Keep batch-atomic-writes turned on for journal_mode=MEMORY, but turn them

off for synchronous=OFF.  Refuse to compile with both SQLITE_MMAP_READWRITE
and SQLITE_ENABLE_BATCH_ATOMIC_WRITE.  Fix up some comments in the commit
logic.

FossilOrigin-Name: 2e80e19e4faac30947ed56aa3601c45c758cafb27f84780df255fdbcdc9a6999

manifest

@@ -1,5 +1,5 @@
-C Omit\sunused\sbatch-atomic-write\scode\sif\sSQLITE_ENABLE_BATCH_ATOMIC_WRITE\sis\nnot\sdefined.
-D 2017-07-22T16:00:34.947
+C Keep\sbatch-atomic-writes\sturned\son\sfor\sjournal_mode=MEMORY,\sbut\sturn\sthem\noff\sfor\ssynchronous=OFF.\s\sRefuse\sto\scompile\swith\sboth\sSQLITE_MMAP_READWRITE\nand\sSQLITE_ENABLE_BATCH_ATOMIC_WRITE.\s\sFix\sup\ssome\scomments\sin\sthe\scommit\nlogic.
+D 2017-07-22T16:32:33.230
 F Makefile.in d9873c9925917cca9990ee24be17eb9613a668012c85a343aef7e5536ae266e8
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc 02b469e9dcd5b7ee63fc1fb05babc174260ee4cfa4e0ef2e48c3c6801567a016
@@ -439,7 +439,7 @@ F src/os_setup.h 0dbaea40a7d36bf311613d31342e0b99e2536586
 F src/os_unix.c 9e7300ba4564bf1b95ef6f4ea5635a55d5b609fb8ec621183e7aadd48930ae45
 F src/os_win.c 2a6c73eef01c51a048cc4ddccd57f981afbec18a
 F src/os_win.h 7b073010f1451abe501be30d12f6bc599824944a
-F src/pager.c 5e5e39f192e714ff1c07ea5b892da91db0cd824b58c4d1c389d141c3d82a8671
+F src/pager.c 1e63b0299cf123cf38c48413ec03190f56c1e7d0ccc6573c467d8ac240b898e9
 F src/pager.h f2a99646c5533ffe11afa43e9e0bea74054e4efa
 F src/parse.y e384cb73f99e1b074085c974b37f4d830e885359e4b60837e30f7d67c16ba65b
 F src/pcache.c 62835bed959e2914edd26afadfecce29ece0e870
@@ -458,7 +458,7 @@ F src/shell.c.in b5725acacba95ccefa57b6d068f710e29ba8239c3aa704628a1902a1f729c17
 F src/sqlite.h.in eacc9cd3fa971f6056c0a312a61430df7c8d0b1fc01774e9209becf2c184b251
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h 967154985ed2ae62f90d9029bb5b5071793d847f1696a2ebe9e8cc0b042ae60b
-F src/sqliteInt.h 437217b5d22e9c8f3c53f90324915a535f649262b1281eaabed4e31653576b51
+F src/sqliteInt.h 3cbbcb67ba66ffe44a6768c95df22137335e9ef167d5da93bf0c1ed20a91b992
 F src/sqliteLimit.h 1513bfb7b20378aa0041e7022d04acb73525de35b80b252f1b83fedb4de6a76b
 F src/status.c a9e66593dfb28a9e746cba7153f84d49c1ddc4b1
 F src/table.c b46ad567748f24a326d9de40e5b9659f96ffff34
@@ -1637,7 +1637,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 532bbf1f2b1028db4e581c756533aa660e482d833caaed4eafb299ef9b584f3a
-R f8cc85762105a69ca21fc4aefd58063e
+P a89b62c4966cd297326e8712da40e0962d2328d7ba1f201d5abcec911eeef347
+R 88801a01fa2ca8fc5930da1c8e878132
 U drh
-Z 90f565a84bb7c55ed3503f958b4951cd
+Z dd2162169e6c906aa4638965a08ee342

manifest.uuid

@@ -1 +1 @@
-a89b62c4966cd297326e8712da40e0962d2328d7ba1f201d5abcec911eeef347
+2e80e19e4faac30947ed56aa3601c45c758cafb27f84780df255fdbcdc9a6999

src/pager.c

@@ -6369,6 +6369,21 @@ int sqlite3PagerCommitPhaseOne(
         sqlite3PcacheCleanAll(pPager->pPCache);
       }
     }else{
+      /* The bBatch boolean is true if the batch-atomic-write commit method
+      ** should be used.  No rollback journal is created if batch-atomic-write
+      ** is enabled.
+      */
+      sqlite3_file *fd = pPager->fd;
+#ifdef SQLITE_ENABLE_BATCH_ATOMIC_WRITE
+      const int bBatch = zMaster==0    /* An SQLITE_IOCAP_BATCH_ATOMIC commit */
+        && (sqlite3OsDeviceCharacteristics(fd) & SQLITE_IOCAP_BATCH_ATOMIC)
+        && !pPager->noSync
+        && sqlite3JournalIsInMemory(pPager->jfd);
+#else
+# define bBatch 0
+#endif
+
+#ifdef SQLITE_ENABLE_ATOMIC_WRITE
       /* The following block updates the change-counter. Exactly how it
       ** does this depends on whether or not the atomic-update optimization
       ** was enabled at compile time, and if this transaction meets the 
@@ -6392,17 +6407,6 @@ int sqlite3PagerCommitPhaseOne(
       ** in 'direct' mode. In this case the journal file will never be
       ** created for this transaction.
       */
-      sqlite3_file *fd = pPager->fd;
-#ifdef SQLITE_ENABLE_BATCH_ATOMIC_WRITE
-      const int bBatch = zMaster==0    /* An SQLITE_IOCAP_BATCH_ATOMIC commit */
-        && (sqlite3OsDeviceCharacteristics(fd) & SQLITE_IOCAP_BATCH_ATOMIC)
-        && pPager->journalMode!=PAGER_JOURNALMODE_MEMORY
-        && sqlite3JournalIsInMemory(pPager->jfd);
-#else
-# define bBatch 0
-#endif
-
-#ifdef SQLITE_ENABLE_ATOMIC_WRITE
       if( bBatch==0 ){
         PgHdr *pPg;
         assert( isOpen(pPager->jfd) 

src/sqliteInt.h

@@ -630,6 +630,15 @@
 # define SQLITE_DEFAULT_PCACHE_INITSZ 20
 #endif
 
+/*
+** The compile-time options SQLITE_MMAP_READWRITE and 
+** SQLITE_ENABLE_BATCH_ATOMIC_WRITE are not compatible with one another.
+** You must choose one or the other (or neither) but not both.
+*/
+#if defined(SQLITE_MMAP_READWRITE) && defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE)
+#error Cannot use both SQLITE_MMAP_READWRITE and SQLITE_ENABLE_BATCH_ATOMIC_WRITE
+#endif
+
 /*
 ** GCC does not define the offsetof() macro so we'll have to do it
 ** ourselves.