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Two-phase commit. Original patch by Heikki Linnakangas, with additional

Browse Source 
hacking by Alvaro Herrera and Tom Lane.
This commit is contained in:
Tom Lane 2005-06-17 22:32:51 +00:00
parent 5495575903
commit d0a89683a3
61 changed files with 4454 additions and 439 deletions
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94
doc/src/sgml/catalogs.sgml
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@ -1,6 +1,6 @@
<!--
Documentation of the system catalogs, directed toward PostgreSQL developers
$PostgreSQL: pgsql/doc/src/sgml/catalogs.sgml,v 2.103 2005/06/13 23:14:47 tgl Exp $
$PostgreSQL: pgsql/doc/src/sgml/catalogs.sgml,v 2.104 2005/06/17 22:32:41 tgl Exp $
-->
<chapter id="catalogs">
@ -3932,6 +3932,11 @@
<entry>currently held locks</entry>
</row>
<row>
<entry><link linkend="view-pg-prepared-xacts"><structname>pg_prepared_xacts</structname></link></entry>
<entry>currently prepared transactions</entry>
</row>
<row>
<entry><link linkend="view-pg-rules"><structname>pg_rules</structname></link></entry>
<entry>rules</entry>
@ -4167,8 +4172,10 @@
<entry><structfield>pid</structfield></entry>
<entry><type>integer</type></entry>
<entry></entry>
<entry>process ID of the server process holding or awaiting this
lock</entry>
<entry>
Process ID of the server process holding or awaiting this
lock. Zero if the lock is held by a prepared transaction.
</entry>
</row>
<row>
<entry><structfield>mode</structfield></entry>
@ -4250,6 +4257,87 @@
</sect1>
<sect1 id="view-pg-prepared-xacts">
<title><structname>pg_prepared_xacts</structname></title>
<indexterm zone="view-pg-prepared-xacts">
<primary>pg_prepared_xacts</primary>
</indexterm>
<para>
The view <structname>pg_prepared_xacts</structname> displays
information about transactions that are currently prepared for two-phase
commit (see <xref linkend="sql-prepare-transaction"
endterm="sql-prepare-transaction-title"> for details).
</para>
<para>
<structname>pg_prepared_xacts</structname> contains one row per prepared
transaction. An entry is removed when the transaction is committed or
rolled back.
</para>
<table>
<title><structname>pg_prepared_xacts</> Columns</title>
<tgroup cols=4>
<thead>
<row>
<entry>Name</entry>
<entry>Type</entry>
<entry>References</entry>
<entry>Description</entry>
</row>
</thead>
<tbody>
<row>
<entry><structfield>transaction</structfield></entry>
<entry><type>xid</type></entry>
<entry></entry>
<entry>
Numeric transaction identifier of the prepared transaction
</entry>
</row>
<row>
<entry><structfield>gid</structfield></entry>
<entry><type>text</type></entry>
<entry></entry>
<entry>
Global transaction identifier that was assigned to the transaction
</entry>
</row>
<row>
<entry><structfield>owner</structfield></entry>
<entry><type>name</type></entry>
<entry><literal><link linkend="catalog-pg-shadow"><structname>pg_shadow</structname></link>.usename</literal></entry>
<entry>
Name of the user that executed the transaction
</entry>
</row>
<row>
<entry><structfield>database</structfield></entry>
<entry><type>name</type></entry>
<entry><literal><link linkend="catalog-pg-database"><structname>pg_database</structname></link>.datname</literal></entry>
<entry>
Name of the database in which the transaction was executed
</entry>
</row>
</tbody>
</tgroup>
</table>
<para>
When the <structname>pg_prepared_xacts</structname> view is accessed, the
internal transaction manager data structures are momentarily locked, and
a copy is made for the view to display. This ensures that the
view produces a consistent set of results, while not blocking
normal operations longer than necessary. Nonetheless
there could be some impact on database performance if this view is
read often.
</para>
</sect1>
<sect1 id="view-pg-rules">
<title><structname>pg_rules</structname></title>

5
doc/src/sgml/ref/allfiles.sgml
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@ -1,5 +1,5 @@
<!--
$PostgreSQL: pgsql/doc/src/sgml/ref/allfiles.sgml,v 1.62 2004/08/21 16:16:04 tgl Exp $
$PostgreSQL: pgsql/doc/src/sgml/ref/allfiles.sgml,v 1.63 2005/06/17 22:32:42 tgl Exp $
PostgreSQL documentation
Complete list of usable sgml source files in this directory.
-->
@ -30,6 +30,7 @@ Complete list of usable sgml source files in this directory.
<!entity cluster system "cluster.sgml">
<!entity commentOn system "comment.sgml">
<!entity commit system "commit.sgml">
<!entity commitPrepared system "commit_prepared.sgml">
<!entity copyTable system "copy.sgml">
<!entity createAggregate system "create_aggregate.sgml">
<!entity createCast system "create_cast.sgml">
@ -88,11 +89,13 @@ Complete list of usable sgml source files in this directory.
<!entity move system "move.sgml">
<!entity notify system "notify.sgml">
<!entity prepare system "prepare.sgml">
<!entity prepareTransaction system "prepare_transaction.sgml">
<!entity reindex system "reindex.sgml">
<!entity releaseSavepoint system "release_savepoint.sgml">
<!entity reset system "reset.sgml">
<!entity revoke system "revoke.sgml">
<!entity rollback system "rollback.sgml">
<!entity rollbackPrepared system "rollback_prepared.sgml">
<!entity rollbackTo system "rollback_to.sgml">
<!entity savepoint system "savepoint.sgml">
<!entity select system "select.sgml">

111
doc/src/sgml/ref/commit_prepared.sgml Normal file
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@ -0,0 +1,111 @@
<!--
$PostgreSQL: pgsql/doc/src/sgml/ref/commit_prepared.sgml,v 1.1 2005/06/17 22:32:42 tgl Exp $
PostgreSQL documentation
-->
<refentry id="SQL-COMMIT-PREPARED">
<refmeta>
<refentrytitle id="sql-commit-prepared-title">COMMIT PREPARED</refentrytitle>
<refmiscinfo>SQL - Language Statements</refmiscinfo>
</refmeta>
<refnamediv>
<refname>COMMIT PREPARED</refname>
<refpurpose>commit a transaction that was earlier prepared for two-phase commit</refpurpose>
</refnamediv>
<indexterm zone="sql-commit-prepared">
<primary>COMMIT PREPARED</primary>
</indexterm>
<refsynopsisdiv>
<synopsis>
COMMIT PREPARED <replaceable class="PARAMETER">transaction_id</replaceable>
</synopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>
<command>COMMIT PREPARED</command> commits a transaction that is in
prepared state.
</para>
</refsect1>
<refsect1>
<title>Parameters</title>
<variablelist>
<varlistentry>
<term><replaceable class="PARAMETER">transaction_id</replaceable></term>
<listitem>
<para>
The transaction identifier of the transaction that is to be
committed.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Notes</title>
<para>
To commit a prepared transaction, you must be either the same user that
executed the transaction originally, or a superuser. But you do not
have to be in the same session that executed the transaction.
</para>
<para>
This command cannot be executed inside a transaction block. The prepared
transaction is committed immediately.
</para>
<para>
All currently available prepared transactions are listed in the
<structname>pg_prepared_xacts</> system view.
</para>
</refsect1>
<refsect1 id="sql-commit-prepared-examples">
<title id="sql-commit-prepared-examples-title">Examples</title>
<para>
Commit the transaction identified by the transaction
identifier <literal>foobar</>:
<programlisting>
COMMIT PREPARED 'foobar';
</programlisting>
</para>
</refsect1>
<refsect1>
<title>See Also</title>
<simplelist type="inline">
<member><xref linkend="sql-prepare-transaction" endterm="sql-prepare-transaction-title"></member>
<member><xref linkend="sql-rollback-prepared" endterm="sql-rollback-prepared-title"></member>
</simplelist>
</refsect1>
</refentry>
<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:nil
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
sgml-parent-document:nil
sgml-default-dtd-file:"../reference.ced"
sgml-exposed-tags:nil
sgml-local-catalogs:"/usr/lib/sgml/catalog"
sgml-local-ecat-files:nil
End:
-->

160
doc/src/sgml/ref/prepare_transaction.sgml Normal file
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@ -0,0 +1,160 @@
<!--
$PostgreSQL: pgsql/doc/src/sgml/ref/prepare_transaction.sgml,v 1.1 2005/06/17 22:32:42 tgl Exp $
PostgreSQL documentation
-->
<refentry id="SQL-PREPARE-TRANSACTION">
<refmeta>
<refentrytitle id="sql-prepare-transaction-title">PREPARE TRANSACTION</refentrytitle>
<refmiscinfo>SQL - Language Statements</refmiscinfo>
</refmeta>
<refnamediv>
<refname>PREPARE TRANSACTION</refname>
<refpurpose>prepare the current transaction for two-phase commit</refpurpose>
</refnamediv>
<indexterm zone="sql-prepare-transaction">
<primary>PREPARE TRANSACTION</primary>
</indexterm>
<refsynopsisdiv>
<synopsis>
PREPARE TRANSACTION <replaceable class="PARAMETER">transaction_id</replaceable>
</synopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>
<command>PREPARE TRANSACTION</command> prepares the current transaction
for two-phase commit. After this command, the transaction is no longer
associated with the current session; instead, its state is fully stored on
disk, and there is a very high probability that it can be committed
successfully, even if a database crash occurs before the commit is
requested.
</para>
<para>
Once prepared, a transaction can later be committed or rolled
back with <command>COMMIT PREPARED</command> or
<command>ROLLBACK PREPARED</command>, respectively. Those commands
can be issued from any session, not only the one that executed the
original transaction.
</para>
<para>
From the point of view of the issuing session, <command>PREPARE
TRANSACTION</command> is not unlike a <command>ROLLBACK</> command:
after executing it, there is no active current transaction, and the
effects of the prepared transaction are no longer visible. (The effects
will become visible again if the transaction is committed.)
</para>
<para>
If the <command>PREPARE TRANSACTION</command> command fails for any
reason, it becomes a <command>ROLLBACK</>: the current transaction
is canceled.
</para>
</refsect1>
<refsect1>
<title>Parameters</title>
<variablelist>
<varlistentry>
<term><replaceable class="PARAMETER">transaction_id</replaceable></term>
<listitem>
<para>
An arbitrary identifier that later identifies this transaction for
<command>COMMIT PREPARED</> or <command>ROLLBACK PREPARED</>.
The identifier must be written as a string literal, and must be
less than 200 bytes long. It must not be the same as the identifier
used for any currently prepared transaction.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Notes</title>
<para>
This command must be used inside a transaction block. Use
<command>BEGIN</command> to start one.
</para>
<para>
It is not currently allowed to <command>PREPARE</> a transaction that
has executed any operations involving temporary tables nor
created any cursors <literal>WITH HOLD</>. Those features are too tightly
tied to the current session to be useful in a transaction to be prepared.
</para>
<para>
If the transaction modified any run-time parameters with <command>SET</>,
those effects persist after <command>PREPARE TRANSACTION</>, and will not
be affected by any later <command>COMMIT PREPARED</command> or
<command>ROLLBACK PREPARED</command>. Thus, in this one respect
<command>PREPARE TRANSACTION</> acts more like <command>COMMIT</> than
<command>ROLLBACK</>.
</para>
<para>
All currently available prepared transactions are listed in the
<structname>pg_prepared_xacts</> system view.
</para>
<para>
From a performance standpoint, it is unwise to leave transactions in
the prepared state for a long time: this will for instance interfere with
the ability of <command>VACUUM</> to reclaim storage. Keep in mind also
that the transaction continues to hold whatever locks it held.
The intended
usage of the feature is that a prepared transaction will normally be
committed or rolled back as soon as an external transaction manager
has verified that other databases are also prepared to commit.
</para>
</refsect1>
<refsect1 id="sql-prepare-transaction-examples">
<title id="sql-prepare-transaction-examples-title">Examples</title>
<para>
Prepare the current transaction for two-phase commit, using
<literal>foobar</> as the transaction identifier:
<programlisting>
PREPARE TRANSACTION 'foobar';
</programlisting>
</para>
</refsect1>
<refsect1>
<title>See Also</title>
<simplelist type="inline">
<member><xref linkend="sql-commit-prepared" endterm="sql-commit-prepared-title"></member>
<member><xref linkend="sql-rollback-prepared" endterm="sql-rollback-prepared-title"></member>
</simplelist>
</refsect1>
</refentry>
<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:nil
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
sgml-parent-document:nil
sgml-default-dtd-file:"../reference.ced"
sgml-exposed-tags:nil
sgml-local-catalogs:"/usr/lib/sgml/catalog"
sgml-local-ecat-files:nil
End:
-->

111
doc/src/sgml/ref/rollback_prepared.sgml Normal file
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@ -0,0 +1,111 @@
<!--
$PostgreSQL: pgsql/doc/src/sgml/ref/rollback_prepared.sgml,v 1.1 2005/06/17 22:32:42 tgl Exp $
PostgreSQL documentation
-->
<refentry id="SQL-ROLLBACK-PREPARED">
<refmeta>
<refentrytitle id="sql-rollback-prepared-title">ROLLBACK PREPARED</refentrytitle>
<refmiscinfo>SQL - Language Statements</refmiscinfo>
</refmeta>
<refnamediv>
<refname>ROLLBACK PREPARED</refname>
<refpurpose>cancel a transaction that was earlier prepared for two-phase commit</refpurpose>
</refnamediv>
<indexterm zone="sql-rollback-prepared">
<primary>ROLLBACK PREPARED</primary>
</indexterm>
<refsynopsisdiv>
<synopsis>
ROLLBACK PREPARED <replaceable class="PARAMETER">transaction_id</replaceable>
</synopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>
<command>ROLLBACK PREPARED</command> rolls back a transaction that is in
prepared state.
</para>
</refsect1>
<refsect1>
<title>Parameters</title>
<variablelist>
<varlistentry>
<term><replaceable class="PARAMETER">transaction_id</replaceable></term>
<listitem>
<para>
The transaction identifier of the transaction that is to be
rolled back.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Notes</title>
<para>
To roll back a prepared transaction, you must be either the same user that
executed the transaction originally, or a superuser. But you do not
have to be in the same session that executed the transaction.
</para>
<para>
This command cannot be executed inside a transaction block. The prepared
transaction is rolled back immediately.
</para>
<para>
All currently available prepared transactions are listed in the
<structname>pg_prepared_xacts</> system view.
</para>
</refsect1>
<refsect1 id="sql-rollback-prepared-examples">
<title id="sql-rollback-prepared-examples-title">Examples</title>
<para>
Roll back the transaction identified by the transaction
identifier <literal>foobar</>:
<programlisting>
ROLLBACK PREPARED 'foobar';
</programlisting>
</para>
</refsect1>
<refsect1>
<title>See Also</title>
<simplelist type="inline">
<member><xref linkend="sql-prepare-transaction" endterm="sql-prepare-transaction-title"></member>
<member><xref linkend="sql-commit-prepared" endterm="sql-commit-prepared-title"></member>
</simplelist>
</refsect1>
</refentry>
<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:nil
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
sgml-parent-document:nil
sgml-default-dtd-file:"../reference.ced"
sgml-exposed-tags:nil
sgml-local-catalogs:"/usr/lib/sgml/catalog"
sgml-local-ecat-files:nil
End:
-->

5
doc/src/sgml/reference.sgml
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@ -1,5 +1,5 @@
<!-- reference.sgml
$PostgreSQL: pgsql/doc/src/sgml/reference.sgml,v 1.52 2004/08/21 16:16:03 tgl Exp $
$PostgreSQL: pgsql/doc/src/sgml/reference.sgml,v 1.53 2005/06/17 22:32:42 tgl Exp $
PostgreSQL Reference Manual
-->
@ -62,6 +62,7 @@ PostgreSQL Reference Manual
&cluster;
&commentOn;
&commit;
&commitPrepared;
&copyTable;
&createAggregate;
&createCast;
@ -120,11 +121,13 @@ PostgreSQL Reference Manual
&move;
&notify;
&prepare;
&prepareTransaction;
&reindex;
&releaseSavepoint;
&reset;
&revoke;
&rollback;
&rollbackPrepared;
&rollbackTo;
&savepoint;
&select;

31
doc/src/sgml/runtime.sgml
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@ -1,5 +1,5 @@
<!--
$PostgreSQL: pgsql/doc/src/sgml/runtime.sgml,v 1.328 2005/06/17 13:12:01 momjian Exp $
$PostgreSQL: pgsql/doc/src/sgml/runtime.sgml,v 1.329 2005/06/17 22:32:42 tgl Exp $
-->
<chapter Id="runtime">
@ -956,7 +956,7 @@ SET ENABLE_SEQSCAN TO OFF;
<para>
Sets the location of the Kerberos server key file. See
<xref linkend="kerberos-auth"> for details. This parameter
can only be set at server start.
can only be set at server start.
</para>
</listitem>
</varlistentry>
@ -1113,6 +1113,33 @@ SET ENABLE_SEQSCAN TO OFF;
</listitem>
</varlistentry>
<varlistentry id="guc-max-prepared-transactions" xreflabel="max_prepared_transactions">
<term><varname>max_prepared_transactions</varname> (<type>integer</type>)</term>
<indexterm>
<primary><varname>max_prepared_transactions</> configuration parameter</primary>
</indexterm>
<listitem>
<para>
Sets the maximum number of transactions that can be in the
<quote>prepared</> state simultaneously (see <xref
linkend="sql-prepare-transaction"
endterm="sql-prepare-transaction-title">).
Setting this parameter to zero disables the prepared-transaction
feature.
The default is 50.
This option can only be set at server start.
</para>
<para>
Increasing this parameter may cause <productname>PostgreSQL</>
to request more <systemitem class="osname">System V</> shared
memory than your operating system's default configuration
allows. See <xref linkend="sysvipc"> for information on how to
adjust those parameters, if necessary.
</para>
</listitem>
</varlistentry>
<varlistentry id="guc-work-mem" xreflabel="work_mem">
<term><varname>work_mem</varname> (<type>integer</type>)</term>
<indexterm>

4
src/backend/access/transam/Makefile
View File

@ -4,7 +4,7 @@
# Makefile for access/transam
#
# IDENTIFICATION
# $PostgreSQL: pgsql/src/backend/access/transam/Makefile,v 1.20 2005/04/28 21:47:10 tgl Exp $
# $PostgreSQL: pgsql/src/backend/access/transam/Makefile,v 1.21 2005/06/17 22:32:42 tgl Exp $
#
#-------------------------------------------------------------------------
@ -12,7 +12,7 @@ subdir = src/backend/access/transam
top_builddir = ../../../..
include $(top_builddir)/src/Makefile.global
OBJS = clog.o transam.o varsup.o xact.o xlog.o xlogutils.o rmgr.o slru.o subtrans.o multixact.o
OBJS = clog.o transam.o varsup.o xact.o xlog.o xlogutils.o rmgr.o slru.o subtrans.o multixact.o twophase.o twophase_rmgr.o
all: SUBSYS.o

19
src/backend/access/transam/subtrans.c
View File

@ -22,7 +22,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/backend/access/transam/subtrans.c,v 1.8 2005/05/19 21:35:45 tgl Exp $
* $PostgreSQL: pgsql/src/backend/access/transam/subtrans.c,v 1.9 2005/06/17 22:32:42 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -222,22 +222,33 @@ ZeroSUBTRANSPage(int pageno)
/*
* This must be called ONCE during postmaster or standalone-backend startup,
* after StartupXLOG has initialized ShmemVariableCache->nextXid.
*
* oldestActiveXID is the oldest XID of any prepared transaction, or nextXid
* if there are none.
*/
void
StartupSUBTRANS(void)
StartupSUBTRANS(TransactionId oldestActiveXID)
{
int startPage;
int endPage;
/*
* Since we don't expect pg_subtrans to be valid across crashes, we
* initialize the currently-active page to zeroes during startup.
* initialize the currently-active page(s) to zeroes during startup.
* Whenever we advance into a new page, ExtendSUBTRANS will likewise
* zero the new page without regard to whatever was previously on
* disk.
*/
LWLockAcquire(SubtransControlLock, LW_EXCLUSIVE);
startPage = TransactionIdToPage(ShmemVariableCache->nextXid);
startPage = TransactionIdToPage(oldestActiveXID);
endPage = TransactionIdToPage(ShmemVariableCache->nextXid);
while (startPage != endPage)
{
(void) ZeroSUBTRANSPage(startPage);
startPage++;
}
(void) ZeroSUBTRANSPage(startPage);
LWLockRelease(SubtransControlLock);

25
src/backend/access/transam/transam.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/access/transam/transam.c,v 1.64 2005/02/20 21:46:48 tgl Exp $
* $PostgreSQL: pgsql/src/backend/access/transam/transam.c,v 1.65 2005/06/17 22:32:42 tgl Exp $
*
* NOTES
* This file contains the high level access-method interface to the
@ -173,6 +173,14 @@ TransactionIdDidCommit(TransactionId transactionId)
* recursively. However, if it's older than TransactionXmin, we can't
* look at pg_subtrans; instead assume that the parent crashed without
* cleaning up its children.
*
* Originally we Assert'ed that the result of SubTransGetParent was
* not zero. However with the introduction of prepared transactions,
* there can be a window just after database startup where we do not
* have complete knowledge in pg_subtrans of the transactions after
* TransactionXmin. StartupSUBTRANS() has ensured that any missing
* information will be zeroed. Since this case should not happen under
* normal conditions, it seems reasonable to emit a WARNING for it.
*/
if (xidstatus == TRANSACTION_STATUS_SUB_COMMITTED)
{
@ -181,7 +189,12 @@ TransactionIdDidCommit(TransactionId transactionId)
if (TransactionIdPrecedes(transactionId, TransactionXmin))
return false;
parentXid = SubTransGetParent(transactionId);
Assert(TransactionIdIsValid(parentXid));
if (!TransactionIdIsValid(parentXid))
{
elog(WARNING, "no pg_subtrans entry for subcommitted XID %u",
transactionId);
return false;
}
return TransactionIdDidCommit(parentXid);
}
@ -224,7 +237,13 @@ TransactionIdDidAbort(TransactionId transactionId)
if (TransactionIdPrecedes(transactionId, TransactionXmin))
return true;
parentXid = SubTransGetParent(transactionId);
Assert(TransactionIdIsValid(parentXid));
if (!TransactionIdIsValid(parentXid))
{
/* see notes in TransactionIdDidCommit */
elog(WARNING, "no pg_subtrans entry for subcommitted XID %u",
transactionId);
return true;
}
return TransactionIdDidAbort(parentXid);
}

1659
src/backend/access/transam/twophase.c Normal file
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49
src/backend/access/transam/twophase_rmgr.c Normal file
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@ -0,0 +1,49 @@
/*-------------------------------------------------------------------------
*
* twophase_rmgr.c
* Two-phase-commit resource managers tables
*
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/access/transam/twophase_rmgr.c,v 1.1 2005/06/17 22:32:42 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/twophase_rmgr.h"
#include "commands/async.h"
#include "storage/lock.h"
#include "utils/flatfiles.h"
#include "utils/inval.h"
const TwoPhaseCallback twophase_recover_callbacks[TWOPHASE_RM_MAX_ID + 1] =
{
NULL, /* END ID */
lock_twophase_recover, /* Lock */
NULL, /* Inval */
NULL, /* flat file update */
NULL /* notify/listen */
};
const TwoPhaseCallback twophase_postcommit_callbacks[TWOPHASE_RM_MAX_ID + 1] =
{
NULL, /* END ID */
lock_twophase_postcommit, /* Lock */
inval_twophase_postcommit, /* Inval */
flatfile_twophase_postcommit, /* flat file update */
notify_twophase_postcommit /* notify/listen */
};
const TwoPhaseCallback twophase_postabort_callbacks[TWOPHASE_RM_MAX_ID + 1] =
{
NULL, /* END ID */
lock_twophase_postabort, /* Lock */
NULL, /* Inval */
NULL, /* flat file update */
NULL /* notify/listen */
};

650
src/backend/access/transam/xact.c
View File

@ -10,7 +10,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/access/transam/xact.c,v 1.204 2005/06/06 20:22:57 tgl Exp $
* $PostgreSQL: pgsql/src/backend/access/transam/xact.c,v 1.205 2005/06/17 22:32:42 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -22,6 +22,7 @@
#include "access/multixact.h"
#include "access/subtrans.h"
#include "access/twophase.h"
#include "access/xact.h"
#include "catalog/heap.h"
#include "catalog/index.h"
@ -68,7 +69,8 @@ typedef enum TransState
TRANS_START,
TRANS_INPROGRESS,
TRANS_COMMIT,
TRANS_ABORT
TRANS_ABORT,
TRANS_PREPARE
} TransState;
/*
@ -90,6 +92,7 @@ typedef enum TBlockState
TBLOCK_ABORT, /* failed xact, awaiting ROLLBACK */
TBLOCK_ABORT_END, /* failed xact, ROLLBACK received */
TBLOCK_ABORT_PENDING, /* live xact, ROLLBACK received */
TBLOCK_PREPARE, /* live xact, PREPARE received */
/* subtransaction states */
TBLOCK_SUBBEGIN, /* starting a subtransaction */
@ -172,6 +175,12 @@ static CommandId currentCommandId;
static AbsoluteTime xactStartTime; /* integer part */
static int xactStartTimeUsec; /* microsecond part */
/*
* GID to be used for preparing the current transaction. This is also
* global to a whole transaction, so we don't keep it in the state stack.
*/
static char *prepareGID;
/*
* List of add-on start- and end-of-xact callbacks
@ -267,10 +276,12 @@ IsTransactionState(void)
return true;
case TRANS_ABORT:
return true;
case TRANS_PREPARE:
return true;
}
/*
* Shouldn't get here, but lint is not happy with this...
* Shouldn't get here, but lint is not happy without this...
*/
return false;
}
@ -660,12 +671,12 @@ void
RecordTransactionCommit(void)
{
int nrels;
RelFileNode *rptr;
RelFileNode *rels;
int nchildren;
TransactionId *children;
/* Get data needed for commit record */
nrels = smgrGetPendingDeletes(true, &rptr);
nrels = smgrGetPendingDeletes(true, &rels);
nchildren = xactGetCommittedChildren(&children);
/*
@ -726,7 +737,7 @@ RecordTransactionCommit(void)
if (nrels > 0)
{
rdata[0].next = &(rdata[1]);
rdata[1].data = (char *) rptr;
rdata[1].data = (char *) rels;
rdata[1].len = nrels * sizeof(RelFileNode);
rdata[1].buffer = InvalidBuffer;
lastrdata = 1;
@ -809,12 +820,9 @@ RecordTransactionCommit(void)
MyXactMadeXLogEntry = false;
MyXactMadeTempRelUpdate = false;
/* Show myself as out of the transaction in PGPROC array */
MyProc->logRec.xrecoff = 0;
/* And clean up local data */
if (rptr)
pfree(rptr);
if (rels)
pfree(rels);
if (children)
pfree(children);
}
@ -970,12 +978,12 @@ static void
RecordTransactionAbort(void)
{
int nrels;
RelFileNode *rptr;
RelFileNode *rels;
int nchildren;
TransactionId *children;
/* Get data needed for abort record */
nrels = smgrGetPendingDeletes(false, &rptr);
nrels = smgrGetPendingDeletes(false, &rels);
nchildren = xactGetCommittedChildren(&children);
/*
@ -1026,7 +1034,7 @@ RecordTransactionAbort(void)
if (nrels > 0)
{
rdata[0].next = &(rdata[1]);
rdata[1].data = (char *) rptr;
rdata[1].data = (char *) rels;
rdata[1].len = nrels * sizeof(RelFileNode);
rdata[1].buffer = InvalidBuffer;
lastrdata = 1;
@ -1069,12 +1077,9 @@ RecordTransactionAbort(void)
MyXactMadeXLogEntry = false;
MyXactMadeTempRelUpdate = false;
/* Show myself as out of the transaction in PGPROC array */
MyProc->logRec.xrecoff = 0;
/* And clean up local data */
if (rptr)
pfree(rptr);
if (rels)
pfree(rels);
if (children)
pfree(children);
}
@ -1166,13 +1171,13 @@ static void
RecordSubTransactionAbort(void)
{
int nrels;
RelFileNode *rptr;
RelFileNode *rels;
TransactionId xid = GetCurrentTransactionId();
int nchildren;
TransactionId *children;
/* Get data needed for abort record */
nrels = smgrGetPendingDeletes(false, &rptr);
nrels = smgrGetPendingDeletes(false, &rels);
nchildren = xactGetCommittedChildren(&children);
/*
@ -1212,7 +1217,7 @@ RecordSubTransactionAbort(void)
if (nrels > 0)
{
rdata[0].next = &(rdata[1]);
rdata[1].data = (char *) rptr;
rdata[1].data = (char *) rels;
rdata[1].len = nrels * sizeof(RelFileNode);
rdata[1].buffer = InvalidBuffer;
lastrdata = 1;
@ -1256,8 +1261,8 @@ RecordSubTransactionAbort(void)
XidCacheRemoveRunningXids(xid, nchildren, children);
/* And clean up local data */
if (rptr)
pfree(rptr);
if (rels)
pfree(rels);
if (children)
pfree(children);
}
@ -1419,8 +1424,11 @@ StartTransaction(void)
ShowTransactionState("StartTransaction");
}
/*
* CommitTransaction
*
* NB: if you change this routine, better look at PrepareTransaction too!
*/
static void
CommitTransaction(void)
@ -1510,6 +1518,8 @@ CommitTransaction(void)
* xid 0 as running as well, or it will be able to see two tuple versions
* - one deleted by xid 1 and one inserted by xid 0. See notes in
* GetSnapshotData.
*
* Note: MyProc may be null during bootstrap.
*----------
*/
if (MyProc != NULL)
@ -1608,6 +1618,225 @@ CommitTransaction(void)
RESUME_INTERRUPTS();
}
/*
* PrepareTransaction
*
* NB: if you change this routine, better look at CommitTransaction too!
*/
static void
PrepareTransaction(void)
{
TransactionState s = CurrentTransactionState;
TransactionId xid = GetCurrentTransactionId();
GlobalTransaction gxact;
ShowTransactionState("PrepareTransaction");
/*
* check the current transaction state
*/
if (s->state != TRANS_INPROGRESS)
elog(WARNING, "PrepareTransaction while in %s state",
TransStateAsString(s->state));
Assert(s->parent == NULL);
/*
* Do pre-commit processing (most of this stuff requires database
* access, and in fact could still cause an error...)
*
* It is possible for PrepareHoldablePortals to invoke functions that
* queue deferred triggers, and it's also possible that triggers create
* holdable cursors. So we have to loop until there's nothing left to
* do.
*/
for (;;)
{
/*
* Fire all currently pending deferred triggers.
*/
AfterTriggerFireDeferred();
/*
* Convert any open holdable cursors into static portals. If there
* weren't any, we are done ... otherwise loop back to check if they
* queued deferred triggers. Lather, rinse, repeat.
*/
if (!PrepareHoldablePortals())
break;
}
/* Now we can shut down the deferred-trigger manager */
AfterTriggerEndXact(true);
/* Close any open regular cursors */
AtCommit_Portals();
/*
* Let ON COMMIT management do its thing (must happen after closing
* cursors, to avoid dangling-reference problems)
*/
PreCommit_on_commit_actions();
/* close large objects before lower-level cleanup */
AtEOXact_LargeObject(true);
/* NOTIFY and flatfiles will be handled below */
/* Prevent cancel/die interrupt while cleaning up */
HOLD_INTERRUPTS();
/*
* set the current transaction state information appropriately during
* the processing
*/
s->state = TRANS_PREPARE;
/* Tell bufmgr and smgr to prepare for commit */
BufmgrCommit();
/*
* Reserve the GID for this transaction. This could fail if the
* requested GID is invalid or already in use.
*/
gxact = MarkAsPreparing(xid, MyDatabaseId, prepareGID, GetUserId());
prepareGID = NULL;
/*
* Collect data for the 2PC state file. Note that in general, no actual
* state change should happen in the called modules during this step,
* since it's still possible to fail before commit, and in that case we
* want transaction abort to be able to clean up. (In particular, the
* AtPrepare routines may error out if they find cases they cannot
* handle.) State cleanup should happen in the PostPrepare routines
* below. However, some modules can go ahead and clear state here
* because they wouldn't do anything with it during abort anyway.
*
* Note: because the 2PC state file records will be replayed in the same
* order they are made, the order of these calls has to match the order
* in which we want things to happen during COMMIT PREPARED or
* ROLLBACK PREPARED; in particular, pay attention to whether things
* should happen before or after releasing the transaction's locks.
*/
StartPrepare(gxact);
AtPrepare_Notify();
AtPrepare_UpdateFlatFiles();
AtPrepare_Inval();
AtPrepare_Locks();
/*
* Here is where we really truly prepare.
*
* We have to record transaction prepares even if we didn't
* make any updates, because the transaction manager might
* get confused if we lose a global transaction.
*/
EndPrepare(gxact);
/*
* Mark the prepared transaction as valid. As soon as we mark ourselves
* not running in MyProc below, others can commit/rollback the xact.
*
* NB: a side effect of this is to make a dummy ProcArray entry for the
* prepared XID. This must happen before we clear the XID from MyProc,
* else there is a window where the XID is not running according to
* TransactionIdInProgress, and onlookers would be entitled to assume
* the xact crashed. Instead we have a window where the same XID
* appears twice in ProcArray, which is OK.
*/
MarkAsPrepared(gxact);
/*
* Now we clean up backend-internal state and release internal
* resources.
*/
/* Break the chain of back-links in the XLOG records I output */
MyLastRecPtr.xrecoff = 0;
MyXactMadeXLogEntry = false;
MyXactMadeTempRelUpdate = false;
/*
* Let others know about no transaction in progress by me. This has
* to be done *after* the prepared transaction has been marked valid,
* else someone may think it is unlocked and recyclable.
*/
/* Lock ProcArrayLock because that's what GetSnapshotData uses. */
LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
MyProc->xid = InvalidTransactionId;
MyProc->xmin = InvalidTransactionId;
/* Clear the subtransaction-XID cache too while holding the lock */
MyProc->subxids.nxids = 0;
MyProc->subxids.overflowed = false;
LWLockRelease(ProcArrayLock);
/*
* This is all post-transaction cleanup. Note that if an error is raised
* here, it's too late to abort the transaction. This should be just
* noncritical resource releasing. See notes in CommitTransaction.
*/
CallXactCallbacks(XACT_EVENT_PREPARE);
ResourceOwnerRelease(TopTransactionResourceOwner,
RESOURCE_RELEASE_BEFORE_LOCKS,
true, true);
/* Check we've released all buffer pins */
AtEOXact_Buffers(true);
/* notify and flatfiles don't need a postprepare call */
PostPrepare_Inval();
PostPrepare_smgr();
AtEOXact_MultiXact();
PostPrepare_Locks(xid);
ResourceOwnerRelease(TopTransactionResourceOwner,
RESOURCE_RELEASE_LOCKS,
true, true);
ResourceOwnerRelease(TopTransactionResourceOwner,
RESOURCE_RELEASE_AFTER_LOCKS,
true, true);
/* PREPARE acts the same as COMMIT as far as GUC is concerned */
AtEOXact_GUC(true, false);
AtEOXact_SPI(true);
AtEOXact_on_commit_actions(true);
AtEOXact_Namespace(true);
/* smgrcommit already done */
AtEOXact_Files();
CurrentResourceOwner = NULL;
ResourceOwnerDelete(TopTransactionResourceOwner);
s->curTransactionOwner = NULL;
CurTransactionResourceOwner = NULL;
TopTransactionResourceOwner = NULL;
AtCommit_Memory();
s->transactionId = InvalidTransactionId;
s->subTransactionId = InvalidSubTransactionId;
s->nestingLevel = 0;
s->childXids = NIL;
/*
* done with 1st phase commit processing, set current transaction
* state back to default
*/
s->state = TRANS_DEFAULT;
RESUME_INTERRUPTS();
}
/*
* AbortTransaction
*/
@ -1640,7 +1869,7 @@ AbortTransaction(void)
/*
* check the current transaction state
*/
if (s->state != TRANS_INPROGRESS)
if (s->state != TRANS_INPROGRESS && s->state != TRANS_PREPARE)
elog(WARNING, "AbortTransaction while in %s state",
TransStateAsString(s->state));
Assert(s->parent == NULL);
@ -1833,6 +2062,7 @@ StartTransactionCommand(void)
case TBLOCK_SUBABORT_PENDING:
case TBLOCK_SUBRESTART:
case TBLOCK_SUBABORT_RESTART:
case TBLOCK_PREPARE:
elog(ERROR, "StartTransactionCommand: unexpected state %s",
BlockStateAsString(s->blockState));
break;
@ -1934,6 +2164,15 @@ CommitTransactionCommand(void)
s->blockState = TBLOCK_DEFAULT;
break;
/*
* We are completing a "PREPARE TRANSACTION" command. Do it and
* return to the idle state.
*/
case TBLOCK_PREPARE:
PrepareTransaction();
s->blockState = TBLOCK_DEFAULT;
break;
/*
* We were just issued a SAVEPOINT inside a transaction block.
* Start a subtransaction. (DefineSavepoint already did
@ -1964,6 +2203,12 @@ CommitTransactionCommand(void)
CommitTransaction();
s->blockState = TBLOCK_DEFAULT;
}
else if (s->blockState == TBLOCK_PREPARE)
{
Assert(s->parent == NULL);
PrepareTransaction();
s->blockState = TBLOCK_DEFAULT;
}
else
{
Assert(s->blockState == TBLOCK_INPROGRESS ||
@ -2155,6 +2400,17 @@ AbortCurrentTransaction(void)
s->blockState = TBLOCK_DEFAULT;
break;
/*
* Here, we failed while trying to PREPARE. Clean up the
* transaction and return to idle state (we do not want to
* stay in the transaction).
*/
case TBLOCK_PREPARE:
AbortTransaction();
CleanupTransaction();
s->blockState = TBLOCK_DEFAULT;
break;
/*
* We got an error inside a subtransaction. Abort just the
* subtransaction, and go to the persistent SUBABORT state
@ -2487,12 +2743,64 @@ BeginTransactionBlock(void)
case TBLOCK_SUBABORT_PENDING:
case TBLOCK_SUBRESTART:
case TBLOCK_SUBABORT_RESTART:
case TBLOCK_PREPARE:
elog(FATAL, "BeginTransactionBlock: unexpected state %s",
BlockStateAsString(s->blockState));
break;
}
}
/*
* PrepareTransactionBlock
* This executes a PREPARE command.
*
* Since PREPARE may actually do a ROLLBACK, the result indicates what
* happened: TRUE for PREPARE, FALSE for ROLLBACK.
*
* Note that we don't actually do anything here except change blockState.
* The real work will be done in the upcoming PrepareTransaction().
* We do it this way because it's not convenient to change memory context,
* resource owner, etc while executing inside a Portal.
*/
bool
PrepareTransactionBlock(char *gid)
{
TransactionState s;
bool result;
/* Set up to commit the current transaction */
result = EndTransactionBlock();
/* If successful, change outer tblock state to PREPARE */
if (result)
{
s = CurrentTransactionState;
while (s->parent != NULL)
s = s->parent;
if (s->blockState == TBLOCK_END)
{
/* Save GID where PrepareTransaction can find it again */
prepareGID = MemoryContextStrdup(TopTransactionContext, gid);
s->blockState = TBLOCK_PREPARE;
}
else
{
/*
* ignore case where we are not in a transaction;
* EndTransactionBlock already issued a warning.
*/
Assert(s->blockState == TBLOCK_STARTED);
/* Don't send back a PREPARE result tag... */
result = false;
}
}
return result;
}
/*
* EndTransactionBlock
* This executes a COMMIT command.
@ -2603,6 +2911,7 @@ EndTransactionBlock(void)
case TBLOCK_SUBABORT_PENDING:
case TBLOCK_SUBRESTART:
case TBLOCK_SUBABORT_RESTART:
case TBLOCK_PREPARE:
elog(FATAL, "EndTransactionBlock: unexpected state %s",
BlockStateAsString(s->blockState));
break;
@ -2694,6 +3003,7 @@ UserAbortTransactionBlock(void)
case TBLOCK_SUBABORT_PENDING:
case TBLOCK_SUBRESTART:
case TBLOCK_SUBABORT_RESTART:
case TBLOCK_PREPARE:
elog(FATAL, "UserAbortTransactionBlock: unexpected state %s",
BlockStateAsString(s->blockState));
break;
@ -2740,6 +3050,7 @@ DefineSavepoint(char *name)
case TBLOCK_SUBABORT_PENDING:
case TBLOCK_SUBRESTART:
case TBLOCK_SUBABORT_RESTART:
case TBLOCK_PREPARE:
elog(FATAL, "DefineSavepoint: unexpected state %s",
BlockStateAsString(s->blockState));
break;
@ -2795,6 +3106,7 @@ ReleaseSavepoint(List *options)
case TBLOCK_SUBABORT_PENDING:
case TBLOCK_SUBRESTART:
case TBLOCK_SUBABORT_RESTART:
case TBLOCK_PREPARE:
elog(FATAL, "ReleaseSavepoint: unexpected state %s",
BlockStateAsString(s->blockState));
break;
@ -2892,6 +3204,7 @@ RollbackToSavepoint(List *options)
case TBLOCK_SUBABORT_PENDING:
case TBLOCK_SUBRESTART:
case TBLOCK_SUBABORT_RESTART:
case TBLOCK_PREPARE:
elog(FATAL, "RollbackToSavepoint: unexpected state %s",
BlockStateAsString(s->blockState));
break;
@ -2999,6 +3312,7 @@ BeginInternalSubTransaction(char *name)
case TBLOCK_SUBABORT_PENDING:
case TBLOCK_SUBRESTART:
case TBLOCK_SUBABORT_RESTART:
case TBLOCK_PREPARE:
elog(FATAL, "BeginInternalSubTransaction: unexpected state %s",
BlockStateAsString(s->blockState));
break;
@ -3064,6 +3378,7 @@ RollbackAndReleaseCurrentSubTransaction(void)
case TBLOCK_SUBABORT_PENDING:
case TBLOCK_SUBRESTART:
case TBLOCK_SUBABORT_RESTART:
case TBLOCK_PREPARE:
elog(FATAL, "RollbackAndReleaseCurrentSubTransaction: unexpected state %s",
BlockStateAsString(s->blockState));
break;
@ -3111,6 +3426,7 @@ AbortOutOfAnyTransaction(void)
case TBLOCK_INPROGRESS:
case TBLOCK_END:
case TBLOCK_ABORT_PENDING:
case TBLOCK_PREPARE:
/* In a transaction, so clean up */
AbortTransaction();
CleanupTransaction();
@ -3202,6 +3518,7 @@ TransactionBlockStatusCode(void)
case TBLOCK_SUBINPROGRESS:
case TBLOCK_END:
case TBLOCK_SUBEND:
case TBLOCK_PREPARE:
return 'T'; /* in transaction */
case TBLOCK_ABORT:
case TBLOCK_SUBABORT:
@ -3684,6 +4001,8 @@ BlockStateAsString(TBlockState blockState)
return "ABORT END";
case TBLOCK_ABORT_PENDING:
return "ABORT PEND";
case TBLOCK_PREPARE:
return "PREPARE";
case TBLOCK_SUBBEGIN:
return "SUB BEGIN";
case TBLOCK_SUBINPROGRESS:
@ -3717,12 +4036,14 @@ TransStateAsString(TransState state)
return "DEFAULT";
case TRANS_START:
return "START";
case TRANS_INPROGRESS:
return "INPROGR";
case TRANS_COMMIT:
return "COMMIT";
case TRANS_ABORT:
return "ABORT";
case TRANS_INPROGRESS:
return "INPROGR";
case TRANS_PREPARE:
return "PREPARE";
}
return "UNRECOGNIZED";
}
@ -3767,6 +4088,76 @@ xactGetCommittedChildren(TransactionId **ptr)
* XLOG support routines
*/
static void
xact_redo_commit(xl_xact_commit *xlrec, TransactionId xid)
{
TransactionId *sub_xids;
TransactionId max_xid;
int i;
TransactionIdCommit(xid);
/* Mark committed subtransactions as committed */
sub_xids = (TransactionId *) &(xlrec->xnodes[xlrec->nrels]);
TransactionIdCommitTree(xlrec->nsubxacts, sub_xids);
/* Make sure nextXid is beyond any XID mentioned in the record */
max_xid = xid;
for (i = 0; i < xlrec->nsubxacts; i++)
{
if (TransactionIdPrecedes(max_xid, sub_xids[i]))
max_xid = sub_xids[i];
}
if (TransactionIdFollowsOrEquals(max_xid,
ShmemVariableCache->nextXid))
{
ShmemVariableCache->nextXid = max_xid;
TransactionIdAdvance(ShmemVariableCache->nextXid);
}
/* Make sure files supposed to be dropped are dropped */
for (i = 0; i < xlrec->nrels; i++)
{
XLogCloseRelation(xlrec->xnodes[i]);
smgrdounlink(smgropen(xlrec->xnodes[i]), false, true);
}
}
static void
xact_redo_abort(xl_xact_abort *xlrec, TransactionId xid)
{
TransactionId *sub_xids;
TransactionId max_xid;
int i;
TransactionIdAbort(xid);
/* Mark subtransactions as aborted */
sub_xids = (TransactionId *) &(xlrec->xnodes[xlrec->nrels]);
TransactionIdAbortTree(xlrec->nsubxacts, sub_xids);
/* Make sure nextXid is beyond any XID mentioned in the record */
max_xid = xid;
for (i = 0; i < xlrec->nsubxacts; i++)
{
if (TransactionIdPrecedes(max_xid, sub_xids[i]))
max_xid = sub_xids[i];
}
if (TransactionIdFollowsOrEquals(max_xid,
ShmemVariableCache->nextXid))
{
ShmemVariableCache->nextXid = max_xid;
TransactionIdAdvance(ShmemVariableCache->nextXid);
}
/* Make sure files supposed to be dropped are dropped */
for (i = 0; i < xlrec->nrels; i++)
{
XLogCloseRelation(xlrec->xnodes[i]);
smgrdounlink(smgropen(xlrec->xnodes[i]), false, true);
}
}
void
xact_redo(XLogRecPtr lsn, XLogRecord *record)
{
@ -3775,138 +4166,137 @@ xact_redo(XLogRecPtr lsn, XLogRecord *record)
if (info == XLOG_XACT_COMMIT)
{
xl_xact_commit *xlrec = (xl_xact_commit *) XLogRecGetData(record);
TransactionId *sub_xids;
TransactionId max_xid;
int i;
TransactionIdCommit(record->xl_xid);
/* Mark committed subtransactions as committed */
sub_xids = (TransactionId *) &(xlrec->xnodes[xlrec->nrels]);
TransactionIdCommitTree(xlrec->nsubxacts, sub_xids);
/* Make sure nextXid is beyond any XID mentioned in the record */
max_xid = record->xl_xid;
for (i = 0; i < xlrec->nsubxacts; i++)
{
if (TransactionIdPrecedes(max_xid, sub_xids[i]))
max_xid = sub_xids[i];
}
if (TransactionIdFollowsOrEquals(max_xid,
ShmemVariableCache->nextXid))
{
ShmemVariableCache->nextXid = max_xid;
TransactionIdAdvance(ShmemVariableCache->nextXid);
}
/* Make sure files supposed to be dropped are dropped */
for (i = 0; i < xlrec->nrels; i++)
{
XLogCloseRelation(xlrec->xnodes[i]);
smgrdounlink(smgropen(xlrec->xnodes[i]), false, true);
}
xact_redo_commit(xlrec, record->xl_xid);
}
else if (info == XLOG_XACT_ABORT)
{
xl_xact_abort *xlrec = (xl_xact_abort *) XLogRecGetData(record);
TransactionId *sub_xids;
TransactionId max_xid;
int i;
TransactionIdAbort(record->xl_xid);
xact_redo_abort(xlrec, record->xl_xid);
}
else if (info == XLOG_XACT_PREPARE)
{
/* the record contents are exactly the 2PC file */
RecreateTwoPhaseFile(record->xl_xid,
XLogRecGetData(record), record->xl_len);
}
else if (info == XLOG_XACT_COMMIT_PREPARED)
{
xl_xact_commit_prepared *xlrec = (xl_xact_commit_prepared *) XLogRecGetData(record);
/* Mark subtransactions as aborted */
sub_xids = (TransactionId *) &(xlrec->xnodes[xlrec->nrels]);
TransactionIdAbortTree(xlrec->nsubxacts, sub_xids);
xact_redo_commit(&xlrec->crec, xlrec->xid);
RemoveTwoPhaseFile(xlrec->xid, false);
}
else if (info == XLOG_XACT_ABORT_PREPARED)
{
xl_xact_abort_prepared *xlrec = (xl_xact_abort_prepared *) XLogRecGetData(record);
/* Make sure nextXid is beyond any XID mentioned in the record */
max_xid = record->xl_xid;
for (i = 0; i < xlrec->nsubxacts; i++)
{
if (TransactionIdPrecedes(max_xid, sub_xids[i]))
max_xid = sub_xids[i];
}
if (TransactionIdFollowsOrEquals(max_xid,
ShmemVariableCache->nextXid))
{
ShmemVariableCache->nextXid = max_xid;
TransactionIdAdvance(ShmemVariableCache->nextXid);
}
/* Make sure files supposed to be dropped are dropped */
for (i = 0; i < xlrec->nrels; i++)
{
XLogCloseRelation(xlrec->xnodes[i]);
smgrdounlink(smgropen(xlrec->xnodes[i]), false, true);
}
xact_redo_abort(&xlrec->arec, xlrec->xid);
RemoveTwoPhaseFile(xlrec->xid, false);
}
else
elog(PANIC, "xact_redo: unknown op code %u", info);
}
static void
xact_desc_commit(char *buf, xl_xact_commit *xlrec)
{
struct tm *tm = localtime(&xlrec->xtime);
int i;
sprintf(buf + strlen(buf), "%04u-%02u-%02u %02u:%02u:%02u",
tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
tm->tm_hour, tm->tm_min, tm->tm_sec);
if (xlrec->nrels > 0)
{
sprintf(buf + strlen(buf), "; rels:");
for (i = 0; i < xlrec->nrels; i++)
{
RelFileNode rnode = xlrec->xnodes[i];
sprintf(buf + strlen(buf), " %u/%u/%u",
rnode.spcNode, rnode.dbNode, rnode.relNode);
}
}
if (xlrec->nsubxacts > 0)
{
TransactionId *xacts = (TransactionId *)
&xlrec->xnodes[xlrec->nrels];
sprintf(buf + strlen(buf), "; subxacts:");
for (i = 0; i < xlrec->nsubxacts; i++)
sprintf(buf + strlen(buf), " %u", xacts[i]);
}
}
static void
xact_desc_abort(char *buf, xl_xact_abort *xlrec)
{
struct tm *tm = localtime(&xlrec->xtime);
int i;
sprintf(buf + strlen(buf), "%04u-%02u-%02u %02u:%02u:%02u",
tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
tm->tm_hour, tm->tm_min, tm->tm_sec);
if (xlrec->nrels > 0)
{
sprintf(buf + strlen(buf), "; rels:");
for (i = 0; i < xlrec->nrels; i++)
{
RelFileNode rnode = xlrec->xnodes[i];
sprintf(buf + strlen(buf), " %u/%u/%u",
rnode.spcNode, rnode.dbNode, rnode.relNode);
}
}
if (xlrec->nsubxacts > 0)
{
TransactionId *xacts = (TransactionId *)
&xlrec->xnodes[xlrec->nrels];
sprintf(buf + strlen(buf), "; subxacts:");
for (i = 0; i < xlrec->nsubxacts; i++)
sprintf(buf + strlen(buf), " %u", xacts[i]);
}
}
void
xact_desc(char *buf, uint8 xl_info, char *rec)
{
uint8 info = xl_info & ~XLR_INFO_MASK;
int i;
if (info == XLOG_XACT_COMMIT)
{
xl_xact_commit *xlrec = (xl_xact_commit *) rec;
struct tm *tm = localtime(&xlrec->xtime);
sprintf(buf + strlen(buf), "commit: %04u-%02u-%02u %02u:%02u:%02u",
tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
tm->tm_hour, tm->tm_min, tm->tm_sec);
if (xlrec->nrels > 0)
{
sprintf(buf + strlen(buf), "; rels:");
for (i = 0; i < xlrec->nrels; i++)
{
RelFileNode rnode = xlrec->xnodes[i];
sprintf(buf + strlen(buf), " %u/%u/%u",
rnode.spcNode, rnode.dbNode, rnode.relNode);
}
}
if (xlrec->nsubxacts > 0)
{
TransactionId *xacts = (TransactionId *)
&xlrec->xnodes[xlrec->nrels];
sprintf(buf + strlen(buf), "; subxacts:");
for (i = 0; i < xlrec->nsubxacts; i++)
sprintf(buf + strlen(buf), " %u", xacts[i]);
}
strcat(buf, "commit: ");
xact_desc_commit(buf, xlrec);
}
else if (info == XLOG_XACT_ABORT)
{
xl_xact_abort *xlrec = (xl_xact_abort *) rec;
struct tm *tm = localtime(&xlrec->xtime);
sprintf(buf + strlen(buf), "abort: %04u-%02u-%02u %02u:%02u:%02u",
tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
tm->tm_hour, tm->tm_min, tm->tm_sec);
if (xlrec->nrels > 0)
{
sprintf(buf + strlen(buf), "; rels:");
for (i = 0; i < xlrec->nrels; i++)
{
RelFileNode rnode = xlrec->xnodes[i];
strcat(buf, "abort: ");
xact_desc_abort(buf, xlrec);
}
else if (info == XLOG_XACT_PREPARE)
{
strcat(buf, "prepare");
}
else if (info == XLOG_XACT_COMMIT_PREPARED)
{
xl_xact_commit_prepared *xlrec = (xl_xact_commit_prepared *) rec;
sprintf(buf + strlen(buf), " %u/%u/%u",
rnode.spcNode, rnode.dbNode, rnode.relNode);
}
}
if (xlrec->nsubxacts > 0)
{
TransactionId *xacts = (TransactionId *)
&xlrec->xnodes[xlrec->nrels];
sprintf(buf + strlen(buf), "commit %u: ", xlrec->xid);
xact_desc_commit(buf, &xlrec->crec);
}
else if (info == XLOG_XACT_ABORT_PREPARED)
{
xl_xact_abort_prepared *xlrec = (xl_xact_abort_prepared *) rec;
sprintf(buf + strlen(buf), "; subxacts:");
for (i = 0; i < xlrec->nsubxacts; i++)
sprintf(buf + strlen(buf), " %u", xacts[i]);
}
sprintf(buf + strlen(buf), "abort %u: ", xlrec->xid);
xact_desc_abort(buf, &xlrec->arec);
}
else
strcat(buf, "UNKNOWN");

92
src/backend/access/transam/xlog.c
View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.200 2005/06/15 01:36:08 momjian Exp $
* $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.201 2005/06/17 22:32:43 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -25,6 +25,7 @@
#include "access/clog.h"
#include "access/multixact.h"
#include "access/subtrans.h"
#include "access/twophase.h"
#include "access/xact.h"
#include "access/xlog.h"
#include "access/xlog_internal.h"
@ -814,18 +815,6 @@ begin:;
/* Compute record's XLOG location */
INSERT_RECPTR(RecPtr, Insert, curridx);
/* If first XLOG record of transaction, save it in PGPROC array */
if (MyLastRecPtr.xrecoff == 0 && !no_tran)
{
/*
* We do not acquire ProcArrayLock here because of possible deadlock.
* Anyone who wants to inspect other procs' logRec must acquire
* WALInsertLock, instead. A better solution would be a per-PROC
* spinlock, but no time for that before 7.2 --- tgl 12/19/01.
*/
MyProc->logRec = RecPtr;
}
#ifdef WAL_DEBUG
if (XLOG_DEBUG)
{
@ -3827,6 +3816,7 @@ BootStrapXLOG(void)
BootStrapCLOG();
BootStrapSUBTRANS();
BootStrapMultiXact();
free(buffer);
}
@ -4268,6 +4258,7 @@ StartupXLOG(void)
uint32 endLogSeg;
XLogRecord *record;
uint32 freespace;
TransactionId oldestActiveXID;
CritSectionCount++;
@ -4678,33 +4669,8 @@ StartupXLOG(void)
XLogCtl->Write.curridx = NextBufIdx(0);
}
#ifdef NOT_USED
/* UNDO */
if (InRecovery)
{
RecPtr = ReadRecPtr;
if (XLByteLT(checkPoint.undo, RecPtr))
{
ereport(LOG,
(errmsg("undo starts at %X/%X",
RecPtr.xlogid, RecPtr.xrecoff)));
do
{
record = ReadRecord(&RecPtr, PANIC);
if (TransactionIdIsValid(record->xl_xid) &&
!TransactionIdDidCommit(record->xl_xid))
RmgrTable[record->xl_rmid].rm_undo(EndRecPtr, record);
RecPtr = record->xl_prev;
} while (XLByteLE(checkPoint.undo, RecPtr));
ereport(LOG,
(errmsg("undo done at %X/%X",
ReadRecPtr.xlogid, ReadRecPtr.xrecoff)));
}
else
ereport(LOG,
(errmsg("undo is not required")));
}
#endif
/* Pre-scan prepared transactions to find out the range of XIDs present */
oldestActiveXID = PrescanPreparedTransactions();
if (InRecovery)
{
@ -4767,9 +4733,12 @@ StartupXLOG(void)
/* Start up the commit log and related stuff, too */
StartupCLOG();
StartupSUBTRANS();
StartupSUBTRANS(oldestActiveXID);
StartupMultiXact();
/* Reload shared-memory state for prepared transactions */
RecoverPreparedTransactions();
ereport(LOG,
(errmsg("database system is ready")));
CritSectionCount--;
@ -5095,31 +5064,6 @@ CreateCheckPoint(bool shutdown, bool force)
SpinLockRelease_NoHoldoff(&xlogctl->info_lck);
}
/*
* Get UNDO record ptr - this is oldest of PGPROC->logRec values. We
* do this while holding insert lock to ensure that we won't miss any
* about-to-commit transactions (UNDO must include all xacts that have
* commits after REDO point).
*
* XXX temporarily ifdef'd out to avoid three-way deadlock condition:
* GetUndoRecPtr needs to grab ProcArrayLock to ensure that it is looking
* at a stable set of proc records, but grabbing ProcArrayLock while
* holding WALInsertLock is no good. GetNewTransactionId may cause a
* WAL record to be written while holding XidGenLock, and
* GetSnapshotData needs to get XidGenLock while holding ProcArrayLock,
* so there's a risk of deadlock. Need to find a better solution. See
* pgsql-hackers discussion of 17-Dec-01.
*
* XXX actually, the whole UNDO code is dead code and unlikely to ever be
* revived, so the lack of a good solution here is not troubling.
*/
#ifdef NOT_USED
checkPoint.undo = GetUndoRecPtr();
if (shutdown && checkPoint.undo.xrecoff != 0)
elog(PANIC, "active transaction while database system is shutting down");
#endif
/*
* Now we can release insert lock and checkpoint start lock, allowing
* other xacts to proceed even while we are flushing disk buffers.
@ -5195,22 +5139,8 @@ CreateCheckPoint(bool shutdown, bool force)
/*
* Select point at which we can truncate the log, which we base on the
* prior checkpoint's earliest info.
*
* With UNDO support: oldest item is redo or undo, whichever is older;
* but watch out for case that undo = 0.
*
* Without UNDO support: just use the redo pointer. This allows xlog
* space to be freed much faster when there are long-running
* transactions.
*/
#ifdef NOT_USED
if (ControlFile->checkPointCopy.undo.xrecoff != 0 &&
XLByteLT(ControlFile->checkPointCopy.undo,
ControlFile->checkPointCopy.redo))
XLByteToSeg(ControlFile->checkPointCopy.undo, _logId, _logSeg);
else
#endif
XLByteToSeg(ControlFile->checkPointCopy.redo, _logId, _logSeg);
XLByteToSeg(ControlFile->checkPointCopy.redo, _logId, _logSeg);
/*
* Update the control file.

59
src/backend/catalog/system_views.sql
View File

@ -3,7 +3,7 @@
*
* Copyright (c) 1996-2005, PostgreSQL Global Development Group
*
* $PostgreSQL: pgsql/src/backend/catalog/system_views.sql,v 1.13 2005/05/17 21:46:09 tgl Exp $
* $PostgreSQL: pgsql/src/backend/catalog/system_views.sql,v 1.14 2005/06/17 22:32:43 tgl Exp $
*/
CREATE VIEW pg_user AS
@ -102,6 +102,39 @@ CREATE VIEW pg_stats AS
REVOKE ALL on pg_statistic FROM public;
CREATE VIEW pg_locks AS
SELECT *
FROM pg_lock_status() AS L
(locktype text, database oid, relation oid, page int4, tuple int2,
transaction xid, classid oid, objid oid, objsubid int2,
pid int4, mode text, granted boolean);
CREATE VIEW pg_prepared_xacts AS
SELECT P.transaction, P.gid, U.usename AS owner, D.datname AS database
FROM pg_prepared_xact() AS P
(transaction xid, gid text, ownerid int4, dbid oid)
LEFT JOIN pg_database D ON P.dbid = D.oid
LEFT JOIN pg_shadow U ON P.ownerid = U.usesysid;
CREATE VIEW pg_settings AS
SELECT *
FROM pg_show_all_settings() AS A
(name text, setting text, category text, short_desc text, extra_desc text,
context text, vartype text, source text, min_val text, max_val text);
CREATE RULE pg_settings_u AS
ON UPDATE TO pg_settings
WHERE new.name = old.name DO
SELECT set_config(old.name, new.setting, 'f');
CREATE RULE pg_settings_n AS
ON UPDATE TO pg_settings
DO INSTEAD NOTHING;
GRANT SELECT, UPDATE ON pg_settings TO PUBLIC;
-- Statistics views
CREATE VIEW pg_stat_all_tables AS
SELECT
C.oid AS relid,
@ -258,27 +291,3 @@ CREATE VIEW pg_stat_database AS
pg_stat_get_db_blocks_hit(D.oid) AS blks_read,
pg_stat_get_db_blocks_hit(D.oid) AS blks_hit
FROM pg_database D;
CREATE VIEW pg_locks AS
SELECT *
FROM pg_lock_status() AS L
(locktype text, database oid, relation oid, page int4, tuple int2,
transaction xid, classid oid, objid oid, objsubid int2,
pid int4, mode text, granted boolean);
CREATE VIEW pg_settings AS
SELECT *
FROM pg_show_all_settings() AS A
(name text, setting text, category text, short_desc text, extra_desc text,
context text, vartype text, source text, min_val text, max_val text);
CREATE RULE pg_settings_u AS
ON UPDATE TO pg_settings
WHERE new.name = old.name DO
SELECT set_config(old.name, new.setting, 'f');
CREATE RULE pg_settings_n AS
ON UPDATE TO pg_settings
DO INSTEAD NOTHING;
GRANT SELECT, UPDATE ON pg_settings TO PUBLIC;

57
src/backend/commands/async.c
View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/commands/async.c,v 1.122 2005/05/06 17:24:53 tgl Exp $
* $PostgreSQL: pgsql/src/backend/commands/async.c,v 1.123 2005/06/17 22:32:43 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -78,6 +78,7 @@
#include <netinet/in.h>
#include "access/heapam.h"
#include "access/twophase_rmgr.h"
#include "catalog/pg_listener.h"
#include "commands/async.h"
#include "libpq/libpq.h"
@ -407,6 +408,36 @@ Async_UnlistenOnExit(int code, Datum arg)
CommitTransactionCommand();
}
/*
*--------------------------------------------------------------
* AtPrepare_Notify
*
* This is called at the prepare phase of a two-phase
* transaction. Save the state for possible commit later.
*--------------------------------------------------------------
*/
void
AtPrepare_Notify(void)
{
ListCell *p;
foreach(p, pendingNotifies)
{
const char *relname = (const char *) lfirst(p);
RegisterTwoPhaseRecord(TWOPHASE_RM_NOTIFY_ID, 0,
relname, strlen(relname) + 1);
}
/*
* We can clear the state immediately, rather than needing a separate
* PostPrepare call, because if the transaction fails we'd just
* discard the state anyway.
*/
ClearPendingNotifies();
}
/*
*--------------------------------------------------------------
* AtCommit_Notify
@ -1016,8 +1047,9 @@ AsyncExistsPendingNotify(const char *relname)
foreach(p, pendingNotifies)
{
/* Use NAMEDATALEN for relname comparison. DZ - 26-08-1996 */
if (strncmp((const char *) lfirst(p), relname, NAMEDATALEN) == 0)
const char *prelname = (const char *) lfirst(p);
if (strcmp(prelname, relname) == 0)
return true;
}
@ -1037,3 +1069,22 @@ ClearPendingNotifies(void)
*/
pendingNotifies = NIL;
}
/*
* 2PC processing routine for COMMIT PREPARED case.
*
* (We don't have to do anything for ROLLBACK PREPARED.)
*/
void
notify_twophase_postcommit(TransactionId xid, uint16 info,
void *recdata, uint32 len)
{
/*
* Set up to issue the NOTIFY at the end of my own
* current transaction. (XXX this has some issues if my own
* transaction later rolls back, or if there is any significant
* delay before I commit. OK for now because we disallow
* COMMIT PREPARED inside a transaction block.)
*/
Async_Notify((char *) recdata);
}

3
src/backend/nodes/copyfuncs.c
View File

@ -15,7 +15,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.306 2005/06/09 04:18:58 tgl Exp $
* $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.307 2005/06/17 22:32:43 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -2085,6 +2085,7 @@ _copyTransactionStmt(TransactionStmt *from)
COPY_SCALAR_FIELD(kind);
COPY_NODE_FIELD(options);
COPY_STRING_FIELD(gid);
return newnode;
}

3
src/backend/nodes/equalfuncs.c
View File

@ -18,7 +18,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/nodes/equalfuncs.c,v 1.243 2005/06/09 04:18:58 tgl Exp $
* $PostgreSQL: pgsql/src/backend/nodes/equalfuncs.c,v 1.244 2005/06/17 22:32:44 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -1053,6 +1053,7 @@ _equalTransactionStmt(TransactionStmt *a, TransactionStmt *b)
{
COMPARE_SCALAR_FIELD(kind);
COMPARE_NODE_FIELD(options);
COMPARE_STRING_FIELD(gid);
return true;
}

42
src/backend/parser/gram.y
View File

@ -11,7 +11,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.494 2005/06/15 19:44:05 momjian Exp $
* $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.495 2005/06/17 22:32:44 tgl Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
@ -387,7 +387,7 @@ static void doNegateFloat(Value *v);
ORDER OUT_P OUTER_P OVERLAPS OVERLAY OWNER
PARTIAL PASSWORD PLACING POSITION
PRECISION PRESERVE PREPARE PRIMARY
PRECISION PRESERVE PREPARE PREPARED PRIMARY
PRIOR PRIVILEGES PROCEDURAL PROCEDURE
QUOTE
@ -4121,6 +4121,27 @@ TransactionStmt:
(Node *)makeString($4)));
$$ = (Node *)n;
}
| PREPARE TRANSACTION Sconst
{
TransactionStmt *n = makeNode(TransactionStmt);
n->kind = TRANS_STMT_PREPARE;
n->gid = $3;
$$ = (Node *)n;
}
| COMMIT PREPARED Sconst
{
TransactionStmt *n = makeNode(TransactionStmt);
n->kind = TRANS_STMT_COMMIT_PREPARED;
n->gid = $3;
$$ = (Node *)n;
}
| ROLLBACK PREPARED Sconst
{
TransactionStmt *n = makeNode(TransactionStmt);
n->kind = TRANS_STMT_ROLLBACK_PREPARED;
n->gid = $3;
$$ = (Node *)n;
}
;
opt_transaction: WORK {}
@ -6334,19 +6355,18 @@ a_expr: c_expr { $$ = $1; }
{
$$ = (Node *) makeSimpleA_Expr(AEXPR_OF, "!=", $1, (Node *) $6);
}
| a_expr BETWEEN opt_asymmetric b_expr AND b_expr %prec BETWEEN
| a_expr BETWEEN opt_asymmetric b_expr AND b_expr %prec BETWEEN
{
$$ = (Node *) makeA_Expr(AEXPR_AND, NIL,
(Node *) makeSimpleA_Expr(AEXPR_OP, ">=", $1, $4),
(Node *) makeSimpleA_Expr(AEXPR_OP, "<=", $1, $6));
}
| a_expr NOT BETWEEN opt_asymmetric b_expr AND b_expr %prec BETWEEN
| a_expr NOT BETWEEN opt_asymmetric b_expr AND b_expr %prec BETWEEN
{
$$ = (Node *) makeA_Expr(AEXPR_OR, NIL,
(Node *) makeSimpleA_Expr(AEXPR_OP, "<", $1, $5),
(Node *) makeSimpleA_Expr(AEXPR_OP, ">", $1, $7));
}
| a_expr BETWEEN SYMMETRIC b_expr AND b_expr %prec BETWEEN
{
$$ = (Node *) makeA_Expr(AEXPR_OR, NIL,
@ -6367,8 +6387,6 @@ a_expr: c_expr { $$ = $1; }
(Node *) makeSimpleA_Expr(AEXPR_OP, "<", $1, $7),
(Node *) makeSimpleA_Expr(AEXPR_OP, ">", $1, $5)));
}
| a_expr IN_P in_expr
{
/* in_expr returns a SubLink or a list of a_exprs */
@ -6467,11 +6485,6 @@ a_expr: c_expr { $$ = $1; }
}
;
opt_asymmetric: ASYMMETRIC {}
| /*EMPTY*/ {}
;
/*
* Restricted expressions
*
@ -7401,6 +7414,10 @@ opt_indirection:
| opt_indirection indirection_el { $$ = lappend($1, $2); }
;
opt_asymmetric: ASYMMETRIC
| /*EMPTY*/
;
/*****************************************************************************
*
@ -7855,6 +7872,7 @@ unreserved_keyword:
| PARTIAL
| PASSWORD
| PREPARE
| PREPARED
| PRESERVE
| PRIOR
| PRIVILEGES

3
src/backend/parser/keywords.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/parser/keywords.c,v 1.156 2005/06/14 23:47:39 momjian Exp $
* $PostgreSQL: pgsql/src/backend/parser/keywords.c,v 1.157 2005/06/17 22:32:44 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -243,6 +243,7 @@ static const ScanKeyword ScanKeywords[] = {
{"position", POSITION},
{"precision", PRECISION},
{"prepare", PREPARE},
{"prepared", PREPARED},
{"preserve", PRESERVE},
{"primary", PRIMARY},
{"prior", PRIOR},

12
src/backend/postmaster/postmaster.c
View File

@ -37,7 +37,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.453 2005/06/14 21:04:39 momjian Exp $
* $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.454 2005/06/17 22:32:44 tgl Exp $
*
* NOTES
*
@ -252,7 +252,7 @@ static void reg_reply(DNSServiceRegistrationReplyErrorType errorCode,
static void pmdaemonize(void);
static Port *ConnCreate(int serverFd);
static void ConnFree(Port *port);
static void reset_shared(unsigned short port);
static void reset_shared(int port);
static void SIGHUP_handler(SIGNAL_ARGS);
static void pmdie(SIGNAL_ARGS);
static void reaper(SIGNAL_ARGS);
@ -1783,7 +1783,7 @@ ClosePostmasterPorts(bool am_syslogger)
* reset_shared -- reset shared memory and semaphores
*/
static void
reset_shared(unsigned short port)
reset_shared(int port)
{
/*
* Create or re-create shared memory and semaphores.
@ -1793,7 +1793,7 @@ reset_shared(unsigned short port)
* used to determine IPC keys. This helps ensure that we will clean
* up dead IPC objects if the postmaster crashes and is restarted.
*/
CreateSharedMemoryAndSemaphores(false, MaxBackends, port);
CreateSharedMemoryAndSemaphores(false, port);
}
@ -3182,7 +3182,7 @@ SubPostmasterMain(int argc, char *argv[])
/* BackendRun will close sockets */
/* Attach process to shared data structures */
CreateSharedMemoryAndSemaphores(false, MaxBackends, 0);
CreateSharedMemoryAndSemaphores(false, 0);
#ifdef USE_SSL
/*
@ -3203,7 +3203,7 @@ SubPostmasterMain(int argc, char *argv[])
ClosePostmasterPorts(false);
/* Attach process to shared data structures */
CreateSharedMemoryAndSemaphores(false, MaxBackends, 0);
CreateSharedMemoryAndSemaphores(false, 0);
BootstrapMain(argc - 2, argv + 2);
proc_exit(0);

27
src/backend/storage/ipc/ipci.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/storage/ipc/ipci.c,v 1.76 2005/05/19 21:35:46 tgl Exp $
* $PostgreSQL: pgsql/src/backend/storage/ipc/ipci.c,v 1.77 2005/06/17 22:32:45 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -17,6 +17,7 @@
#include "access/clog.h"
#include "access/multixact.h"
#include "access/subtrans.h"
#include "access/twophase.h"
#include "access/xlog.h"
#include "miscadmin.h"
#include "postmaster/bgwriter.h"
@ -54,9 +55,7 @@
* memory. This is true for a standalone backend, false for a postmaster.
*/
void
CreateSharedMemoryAndSemaphores(bool makePrivate,
int maxBackends,
int port)
CreateSharedMemoryAndSemaphores(bool makePrivate, int port)
{
PGShmemHeader *seghdr = NULL;
@ -72,15 +71,16 @@ CreateSharedMemoryAndSemaphores(bool makePrivate,
*/
size = hash_estimate_size(SHMEM_INDEX_SIZE, sizeof(ShmemIndexEnt));
size += BufferShmemSize();
size += LockShmemSize(maxBackends);
size += ProcGlobalShmemSize(maxBackends);
size += LockShmemSize();
size += ProcGlobalShmemSize();
size += XLOGShmemSize();
size += CLOGShmemSize();
size += SUBTRANSShmemSize();
size += TwoPhaseShmemSize();
size += MultiXactShmemSize();
size += LWLockShmemSize();
size += ProcArrayShmemSize(maxBackends);
size += SInvalShmemSize(maxBackends);
size += ProcArrayShmemSize();
size += SInvalShmemSize(MaxBackends);
size += FreeSpaceShmemSize();
size += BgWriterShmemSize();
#ifdef EXEC_BACKEND
@ -100,7 +100,7 @@ CreateSharedMemoryAndSemaphores(bool makePrivate,
/*
* Create semaphores
*/
numSemas = ProcGlobalSemas(maxBackends);
numSemas = ProcGlobalSemas();
numSemas += SpinlockSemas();
PGReserveSemaphores(numSemas, port);
}
@ -144,6 +144,7 @@ CreateSharedMemoryAndSemaphores(bool makePrivate,
XLOGShmemInit();
CLOGShmemInit();
SUBTRANSShmemInit();
TwoPhaseShmemInit();
MultiXactShmemInit();
InitBufferPool();
@ -151,18 +152,18 @@ CreateSharedMemoryAndSemaphores(bool makePrivate,
* Set up lock manager
*/
InitLocks();
InitLockTable(maxBackends);
InitLockTable();
/*
* Set up process table
*/
InitProcGlobal(maxBackends);
CreateSharedProcArray(maxBackends);
InitProcGlobal();
CreateSharedProcArray();
/*
* Set up shared-inval messaging
*/
CreateSharedInvalidationState(maxBackends);
CreateSharedInvalidationState(MaxBackends);
/*
* Set up free-space map

140
src/backend/storage/ipc/procarray.c
View File

@ -11,6 +11,11 @@
* Because of various subtle race conditions it is critical that a backend
* hold the correct locks while setting or clearing its MyProc->xid field.
* See notes in GetSnapshotData.
*
* The process array now also includes PGPROC structures representing
* prepared transactions. The xid and subxids fields of these are valid,
* as is the procLocks list. They can be distinguished from regular backend
* PGPROCs at need by checking for pid == 0.
*
*
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
@ -18,13 +23,14 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/storage/ipc/procarray.c,v 1.2 2005/05/19 23:57:11 tgl Exp $
* $PostgreSQL: pgsql/src/backend/storage/ipc/procarray.c,v 1.3 2005/06/17 22:32:45 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/subtrans.h"
#include "access/twophase.h"
#include "miscadmin.h"
#include "storage/proc.h"
#include "storage/procarray.h"
@ -76,25 +82,23 @@ static void DisplayXidCache(void);
* Report shared-memory space needed by CreateSharedProcArray.
*/
int
ProcArrayShmemSize(int maxBackends)
ProcArrayShmemSize(void)
{
/* sizeof(ProcArrayStruct) includes the first array element */
return MAXALIGN(sizeof(ProcArrayStruct) +
(maxBackends - 1) * sizeof(PGPROC *));
return MAXALIGN(offsetof(ProcArrayStruct, procs) +
(MaxBackends + max_prepared_xacts) * sizeof(PGPROC *));
}
/*
* Initialize the shared PGPROC array during postmaster startup.
*/
void
CreateSharedProcArray(int maxBackends)
CreateSharedProcArray(void)
{
bool found;
/* Create or attach to the ProcArray shared structure */
procArray = (ProcArrayStruct *)
ShmemInitStruct("Proc Array", ProcArrayShmemSize(maxBackends),
&found);
ShmemInitStruct("Proc Array", ProcArrayShmemSize(), &found);
if (!found)
{
@ -102,18 +106,15 @@ CreateSharedProcArray(int maxBackends)
* We're the first - initialize.
*/
procArray->numProcs = 0;
procArray->maxProcs = maxBackends;
procArray->maxProcs = MaxBackends + max_prepared_xacts;
}
}
/*
* Add my own PGPROC (found in the global MyProc) to the shared array.
*
* This must be called during backend startup, after fully initializing
* the contents of MyProc.
* Add the specified PGPROC to the shared array.
*/
void
ProcArrayAddMyself(void)
ProcArrayAdd(PGPROC *proc)
{
ProcArrayStruct *arrayP = procArray;
@ -132,32 +133,32 @@ ProcArrayAddMyself(void)
errmsg("sorry, too many clients already")));
}
arrayP->procs[arrayP->numProcs] = MyProc;
arrayP->procs[arrayP->numProcs] = proc;
arrayP->numProcs++;
LWLockRelease(ProcArrayLock);
}
/*
* Remove my own PGPROC (found in the global MyProc) from the shared array.
*
* This must be called during backend shutdown.
* Remove the specified PGPROC from the shared array.
*/
void
ProcArrayRemoveMyself(void)
ProcArrayRemove(PGPROC *proc)
{
ProcArrayStruct *arrayP = procArray;
int index;
#ifdef XIDCACHE_DEBUG
DisplayXidCache();
/* dump stats at backend shutdown, but not prepared-xact end */
if (proc->pid != 0)
DisplayXidCache();
#endif
LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
for (index = 0; index < arrayP->numProcs; index++)
{
if (arrayP->procs[index] == MyProc)
if (arrayP->procs[index] == proc)
{
arrayP->procs[index] = arrayP->procs[arrayP->numProcs - 1];
arrayP->numProcs--;
@ -169,7 +170,7 @@ ProcArrayRemoveMyself(void)
/* Ooops */
LWLockRelease(ProcArrayLock);
elog(LOG, "failed to find my own proc %p in ProcArray", MyProc);
elog(LOG, "failed to find proc %p in ProcArray", proc);
}
@ -329,6 +330,55 @@ result_known:
return result;
}
/*
* TransactionIdIsActive -- is xid the top-level XID of an active backend?
*
* This differs from TransactionIdIsInProgress in that it ignores prepared
* transactions. Also, we ignore subtransactions since that's not needed
* for current uses.
*/
bool
TransactionIdIsActive(TransactionId xid)
{
bool result = false;
ProcArrayStruct *arrayP = procArray;
int i;
/*
* Don't bother checking a transaction older than RecentXmin; it
* could not possibly still be running.
*/
if (TransactionIdPrecedes(xid, RecentXmin))
return false;
LWLockAcquire(ProcArrayLock, LW_SHARED);
for (i = 0; i < arrayP->numProcs; i++)
{
PGPROC *proc = arrayP->procs[i];
/* Fetch xid just once - see GetNewTransactionId */
TransactionId pxid = proc->xid;
if (!TransactionIdIsValid(pxid))
continue;
if (proc->pid == 0)
continue; /* ignore prepared transactions */
if (TransactionIdEquals(pxid, xid))
{
result = true;
break;
}
}
LWLockRelease(ProcArrayLock);
return result;
}
/*
* GetOldestXmin -- returns oldest transaction that was running
* when any current transaction was started.
@ -441,12 +491,12 @@ GetSnapshotData(Snapshot snapshot, bool serializable)
TransactionIdIsValid(MyProc->xmin));
/*
* Allocating space for MaxBackends xids is usually overkill;
* Allocating space for maxProcs xids is usually overkill;
* numProcs would be sufficient. But it seems better to do the
* malloc while not holding the lock, so we can't look at numProcs.
*
* This does open a possibility for avoiding repeated malloc/free: since
* MaxBackends does not change at runtime, we can simply reuse the
* maxProcs does not change at runtime, we can simply reuse the
* previous xip array if any. (This relies on the fact that all
* callers pass static SnapshotData structs.)
*/
@ -456,7 +506,7 @@ GetSnapshotData(Snapshot snapshot, bool serializable)
* First call for this snapshot
*/
snapshot->xip = (TransactionId *)
malloc(MaxBackends * sizeof(TransactionId));
malloc(arrayP->maxProcs * sizeof(TransactionId));
if (snapshot->xip == NULL)
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
@ -602,14 +652,21 @@ DatabaseHasActiveBackends(Oid databaseId, bool ignoreMyself)
/*
* BackendPidGetProc -- get a backend's PGPROC given its PID
*
* Returns NULL if not found. Note that it is up to the caller to be
* sure that the question remains meaningful for long enough for the
* answer to be used ...
*/
struct PGPROC *
PGPROC *
BackendPidGetProc(int pid)
{
PGPROC *result = NULL;
ProcArrayStruct *arrayP = procArray;
int index;
if (pid == 0) /* never match dummy PGPROCs */
return NULL;
LWLockAcquire(ProcArrayLock, LW_SHARED);
for (index = 0; index < arrayP->numProcs; index++)
@ -642,10 +699,8 @@ IsBackendPid(int pid)
* active transactions. This is used as a heuristic to decide if
* a pre-XLOG-flush delay is worthwhile during commit.
*
* An active transaction is something that has written at least one XLOG
* record; read-only transactions don't count. Also, do not count backends
* that are blocked waiting for locks, since they are not going to get to
* run until someone else commits.
* Do not count backends that are blocked waiting for locks, since they are
* not going to get to run until someone else commits.
*/
int
CountActiveBackends(void)
@ -656,7 +711,7 @@ CountActiveBackends(void)
/*
* Note: for speed, we don't acquire ProcArrayLock. This is a little bit
* bogus, but since we are only testing xrecoff for zero or nonzero,
* bogus, but since we are only testing fields for zero or nonzero,
* it should be OK. The result is only used for heuristic purposes
* anyway...
*/
@ -666,7 +721,9 @@ CountActiveBackends(void)
if (proc == MyProc)
continue; /* do not count myself */
if (proc->logRec.xrecoff == 0)
if (proc->pid == 0)
continue; /* do not count prepared xacts */
if (proc->xid == InvalidTransactionId)
continue; /* do not count if not in a transaction */
if (proc->waitLock != NULL)
continue; /* do not count if blocked on a lock */
@ -676,25 +733,6 @@ CountActiveBackends(void)
return count;
}
/*
* CountEmptyBackendSlots - count empty slots in backend process table
*
* Acquiring the lock here is almost certainly overkill, but just in
* case fetching an int is not atomic on your machine ...
*/
int
CountEmptyBackendSlots(void)
{
int count;
LWLockAcquire(ProcArrayLock, LW_SHARED);
count = procArray->maxProcs - procArray->numProcs;
LWLockRelease(ProcArrayLock);
return count;
}
#define XidCacheRemove(i) \
do { \

7
src/backend/storage/lmgr/lmgr.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/storage/lmgr/lmgr.c,v 1.76 2005/06/14 22:15:32 tgl Exp $
* $PostgreSQL: pgsql/src/backend/storage/lmgr/lmgr.c,v 1.77 2005/06/17 22:32:45 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -77,7 +77,7 @@ static LOCKMETHODID LockTableId = INVALID_LOCKMETHOD;
* Create the lock table described by LockConflicts
*/
void
InitLockTable(int maxBackends)
InitLockTable(void)
{
LOCKMETHODID LongTermTableId;
@ -91,8 +91,7 @@ InitLockTable(int maxBackends)
/* number of lock modes is lengthof()-1 because of dummy zero */
LockTableId = LockMethodTableInit("LockTable",
LockConflicts,
lengthof(LockConflicts) - 1,
maxBackends);
lengthof(LockConflicts) - 1);
if (!LockMethodIsValid(LockTableId))
elog(ERROR, "could not initialize lock table");
Assert(LockTableId == DEFAULT_LOCKMETHOD);

537
src/backend/storage/lmgr/lock.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/storage/lmgr/lock.c,v 1.155 2005/06/14 22:15:32 tgl Exp $
* $PostgreSQL: pgsql/src/backend/storage/lmgr/lock.c,v 1.156 2005/06/17 22:32:45 tgl Exp $
*
* NOTES
* Outside modules can create a lock table and acquire/release
@ -33,6 +33,8 @@
#include <signal.h>
#include <unistd.h>
#include "access/twophase.h"
#include "access/twophase_rmgr.h"
#include "access/xact.h"
#include "miscadmin.h"
#include "storage/proc.h"
@ -44,7 +46,15 @@
/* This configuration variable is used to set the lock table size */
int max_locks_per_xact; /* set by guc.c */
#define NLOCKENTS(maxBackends) (max_locks_per_xact * (maxBackends))
#define NLOCKENTS() (max_locks_per_xact * (MaxBackends + max_prepared_xacts))
/* Record that's written to 2PC state file when a lock is persisted */
typedef struct TwoPhaseLockRecord
{
LOCKTAG locktag;
LOCKMODE lockmode;
} TwoPhaseLockRecord;
/*
@ -168,8 +178,7 @@ static void CleanUpLock(LOCKMETHODID lockmethodid, LOCK *lock,
/*
* InitLocks -- Init the lock module. Create a private data
* structure for constructing conflict masks.
* InitLocks -- Init the lock module. Nothing to do here at present.
*/
void
InitLocks(void)
@ -222,8 +231,7 @@ LockMethodInit(LockMethod lockMethodTable,
LOCKMETHODID
LockMethodTableInit(const char *tabName,
const LOCKMASK *conflictsP,
int numModes,
int maxBackends)
int numModes)
{
LockMethod newLockMethod;
LOCKMETHODID lockmethodid;
@ -239,7 +247,7 @@ LockMethodTableInit(const char *tabName,
numModes, MAX_LOCKMODES - 1);
/* Compute init/max size to request for lock hashtables */
max_table_size = NLOCKENTS(maxBackends);
max_table_size = NLOCKENTS();
init_table_size = max_table_size / 2;
/* Allocate a string for the shmem index table lookups. */
@ -1418,10 +1426,10 @@ LockReleaseAll(LOCKMETHODID lockmethodid, bool allLocks)
while (proclock)
{
bool wakeupNeeded = false;
PROCLOCK *nextHolder;
PROCLOCK *nextplock;
/* Get link first, since we may unlink/delete this proclock */
nextHolder = (PROCLOCK *) SHMQueueNext(procLocks, &proclock->procLink,
nextplock = (PROCLOCK *) SHMQueueNext(procLocks, &proclock->procLink,
offsetof(PROCLOCK, procLink));
Assert(proclock->tag.proc == MAKE_OFFSET(MyProc));
@ -1474,7 +1482,7 @@ LockReleaseAll(LOCKMETHODID lockmethodid, bool allLocks)
CleanUpLock(lockmethodid, lock, proclock, wakeupNeeded);
next_item:
proclock = nextHolder;
proclock = nextplock;
}
LWLockRelease(masterLock);
@ -1605,14 +1613,262 @@ LockReassignCurrentOwner(void)
}
/*
* AtPrepare_Locks
* Do the preparatory work for a PREPARE: make 2PC state file records
* for all locks currently held.
*
* User locks are non-transactional and are therefore ignored.
*
* There are some special cases that we error out on: we can't be holding
* any session locks (should be OK since only VACUUM uses those) and we
* can't be holding any locks on temporary objects (since that would mess
* up the current backend if it tries to exit before the prepared xact is
* committed).
*/
void
AtPrepare_Locks(void)
{
LOCKMETHODID lockmethodid = DEFAULT_LOCKMETHOD;
HASH_SEQ_STATUS status;
LOCALLOCK *locallock;
/*
* We don't need to touch shared memory for this --- all the necessary
* state information is in the locallock table.
*/
hash_seq_init(&status, LockMethodLocalHash[lockmethodid]);
while ((locallock = (LOCALLOCK *) hash_seq_search(&status)) != NULL)
{
TwoPhaseLockRecord record;
LOCALLOCKOWNER *lockOwners = locallock->lockOwners;
int i;
/* Ignore items that are not of the lockmethod to be processed */
if (LOCALLOCK_LOCKMETHOD(*locallock) != lockmethodid)
continue;
/* Ignore it if we don't actually hold the lock */
if (locallock->nLocks <= 0)
continue;
/* Scan to verify there are no session locks */
for (i = locallock->numLockOwners - 1; i >= 0; i--)
{
/* elog not ereport since this should not happen */
if (lockOwners[i].owner == NULL)
elog(ERROR, "cannot PREPARE when session locks exist");
}
/* Can't handle it if the lock is on a temporary object */
if (locallock->isTempObject)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot PREPARE a transaction that has operated on temporary tables")));
/*
* Create a 2PC record.
*/
memcpy(&(record.locktag), &(locallock->tag.lock), sizeof(LOCKTAG));
record.lockmode = locallock->tag.mode;
RegisterTwoPhaseRecord(TWOPHASE_RM_LOCK_ID, 0,
&record, sizeof(TwoPhaseLockRecord));
}
}
/*
* PostPrepare_Locks
* Clean up after successful PREPARE
*
* Here, we want to transfer ownership of our locks to a dummy PGPROC
* that's now associated with the prepared transaction, and we want to
* clean out the corresponding entries in the LOCALLOCK table.
*
* Note: by removing the LOCALLOCK entries, we are leaving dangling
* pointers in the transaction's resource owner. This is OK at the
* moment since resowner.c doesn't try to free locks retail at a toplevel
* transaction commit or abort. We could alternatively zero out nLocks
* and leave the LOCALLOCK entries to be garbage-collected by LockReleaseAll,
* but that probably costs more cycles.
*/
void
PostPrepare_Locks(TransactionId xid)
{
PGPROC *newproc = TwoPhaseGetDummyProc(xid);
LOCKMETHODID lockmethodid = DEFAULT_LOCKMETHOD;
HASH_SEQ_STATUS status;
SHM_QUEUE *procLocks = &(MyProc->procLocks);
LWLockId masterLock;
LockMethod lockMethodTable;
int numLockModes;
LOCALLOCK *locallock;
PROCLOCK *proclock;
PROCLOCKTAG proclocktag;
bool found;
LOCK *lock;
/* This is a critical section: any error means big trouble */
START_CRIT_SECTION();
lockMethodTable = LockMethods[lockmethodid];
if (!lockMethodTable)
elog(ERROR, "unrecognized lock method: %d", lockmethodid);
numLockModes = lockMethodTable->numLockModes;
masterLock = lockMethodTable->masterLock;
/*
* First we run through the locallock table and get rid of unwanted
* entries, then we scan the process's proclocks and transfer them
* to the target proc.
*
* We do this separately because we may have multiple locallock
* entries pointing to the same proclock, and we daren't end up with
* any dangling pointers.
*/
hash_seq_init(&status, LockMethodLocalHash[lockmethodid]);
while ((locallock = (LOCALLOCK *) hash_seq_search(&status)) != NULL)
{
if (locallock->proclock == NULL || locallock->lock == NULL)
{
/*
* We must've run out of shared memory while trying to set up
* this lock. Just forget the local entry.
*/
Assert(locallock->nLocks == 0);
RemoveLocalLock(locallock);
continue;
}
/* Ignore items that are not of the lockmethod to be removed */
if (LOCALLOCK_LOCKMETHOD(*locallock) != lockmethodid)
continue;
/* We already checked there are no session locks */
/* Mark the proclock to show we need to release this lockmode */
if (locallock->nLocks > 0)
locallock->proclock->releaseMask |= LOCKBIT_ON(locallock->tag.mode);
/* And remove the locallock hashtable entry */
RemoveLocalLock(locallock);
}
LWLockAcquire(masterLock, LW_EXCLUSIVE);
proclock = (PROCLOCK *) SHMQueueNext(procLocks, procLocks,
offsetof(PROCLOCK, procLink));
while (proclock)
{
PROCLOCK *nextplock;
LOCKMASK holdMask;
PROCLOCK *newproclock;
/* Get link first, since we may unlink/delete this proclock */
nextplock = (PROCLOCK *) SHMQueueNext(procLocks, &proclock->procLink,
offsetof(PROCLOCK, procLink));
Assert(proclock->tag.proc == MAKE_OFFSET(MyProc));
lock = (LOCK *) MAKE_PTR(proclock->tag.lock);
/* Ignore items that are not of the lockmethod to be removed */
if (LOCK_LOCKMETHOD(*lock) != lockmethodid)
goto next_item;
PROCLOCK_PRINT("PostPrepare_Locks", proclock);
LOCK_PRINT("PostPrepare_Locks", lock, 0);
Assert(lock->nRequested >= 0);
Assert(lock->nGranted >= 0);
Assert(lock->nGranted <= lock->nRequested);
Assert((proclock->holdMask & ~lock->grantMask) == 0);
/*
* Since there were no session locks, we should be releasing all locks
*/
if (proclock->releaseMask != proclock->holdMask)
elog(PANIC, "we seem to have dropped a bit somewhere");
holdMask = proclock->holdMask;
/*
* We cannot simply modify proclock->tag.proc to reassign ownership
* of the lock, because that's part of the hash key and the proclock
* would then be in the wrong hash chain. So, unlink and delete the
* old proclock; create a new one with the right contents; and link
* it into place. We do it in this order to be certain we won't
* run out of shared memory (the way dynahash.c works, the deleted
* object is certain to be available for reallocation).
*/
SHMQueueDelete(&proclock->lockLink);
SHMQueueDelete(&proclock->procLink);
if (!hash_search(LockMethodProcLockHash[lockmethodid],
(void *) &(proclock->tag),
HASH_REMOVE, NULL))
elog(PANIC, "proclock table corrupted");
/*
* Create the hash key for the new proclock table.
*/
MemSet(&proclocktag, 0, sizeof(PROCLOCKTAG));
proclocktag.lock = MAKE_OFFSET(lock);
proclocktag.proc = MAKE_OFFSET(newproc);
newproclock = (PROCLOCK *) hash_search(LockMethodProcLockHash[lockmethodid],
(void *) &proclocktag,
HASH_ENTER_NULL, &found);
if (!newproclock)
ereport(PANIC, /* should not happen */
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of shared memory"),
errdetail("Not enough memory for reassigning the prepared transaction's locks.")));
/*
* If new, initialize the new entry
*/
if (!found)
{
newproclock->holdMask = 0;
newproclock->releaseMask = 0;
/* Add new proclock to appropriate lists */
SHMQueueInsertBefore(&lock->procLocks, &newproclock->lockLink);
SHMQueueInsertBefore(&newproc->procLocks, &newproclock->procLink);
PROCLOCK_PRINT("PostPrepare_Locks: new", newproclock);
}
else
{
PROCLOCK_PRINT("PostPrepare_Locks: found", newproclock);
Assert((newproclock->holdMask & ~lock->grantMask) == 0);
}
/*
* Pass over the identified lock ownership.
*/
Assert((newproclock->holdMask & holdMask) == 0);
newproclock->holdMask |= holdMask;
next_item:
proclock = nextplock;
}
LWLockRelease(masterLock);
END_CRIT_SECTION();
}
/*
* Estimate shared-memory space used for lock tables
*/
int
LockShmemSize(int maxBackends)
LockShmemSize(void)
{
int size = 0;
long max_table_size = NLOCKENTS(maxBackends);
long max_table_size = NLOCKENTS();
/* lock method headers */
size += MAX_LOCK_METHODS * MAXALIGN(sizeof(LockMethodData));
@ -1704,21 +1960,19 @@ GetLockmodeName(LOCKMODE mode)
#ifdef LOCK_DEBUG
/*
* Dump all locks in the MyProc->procLocks list.
* Dump all locks in the given proc's procLocks list.
*
* Must have already acquired the masterLock.
*/
void
DumpLocks(void)
DumpLocks(PGPROC *proc)
{
PGPROC *proc;
SHM_QUEUE *procLocks;
PROCLOCK *proclock;
LOCK *lock;
int lockmethodid = DEFAULT_LOCKMETHOD;
LockMethod lockMethodTable;
proc = MyProc;
if (proc == NULL)
return;
@ -1793,3 +2047,254 @@ DumpAllLocks(void)
}
#endif /* LOCK_DEBUG */
/*
* LOCK 2PC resource manager's routines
*/
/*
* Re-acquire a lock belonging to a transaction that was prepared.
*
* Because this function is run at db startup, re-acquiring the locks should
* never conflict with running transactions because there are none. We
* assume that the lock state represented by the stored 2PC files is legal.
*/
void
lock_twophase_recover(TransactionId xid, uint16 info,
void *recdata, uint32 len)
{
TwoPhaseLockRecord *rec = (TwoPhaseLockRecord *) recdata;
PGPROC *proc = TwoPhaseGetDummyProc(xid);
LOCKTAG *locktag;
LOCKMODE lockmode;
LOCKMETHODID lockmethodid;
LOCK *lock;
PROCLOCK *proclock;
PROCLOCKTAG proclocktag;
bool found;
LWLockId masterLock;
LockMethod lockMethodTable;
Assert(len == sizeof(TwoPhaseLockRecord));
locktag = &rec->locktag;
lockmode = rec->lockmode;
lockmethodid = locktag->locktag_lockmethodid;
Assert(lockmethodid < NumLockMethods);
lockMethodTable = LockMethods[lockmethodid];
if (!lockMethodTable)
elog(ERROR, "unrecognized lock method: %d", lockmethodid);
masterLock = lockMethodTable->masterLock;
LWLockAcquire(masterLock, LW_EXCLUSIVE);
/*
* Find or create a lock with this tag.
*/
lock = (LOCK *) hash_search(LockMethodLockHash[lockmethodid],
(void *) locktag,
HASH_ENTER_NULL, &found);
if (!lock)
{
LWLockRelease(masterLock);
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of shared memory"),
errhint("You may need to increase max_locks_per_transaction.")));
}
/*
* if it's a new lock object, initialize it
*/
if (!found)
{
lock->grantMask = 0;
lock->waitMask = 0;
SHMQueueInit(&(lock->procLocks));
ProcQueueInit(&(lock->waitProcs));
lock->nRequested = 0;
lock->nGranted = 0;
MemSet(lock->requested, 0, sizeof(int) * MAX_LOCKMODES);
MemSet(lock->granted, 0, sizeof(int) * MAX_LOCKMODES);
LOCK_PRINT("lock_twophase_recover: new", lock, lockmode);
}
else
{
LOCK_PRINT("lock_twophase_recover: found", lock, lockmode);
Assert((lock->nRequested >= 0) && (lock->requested[lockmode] >= 0));
Assert((lock->nGranted >= 0) && (lock->granted[lockmode] >= 0));
Assert(lock->nGranted <= lock->nRequested);
}
/*
* Create the hash key for the proclock table.
*/
MemSet(&proclocktag, 0, sizeof(PROCLOCKTAG)); /* must clear padding */
proclocktag.lock = MAKE_OFFSET(lock);
proclocktag.proc = MAKE_OFFSET(proc);
/*
* Find or create a proclock entry with this tag
*/
proclock = (PROCLOCK *) hash_search(LockMethodProcLockHash[lockmethodid],
(void *) &proclocktag,
HASH_ENTER_NULL, &found);
if (!proclock)
{
/* Ooops, not enough shmem for the proclock */
if (lock->nRequested == 0)
{
/*
* There are no other requestors of this lock, so garbage-collect
* the lock object. We *must* do this to avoid a permanent leak
* of shared memory, because there won't be anything to cause
* anyone to release the lock object later.
*/
Assert(SHMQueueEmpty(&(lock->procLocks)));
if (!hash_search(LockMethodLockHash[lockmethodid],
(void *) &(lock->tag),
HASH_REMOVE, NULL))
elog(PANIC, "lock table corrupted");
}
LWLockRelease(masterLock);
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of shared memory"),
errhint("You may need to increase max_locks_per_transaction.")));
}
/*
* If new, initialize the new entry
*/
if (!found)
{
proclock->holdMask = 0;
proclock->releaseMask = 0;
/* Add proclock to appropriate lists */
SHMQueueInsertBefore(&lock->procLocks, &proclock->lockLink);
SHMQueueInsertBefore(&proc->procLocks, &proclock->procLink);
PROCLOCK_PRINT("lock_twophase_recover: new", proclock);
}
else
{
PROCLOCK_PRINT("lock_twophase_recover: found", proclock);
Assert((proclock->holdMask & ~lock->grantMask) == 0);
}
/*
* lock->nRequested and lock->requested[] count the total number of
* requests, whether granted or waiting, so increment those
* immediately.
*/
lock->nRequested++;
lock->requested[lockmode]++;
Assert((lock->nRequested > 0) && (lock->requested[lockmode] > 0));
/*
* We shouldn't already hold the desired lock.
*/
if (proclock->holdMask & LOCKBIT_ON(lockmode))
elog(ERROR, "lock %s on object %u/%u/%u is already held",
lock_mode_names[lockmode],
lock->tag.locktag_field1, lock->tag.locktag_field2,
lock->tag.locktag_field3);
/*
* We ignore any possible conflicts and just grant ourselves the lock.
*/
GrantLock(lock, proclock, lockmode);
LWLockRelease(masterLock);
}
/*
* 2PC processing routine for COMMIT PREPARED case.
*
* Find and release the lock indicated by the 2PC record.
*/
void
lock_twophase_postcommit(TransactionId xid, uint16 info,
void *recdata, uint32 len)
{
TwoPhaseLockRecord *rec = (TwoPhaseLockRecord *) recdata;
PGPROC *proc = TwoPhaseGetDummyProc(xid);
LOCKTAG *locktag;
LOCKMODE lockmode;
LOCKMETHODID lockmethodid;
PROCLOCKTAG proclocktag;
LOCK *lock;
PROCLOCK *proclock;
LWLockId masterLock;
LockMethod lockMethodTable;
bool wakeupNeeded;
Assert(len == sizeof(TwoPhaseLockRecord));
locktag = &rec->locktag;
lockmode = rec->lockmode;
lockmethodid = locktag->locktag_lockmethodid;
Assert(lockmethodid < NumLockMethods);
lockMethodTable = LockMethods[lockmethodid];
if (!lockMethodTable)
elog(ERROR, "unrecognized lock method: %d", lockmethodid);
masterLock = lockMethodTable->masterLock;
LWLockAcquire(masterLock, LW_EXCLUSIVE);
/*
* Re-find the lock object (it had better be there).
*/
lock = (LOCK *) hash_search(LockMethodLockHash[lockmethodid],
(void *) locktag,
HASH_FIND, NULL);
if (!lock)
elog(PANIC, "failed to re-find shared lock object");
/*
* Re-find the proclock object (ditto).
*/
MemSet(&proclocktag, 0, sizeof(PROCLOCKTAG)); /* must clear padding */
proclocktag.lock = MAKE_OFFSET(lock);
proclocktag.proc = MAKE_OFFSET(proc);
proclock = (PROCLOCK *) hash_search(LockMethodProcLockHash[lockmethodid],
(void *) &proclocktag,
HASH_FIND, NULL);
if (!proclock)
elog(PANIC, "failed to re-find shared proclock object");
/*
* Double-check that we are actually holding a lock of the type we
* want to release.
*/
if (!(proclock->holdMask & LOCKBIT_ON(lockmode)))
{
PROCLOCK_PRINT("lock_twophase_postcommit: WRONGTYPE", proclock);
LWLockRelease(masterLock);
elog(WARNING, "you don't own a lock of type %s",
lock_mode_names[lockmode]);
return;
}
/*
* Do the releasing. CleanUpLock will waken any now-wakable waiters.
*/
wakeupNeeded = UnGrantLock(lock, lockmode, proclock, lockMethodTable);
CleanUpLock(lockmethodid, lock, proclock, wakeupNeeded);
LWLockRelease(masterLock);
}
/*
* 2PC processing routine for ROLLBACK PREPARED case.
*
* This is actually just the same as the COMMIT case.
*/
void
lock_twophase_postabort(TransactionId xid, uint16 info,
void *recdata, uint32 len)
{
lock_twophase_postcommit(xid, info, recdata, len);
}

53
src/backend/storage/lmgr/proc.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/storage/lmgr/proc.c,v 1.159 2005/06/14 22:15:32 tgl Exp $
* $PostgreSQL: pgsql/src/backend/storage/lmgr/proc.c,v 1.160 2005/06/17 22:32:45 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -92,13 +92,13 @@ static bool CheckStatementTimeout(void);
* Report shared-memory space needed by InitProcGlobal.
*/
int
ProcGlobalShmemSize(int maxBackends)
ProcGlobalShmemSize(void)
{
int size = 0;
size += MAXALIGN(sizeof(PROC_HDR)); /* ProcGlobal */
size += MAXALIGN(NUM_DUMMY_PROCS * sizeof(PGPROC)); /* DummyProcs */
size += MAXALIGN(maxBackends * sizeof(PGPROC)); /* MyProcs */
size += MAXALIGN(MaxBackends * sizeof(PGPROC)); /* MyProcs */
size += MAXALIGN(sizeof(slock_t)); /* ProcStructLock */
return size;
@ -108,10 +108,10 @@ ProcGlobalShmemSize(int maxBackends)
* Report number of semaphores needed by InitProcGlobal.
*/
int
ProcGlobalSemas(int maxBackends)
ProcGlobalSemas(void)
{
/* We need a sema per backend, plus one for each dummy process. */
return maxBackends + NUM_DUMMY_PROCS;
return MaxBackends + NUM_DUMMY_PROCS;
}
/*
@ -134,7 +134,7 @@ ProcGlobalSemas(int maxBackends)
* postmaster, not in backends.
*/
void
InitProcGlobal(int maxBackends)
InitProcGlobal(void)
{
bool foundProcGlobal,
foundDummy;
@ -170,13 +170,13 @@ InitProcGlobal(int maxBackends)
* Pre-create the PGPROC structures and create a semaphore for
* each.
*/
procs = (PGPROC *) ShmemAlloc(maxBackends * sizeof(PGPROC));
procs = (PGPROC *) ShmemAlloc(MaxBackends * sizeof(PGPROC));
if (!procs)
ereport(FATAL,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of shared memory")));
MemSet(procs, 0, maxBackends * sizeof(PGPROC));
for (i = 0; i < maxBackends; i++)
MemSet(procs, 0, MaxBackends * sizeof(PGPROC));
for (i = 0; i < MaxBackends; i++)
{
PGSemaphoreCreate(&(procs[i].sem));
procs[i].links.next = ProcGlobal->freeProcs;
@ -254,7 +254,6 @@ InitProcess(void)
MyProc->xmin = InvalidTransactionId;
MyProc->pid = MyProcPid;
MyProc->databaseId = MyDatabaseId;
MyProc->logRec.xrecoff = 0;
MyProc->lwWaiting = false;
MyProc->lwExclusive = false;
MyProc->lwWaitLink = NULL;
@ -265,7 +264,7 @@ InitProcess(void)
/*
* Add our PGPROC to the PGPROC array in shared memory.
*/
ProcArrayAddMyself();
ProcArrayAdd(MyProc);
/*
* Arrange to clean up at backend exit.
@ -332,7 +331,6 @@ InitDummyProcess(int proctype)
MyProc->xid = InvalidTransactionId;
MyProc->xmin = InvalidTransactionId;
MyProc->databaseId = MyDatabaseId;
MyProc->logRec.xrecoff = 0;
MyProc->lwWaiting = false;
MyProc->lwExclusive = false;
MyProc->lwWaitLink = NULL;
@ -352,6 +350,35 @@ InitDummyProcess(int proctype)
PGSemaphoreReset(&MyProc->sem);
}
/*
* Check whether there are at least N free PGPROC objects.
*
* Note: this is designed on the assumption that N will generally be small.
*/
bool
HaveNFreeProcs(int n)
{
SHMEM_OFFSET offset;
PGPROC *proc;
/* use volatile pointer to prevent code rearrangement */
volatile PROC_HDR *procglobal = ProcGlobal;
SpinLockAcquire(ProcStructLock);
offset = procglobal->freeProcs;
while (n > 0 && offset != INVALID_OFFSET)
{
proc = (PGPROC *) MAKE_PTR(offset);
offset = proc->links.next;
n--;
}
SpinLockRelease(ProcStructLock);
return (n <= 0);
}
/*
* Cancel any pending wait for lock, when aborting a transaction.
*
@ -478,7 +505,7 @@ ProcKill(int code, Datum arg)
#endif
/* Remove our PGPROC from the PGPROC array in shared memory */
ProcArrayRemoveMyself();
ProcArrayRemove(MyProc);
SpinLockAcquire(ProcStructLock);

28
src/backend/storage/smgr/smgr.c
View File

@ -11,7 +11,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/storage/smgr/smgr.c,v 1.89 2005/06/06 20:22:58 tgl Exp $
* $PostgreSQL: pgsql/src/backend/storage/smgr/smgr.c,v 1.90 2005/06/17 22:32:46 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -434,7 +434,7 @@ smgrscheduleunlink(SMgrRelation reln, bool isTemp)
* during transactional operations, since it can't be undone.
*
* If isRedo is true, it is okay for the underlying file to be gone
* already. (In practice isRedo will always be true.)
* already.
*
* This also implies smgrclose() on the SMgrRelation object.
*/
@ -677,6 +677,30 @@ smgrimmedsync(SMgrRelation reln)
reln->smgr_rnode.relNode)));
}
/*
* PostPrepare_smgr -- Clean up after a successful PREPARE
*
* What we have to do here is throw away the in-memory state about pending
* relation deletes. It's all been recorded in the 2PC state file and
* it's no longer smgr's job to worry about it.
*/
void
PostPrepare_smgr(void)
{
PendingRelDelete *pending;
PendingRelDelete *next;
for (pending = pendingDeletes; pending != NULL; pending = next)
{
next = pending->next;
pendingDeletes = next;
/* must explicitly free the list entry */
pfree(pending);
}
}
/*
* smgrDoPendingDeletes() -- Take care of relation deletes at end of xact.
*

5
src/backend/tcop/postgres.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/tcop/postgres.c,v 1.448 2005/06/14 21:04:40 momjian Exp $
* $PostgreSQL: pgsql/src/backend/tcop/postgres.c,v 1.449 2005/06/17 22:32:46 tgl Exp $
*
* NOTES
* this is the "main" module of the postgres backend and
@ -930,6 +930,7 @@ exec_simple_query(const char *query_string)
TransactionStmt *stmt = (TransactionStmt *) parsetree;
if (stmt->kind == TRANS_STMT_COMMIT ||
stmt->kind == TRANS_STMT_PREPARE ||
stmt->kind == TRANS_STMT_ROLLBACK ||
stmt->kind == TRANS_STMT_ROLLBACK_TO)
allowit = true;
@ -1261,6 +1262,7 @@ exec_parse_message(const char *query_string, /* string to execute */
TransactionStmt *stmt = (TransactionStmt *) parsetree;
if (stmt->kind == TRANS_STMT_COMMIT ||
stmt->kind == TRANS_STMT_PREPARE ||
stmt->kind == TRANS_STMT_ROLLBACK ||
stmt->kind == TRANS_STMT_ROLLBACK_TO)
allowit = true;
@ -1751,6 +1753,7 @@ exec_execute_message(const char *portal_name, long max_rows)
is_trans_stmt = true;
if (stmt->kind == TRANS_STMT_COMMIT ||
stmt->kind == TRANS_STMT_PREPARE ||
stmt->kind == TRANS_STMT_ROLLBACK ||
stmt->kind == TRANS_STMT_ROLLBACK_TO)
is_trans_exit = true;

38
src/backend/tcop/utility.c
View File

@ -10,13 +10,14 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/tcop/utility.c,v 1.236 2005/04/28 21:47:15 tgl Exp $
* $PostgreSQL: pgsql/src/backend/tcop/utility.c,v 1.237 2005/06/17 22:32:46 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/heapam.h"
#include "access/twophase.h"
#include "catalog/catalog.h"
#include "catalog/namespace.h"
#include "catalog/pg_shadow.h"
@ -383,11 +384,11 @@ ProcessUtility(Node *parsetree,
if (strcmp(item->defname, "transaction_isolation") == 0)
SetPGVariable("transaction_isolation",
list_make1(item->arg),
false);
true);
else if (strcmp(item->defname, "transaction_read_only") == 0)
SetPGVariable("transaction_read_only",
list_make1(item->arg),
false);
true);
}
}
break;
@ -401,6 +402,25 @@ ProcessUtility(Node *parsetree,
}
break;
case TRANS_STMT_PREPARE:
if (!PrepareTransactionBlock(stmt->gid))
{
/* report unsuccessful commit in completionTag */
if (completionTag)
strcpy(completionTag, "ROLLBACK");
}
break;
case TRANS_STMT_COMMIT_PREPARED:
PreventTransactionChain(stmt, "COMMIT PREPARED");
FinishPreparedTransaction(stmt->gid, true);
break;
case TRANS_STMT_ROLLBACK_PREPARED:
PreventTransactionChain(stmt, "ROLLBACK PREPARED");
FinishPreparedTransaction(stmt->gid, false);
break;
case TRANS_STMT_ROLLBACK:
UserAbortTransactionBlock();
break;
@ -1215,6 +1235,18 @@ CreateCommandTag(Node *parsetree)
tag = "RELEASE";
break;
case TRANS_STMT_PREPARE:
tag = "PREPARE TRANSACTION";
break;
case TRANS_STMT_COMMIT_PREPARED:
tag = "COMMIT PREPARED";
break;
case TRANS_STMT_ROLLBACK_PREPARED:
tag = "ROLLBACK PREPARED";
break;
default:
tag = "???";
break;

101
src/backend/utils/cache/inval.c vendored
View File

@ -80,12 +80,13 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/cache/inval.c,v 1.71 2005/04/14 01:38:19 tgl Exp $
* $PostgreSQL: pgsql/src/backend/utils/cache/inval.c,v 1.72 2005/06/17 22:32:46 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/twophase_rmgr.h"
#include "access/xact.h"
#include "catalog/catalog.h"
#include "miscadmin.h"
@ -171,6 +172,13 @@ static struct CACHECALLBACK
static int cache_callback_count = 0;
/* info values for 2PC callback */
#define TWOPHASE_INFO_MSG 0 /* SharedInvalidationMessage */
#define TWOPHASE_INFO_FILE_BEFORE 1 /* relcache file inval */
#define TWOPHASE_INFO_FILE_AFTER 2 /* relcache file inval */
static void PersistInvalidationMessage(SharedInvalidationMessage *msg);
/* ----------------------------------------------------------------
* Invalidation list support functions
@ -636,6 +644,56 @@ AtStart_Inval(void)
transInvalInfo->my_level = GetCurrentTransactionNestLevel();
}
/*
* AtPrepare_Inval
* Save the inval lists state at 2PC transaction prepare.
*
* In this phase we just generate 2PC records for all the pending invalidation
* work.
*/
void
AtPrepare_Inval(void)
{
/* Must be at top of stack */
Assert(transInvalInfo != NULL && transInvalInfo->parent == NULL);
/*
* Relcache init file invalidation requires processing both before
* and after we send the SI messages.
*/
if (transInvalInfo->RelcacheInitFileInval)
RegisterTwoPhaseRecord(TWOPHASE_RM_INVAL_ID, TWOPHASE_INFO_FILE_BEFORE,
NULL, 0);
AppendInvalidationMessages(&transInvalInfo->PriorCmdInvalidMsgs,
&transInvalInfo->CurrentCmdInvalidMsgs);
ProcessInvalidationMessages(&transInvalInfo->PriorCmdInvalidMsgs,
PersistInvalidationMessage);
if (transInvalInfo->RelcacheInitFileInval)
RegisterTwoPhaseRecord(TWOPHASE_RM_INVAL_ID, TWOPHASE_INFO_FILE_AFTER,
NULL, 0);
}
/*
* PostPrepare_Inval
* Clean up after successful PREPARE.
*
* Here, we want to act as though the transaction aborted, so that we will
* undo any syscache changes it made, thereby bringing us into sync with the
* outside world, which doesn't believe the transaction committed yet.
*
* If the prepared transaction is later aborted, there is nothing more to
* do; if it commits, we will receive the consequent inval messages just
* like everyone else.
*/
void
PostPrepare_Inval(void)
{
AtEOXact_Inval(false);
}
/*
* AtSubStart_Inval
* Initialize inval lists at start of a subtransaction.
@ -654,6 +712,47 @@ AtSubStart_Inval(void)
transInvalInfo = myInfo;
}
/*
* PersistInvalidationMessage
* Write an invalidation message to the 2PC state file.
*/
static void
PersistInvalidationMessage(SharedInvalidationMessage *msg)
{
RegisterTwoPhaseRecord(TWOPHASE_RM_INVAL_ID, TWOPHASE_INFO_MSG,
msg, sizeof(SharedInvalidationMessage));
}
/*
* inval_twophase_postcommit
* Process an invalidation message from the 2PC state file.
*/
void
inval_twophase_postcommit(TransactionId xid, uint16 info,
void *recdata, uint32 len)
{
SharedInvalidationMessage *msg;
switch (info)
{
case TWOPHASE_INFO_MSG:
msg = (SharedInvalidationMessage *) recdata;
Assert(len == sizeof(SharedInvalidationMessage));
SendSharedInvalidMessage(msg);
break;
case TWOPHASE_INFO_FILE_BEFORE:
RelationCacheInitFileInvalidate(true);
break;
case TWOPHASE_INFO_FILE_AFTER:
RelationCacheInitFileInvalidate(false);
break;
default:
Assert(false);
break;
}
}
/*
* AtEOXact_Inval
* Process queued-up invalidation messages at end of main transaction.

71
src/backend/utils/init/flatfiles.c
View File

@ -22,7 +22,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/backend/utils/init/flatfiles.c,v 1.7 2005/06/06 17:01:24 tgl Exp $
* $PostgreSQL: pgsql/src/backend/utils/init/flatfiles.c,v 1.8 2005/06/17 22:32:47 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -32,6 +32,7 @@
#include <unistd.h>
#include "access/heapam.h"
#include "access/twophase_rmgr.h"
#include "catalog/pg_database.h"
#include "catalog/pg_group.h"
#include "catalog/pg_namespace.h"
@ -48,10 +49,16 @@
#include "utils/syscache.h"
/* Actual names of the flat files (within $PGDATA/global/) */
#define DATABASE_FLAT_FILE "pg_database"
#define GROUP_FLAT_FILE "pg_group"
#define USER_FLAT_FILE "pg_pwd"
/* Info bits in a flatfiles 2PC record */
#define FF_BIT_DATABASE 1
#define FF_BIT_GROUP 2
#define FF_BIT_USER 4
/*
* The need-to-update-files flags are SubTransactionIds that show
@ -757,6 +764,43 @@ AtEOXact_UpdateFlatFiles(bool isCommit)
SendPostmasterSignal(PMSIGNAL_PASSWORD_CHANGE);
}
/*
* This routine is called during transaction prepare.
*
* Record which files need to be refreshed if this transaction later
* commits.
*
* Note: it's OK to clear the flags immediately, since if the PREPARE fails
* further on, we'd only reset the flags anyway. So there's no need for a
* separate PostPrepare call.
*/
void
AtPrepare_UpdateFlatFiles(void)
{
uint16 info = 0;
if (database_file_update_subid != InvalidSubTransactionId)
{
database_file_update_subid = InvalidSubTransactionId;
info |= FF_BIT_DATABASE;
}
if (group_file_update_subid != InvalidSubTransactionId)
{
group_file_update_subid = InvalidSubTransactionId;
info |= FF_BIT_GROUP;
}
if (user_file_update_subid != InvalidSubTransactionId)
{
user_file_update_subid = InvalidSubTransactionId;
info |= FF_BIT_USER;
}
if (info != 0)
RegisterTwoPhaseRecord(TWOPHASE_RM_FLATFILES_ID, info,
NULL, 0);
}
/*
* AtEOSubXact_UpdateFlatFiles
*
@ -831,3 +875,28 @@ flatfile_update_trigger(PG_FUNCTION_ARGS)
return PointerGetDatum(NULL);
}
/*
* 2PC processing routine for COMMIT PREPARED case.
*
* (We don't have to do anything for ROLLBACK PREPARED.)
*/
void
flatfile_twophase_postcommit(TransactionId xid, uint16 info,
void *recdata, uint32 len)
{
/*
* Set flags to do the needed file updates at the end of my own
* current transaction. (XXX this has some issues if my own
* transaction later rolls back, or if there is any significant
* delay before I commit. OK for now because we disallow
* COMMIT PREPARED inside a transaction block.)
*/
if (info & FF_BIT_DATABASE)
database_file_update_needed();
if (info & FF_BIT_GROUP)
group_file_update_needed();
if (info & FF_BIT_USER)
user_file_update_needed();
}

6
src/backend/utils/init/postinit.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/init/postinit.c,v 1.147 2005/05/19 21:35:47 tgl Exp $
* $PostgreSQL: pgsql/src/backend/utils/init/postinit.c,v 1.148 2005/06/17 22:32:47 tgl Exp $
*
*
*-------------------------------------------------------------------------
@ -232,7 +232,7 @@ InitCommunication(void)
* We're running a postgres bootstrap process or a standalone
* backend. Create private "shmem" and semaphores.
*/
CreateSharedMemoryAndSemaphores(true, MaxBackends, 0);
CreateSharedMemoryAndSemaphores(true, 0);
}
}
@ -456,7 +456,7 @@ InitPostgres(const char *dbname, const char *username)
*/
if (!am_superuser &&
ReservedBackends > 0 &&
CountEmptyBackendSlots() < ReservedBackends)
!HaveNFreeProcs(ReservedBackends))
ereport(FATAL,
(errcode(ERRCODE_TOO_MANY_CONNECTIONS),
errmsg("connection limit exceeded for non-superusers")));

12
src/backend/utils/misc/guc.c
View File

@ -10,7 +10,7 @@
* Written by Peter Eisentraut <peter_e@gmx.net>.
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.267 2005/06/16 20:47:20 momjian Exp $
* $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.268 2005/06/17 22:32:47 tgl Exp $
*
*--------------------------------------------------------------------
*/
@ -25,6 +25,7 @@
#include "utils/guc.h"
#include "utils/guc_tables.h"
#include "access/twophase.h"
#include "catalog/namespace.h"
#include "catalog/pg_type.h"
#include "commands/async.h"
@ -1102,6 +1103,15 @@ static struct config_int ConfigureNamesInt[] =
1000, 25, INT_MAX, NULL, NULL
},
{
{"max_prepared_transactions", PGC_POSTMASTER, RESOURCES,
gettext_noop("Sets the maximum number of simultaneously prepared transactions."),
NULL
},
&max_prepared_xacts,
50, 0, 10000, NULL, NULL
},
#ifdef LOCK_DEBUG
{
{"trace_lock_oidmin", PGC_SUSET, DEVELOPER_OPTIONS,

1
src/backend/utils/misc/postgresql.conf.sample
View File

@ -79,6 +79,7 @@
#shared_buffers = 1000 # min 16, at least max_connections*2, 8KB each
#temp_buffers = 1000 # min 100, 8KB each
#max_prepared_transactions = 50 # 0-10000
#work_mem = 1024 # min 64, size in KB
#maintenance_work_mem = 16384 # min 1024, size in KB
#max_stack_depth = 2048 # min 100, size in KB

44
src/backend/utils/mmgr/portalmem.c
View File

@ -12,7 +12,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/mmgr/portalmem.c,v 1.80 2005/05/29 04:23:06 tgl Exp $
* $PostgreSQL: pgsql/src/backend/utils/mmgr/portalmem.c,v 1.81 2005/06/17 22:32:47 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -466,6 +466,48 @@ CommitHoldablePortals(void)
return result;
}
/*
* Pre-prepare processing for portals.
*
* Currently we refuse PREPARE if the transaction created any holdable
* cursors, since it's quite unclear what to do with one. However, this
* has the same API as CommitHoldablePortals and is invoked in the same
* way by xact.c, so that we can easily do something reasonable if anyone
* comes up with something reasonable to do.
*
* Returns TRUE if any holdable cursors were processed, FALSE if not.
*/
bool
PrepareHoldablePortals(void)
{
bool result = false;
HASH_SEQ_STATUS status;
PortalHashEnt *hentry;
hash_seq_init(&status, PortalHashTable);
while ((hentry = (PortalHashEnt *) hash_seq_search(&status)) != NULL)
{
Portal portal = hentry->portal;
/* Is it a holdable portal created in the current xact? */
if ((portal->cursorOptions & CURSOR_OPT_HOLD) &&
portal->createSubid != InvalidSubTransactionId &&
portal->status == PORTAL_READY)
{
/*
* We are exiting the transaction that created a holdable
* cursor. Can't do PREPARE.
*/
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot PREPARE a transaction that has created a cursor WITH HOLD")));
}
}
return result;
}
/*
* Pre-commit processing for portals.
*

3
src/bin/initdb/initdb.c
View File

@ -39,7 +39,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
* Portions taken from FreeBSD.
*
* $PostgreSQL: pgsql/src/bin/initdb/initdb.c,v 1.83 2005/04/30 08:08:51 neilc Exp $
* $PostgreSQL: pgsql/src/bin/initdb/initdb.c,v 1.84 2005/06/17 22:32:47 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -2124,6 +2124,7 @@ main(int argc, char *argv[])
"pg_xlog/archive_status",
"pg_clog",
"pg_subtrans",
"pg_twophase",
"pg_multixact/members",
"pg_multixact/offsets",
"base",

17
src/bin/psql/common.c
View File

@ -3,7 +3,7 @@
*
* Copyright (c) 2000-2005, PostgreSQL Global Development Group
*
* $PostgreSQL: pgsql/src/bin/psql/common.c,v 1.102 2005/06/14 02:57:41 momjian Exp $
* $PostgreSQL: pgsql/src/bin/psql/common.c,v 1.103 2005/06/17 22:32:47 tgl Exp $
*/
#include "postgres_fe.h"
#include "common.h"
@ -1216,6 +1216,21 @@ command_no_begin(const char *query)
return true;
if (wordlen == 8 && pg_strncasecmp(query, "rollback", 8) == 0)
return true;
if (wordlen == 7 && pg_strncasecmp(query, "prepare", 7) == 0)
{
/* PREPARE TRANSACTION is a TC command, PREPARE foo is not */
query += wordlen;
query = skip_white_space(query);
wordlen = 0;
while (isalpha((unsigned char) query[wordlen]))
wordlen += PQmblen(&query[wordlen], pset.encoding);
if (wordlen == 11 && pg_strncasecmp(query, "transaction", 11) == 0)
return true;
return false;
}
/*
* Commands not allowed within transactions. The statements checked

4
src/include/access/subtrans.h
View File

@ -6,7 +6,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/access/subtrans.h,v 1.5 2004/12/31 22:03:21 pgsql Exp $
* $PostgreSQL: pgsql/src/include/access/subtrans.h,v 1.6 2005/06/17 22:32:48 tgl Exp $
*/
#ifndef SUBTRANS_H
#define SUBTRANS_H
@ -18,7 +18,7 @@ extern TransactionId SubTransGetTopmostTransaction(TransactionId xid);
extern int SUBTRANSShmemSize(void);
extern void SUBTRANSShmemInit(void);
extern void BootStrapSUBTRANS(void);
extern void StartupSUBTRANS(void);
extern void StartupSUBTRANS(TransactionId oldestActiveXID);
extern void ShutdownSUBTRANS(void);
extern void CheckPointSUBTRANS(void);
extern void ExtendSUBTRANS(TransactionId newestXact);

49
src/include/access/twophase.h Normal file
View File

@ -0,0 +1,49 @@
/*-------------------------------------------------------------------------
*
* twophase.h
* Two-phase-commit related declarations.
*
*
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/access/twophase.h,v 1.1 2005/06/17 22:32:48 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#ifndef TWOPHASE_H
#define TWOPHASE_H
#include "storage/lock.h"
/*
* GlobalTransactionData is defined in twophase.c; other places have no
* business knowing the internal definition.
*/
typedef struct GlobalTransactionData *GlobalTransaction;
/* GUC variable */
extern int max_prepared_xacts;
extern int TwoPhaseShmemSize(void);
extern void TwoPhaseShmemInit(void);
extern PGPROC *TwoPhaseGetDummyProc(TransactionId xid);
extern GlobalTransaction MarkAsPreparing(TransactionId xid, Oid databaseid,
char *gid, AclId owner);
extern void MarkAsPrepared(GlobalTransaction gxact);
extern void StartPrepare(GlobalTransaction gxact);
extern void EndPrepare(GlobalTransaction gxact);
extern TransactionId PrescanPreparedTransactions(void);
extern void RecoverPreparedTransactions(void);
extern void RecreateTwoPhaseFile(TransactionId xid, void *content, int len);
extern void RemoveTwoPhaseFile(TransactionId xid, bool giveWarning);
extern void FinishPreparedTransaction(char *gid, bool isCommit);
#endif /* TWOPHASE_H */

39
src/include/access/twophase_rmgr.h Normal file
View File

@ -0,0 +1,39 @@
/*-------------------------------------------------------------------------
*
* twophase_rmgr.h
* Two-phase-commit resource managers definition
*
*
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/access/twophase_rmgr.h,v 1.1 2005/06/17 22:32:48 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#ifndef TWOPHASE_RMGR_H
#define TWOPHASE_RMGR_H
typedef void (*TwoPhaseCallback) (TransactionId xid, uint16 info,
void *recdata, uint32 len);
typedef uint8 TwoPhaseRmgrId;
/*
* Built-in resource managers
*/
#define TWOPHASE_RM_END_ID 0
#define TWOPHASE_RM_LOCK_ID 1
#define TWOPHASE_RM_INVAL_ID 2
#define TWOPHASE_RM_FLATFILES_ID 3
#define TWOPHASE_RM_NOTIFY_ID 4
#define TWOPHASE_RM_MAX_ID TWOPHASE_RM_NOTIFY_ID
extern const TwoPhaseCallback twophase_recover_callbacks[];
extern const TwoPhaseCallback twophase_postcommit_callbacks[];
extern const TwoPhaseCallback twophase_postabort_callbacks[];
extern void RegisterTwoPhaseRecord(TwoPhaseRmgrId rmid, uint16 info,
const void *data, uint32 len);
#endif /* TWOPHASE_RMGR_H */

38
src/include/access/xact.h
View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/access/xact.h,v 1.76 2005/06/06 17:01:24 tgl Exp $
* $PostgreSQL: pgsql/src/include/access/xact.h,v 1.77 2005/06/17 22:32:48 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -47,7 +47,8 @@ extern bool XactReadOnly;
typedef enum
{
XACT_EVENT_COMMIT,
XACT_EVENT_ABORT
XACT_EVENT_ABORT,
XACT_EVENT_PREPARE
} XactEvent;
typedef void (*XactCallback) (XactEvent event, void *arg);
@ -72,8 +73,11 @@ typedef void (*SubXactCallback) (SubXactEvent event, SubTransactionId mySubid,
* XLOG allows to store some information in high 4 bits of log
* record xl_info field
*/
#define XLOG_XACT_COMMIT 0x00
#define XLOG_XACT_ABORT 0x20
#define XLOG_XACT_COMMIT 0x00
#define XLOG_XACT_PREPARE 0x10
#define XLOG_XACT_ABORT 0x20
#define XLOG_XACT_COMMIT_PREPARED 0x30
#define XLOG_XACT_ABORT_PREPARED 0x40
typedef struct xl_xact_commit
{
@ -99,6 +103,31 @@ typedef struct xl_xact_abort
#define MinSizeOfXactAbort offsetof(xl_xact_abort, xnodes)
/*
* COMMIT_PREPARED and ABORT_PREPARED are identical to COMMIT/ABORT records
* except that we have to store the XID of the prepared transaction explicitly
* --- the XID in the record header will be for the transaction doing the
* COMMIT PREPARED or ABORT PREPARED command.
*/
typedef struct xl_xact_commit_prepared
{
TransactionId xid; /* XID of prepared xact */
xl_xact_commit crec; /* COMMIT record */
/* MORE DATA FOLLOWS AT END OF STRUCT */
} xl_xact_commit_prepared;
#define MinSizeOfXactCommitPrepared offsetof(xl_xact_commit_prepared, crec.xnodes)
typedef struct xl_xact_abort_prepared
{
TransactionId xid; /* XID of prepared xact */
xl_xact_abort arec; /* ABORT record */
/* MORE DATA FOLLOWS AT END OF STRUCT */
} xl_xact_abort_prepared;
#define MinSizeOfXactAbortPrepared offsetof(xl_xact_abort_prepared, arec.xnodes)
/* ----------------
* extern definitions
@ -121,6 +150,7 @@ extern void CommitTransactionCommand(void);
extern void AbortCurrentTransaction(void);
extern void BeginTransactionBlock(void);
extern bool EndTransactionBlock(void);
extern bool PrepareTransactionBlock(char *gid);
extern void UserAbortTransactionBlock(void);
extern void ReleaseSavepoint(List *options);
extern void DefineSavepoint(char *name);

4
src/include/catalog/catversion.h
View File

@ -37,7 +37,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.276 2005/06/15 12:56:35 momjian Exp $
* $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.277 2005/06/17 22:32:48 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -53,6 +53,6 @@
*/
/* yyyymmddN */
#define CATALOG_VERSION_NO 200506151
#define CATALOG_VERSION_NO 200506171
#endif

4
src/include/catalog/pg_proc.h
View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.367 2005/06/14 21:04:41 momjian Exp $
* $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.368 2005/06/17 22:32:48 tgl Exp $
*
* NOTES
* The script catalog/genbki.sh reads this file and generates .bki
@ -3005,6 +3005,8 @@ DATA(insert OID = 2084 ( pg_show_all_settings PGNSP PGUID 12 f f t t s 0 2249 "
DESCR("SHOW ALL as a function");
DATA(insert OID = 1371 ( pg_lock_status PGNSP PGUID 12 f f t t v 0 2249 "" _null_ _null_ _null_ pg_lock_status - _null_ ));
DESCR("view system lock information");
DATA(insert OID = 1065 ( pg_prepared_xact PGNSP PGUID 12 f f t t v 0 2249 "" _null_ _null_ _null_ pg_prepared_xact - _null_ ));
DESCR("view two-phase transactions");
DATA(insert OID = 2079 ( pg_table_is_visible PGNSP PGUID 12 f f t f s 1 16 "26" _null_ _null_ _null_ pg_table_is_visible - _null_ ));
DESCR("is table visible in search path?");

6
src/include/commands/async.h
View File

@ -6,7 +6,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/commands/async.h,v 1.27 2004/12/31 22:03:28 pgsql Exp $
* $PostgreSQL: pgsql/src/include/commands/async.h,v 1.28 2005/06/17 22:32:49 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -26,6 +26,7 @@ extern void AtAbort_Notify(void);
extern void AtSubStart_Notify(void);
extern void AtSubCommit_Notify(void);
extern void AtSubAbort_Notify(void);
extern void AtPrepare_Notify(void);
/* signal handler for inbound notifies (SIGUSR2) */
extern void NotifyInterruptHandler(SIGNAL_ARGS);
@ -38,4 +39,7 @@ extern void NotifyInterruptHandler(SIGNAL_ARGS);
extern void EnableNotifyInterrupt(void);
extern bool DisableNotifyInterrupt(void);
extern void notify_twophase_postcommit(TransactionId xid, uint16 info,
void *recdata, uint32 len);
#endif /* ASYNC_H */

8
src/include/nodes/parsenodes.h
View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.281 2005/06/05 22:32:57 tgl Exp $
* $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.282 2005/06/17 22:32:49 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -1556,7 +1556,10 @@ typedef enum TransactionStmtKind
TRANS_STMT_ROLLBACK,
TRANS_STMT_SAVEPOINT,
TRANS_STMT_RELEASE,
TRANS_STMT_ROLLBACK_TO
TRANS_STMT_ROLLBACK_TO,
TRANS_STMT_PREPARE,
TRANS_STMT_COMMIT_PREPARED,
TRANS_STMT_ROLLBACK_PREPARED
} TransactionStmtKind;
typedef struct TransactionStmt
@ -1564,6 +1567,7 @@ typedef struct TransactionStmt
NodeTag type;
TransactionStmtKind kind; /* see above */
List *options; /* for BEGIN/START and savepoint commands */
char *gid; /* for two-phase-commit related commands */
} TransactionStmt;
/* ----------------------

6
src/include/storage/ipc.h
View File

@ -11,7 +11,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/storage/ipc.h,v 1.70 2004/12/31 22:03:42 pgsql Exp $
* $PostgreSQL: pgsql/src/include/storage/ipc.h,v 1.71 2005/06/17 22:32:49 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -29,8 +29,6 @@ extern void on_shmem_exit(void (*function) (int code, Datum arg), Datum arg);
extern void on_exit_reset(void);
/* ipci.c */
extern void CreateSharedMemoryAndSemaphores(bool makePrivate,
int maxBackends,
int port);
extern void CreateSharedMemoryAndSemaphores(bool makePrivate, int port);
#endif /* IPC_H */

4
src/include/storage/lmgr.h
View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/storage/lmgr.h,v 1.49 2005/06/14 22:15:33 tgl Exp $
* $PostgreSQL: pgsql/src/include/storage/lmgr.h,v 1.50 2005/06/17 22:32:50 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -41,7 +41,7 @@
* so increase that if you want to add more modes.
*/
extern void InitLockTable(int maxBackends);
extern void InitLockTable(void);
extern void RelationInitLockInfo(Relation relation);
/* Lock a relation */

17
src/include/storage/lock.h
View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/storage/lock.h,v 1.88 2005/06/14 22:15:33 tgl Exp $
* $PostgreSQL: pgsql/src/include/storage/lock.h,v 1.89 2005/06/17 22:32:50 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -370,7 +370,7 @@ extern void InitLocks(void);
extern LockMethod GetLocksMethodTable(LOCK *lock);
extern LOCKMETHODID LockMethodTableInit(const char *tabName,
const LOCKMASK *conflictsP,
int numModes, int maxBackends);
int numModes);
extern LOCKMETHODID LockMethodTableRename(LOCKMETHODID lockmethodid);
extern LockAcquireResult LockAcquire(LOCKMETHODID lockmethodid,
LOCKTAG *locktag,
@ -383,13 +383,15 @@ extern bool LockRelease(LOCKMETHODID lockmethodid, LOCKTAG *locktag,
extern void LockReleaseAll(LOCKMETHODID lockmethodid, bool allLocks);
extern void LockReleaseCurrentOwner(void);
extern void LockReassignCurrentOwner(void);
extern void AtPrepare_Locks(void);
extern void PostPrepare_Locks(TransactionId xid);
extern int LockCheckConflicts(LockMethod lockMethodTable,
LOCKMODE lockmode,
LOCK *lock, PROCLOCK *proclock, PGPROC *proc);
extern void GrantLock(LOCK *lock, PROCLOCK *proclock, LOCKMODE lockmode);
extern void GrantAwaitedLock(void);
extern void RemoveFromWaitQueue(PGPROC *proc);
extern int LockShmemSize(int maxBackends);
extern int LockShmemSize(void);
extern bool DeadLockCheck(PGPROC *proc);
extern void DeadLockReport(void);
extern void RememberSimpleDeadLock(PGPROC *proc1,
@ -400,8 +402,15 @@ extern void InitDeadLockChecking(void);
extern LockData *GetLockStatusData(void);
extern const char *GetLockmodeName(LOCKMODE mode);
extern void lock_twophase_recover(TransactionId xid, uint16 info,
void *recdata, uint32 len);
extern void lock_twophase_postcommit(TransactionId xid, uint16 info,
void *recdata, uint32 len);
extern void lock_twophase_postabort(TransactionId xid, uint16 info,
void *recdata, uint32 len);
#ifdef LOCK_DEBUG
extern void DumpLocks(void);
extern void DumpLocks(PGPROC *proc);
extern void DumpAllLocks(void);
#endif

3
src/include/storage/lwlock.h
View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/storage/lwlock.h,v 1.19 2005/05/19 21:35:47 tgl Exp $
* $PostgreSQL: pgsql/src/include/storage/lwlock.h,v 1.20 2005/06/17 22:32:50 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -46,6 +46,7 @@ typedef enum LWLockId
MultiXactMemberControlLock,
RelCacheInitLock,
BgWriterCommLock,
TwoPhaseStateLock,
NumFixedLWLocks, /* must be last except for
* MaxDynamicLWLock */

25
src/include/storage/proc.h
View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/storage/proc.h,v 1.78 2005/05/19 21:35:47 tgl Exp $
* $PostgreSQL: pgsql/src/include/storage/proc.h,v 1.79 2005/06/17 22:32:50 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -46,6 +46,13 @@ struct XidCache
* links: list link for any list the PGPROC is in. When waiting for a lock,
* the PGPROC is linked into that lock's waitProcs queue. A recycled PGPROC
* is linked into ProcGlobal's freeProcs list.
*
* Note: twophase.c also sets up a dummy PGPROC struct for each currently
* prepared transaction. These PGPROCs appear in the ProcArray data structure
* so that the prepared transactions appear to be still running and are
* correctly shown as holding locks. A prepared transaction PGPROC can be
* distinguished from a real one at need by the fact that it has pid == 0.
* The semaphore and lock-related fields in a prepared-xact PGPROC are unused.
*/
struct PGPROC
{
@ -62,16 +69,9 @@ struct PGPROC
* were starting our xact: vacuum must not
* remove tuples deleted by xid >= xmin ! */
int pid; /* This backend's process id */
int pid; /* This backend's process id, or 0 */
Oid databaseId; /* OID of database this backend is using */
/*
* XLOG location of first XLOG record written by this backend's
* current transaction. If backend is not in a transaction or hasn't
* yet modified anything, logRec.xrecoff is zero.
*/
XLogRecPtr logRec;
/* Info about LWLock the process is currently waiting for, if any. */
bool lwWaiting; /* true if waiting for an LW lock */
bool lwExclusive; /* true if waiting for exclusive access */
@ -120,11 +120,12 @@ extern int StatementTimeout;
/*
* Function Prototypes
*/
extern int ProcGlobalSemas(int maxBackends);
extern int ProcGlobalShmemSize(int maxBackends);
extern void InitProcGlobal(int maxBackends);
extern int ProcGlobalSemas(void);
extern int ProcGlobalShmemSize(void);
extern void InitProcGlobal(void);
extern void InitProcess(void);
extern void InitDummyProcess(int proctype);
extern bool HaveNFreeProcs(int n);
extern void ProcReleaseLocks(bool isCommit);
extern void ProcQueueInit(PROC_QUEUE *queue);

18
src/include/storage/procarray.h
View File

@ -7,28 +7,30 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/storage/procarray.h,v 1.1 2005/05/19 21:35:47 tgl Exp $
* $PostgreSQL: pgsql/src/include/storage/procarray.h,v 1.2 2005/06/17 22:32:50 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#ifndef PROCARRAY_H
#define PROCARRAY_H
extern int ProcArrayShmemSize(int maxBackends);
extern void CreateSharedProcArray(int maxBackends);
extern void ProcArrayAddMyself(void);
extern void ProcArrayRemoveMyself(void);
#include "storage/lock.h"
extern int ProcArrayShmemSize(void);
extern void CreateSharedProcArray(void);
extern void ProcArrayAdd(PGPROC *proc);
extern void ProcArrayRemove(PGPROC *proc);
extern bool TransactionIdIsInProgress(TransactionId xid);
extern bool TransactionIdIsActive(TransactionId xid);
extern TransactionId GetOldestXmin(bool allDbs);
/* Use "struct PGPROC", not PGPROC, to avoid including proc.h here */
extern struct PGPROC *BackendPidGetProc(int pid);
extern PGPROC *BackendPidGetProc(int pid);
extern bool IsBackendPid(int pid);
extern bool DatabaseHasActiveBackends(Oid databaseId, bool ignoreMyself);
extern int CountActiveBackends(void);
extern int CountEmptyBackendSlots(void);
extern void XidCacheRemoveRunningXids(TransactionId xid,
int nxids, TransactionId *xids);

3
src/include/storage/smgr.h
View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/storage/smgr.h,v 1.51 2005/06/06 17:01:25 tgl Exp $
* $PostgreSQL: pgsql/src/include/storage/smgr.h,v 1.52 2005/06/17 22:32:50 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -79,6 +79,7 @@ extern void smgrDoPendingDeletes(bool isCommit);
extern int smgrGetPendingDeletes(bool forCommit, RelFileNode **ptr);
extern void AtSubCommit_smgr(void);
extern void AtSubAbort_smgr(void);
extern void PostPrepare_smgr(void);
extern void smgrcommit(void);
extern void smgrabort(void);
extern void smgrsync(void);

5
src/include/utils/builtins.h
View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.257 2005/05/27 00:57:49 neilc Exp $
* $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.258 2005/06/17 22:32:50 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -825,6 +825,9 @@ extern Datum show_all_settings(PG_FUNCTION_ARGS);
/* lockfuncs.c */
extern Datum pg_lock_status(PG_FUNCTION_ARGS);
/* access/transam/twophase.c */
extern Datum pg_prepared_xact(PG_FUNCTION_ARGS);
/* catalog/pg_conversion.c */
extern Datum pg_convert_using(PG_FUNCTION_ARGS);

6
src/include/utils/flatfiles.h
View File

@ -4,7 +4,7 @@
* Routines for maintaining "flat file" images of the shared catalogs.
*
*
* $PostgreSQL: pgsql/src/include/utils/flatfiles.h,v 1.3 2005/05/10 22:27:30 momjian Exp $
* $PostgreSQL: pgsql/src/include/utils/flatfiles.h,v 1.4 2005/06/17 22:32:50 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -23,6 +23,7 @@ extern char *user_getflatfilename(void);
extern void BuildFlatFiles(bool database_only);
extern void AtPrepare_UpdateFlatFiles(void);
extern void AtEOXact_UpdateFlatFiles(bool isCommit);
extern void AtEOSubXact_UpdateFlatFiles(bool isCommit,
SubTransactionId mySubid,
@ -30,4 +31,7 @@ extern void AtEOSubXact_UpdateFlatFiles(bool isCommit,
extern Datum flatfile_update_trigger(PG_FUNCTION_ARGS);
extern void flatfile_twophase_postcommit(TransactionId xid, uint16 info,
void *recdata, uint32 len);
#endif /* FLATFILES_H */

9
src/include/utils/inval.h
View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/utils/inval.h,v 1.35 2004/12/31 22:03:46 pgsql Exp $
* $PostgreSQL: pgsql/src/include/utils/inval.h,v 1.36 2005/06/17 22:32:50 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -30,6 +30,10 @@ extern void AtEOXact_Inval(bool isCommit);
extern void AtEOSubXact_Inval(bool isCommit);
extern void AtPrepare_Inval(void);
extern void PostPrepare_Inval(void);
extern void CommandEndInvalidationMessages(void);
extern void CacheInvalidateHeapTuple(Relation relation, HeapTuple tuple);
@ -47,4 +51,7 @@ extern void CacheRegisterSyscacheCallback(int cacheid,
extern void CacheRegisterRelcacheCallback(CacheCallbackFunction func,
Datum arg);
extern void inval_twophase_postcommit(TransactionId xid, uint16 info,
void *recdata, uint32 len);
#endif /* INVAL_H */

3
src/include/utils/portal.h
View File

@ -39,7 +39,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/utils/portal.h,v 1.55 2005/04/11 19:51:16 tgl Exp $
* $PostgreSQL: pgsql/src/include/utils/portal.h,v 1.56 2005/06/17 22:32:50 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -183,6 +183,7 @@ typedef struct PortalData
/* Prototypes for functions in utils/mmgr/portalmem.c */
extern void EnablePortalManager(void);
extern bool CommitHoldablePortals(void);
extern bool PrepareHoldablePortals(void);
extern void AtCommit_Portals(void);
extern void AtAbort_Portals(void);
extern void AtCleanup_Portals(void);

213
src/test/regress/expected/prepared_xacts.out Normal file
View File

@ -0,0 +1,213 @@
--
-- PREPARED TRANSACTIONS (two-phase commit)
--
-- We can't readily test persistence of prepared xacts within the
-- regression script framework, unfortunately. Note that a crash
-- isn't really needed ... stopping and starting the postmaster would
-- be enough, but we can't even do that here.
-- create a simple table that we'll use in the tests
CREATE TABLE pxtest1 (foobar VARCHAR(10));
INSERT INTO pxtest1 VALUES ('aaa');
-- Test PREPARE TRANSACTION
BEGIN;
UPDATE pxtest1 SET foobar = 'bbb' WHERE foobar = 'aaa';
SELECT * FROM pxtest1;
foobar
--------
bbb
(1 row)
PREPARE TRANSACTION 'foo1';
SELECT * FROM pxtest1;
foobar
--------
aaa
(1 row)
-- Test pg_prepared_xacts system view
SELECT gid FROM pg_prepared_xacts;
gid
------
foo1
(1 row)
-- Test ROLLBACK PREPARED
ROLLBACK PREPARED 'foo1';
SELECT * FROM pxtest1;
foobar
--------
aaa
(1 row)
SELECT gid FROM pg_prepared_xacts;
gid
-----
(0 rows)
-- Test COMMIT PREPARED
BEGIN;
INSERT INTO pxtest1 VALUES ('ddd');
SELECT * FROM pxtest1;
foobar
--------
aaa
ddd
(2 rows)
PREPARE TRANSACTION 'foo2';
SELECT * FROM pxtest1;
foobar
--------
aaa
(1 row)
COMMIT PREPARED 'foo2';
SELECT * FROM pxtest1;
foobar
--------
aaa
ddd
(2 rows)
-- Test duplicate gids
BEGIN;
UPDATE pxtest1 SET foobar = 'eee' WHERE foobar = 'ddd';
SELECT * FROM pxtest1;
foobar
--------
aaa
eee
(2 rows)
PREPARE TRANSACTION 'foo3';
SELECT gid FROM pg_prepared_xacts;
gid
------
foo3
(1 row)
BEGIN;
INSERT INTO pxtest1 VALUES ('fff');
SELECT * FROM pxtest1;
foobar
--------
aaa
ddd
fff
(3 rows)
-- This should fail, because the gid foo3 is already in use
PREPARE TRANSACTION 'foo3';
ERROR: global transaction identifier "foo3" is already in use
SELECT * FROM pxtest1;
foobar
--------
aaa
ddd
(2 rows)
ROLLBACK PREPARED 'foo3';
SELECT * FROM pxtest1;
foobar
--------
aaa
ddd
(2 rows)
-- Clean up
DROP TABLE pxtest1;
-- Test subtransactions
BEGIN;
CREATE TABLE pxtest2 (a int);
INSERT INTO pxtest2 VALUES (1);
SAVEPOINT a;
INSERT INTO pxtest2 VALUES (2);
ROLLBACK TO a;
SAVEPOINT b;
INSERT INTO pxtest2 VALUES (3);
PREPARE TRANSACTION 'regress-one';
CREATE TABLE pxtest3(fff int);
-- Test shared invalidation
BEGIN;
DROP TABLE pxtest3;
CREATE TABLE pxtest4 (a int);
INSERT INTO pxtest4 VALUES (1);
INSERT INTO pxtest4 VALUES (2);
DECLARE foo CURSOR FOR SELECT * FROM pxtest4;
-- Fetch 1 tuple, keeping the cursor open
FETCH 1 FROM foo;
a
---
1
(1 row)
PREPARE TRANSACTION 'regress-two';
-- No such cursor
FETCH 1 FROM foo;
ERROR: cursor "foo" does not exist
-- Table doesn't exist, the creation hasn't been committed yet
SELECT * FROM pxtest2;
ERROR: relation "pxtest2" does not exist
-- There should be two prepared transactions
SELECT gid FROM pg_prepared_xacts;
gid
-------------
regress-one
regress-two
(2 rows)
-- pxtest3 should be locked because of the pending DROP
set statement_timeout to 1000;
SELECT * FROM pxtest3;
ERROR: canceling query due to user request
reset statement_timeout;
-- Disconnect, we will continue testing in a different backend
\c -
-- There should still be two prepared transactions
SELECT gid FROM pg_prepared_xacts;
gid
-------------
regress-one
regress-two
(2 rows)
-- pxtest3 should still be locked because of the pending DROP
set statement_timeout to 1000;
SELECT * FROM pxtest3;
ERROR: canceling query due to user request
reset statement_timeout;
-- Commit table creation
COMMIT PREPARED 'regress-one';
\d pxtest2
Table "public.pxtest2"
Column | Type | Modifiers
--------+---------+-----------
a | integer |
SELECT * FROM pxtest2;
a
---
1
3
(2 rows)
-- There should be one prepared transaction
SELECT gid FROM pg_prepared_xacts;
gid
-------------
regress-two
(1 row)
-- Commit table drop
COMMIT PREPARED 'regress-two';
SELECT * FROM pxtest3;
ERROR: relation "pxtest3" does not exist
-- There should be no prepared transactions
SELECT gid FROM pg_prepared_xacts;
gid
-----
(0 rows)
-- Clean up
DROP TABLE pxtest2;
DROP TABLE pxtest4;

3
src/test/regress/expected/rules.out
View File

@ -1279,6 +1279,7 @@ SELECT viewname, definition FROM pg_views WHERE schemaname <> 'information_schem
iexit | SELECT ih.name, ih.thepath, interpt_pp(ih.thepath, r.thepath) AS exit FROM ihighway ih, ramp r WHERE (ih.thepath ## r.thepath);
pg_indexes | SELECT n.nspname AS schemaname, c.relname AS tablename, i.relname AS indexname, t.spcname AS "tablespace", pg_get_indexdef(i.oid) AS indexdef FROM ((((pg_index x JOIN pg_class c ON ((c.oid = x.indrelid))) JOIN pg_class i ON ((i.oid = x.indexrelid))) LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace))) LEFT JOIN pg_tablespace t ON ((t.oid = i.reltablespace))) WHERE ((c.relkind = 'r'::"char") AND (i.relkind = 'i'::"char"));
pg_locks | SELECT l.locktype, l."database", l.relation, l.page, l.tuple, l."transaction", l.classid, l.objid, l.objsubid, l.pid, l."mode", l.granted FROM pg_lock_status() l(locktype text, "database" oid, relation oid, page integer, tuple smallint, "transaction" xid, classid oid, objid oid, objsubid smallint, pid integer, "mode" text, granted boolean);
pg_prepared_xacts | SELECT p."transaction", p.gid, u.usename AS "owner", d.datname AS "database" FROM ((pg_prepared_xact() p("transaction" xid, gid text, ownerid integer, dbid oid) LEFT JOIN pg_database d ON ((p.dbid = d.oid))) LEFT JOIN pg_shadow u ON ((p.ownerid = u.usesysid)));
pg_rules | SELECT n.nspname AS schemaname, c.relname AS tablename, r.rulename, pg_get_ruledef(r.oid) AS definition FROM ((pg_rewrite r JOIN pg_class c ON ((c.oid = r.ev_class))) LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace))) WHERE (r.rulename <> '_RETURN'::name);
pg_settings | SELECT a.name, a.setting, a.category, a.short_desc, a.extra_desc, a.context, a.vartype, a.source, a.min_val, a.max_val FROM pg_show_all_settings() a(name text, setting text, category text, short_desc text, extra_desc text, context text, vartype text, source text, min_val text, max_val text);
pg_stat_activity | SELECT d.oid AS datid, d.datname, pg_stat_get_backend_pid(s.backendid) AS procpid, pg_stat_get_backend_userid(s.backendid) AS usesysid, u.usename, pg_stat_get_backend_activity(s.backendid) AS current_query, pg_stat_get_backend_activity_start(s.backendid) AS query_start, pg_stat_get_backend_start(s.backendid) AS backend_start, pg_stat_get_backend_client_addr(s.backendid) AS client_addr, pg_stat_get_backend_client_port(s.backendid) AS client_port FROM pg_database d, (SELECT pg_stat_get_backend_idset() AS backendid) s, pg_shadow u WHERE ((pg_stat_get_backend_dbid(s.backendid) = d.oid) AND (pg_stat_get_backend_userid(s.backendid) = u.usesysid));
@ -1316,7 +1317,7 @@ SELECT viewname, definition FROM pg_views WHERE schemaname <> 'information_schem
shoelace_obsolete | SELECT shoelace.sl_name, shoelace.sl_avail, shoelace.sl_color, shoelace.sl_len, shoelace.sl_unit, shoelace.sl_len_cm FROM shoelace WHERE (NOT (EXISTS (SELECT shoe.shoename FROM shoe WHERE (shoe.slcolor = shoelace.sl_color))));
street | SELECT r.name, r.thepath, c.cname FROM ONLY road r, real_city c WHERE (c.outline ## r.thepath);
toyemp | SELECT emp.name, emp.age, emp."location", (12 * emp.salary) AS annualsal FROM emp;
(40 rows)
(41 rows)
SELECT tablename, rulename, definition FROM pg_rules
ORDER BY tablename, rulename;

2
src/test/regress/parallel_schedule
View File

@ -60,7 +60,7 @@ ignore: random
# ----------
# The fourth group of parallel test
# ----------
test: select_into select_distinct select_distinct_on select_implicit select_having subselect union case join aggregates transactions random portals arrays btree_index hash_index update namespace
test: select_into select_distinct select_distinct_on select_implicit select_having subselect union case join aggregates transactions random portals arrays btree_index hash_index update namespace prepared_xacts
test: privileges
test: misc

3
src/test/regress/serial_schedule
View File

@ -1,4 +1,4 @@
# $PostgreSQL: pgsql/src/test/regress/serial_schedule,v 1.26 2004/06/18 06:14:25 tgl Exp $
# $PostgreSQL: pgsql/src/test/regress/serial_schedule,v 1.27 2005/06/17 22:32:50 tgl Exp $
# This should probably be in an order similar to parallel_schedule.
test: boolean
test: char
@ -74,6 +74,7 @@ test: btree_index
test: hash_index
test: update
test: namespace
test: prepared_xacts
test: privileges
test: misc
test: select_views

137
src/test/regress/sql/prepared_xacts.sql Normal file
View File

@ -0,0 +1,137 @@
--
-- PREPARED TRANSACTIONS (two-phase commit)
--
-- We can't readily test persistence of prepared xacts within the
-- regression script framework, unfortunately. Note that a crash
-- isn't really needed ... stopping and starting the postmaster would
-- be enough, but we can't even do that here.
-- create a simple table that we'll use in the tests
CREATE TABLE pxtest1 (foobar VARCHAR(10));
INSERT INTO pxtest1 VALUES ('aaa');
-- Test PREPARE TRANSACTION
BEGIN;
UPDATE pxtest1 SET foobar = 'bbb' WHERE foobar = 'aaa';
SELECT * FROM pxtest1;
PREPARE TRANSACTION 'foo1';
SELECT * FROM pxtest1;
-- Test pg_prepared_xacts system view
SELECT gid FROM pg_prepared_xacts;
-- Test ROLLBACK PREPARED
ROLLBACK PREPARED 'foo1';
SELECT * FROM pxtest1;
SELECT gid FROM pg_prepared_xacts;
-- Test COMMIT PREPARED
BEGIN;
INSERT INTO pxtest1 VALUES ('ddd');
SELECT * FROM pxtest1;
PREPARE TRANSACTION 'foo2';
SELECT * FROM pxtest1;
COMMIT PREPARED 'foo2';
SELECT * FROM pxtest1;
-- Test duplicate gids
BEGIN;
UPDATE pxtest1 SET foobar = 'eee' WHERE foobar = 'ddd';
SELECT * FROM pxtest1;
PREPARE TRANSACTION 'foo3';
SELECT gid FROM pg_prepared_xacts;
BEGIN;
INSERT INTO pxtest1 VALUES ('fff');
SELECT * FROM pxtest1;
-- This should fail, because the gid foo3 is already in use
PREPARE TRANSACTION 'foo3';
SELECT * FROM pxtest1;
ROLLBACK PREPARED 'foo3';
SELECT * FROM pxtest1;
-- Clean up
DROP TABLE pxtest1;
-- Test subtransactions
BEGIN;
CREATE TABLE pxtest2 (a int);
INSERT INTO pxtest2 VALUES (1);
SAVEPOINT a;
INSERT INTO pxtest2 VALUES (2);
ROLLBACK TO a;
SAVEPOINT b;
INSERT INTO pxtest2 VALUES (3);
PREPARE TRANSACTION 'regress-one';
CREATE TABLE pxtest3(fff int);
-- Test shared invalidation
BEGIN;
DROP TABLE pxtest3;
CREATE TABLE pxtest4 (a int);
INSERT INTO pxtest4 VALUES (1);
INSERT INTO pxtest4 VALUES (2);
DECLARE foo CURSOR FOR SELECT * FROM pxtest4;
-- Fetch 1 tuple, keeping the cursor open
FETCH 1 FROM foo;
PREPARE TRANSACTION 'regress-two';
-- No such cursor
FETCH 1 FROM foo;
-- Table doesn't exist, the creation hasn't been committed yet
SELECT * FROM pxtest2;
-- There should be two prepared transactions
SELECT gid FROM pg_prepared_xacts;
-- pxtest3 should be locked because of the pending DROP
set statement_timeout to 1000;
SELECT * FROM pxtest3;
reset statement_timeout;
-- Disconnect, we will continue testing in a different backend
\c -
-- There should still be two prepared transactions
SELECT gid FROM pg_prepared_xacts;
-- pxtest3 should still be locked because of the pending DROP
set statement_timeout to 1000;
SELECT * FROM pxtest3;
reset statement_timeout;
-- Commit table creation
COMMIT PREPARED 'regress-one';
\d pxtest2
SELECT * FROM pxtest2;
-- There should be one prepared transaction
SELECT gid FROM pg_prepared_xacts;
-- Commit table drop
COMMIT PREPARED 'regress-two';
SELECT * FROM pxtest3;
-- There should be no prepared transactions
SELECT gid FROM pg_prepared_xacts;
-- Clean up
DROP TABLE pxtest2;
DROP TABLE pxtest4;