERT INTO t1 VALUES(randomblob(4000));
+  COMMIT;
+  BEGIN;
+    INSERT INTO t2 VALUES(randomblob(4000));
+    INSERT INTO t2 VALUES(randomblob(4000));
+    INSERT INTO t2 VALUES(randomblob(4000));
+  COMMIT;
+} {wal2 10000 0}
+do_test 2.0.1 {
+  list [file size test.db] [file size test.db-wal] [file size test.db-wal2]
+} {5120 28328 28328}
+
+# Test recovery with both wal files intact.
+#
+do_test 2.1 {
+  db_copy test.db test.db2
+  sqlite3 db2 test.db2
+  execsql {
+    SELECT count(*) FROM t1;
+    SELECT count(*) FROM t2;
+    PRAGMA integrity_check;
+  } db2
+} {3 3 ok}
+
+do_test 2.2 {
+  db2 close
+  db_copy test.db test.db2
+  hexio_write test.db2-wal 16 12345678
+  sqlite3 db2 test.db2
+  execsql {
+    SELECT count(*) FROM t1;
+    SELECT count(*) FROM t2;
+  } db2
+} {0 3}
+
+do_test 2.3 {
+  db2 close
+  db_copy test.db test.db2
+  hexio_write test.db2-wal2 16 12345678
+  sqlite3 db2 test.db2
+  execsql {
+    SELECT count(*) FROM t1;
+    SELECT count(*) FROM t2;
+    PRAGMA integrity_check;
+  } db2
+} {3 0 ok}
+
+do_test 2.4 {
+  db2 close
+  db_copy test.db test.db2
+  forcecopy test.db-wal test.db2-wal2
+  sqlite3 db2 test.db2
+  execsql {
+    SELECT count(*) FROM t1;
+    SELECT count(*) FROM t2;
+    PRAGMA integrity_check;
+  } db2
+} {3 0 ok}
+
+do_test 2.5 {
+  db2 close
+  db_copy test.db test.db2
+  forcecopy test.db-wal  test.db2-wal2
+  forcecopy test.db-wal2  test.db2-wal
+  sqlite3 db2 test.db2
+  execsql {
+    SELECT count(*) FROM t1;
+    SELECT count(*) FROM t2;
+    PRAGMA integrity_check;
+  } db2
+} {3 3 ok}
+
+do_test 2.6 {
+  db2 close
+  db_copy test.db test.db2
+  forcecopy test.db-wal test.db2-wal2
+  close [open test.db-wal w]
+  sqlite3 db2 test.db2
+  execsql {
+    SELECT count(*) FROM t1;
+    SELECT count(*) FROM t2;
+    PRAGMA integrity_check;
+  } db2
+} {3 0 ok}
+
+do_test 2.7 {
+  db2 close
+  db_copy test.db test.db2
+  forcedelete test.db2-wal
+  sqlite3 db2 test.db2
+  execsql {
+    SELECT count(*) FROM t1;
+    SELECT count(*) FROM t2;
+    PRAGMA integrity_check;
+  } db2
+} {0 0 ok}
+db2 close
+
+#-------------------------------------------------------------------------
+#
+reset_db
+do_execsql_test 3.0 {
+  CREATE TABLE t1(a TEXT, b TEXT, c TEXT);
+  CREATE INDEX t1a ON t1(a);
+  CREATE INDEX t1b ON t1(b);
+  CREATE INDEX t1c ON t1(c);
+  PRAGMA journal_mode = wal2;
+  PRAGMA journal_size_limit = 10000;
+  PRAGMA wal_autocheckpoint = 0;
+  PRAGMA cache_size = 5;
+} {wal2 10000 0}
+
+do_execsql_test 3.1 {
+  WITH s(i) AS ( SELECT 1 UNION ALL SELECT i+1 FROM s where i < 200)
+  INSERT INTO t1 SELECT i, i, i FROM s;
+
+  INSERT INTO t1 VALUES(201, 201, 201);
+} {}
+
+do_test 3.2 {
+  list [file size test.db] [file size test.db-wal] [file size test.db-wal2]
+} {5120 15752 4224}
+
+do_test 3.3 {
+  forcecopy test.db test.db2
+  forcecopy test.db-wal test.db2-wal
+  forcecopy test.db-wal2 test.db2-wal2
+  sqlite3 db2 test.db2
+  execsql {
+    PRAGMA journal_size_limit = 10000;
+    PRAGMA wal_autocheckpoint = 0;
+    PRAGMA cache_size = 5;
+    BEGIN;
+      WITH s(i) AS ( SELECT 1 UNION ALL SELECT i+1 FROM s where i < 200)
+      INSERT INTO t1 SELECT i, i, i FROM s;
+  } db2
+  list [file size test.db2] [file size test.db2-wal] [file size test.db2-wal2]
+} {5120 15752 23088}
+
+
+if {$tcl_platform(platform)!="windows"} {
+  # These cannot be run under windows, as the *-shm file may not be read
+  # while it is locked by the database connection. 
+  do_test 3.4 {
+    set fd [open test.db2-shm]
+    fconfigure $fd -translation binary
+    set data [read $fd]
+    close $fd
+  
+    set fd [open test.db-shm w]
+    fconfigure $fd -translation binary
+    puts -nonewline $fd $data
+    close $fd
+  
+    execsql {
+      WITH s(i) AS ( SELECT 1 UNION ALL SELECT i+1 FROM s where i < 10)
+        INSERT INTO t1 SELECT i, i, i FROM s;
+      SELECT count(*) FROM t1;
+      PRAGMA integrity_check;
+    }
+  } {211 ok}
+  
+  do_test 3.5 {
+    list [file size test.db] [file size test.db-wal] [file size test.db-wal2]
+  } {5120 15752 18896}
+}
+
+#-------------------------------------------------------------------------
+#
+reset_db
+do_execsql_test 4.0 {
+  PRAGMA journal_mode = wal2;
+  CREATE TABLE xyz(x, y, z);
+  INSERT INTO xyz VALUES('x', 'y', 'z');
+} {wal2}
+db close
+do_test 4.1 {
+  close [open test.db-wal w]
+  file mkdir test.db-wal2
+  sqlite3 db test.db
+  catchsql { SELECT * FROM xyz }
+} {1 {unable to open database file}}
+db close
+file delete test.db-wal2
+db2 close
+
+do_test 4.2 {
+  sqlite3 db test.db
+  execsql { 
+    INSERT INTO xyz VALUES('a', 'b', 'c');
+  }
+  forcecopy test.db test.db2
+  forcecopy test.db-wal test.db2-wal
+  forcedelete test.db2-wal2
+  file mkdir test.db2-wal2
+  sqlite3 db2 test.db2
+  catchsql { SELECT * FROM xyz } db2
+} {1 {unable to open database file}}
+db2 close
+file delete test.db2-wal2
+
+
+finish_test

test/wal2recover2.test

@@ -0,0 +1,320 @@
+# 2018 December 13
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library.  The
+# focus of this file is testing the operation of the library in
+# "PRAGMA journal_mode=WAL2" mode.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+source $testdir/malloc_common.tcl
+source $testdir/wal_common.tcl
+
+set testprefix wal2recover2
+ifcapable !wal {finish_test ; return }
+
+do_execsql_test 1.0 {
+  CREATE TABLE t1(x);
+  CREATE TABLE t2(x);
+  WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<1500 )
+    INSERT INTO t1 SELECT i FROM s;
+  WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<1500 )
+    INSERT INTO t2 SELECT i FROM s;
+
+  PRAGMA journal_mode = wal2;
+  PRAGMA journal_size_limit = 10000;
+} {wal2 10000}
+
+set ::L 1125750
+set ::M 1126500
+set ::H 1127250
+
+do_execsql_test 1.1 {
+  UPDATE t1 SET x=x+1;
+  UPDATE t2 SET x=x+1 WHERE rowid<=750;
+
+  SELECT sum(x) FROM t1;
+  SELECT sum(x) FROM t2;
+} [list $H $M]
+
+do_test 1.2 {
+  list [file size test.db] [file size test.db-wal] [file size test.db-wal2]
+} {31744 14704 7368}
+
+proc cksum {zIn data} {
+  if {[string length $zIn]==0} {
+    set s0 0
+    set s1 0
+  } else {
+    set s0 [hexio_get_int [string range $zIn 0 7]]
+    set s1 [hexio_get_int [string range $zIn 8 15]]
+  }
+  set n [expr [string length $data] / 8]
+
+  for {set i 0} {$i < $n} {incr i 2} {
+    set x0 [hexio_get_int -l [string range $data [expr $i*8]   [expr $i*8+7]]]
+    set x1 [hexio_get_int -l [string range $data [expr $i*8+8] [expr $i*8+8+7]]]
+
+    set s0 [expr ($s0 + $x0 + $s1) & 0xFFFFFFFF]
+    set s1 [expr ($s1 + $x1 + $s0) & 0xFFFFFFFF]
+  }
+
+  return "[hexio_render_int32 $s0][hexio_render_int32 $s1]"
+}
+
+proc fix_wal_cksums {file} {
+  # Fix the checksum on the wal header.
+  set data [hexio_read $file 0 32]
+  set cksum [cksum {} [string range $data 0 47]]
+  set salt [hexio_read $file 16 8]
+  hexio_write $file 24 $cksum
+
+  # Fix the checksums for all pages in the wal file.
+  set pgsz [hexio_get_int [hexio_read $file 8 4]]
+  set sz [file size $file]
+  for {set off 32} {$off < $sz} {incr off [expr $pgsz+24]} {
+    set e [hexio_read $file $off 8]
+    set cksum [cksum $cksum $e]
+
+    set p [hexio_read $file [expr $off+24] $pgsz]
+    set cksum [cksum $cksum $p]
+
+    hexio_write $file [expr $off+8] $salt
+    hexio_write $file [expr $off+16] $cksum
+  }
+}
+
+proc wal_incr_hdrfield {file field} {
+  switch -- $field {
+    nCkpt { set offset 12 }
+    salt0 { set offset 16 }
+    salt1 { set offset 20 }
+    default {
+      error "unknown field $field - should be \"nCkpt\", \"salt0\" or \"salt1\""
+    }
+  }
+
+  # Increment the value in the wal header.
+  set v [hexio_get_int [hexio_read $file $offset 4]]
+  incr v
+  hexio_write $file $offset [hexio_render_int32 $v]
+  
+  # Fix various checksums
+  fix_wal_cksums $file
+}
+
+proc wal_set_nckpt {file val} {
+  # Increment the value in the wal header.
+  hexio_write $file 12 [hexio_render_int32 $val]
+  
+  # Fix various checksums
+  fix_wal_cksums $file
+}
+
+proc wal_set_follow {file prevfile} {
+  set pgsz [hexio_get_int [hexio_read $prevfile 8 4]]
+  set sz [file size $prevfile]
+  set cksum [hexio_read $prevfile [expr $sz-$pgsz-8] 8]
+
+  hexio_write $file 16 $cksum
+  fix_wal_cksums $file
+}
+
+foreach {tn file field} {
+  1 test.db2-wal    salt0
+  2 test.db2-wal    salt1
+  3 test.db2-wal    nCkpt
+  4 test.db2-wal2   salt0
+  5 test.db2-wal2   salt1
+  6 test.db2-wal2   nCkpt
+} {
+  do_test 1.3.$tn {
+    forcecopy test.db test.db2
+    forcecopy test.db-wal test.db2-wal
+    forcecopy test.db-wal2 test.db2-wal2
+    wal_incr_hdrfield $file $field
+    sqlite3 db2 test.db2
+    execsql {
+      SELECT sum(x) FROM t1;
+      SELECT sum(x) FROM t2;
+    } db2
+  } [list $H $L]
+  db2 close
+}
+
+do_test 1.4 {
+  forcecopy test.db test.db2
+  forcecopy test.db-wal2 test.db2-wal
+  forcedelete test.db2-wal2
+  sqlite3 db2 test.db2
+  execsql {
+    SELECT sum(x) FROM t1;
+    SELECT sum(x) FROM t2;
+  } db2
+} [list $L $M]
+
+do_test 1.5 {
+  db2 close
+  forcecopy test.db test.db2
+  forcecopy test.db-wal2 test.db2-wal
+  forcecopy test.db-wal test.db2-wal2
+  sqlite3 db2 test.db2
+  execsql {
+    SELECT sum(x) FROM t1;
+    SELECT sum(x) FROM t2;
+  } db2
+} [list $H $M]
+
+db2 close
+foreach {tn file field} {
+  1 test.db2-wal    salt0
+  2 test.db2-wal    salt1
+  3 test.db2-wal2   salt0
+  4 test.db2-wal2   salt1
+} {
+  do_test 1.6.$tn {
+    forcecopy test.db test.db2
+    forcecopy test.db-wal2 test.db2-wal
+    forcecopy test.db-wal test.db2-wal2
+    wal_incr_hdrfield $file $field
+    sqlite3 db2 test.db2
+    execsql {
+      SELECT sum(x) FROM t1;
+      SELECT sum(x) FROM t2;
+    } db2
+  } [list $H $L]
+  db2 close
+}
+
+foreach {tn nCkpt1 nCkpt2 res} [list \
+  1   2 1   "$H $M"                  \
+  2   2 2   "$L $M"                  \
+  3   3 1   "$H $L"                  \
+  4   15 14 "$H $M"                  \
+  5   0 15  "$H $M"                  \
+  6   1 15  "$L $M"                  \
+] {
+  do_test 1.7.$tn {
+    forcecopy test.db test.db2
+    forcecopy test.db-wal2 test.db2-wal
+    forcecopy test.db-wal test.db2-wal2
+
+    wal_set_nckpt test.db2-wal2 $nCkpt2
+    wal_set_nckpt test.db2-wal  $nCkpt1
+    wal_set_follow test.db2-wal test.db2-wal2
+
+
+    sqlite3 db2 test.db2
+    execsql {
+      SELECT sum(x) FROM t1;
+      SELECT sum(x) FROM t2;
+    } db2
+  } $res
+  db2 close
+}
+
+
+#-------------------------------------------------------------------------
+reset_db
+do_execsql_test 1.8.1 {
+  PRAGMA autovacuum = 0;
+  PRAGMA page_size = 4096;
+  CREATE TABLE t1(x);
+  CREATE TABLE t2(x);
+  WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<1500 )
+    INSERT INTO t1 SELECT i FROM s;
+  WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<1500 )
+    INSERT INTO t2 SELECT i FROM s;
+
+  PRAGMA journal_mode = wal2;
+  PRAGMA journal_size_limit = 10000;
+
+  WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<1500 )
+    INSERT INTO t2 SELECT i FROM s;
+} {wal2 10000}
+
+do_test 1.8.2 {
+  list [file size test.db-wal] [file size test.db-wal2]
+} {24752 0}
+
+do_execsql_test 1.8.3 { PRAGMA user_version = 123 }
+do_test 1.8.4 {
+  list [file size test.db-wal] [file size test.db-wal2]
+} {24752 4152}
+
+do_test 1.8.5 {
+  hexio_write test.db-wal2 [expr 56+16] 0400
+  fix_wal_cksums test.db-wal2
+} {}
+
+ifcapable oversize_cell_check {
+  set msg {database disk image is malformed}
+} else {
+  set msg {malformed database schema (?)}
+}
+
+do_test 1.8.6 {
+  forcecopy test.db test.db2
+  forcecopy test.db-wal test.db2-wal
+  forcecopy test.db-wal2 test.db2-wal2
+  sqlite3 db2 test.db2
+  catchsql { SELECT * FROM sqlite_master } db2
+} [list 1 $msg]
+db2 close
+
+#-------------------------------------------------------------------------
+reset_db
+do_execsql_test 1.0 {
+  CREATE TABLE t1(a, b, c);
+  CREATE INDEX t1a ON t1(a);
+  CREATE INDEX t1b ON t1(b);
+  CREATE INDEX t1c ON t1(c);
+  PRAGMA journal_mode = wal2;
+
+  INSERT INTO t1 VALUES(randomblob(50), randomblob(50), randomblob(50));
+  INSERT INTO t1 VALUES(randomblob(50), randomblob(50), randomblob(50));
+  INSERT INTO t1 VALUES(randomblob(50), randomblob(50), randomblob(50));
+  PRAGMA journal_size_limit = 5000;
+  INSERT INTO t1 VALUES(randomblob(50), randomblob(50), randomblob(50));
+  INSERT INTO t1 VALUES(randomblob(50), randomblob(50), randomblob(50));
+  INSERT INTO t1 VALUES(randomblob(50), randomblob(50), randomblob(50));
+  INSERT INTO t1 VALUES(randomblob(50), randomblob(50), randomblob(50));
+  INSERT INTO t1 VALUES(randomblob(50), randomblob(50), randomblob(50));
+} {wal2 5000}
+
+do_test 2.1 {
+  forcecopy test.db test.db2
+  forcecopy test.db-wal2 test.db2-wal
+  forcecopy test.db-wal test.db2-wal2
+  
+  hexio_write test.db2-wal 5000 1234567890
+} {5}
+
+do_test 2.2 {
+  sqlite3 db2 test.db2
+  breakpoint
+  execsql {
+    SELECT count(*) FROM t1;
+    PRAGMA integrity_check
+  } db2
+} {4 ok}
+
+do_test 2.3 {
+  execsql {
+    INSERT INTO t1 VALUES(randomblob(50), randomblob(50), randomblob(50));
+    SELECT count(*) FROM t1;
+    PRAGMA integrity_check
+  } db2
+} {5 ok}
+
+
+finish_test

test/wal2recover3.test

@@ -0,0 +1,52 @@
+# 2022 June 28
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library.  The
+# focus of this file is testing the operation of the library in
+# "PRAGMA journal_mode=WAL2" mode.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+source $testdir/malloc_common.tcl
+source $testdir/wal_common.tcl
+
+set testprefix wal2recover3
+ifcapable !wal {finish_test ; return }
+
+do_execsql_test 1.0 {
+  CREATE TABLE t1(x);
+  CREATE TABLE t2(x);
+  PRAGMA journal_mode = wal2;
+  PRAGMA wal_autocheckpoint = 0;
+  PRAGMA journal_size_limit = 10000;
+} {wal2 0 10000}
+
+do_execsql_test 1.1 {
+  WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<1500 )
+    INSERT INTO t1 SELECT i FROM s;
+  WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<1500 )
+    INSERT INTO t2 SELECT i FROM s;
+}
+
+db_save_and_close
+set fd [open sv_test.db-wal2 r+]
+seek $fd 4000
+puts -nonewline $fd 0
+close $fd
+
+db_restore_and_reopen
+do_execsql_test 1.2 {
+  SELECT sql FROM sqlite_schema;
+} {{CREATE TABLE t1(x)} {CREATE TABLE t2(x)}}
+
+finish_test
+

test/wal2rewrite.test

@@ -0,0 +1,92 @@
+# 2017 September 19
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library.  The
+# focus of this file is testing the operation of the library in
+# "PRAGMA journal_mode=WAL2" mode.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+source $testdir/malloc_common.tcl
+source $testdir/wal_common.tcl
+
+set testprefix wal2rewrite
+ifcapable !wal {finish_test ; return }
+
+proc filesize {filename} {
+  if {[file exists $filename]} {
+    return [file size $filename]
+  }
+  return 0
+}
+
+foreach {tn jrnlmode} {
+  1 wal
+  2 wal2
+} {
+  reset_db
+  execsql "PRAGMA journal_mode = $jrnlmode"
+  do_execsql_test $tn.1 {
+    PRAGMA journal_size_limit = 10000;
+    PRAGMA cache_size = 5;
+    PRAGMA wal_autocheckpoint = 10;
+  
+    CREATE TABLE t1(a INTEGER PRIMARY KEY, b INTEGER, c BLOB);
+    CREATE INDEX t1b ON t1(b);
+    CREATE INDEX t1c ON t1(c);
+  
+    WITH s(i) AS (
+      SELECT 1 UNION SELECT i+1 FROM s WHERE i<10
+    )
+    INSERT INTO t1 SELECT i, i, randomblob(800) FROM s;
+  } {10000 10}
+  
+  for {set i 0} {$i < 4} {incr i} {
+    do_execsql_test $tn.$i.1 {
+      UPDATE t1 SET c=randomblob(800) WHERE (b%10)==5 AND ($i%2)
+    }
+    do_execsql_test $tn.$i.2 {
+      BEGIN;
+      UPDATE t1 SET b=b+10, c=randomblob(800);
+      UPDATE t1 SET b=b+10, c=randomblob(800);
+      UPDATE t1 SET b=b+10, c=randomblob(800);
+      UPDATE t1 SET b=b+10, c=randomblob(800);
+      UPDATE t1 SET b=b+10, c=randomblob(800);
+      UPDATE t1 SET b=b+10, c=randomblob(800);
+      UPDATE t1 SET b=b+10, c=randomblob(800);
+      UPDATE t1 SET b=b+10, c=randomblob(800);
+      UPDATE t1 SET b=b+10, c=randomblob(800);
+      UPDATE t1 SET b=b+10, c=randomblob(800);
+    }
+    execsql COMMIT
+
+    do_test $tn.$i.3 { expr [filesize test.db-wal]  < 100000 } 1
+    do_test $tn.$i.4 { expr [filesize test.db-wal2] < 100000 } 1
+
+    set sum [db eval {SELECT sum(b), md5sum(c) FROM t1}]
+
+    do_test $tn.$i.5 {
+      foreach f [glob -nocomplain test.db2*] {forcedelete $f}
+      foreach f [glob -nocomplain test.db*] {
+        forcecopy $f [string map {test.db test.db2} $f]
+      }
+
+      sqlite3 db2 test.db2
+      db2 eval {SELECT sum(b), md5sum(c) FROM t1}
+    } $sum
+    db2 close
+  }
+}
+    
+
+
+finish_test

test/wal2rollback.test

@@ -0,0 +1,62 @@
+# 2017 September 19
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library.  The
+# focus of this file is testing the operation of the library in
+# "PRAGMA journal_mode=WAL2" mode.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+source $testdir/malloc_common.tcl
+source $testdir/wal_common.tcl
+
+set testprefix wal2rollback
+ifcapable !wal {finish_test ; return }
+
+do_execsql_test 1.0 {
+  CREATE TABLE t1(a, b, c);
+  CREATE TABLE t2(a, b, c);
+  CREATE INDEX i1 ON t1(a);
+  CREATE INDEX i2 ON t1(b);
+  PRAGMA journal_mode = wal2;
+  PRAGMA cache_size = 5;
+  PRAGMA journal_size_limit = 10000;
+  WITH s(i) AS (
+    SELECT 1 UNION ALL SELECT i+1 FROM s LIMIT 1000
+  )
+  INSERT INTO t1 SELECT i, i, randomblob(200) FROM s;
+} {wal2 10000}
+
+do_test 1.1 {
+  expr [file size test.db-wal] > 10000
+} 1
+
+do_test 1.2 {
+  execsql {
+    BEGIN;
+      UPDATE t1 SET b=b+1;
+      INSERT INTO t2 VALUES(1,2,3);
+  }
+  expr [file size test.db-wal2] > 10000
+} {1}
+
+breakpoint
+do_execsql_test 1.3 {
+  ROLLBACK;
+  SELECT * FROM t2;
+  SELECT count(*) FROM t1 WHERE a=b;
+  PRAGMA integrity_check;
+} {1000 ok}
+
+
+
+finish_test

test/wal2savepoint.test

@@ -0,0 +1,74 @@
+# 2018 December 13
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library.  The
+# focus of this file is testing the operation of the library in
+# "PRAGMA journal_mode=WAL2" mode.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+source $testdir/malloc_common.tcl
+source $testdir/wal_common.tcl
+
+set testprefix wal2savepoint
+ifcapable !wal {finish_test ; return }
+
+do_execsql_test 1.0 {
+  CREATE TABLE t1(a, b, c);
+  CREATE INDEX t1a ON t1(a);
+  CREATE INDEX t1b ON t1(b);
+  CREATE INDEX t1c ON t1(c);
+  PRAGMA journal_mode = wal2;
+  PRAGMA journal_size_limit = 15000;
+  PRAGMA wal_autocheckpoint = 0;
+  PRAGMA cache_size = 5;
+} {wal2 15000 0}
+
+do_execsql_test 1.1 {
+  WITH s(i) AS ( SELECT 1 UNION ALL SELECT i+1 FROM s where i < 200)
+  INSERT INTO t1 SELECT random(), random(), random() FROM s;
+} {}
+
+do_test 1.2 {
+  list [file size test.db] [file size test.db-wal2] \
+       [expr [file size test.db-wal]>20000]
+} {5120 0 1}
+
+do_execsql_test 1.3 {
+  BEGIN;
+    SAVEPOINT abc;
+      WITH s(i) AS ( SELECT 1 UNION ALL SELECT i+1 FROM s where i < 100)
+      INSERT INTO t1 SELECT random(), random(), random() FROM s;
+    ROLLBACK TO abc;
+    WITH s(i) AS ( SELECT 1 UNION ALL SELECT i+1 FROM s where i < 10)
+    INSERT INTO t1 SELECT random(), random(), random() FROM s;
+  COMMIT;
+  SELECT count(*) FROM t1;
+  PRAGMA integrity_check;
+} {210 ok}
+
+do_execsql_test 1.4 {
+  BEGIN;
+    SAVEPOINT abc;
+      WITH s(i) AS ( SELECT 1 UNION ALL SELECT i+1 FROM s where i < 100)
+      INSERT INTO t1 SELECT random(), random(), random() FROM s;
+    ROLLBACK TO abc;
+    WITH s(i) AS ( SELECT 1 UNION ALL SELECT i+1 FROM s where i < 10)
+    INSERT INTO t1 SELECT random(), random(), random() FROM s;
+  COMMIT;
+  SELECT count(*) FROM t1;
+  PRAGMA integrity_check;
+} {220 ok}
+
+
+finish_test
+

test/wal2simple.test

@@ -0,0 +1,475 @@
+# 2017 September 19
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library.  The
+# focus of this file is testing the operation of the library in
+# "PRAGMA journal_mode=WAL2" mode.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+source $testdir/malloc_common.tcl
+source $testdir/wal_common.tcl
+
+set testprefix wal2simple
+ifcapable !wal {finish_test ; return }
+
+#-------------------------------------------------------------------------
+# The following tests verify that a client can switch in and out of wal
+# and wal2 mode. But that it is not possible to change directly from wal
+# to wal2, or from wal2 to wal mode.
+#
+do_execsql_test 1.1.0 {
+  PRAGMA journal_mode = wal2
+} {wal2}
+execsql { SELECT * FROM sqlite_master} 
+do_execsql_test 1.x {
+  PRAGMA journal_mode;
+  PRAGMA main.journal_mode;
+} {wal2 wal2}
+db close
+do_test 1.1.1 { file size test.db } {1024}
+do_test 1.1.2 { hexio_read test.db 18 2 } 0303
+
+sqlite3 db test.db
+do_execsql_test 1.2.0 {
+  SELECT * FROM sqlite_master;
+  PRAGMA journal_mode = delete;
+} {delete}
+db close
+do_test 1.2.1 { file size test.db } {1024}
+do_test 1.2.2 { hexio_read test.db 18 2 } 0101
+
+sqlite3 db test.db
+do_execsql_test 1.3.0 {
+  SELECT * FROM sqlite_master;
+  PRAGMA journal_mode = wal;
+} {wal}
+db close
+do_test 1.3.1 { file size test.db } {1024}
+do_test 1.3.2 { hexio_read test.db 18 2 } 0202
+
+sqlite3 db test.db
+do_catchsql_test 1.4.0 {
+  PRAGMA journal_mode = wal2;
+} {1 {cannot change from wal to wal2 mode}}
+do_execsql_test 1.4.1 {
+  PRAGMA journal_mode = wal;
+  PRAGMA journal_mode = delete;
+  PRAGMA journal_mode = wal2;
+  PRAGMA journal_mode = wal2;
+} {wal delete wal2 wal2}
+do_catchsql_test 1.4.2 {
+  PRAGMA journal_mode = wal;
+} {1 {cannot change from wal2 to wal mode}}
+db close
+do_test 1.4.3 { hexio_read test.db 18 2 } 0303
+
+#-------------------------------------------------------------------------
+# Test that recovery in wal2 mode works.
+#
+forcedelete test.db test.db-wal test.db-wal2
+reset_db
+do_execsql_test 2.0 {
+  CREATE TABLE t1(a INTEGER PRIMARY KEY, b);
+  PRAGMA journal_mode = wal2;
+  PRAGMA journal_size_limit = 5000;
+} {wal2 5000}
+
+proc wal_hook {DB nm nFrame} { $DB eval { PRAGMA wal_checkpoint } }
+db wal_hook {wal_hook db}
+
+for {set i 1} {$i <= 200} {incr i} {
+  execsql { INSERT INTO t1 VALUES(NULL, randomblob(100)) }
+  set res [db eval { SELECT sum(a), md5sum(b) FROM t1 }]
+
+  do_test 2.1.$i {
+    foreach f [glob -nocomplain test.db2*] { forcedelete $f }
+    forcecopy test.db      test.db2
+    forcecopy test.db-wal  test.db2-wal
+    forcecopy test.db-wal2 test.db2-wal2
+
+    sqlite3 db2 test.db2
+    db2 eval { SELECT sum(a), md5sum(b) FROM t1 }
+  } $res
+
+  db2 close
+}
+
+#-------------------------------------------------------------------------
+
+reset_db
+do_execsql_test 3.0 {
+  CREATE TABLE t1(x BLOB, y INTEGER PRIMARY KEY);
+  CREATE INDEX i1 ON t1(x);
+  PRAGMA cache_size = 5;
+  PRAGMA journal_mode = wal2;
+} {wal2}
+
+do_test 3.1 {
+  execsql BEGIN
+  for {set i 1} {$i < 1000} {incr i} {
+    execsql { INSERT INTO t1 VALUES(randomblob(800), $i) }
+  }
+  execsql COMMIT
+} {}
+
+do_execsql_test 3.2 {
+  PRAGMA integrity_check;
+} {ok}
+
+#-------------------------------------------------------------------------
+catch { db close }
+foreach f [glob -nocomplain test.db*] { forcedelete $f }
+reset_db
+do_execsql_test 4.0 {
+  CREATE TABLE t1(x, y);
+  PRAGMA journal_mode = wal2;
+} {wal2}
+
+do_execsql_test 4.1 {
+  SELECT * FROM t1;
+} {}
+
+do_execsql_test 4.2 {
+  INSERT INTO t1 VALUES(1, 2);
+} {}
+
+do_execsql_test 4.3 {
+  SELECT * FROM t1;
+} {1 2}
+
+do_test 4.4 {
+  sqlite3 db2 test.db
+  execsql { SELECT * FROM t1 } db2
+} {1 2}
+
+do_test 4.5 {
+  lsort [glob test.db*]
+} {test.db test.db-shm test.db-wal test.db-wal2}
+
+do_test 4.6 {
+  db close
+  db2 close
+  sqlite3 db test.db
+  execsql { SELECT * FROM t1 }
+} {1 2}
+
+do_execsql_test 4.7 {
+  PRAGMA journal_size_limit = 4000;
+  INSERT INTO t1 VALUES(3, 4);
+  INSERT INTO t1 VALUES(5, 6);
+  INSERT INTO t1 VALUES(7, 8);
+  INSERT INTO t1 VALUES(9, 10);
+  INSERT INTO t1 VALUES(11, 12);
+  INSERT INTO t1 VALUES(13, 14);
+  INSERT INTO t1 VALUES(15, 16);
+  INSERT INTO t1 VALUES(17, 18);
+  SELECT * FROM t1;
+} {4000 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18}
+
+do_test 4.8 {
+  sqlite3 db2 test.db
+  execsql { SELECT * FROM t1 } db2
+} {1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18}
+
+do_test 4.9 {
+  db close
+  db2 close
+  lsort [glob test.db*]
+} {test.db}
+
+#-------------------------------------------------------------------------
+reset_db
+do_execsql_test 5.0 {
+  CREATE TABLE t1(a INTEGER PRIMARY KEY, b, c);
+  CREATE INDEX i1 ON t1(b, c);
+  PRAGMA journal_mode = wal2;
+  PRAGMA journal_size_limit = 4000;
+} {wal2 4000}
+
+proc wal_hook {DB nm nFrame} {
+  $DB eval { PRAGMA wal_checkpoint }
+}
+db wal_hook [list wal_hook db]
+
+
+foreach js {4000 8000 12000} {
+  foreach NROW [list 100 200 300 400 500 600 1000] {
+    do_test 5.$js.$NROW.1 {
+      db eval "DELETE FROM t1"
+      db eval "PRAGMA journal_size_limit = $js"
+      set nTotal 0
+      for {set i 0} {$i < $NROW} {incr i} {
+        db eval { INSERT INTO t1 VALUES($i, $i, randomblob(abs(random()%50))) }
+        incr nTotal $i
+      }
+      set {} {}
+    } {}
+
+    do_test 5.$js.$NROW.2 {
+      sqlite3 db2 test.db
+      db2 eval { 
+        PRAGMA integrity_check;
+        SELECT count(*), sum(b) FROM t1;
+      }
+    } [list ok $NROW $nTotal]
+
+    db2 close
+  }
+}
+
+
+#-------------------------------------------------------------------------
+reset_db
+do_execsql_test 6.0 {
+  CREATE TABLE tx(x);
+  PRAGMA journal_mode = wal2;
+  PRAGMA journal_size_limit = 3500;
+} {wal2 3500}
+
+do_test 6.1 {
+  for {set i 0} {$i < 10} {incr i} {
+    execsql "CREATE TABLE t$i (x);"
+  }
+} {}
+
+do_test 6.2.1 {
+  foreach f [glob -nocomplain test.db2*] { forcedelete $f }
+  forcecopy test.db-wal2 test.db2-wal2
+  sqlite3 db2 test.db2
+  db2 eval { SELECT * FROM sqlite_master }
+} {}
+do_test 6.2.2 {
+  db2 eval {
+    PRAGMA journal_mode = wal2;
+    SELECT * FROM sqlite_master;
+  }
+} {wal2}
+
+do_test 6.3.1 {
+  db2 close
+  foreach f [glob -nocomplain test.db2*] { forcedelete $f }
+  forcecopy test.db-wal2 test.db2-wal2
+  forcecopy test.db test.db2
+  sqlite3 db2 test.db2
+  db2 eval { SELECT * FROM sqlite_master }
+} {table tx tx 2 {CREATE TABLE tx(x)}}
+do_test 6.3.2 {
+  db2 eval {
+    PRAGMA journal_mode = wal2;
+    SELECT * FROM sqlite_master;
+  }
+} {wal2 table tx tx 2 {CREATE TABLE tx(x)}}
+
+do_test 6.4.1 {
+  db2 close
+  foreach f [glob -nocomplain test.db2*] { forcedelete $f }
+  forcecopy test.db-wal2 test.db2-wal2
+  forcecopy test.db-wal test.db2-wal
+  sqlite3 db2 test.db2
+  db2 eval { SELECT * FROM sqlite_master }
+} {}
+do_test 6.4.2 {
+  db2 eval {
+    PRAGMA journal_mode = wal2;
+    SELECT * FROM sqlite_master;
+  }
+} {wal2}
+db2 close
+
+#-------------------------------------------------------------------------
+reset_db
+sqlite3 db2 test.db
+do_execsql_test 7.0 {
+  PRAGMA journal_size_limit = 10000;
+  PRAGMA journal_mode = wal2;
+  PRAGMA wal_autocheckpoint = 0;
+  BEGIN;
+    CREATE TABLE t1(a);
+    INSERT INTO t1 VALUES( randomblob(8000) );
+  COMMIT;
+} {10000 wal2 0}
+
+do_test 7.1 {
+  list [file size test.db-wal] [file size test.db-wal2]
+} {9464 0}
+
+# Connection db2 is holding a PART1 lock. 
+#
+#   7.2.2: Test that the PART1 does not prevent db from switching to the
+#          other wal file.
+#
+#   7.2.3: Test that the PART1 does prevent a checkpoint of test.db-wal.
+#
+#   7.2.4: Test that after the PART1 is released the checkpoint is possible.
+#
+do_test 7.2.1 {
+  execsql {
+    BEGIN;
+      SELECT count(*) FROM t1;
+  } db2
+} {1}
+do_test 7.2.2 {
+  execsql {
+    INSERT INTO t1 VALUES( randomblob(800) );
+    INSERT INTO t1 VALUES( randomblob(800) );
+  }
+  list [file size test.db-wal] [file size test.db-wal2] [file size test.db]
+} {13656 3176 1024}
+do_test 7.2.3 {
+  execsql { PRAGMA wal_checkpoint }
+  list [file size test.db-wal] [file size test.db-wal2] [file size test.db]
+} {13656 3176 1024}
+do_test 7.2.4 {
+  execsql { END } db2
+  execsql { PRAGMA wal_checkpoint }
+  list [file size test.db-wal] [file size test.db-wal2] [file size test.db]
+} {13656 3176 11264}
+
+# Connection db2 is holding a PART2_FULL1 lock. 
+#
+#   7.3.2: Test that the lock does not prevent checkpointing.
+#
+#   7.3.3: Test that the lock does prevent the writer from overwriting 
+#          test.db-wal.
+#
+#   7.3.4: Test that after the PART2_FULL1 is released the writer can
+#          switch wal files and overwrite test.db-wal
+#
+db close
+db2 close
+sqlite3 db test.db
+sqlite3 db2 test.db
+do_test 7.3.1 {
+  execsql {
+    PRAGMA wal_autocheckpoint = 0;
+    PRAGMA journal_size_limit = 10000;
+    INSERT INTO t1 VALUES(randomblob(10000));
+    INSERT INTO t1 VALUES(randomblob(500));
+  }
+  execsql {
+    BEGIN;
+      SELECT count(*) FROM t1;
+  } db2
+  list [file size test.db-wal] [file size test.db-wal2] [file size test.db]
+} {12608 3176 12288}
+do_test 7.3.2 {
+  execsql { PRAGMA wal_checkpoint }
+  list [file size test.db-wal] [file size test.db-wal2] [file size test.db]
+} {12608 3176 22528}
+do_test 7.3.3 {
+  execsql { 
+    INSERT INTO t1 VALUES(randomblob(10000));
+    INSERT INTO t1 VALUES(randomblob(500));
+  }
+  list [file size test.db-wal] [file size test.db-wal2] [file size test.db]
+} {12608 18896 22528}
+do_test 7.3.4 {
+  execsql END db2
+  execsql { INSERT INTO t1 VALUES(randomblob(5000)); }
+  list [file size test.db-wal] [file size test.db-wal2] [file size test.db]
+} {12608 18896 22528}
+
+# Connection db2 is holding a PART2 lock. 
+#
+#   7.4.2: Test that the lock does not prevent writer switching to test.db-wal.
+#
+#   7.3.3: Test that the lock does prevent checkpointing of test.db-wal2.
+#
+#   7.3.4: Test that after the PART2 is released test.db-wal2 can be
+#          checkpointed.
+#
+db close
+db2 close
+breakpoint
+sqlite3 db test.db
+sqlite3 db2 test.db
+do_test 7.4.1 {
+  execsql {
+    PRAGMA wal_autocheckpoint = 0;
+    PRAGMA journal_size_limit = 10000;
+    INSERT INTO t1 VALUES(randomblob(10000));
+    INSERT INTO t1 VALUES(randomblob(10000));
+    PRAGMA wal_checkpoint;
+  }
+  execsql {
+    BEGIN;
+      SELECT count(*) FROM t1;
+  } db2
+  list [file size test.db-wal] [file size test.db-wal2] [file size test.db]
+} {12608 12608 50176}
+do_test 7.4.2 {
+  execsql { 
+    INSERT INTO t1 VALUES(randomblob(5000));
+  }
+  list [file size test.db-wal] [file size test.db-wal2] [file size test.db]
+} {12608 12608 50176}
+do_test 7.4.3 {
+  execsql { PRAGMA wal_checkpoint }
+  list [file size test.db-wal] [file size test.db-wal2] [file size test.db]
+} {12608 12608 50176}
+do_test 7.4.4 {
+  execsql END db2
+  execsql { PRAGMA wal_checkpoint }
+  list [file size test.db-wal] [file size test.db-wal2] [file size test.db]
+} {12608 12608 60416}
+
+# Connection db2 is holding a PART1_FULL2 lock. 
+#
+#   7.5.2: Test that the lock does not prevent a checkpoint of test.db-wal2.
+#
+#   7.5.3: Test that the lock does prevent the writer from overwriting
+#          test.db-wal2.
+#
+#   7.5.4: Test that after the PART1_FULL2 lock is released, the writer
+#          can switch to test.db-wal2.
+#
+db close
+db2 close
+sqlite3 db test.db
+sqlite3 db2 test.db
+do_test 7.5.1 {
+  execsql {
+    PRAGMA wal_autocheckpoint = 0;
+    PRAGMA journal_size_limit = 10000;
+    INSERT INTO t1 VALUES(randomblob(10000));
+    INSERT INTO t1 VALUES(randomblob(10000));
+    PRAGMA wal_checkpoint;
+    INSERT INTO t1 VALUES(randomblob(5000));
+  }
+  execsql {
+    BEGIN;
+      SELECT count(*) FROM t1;
+  } db2
+  list [file size test.db-wal] [file size test.db-wal2] [file size test.db]
+} {12608 12608 76800}
+do_test 7.5.2 {
+  execsql { PRAGMA wal_checkpoint }
+  list [file size test.db-wal] [file size test.db-wal2] [file size test.db]
+} {12608 12608 87040}
+do_test 7.5.3.1 {
+  execsql { INSERT INTO t1 VALUES(randomblob(5000)) }
+  list [file size test.db-wal] [file size test.db-wal2] [file size test.db]
+} {14704 12608 87040}
+do_test 7.5.3.2 {
+  execsql { INSERT INTO t1 VALUES(randomblob(5000)) }
+  list [file size test.db-wal] [file size test.db-wal2] [file size test.db]
+} {22040 12608 87040}
+do_test 7.5.4 {
+  execsql END db2
+  execsql { INSERT INTO t1 VALUES(randomblob(5000)) }
+  list [file size test.db-wal] [file size test.db-wal2] [file size test.db]
+} {22040 12608 87040}
+
+
+finish_test
+

test/wal2snapshot.test

@@ -0,0 +1,94 @@
+# 2018 December 5
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library.  The
+# focus of this file is testing the operation of the library in
+# "PRAGMA journal_mode=WAL2" mode.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+
+set testprefix wal2snapshot
+ifcapable !wal {finish_test ; return }
+ifcapable !snapshot {finish_test; return}
+
+foreach {tn mode} {1 wal 2 wal2} {
+  reset_db
+  do_execsql_test $tn.1 "PRAGMA journal_mode = $mode" $mode
+
+  do_execsql_test $tn.2 {
+    CREATE TABLE t1(a, b);
+    INSERT INTO t1 VALUES(1, 2);
+    INSERT INTO t1 VALUES(3, 4);
+    BEGIN;
+  }
+
+  # Check that sqlite3_snapshot_get() is an error for a wal2 db.
+  #
+  if {$tn==1} {
+    do_test 1.3 {
+      set S [sqlite3_snapshot_get db main]
+      sqlite3_snapshot_free $S
+    } {}
+  } else {
+    do_test 2.3 {
+      list [catch { sqlite3_snapshot_get db main } msg] $msg
+    } {1 SQLITE_ERROR}
+  }
+  
+  # Check that sqlite3_snapshot_recover() is an error for a wal2 db.
+  #
+  do_execsql_test $tn.4 COMMIT
+  if {$tn==1} {
+    do_test 1.5 {
+      sqlite3_snapshot_recover db main
+    } {}
+  } else {
+    do_test 2.5 {
+      list [catch { sqlite3_snapshot_recover db main } msg] $msg
+    } {1 SQLITE_ERROR}
+  }
+ 
+  # Check that sqlite3_snapshot_open() is an error for a wal2 db.
+  #
+  if {$tn==1} {
+    do_test 1.6 {
+      execsql BEGIN
+      set SNAPSHOT [sqlite3_snapshot_get_blob db main]
+      sqlite3_snapshot_open_blob db main $SNAPSHOT
+      execsql COMMIT
+    } {}
+  } else {
+
+    do_test 2.6.1 {
+      execsql BEGIN
+      set res [
+        list [catch { sqlite3_snapshot_open_blob db main $SNAPSHOT } msg] $msg
+      ]
+      execsql COMMIT
+      set res
+    } {1 SQLITE_ERROR}
+    do_test 2.6.2 {
+      execsql BEGIN
+      execsql {SELECT * FROM sqlite_master}
+      set res [
+        list [catch { sqlite3_snapshot_open_blob db main $SNAPSHOT } msg] $msg
+      ]
+      execsql COMMIT
+      set res
+    } {1 SQLITE_ERROR}
+  }
+}
+
+
+finish_test
+
+