diff options
61 files changed, 4449 insertions, 434 deletions
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml index 41d7a4e34d5..c5473b9501b 100644 --- a/doc/src/sgml/catalogs.sgml +++ b/doc/src/sgml/catalogs.sgml @@ -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"> @@ -3933,6 +3933,11 @@ </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> </row> @@ -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> diff --git a/doc/src/sgml/ref/allfiles.sgml b/doc/src/sgml/ref/allfiles.sgml index 6326f96f72f..33e9e68b9d5 100644 --- a/doc/src/sgml/ref/allfiles.sgml +++ b/doc/src/sgml/ref/allfiles.sgml @@ -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"> diff --git a/doc/src/sgml/ref/commit_prepared.sgml b/doc/src/sgml/ref/commit_prepared.sgml new file mode 100644 index 00000000000..b18175815b2 --- /dev/null +++ b/doc/src/sgml/ref/commit_prepared.sgml @@ -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: +--> diff --git a/doc/src/sgml/ref/prepare_transaction.sgml b/doc/src/sgml/ref/prepare_transaction.sgml new file mode 100644 index 00000000000..773689ae06d --- /dev/null +++ b/doc/src/sgml/ref/prepare_transaction.sgml @@ -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: +--> diff --git a/doc/src/sgml/ref/rollback_prepared.sgml b/doc/src/sgml/ref/rollback_prepared.sgml new file mode 100644 index 00000000000..51df9226321 --- /dev/null +++ b/doc/src/sgml/ref/rollback_prepared.sgml @@ -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: +--> diff --git a/doc/src/sgml/reference.sgml b/doc/src/sgml/reference.sgml index 01dc578b9d3..4edec85c122 100644 --- a/doc/src/sgml/reference.sgml +++ b/doc/src/sgml/reference.sgml @@ -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; ©Table; &createAggregate; &createCast; @@ -120,11 +121,13 @@ PostgreSQL Reference Manual &move; ¬ify; &prepare; + &prepareTransaction; &reindex; &releaseSavepoint; &reset; &revoke; &rollback; + &rollbackPrepared; &rollbackTo; &savepoint; &select; diff --git a/doc/src/sgml/runtime.sgml b/doc/src/sgml/runtime.sgml index dfb86511c3e..1a2a9935cc3 100644 --- a/doc/src/sgml/runtime.sgml +++ b/doc/src/sgml/runtime.sgml @@ -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> diff --git a/src/backend/access/transam/Makefile b/src/backend/access/transam/Makefile index 295ecf9e14f..c6ecef17246 100644 --- a/src/backend/access/transam/Makefile +++ b/src/backend/access/transam/Makefile @@ -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 diff --git a/src/backend/access/transam/subtrans.c b/src/backend/access/transam/subtrans.c index 0b774363888..cea778d6a1c 100644 --- a/src/backend/access/transam/subtrans.c +++ b/src/backend/access/transam/subtrans.c @@ -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); diff --git a/src/backend/access/transam/transam.c b/src/backend/access/transam/transam.c index f88c25a37db..5fa6f82daf4 100644 --- a/src/backend/access/transam/transam.c +++ b/src/backend/access/transam/transam.c @@ -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); } diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c new file mode 100644 index 00000000000..01cc50a6a46 --- /dev/null +++ b/src/backend/access/transam/twophase.c @@ -0,0 +1,1659 @@ +/*------------------------------------------------------------------------- + * + * twophase.c + * Two-phase commit support functions. + * + * 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.c,v 1.1 2005/06/17 22:32:42 tgl Exp $ + * + * NOTES + * Each global transaction is associated with a global transaction + * identifier (GID). The client assigns a GID to a postgres + * transaction with the PREPARE TRANSACTION command. + * + * We keep all active global transactions in a shared memory array. + * When the PREPARE TRANSACTION command is issued, the GID is + * reserved for the transaction in the array. This is done before + * a WAL entry is made, because the reservation checks for duplicate + * GIDs and aborts the transaction if there already is a global + * transaction in prepared state with the same GID. + * + * A global transaction (gxact) also has a dummy PGPROC that is entered + * into the ProcArray array; this is what keeps the XID considered + * running by TransactionIdIsInProgress. It is also convenient as a + * PGPROC to hook the gxact's locks to. + * + * In order to survive crashes and shutdowns, all prepared + * transactions must be stored in permanent storage. This includes + * locking information, pending notifications etc. All that state + * information is written to the per-transaction state file in + * the pg_twophase directory. + * + *------------------------------------------------------------------------- + */ +#include "postgres.h" + +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <unistd.h> + +#include "access/heapam.h" +#include "access/subtrans.h" +#include "access/twophase.h" +#include "access/twophase_rmgr.h" +#include "access/xact.h" +#include "catalog/pg_type.h" +#include "funcapi.h" +#include "miscadmin.h" +#include "storage/fd.h" +#include "storage/proc.h" +#include "storage/procarray.h" +#include "storage/smgr.h" +#include "utils/builtins.h" +#include "pgstat.h" + + +/* + * Directory where Two-phase commit files reside within PGDATA + */ +#define TWOPHASE_DIR "pg_twophase" + +/* GUC variable, can't be changed after startup */ +int max_prepared_xacts = 50; + +/* + * This struct describes one global transaction that is in prepared state + * or attempting to become prepared. + * + * The first component of the struct is a dummy PGPROC that is inserted + * into the global ProcArray so that the transaction appears to still be + * running and holding locks. It must be first because we cast pointers + * to PGPROC and pointers to GlobalTransactionData back and forth. + * + * The lifecycle of a global transaction is: + * + * 1. After checking that the requested GID is not in use, set up an + * entry in the TwoPhaseState->prepXacts array with the correct XID and GID, + * with locking_xid = my own XID and valid = false. + * + * 2. After successfully completing prepare, set valid = true and enter the + * contained PGPROC into the global ProcArray. + * + * 3. To begin COMMIT PREPARED or ROLLBACK PREPARED, check that the entry + * is valid and its locking_xid is no longer active, then store my current + * XID into locking_xid. This prevents concurrent attempts to commit or + * rollback the same prepared xact. + * + * 4. On completion of COMMIT PREPARED or ROLLBACK PREPARED, remove the entry + * from the ProcArray and the TwoPhaseState->prepXacts array and return it to + * the freelist. + * + * Note that if the preparing transaction fails between steps 1 and 2, the + * entry will remain in prepXacts until recycled. We can detect recyclable + * entries by checking for valid = false and locking_xid no longer active. + * + * typedef struct GlobalTransactionData *GlobalTransaction appears in + * twophase.h + */ +#define GIDSIZE 200 + +typedef struct GlobalTransactionData +{ + PGPROC proc; /* dummy proc */ + AclId owner; /* ID of user that executed the xact */ + TransactionId locking_xid; /* top-level XID of backend working on xact */ + bool valid; /* TRUE if fully prepared */ + char gid[GIDSIZE]; /* The GID assigned to the prepared xact */ +} GlobalTransactionData; + +/* + * Two Phase Commit shared state. Access to this struct is protected + * by TwoPhaseStateLock. + */ +typedef struct TwoPhaseStateData +{ + /* Head of linked list of free GlobalTransactionData structs */ + SHMEM_OFFSET freeGXacts; + + /* Number of valid prepXacts entries. */ + int numPrepXacts; + + /* + * There are max_prepared_xacts items in this array, but C wants a + * fixed-size array. + */ + GlobalTransaction prepXacts[1]; /* VARIABLE LENGTH ARRAY */ +} TwoPhaseStateData; /* VARIABLE LENGTH STRUCT */ + +static TwoPhaseStateData *TwoPhaseState; + + +static void RecordTransactionCommitPrepared(TransactionId xid, + int nchildren, + TransactionId *children, + int nrels, + RelFileNode *rels); +static void RecordTransactionAbortPrepared(TransactionId xid, + int nchildren, + TransactionId *children, + int nrels, + RelFileNode *rels); +static void ProcessRecords(char *bufptr, TransactionId xid, + const TwoPhaseCallback callbacks[]); + + +/* + * Initialization of shared memory + */ +int +TwoPhaseShmemSize(void) +{ + /* Need the fixed struct, the array of pointers, and the GTD structs */ + return MAXALIGN(offsetof(TwoPhaseStateData, prepXacts) + + sizeof(GlobalTransaction) * max_prepared_xacts) + + sizeof(GlobalTransactionData) * max_prepared_xacts; +} + +void +TwoPhaseShmemInit(void) +{ + bool found; + + TwoPhaseState = ShmemInitStruct("Prepared Transaction Table", + TwoPhaseShmemSize(), + &found); + if (!IsUnderPostmaster) + { + GlobalTransaction gxacts; + int i; + + Assert(!found); + TwoPhaseState->freeGXacts = INVALID_OFFSET; + TwoPhaseState->numPrepXacts = 0; + + /* + * Initialize the linked list of free GlobalTransactionData structs + */ + gxacts = (GlobalTransaction) + ((char *) TwoPhaseState + + MAXALIGN(offsetof(TwoPhaseStateData, prepXacts) + + sizeof(GlobalTransaction) * max_prepared_xacts)); + for (i = 0; i < max_prepared_xacts; i++) + { + gxacts[i].proc.links.next = TwoPhaseState->freeGXacts; + TwoPhaseState->freeGXacts = MAKE_OFFSET(&gxacts[i]); + } + } + else + Assert(found); +} + + +/* + * MarkAsPreparing + * Reserve the GID for the given transaction. + * + * Internally, this creates a gxact struct and puts it into the active array. + * NOTE: this is also used when reloading a gxact after a crash; so avoid + * assuming that we can use very much backend context. + */ +GlobalTransaction +MarkAsPreparing(TransactionId xid, Oid databaseid, char *gid, AclId owner) +{ + GlobalTransaction gxact; + int i; + + if (strlen(gid) >= GIDSIZE) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("global transaction identifier \"%s\" is too long", + gid))); + + LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE); + + /* + * First, find and recycle any gxacts that failed during prepare. + * We do this partly to ensure we don't mistakenly say their GIDs + * are still reserved, and partly so we don't fail on out-of-slots + * unnecessarily. + */ + for (i = 0; i < TwoPhaseState->numPrepXacts; i++) + { + gxact = TwoPhaseState->prepXacts[i]; + if (!gxact->valid && !TransactionIdIsActive(gxact->locking_xid)) + { + /* It's dead Jim ... remove from the active array */ + TwoPhaseState->numPrepXacts--; + TwoPhaseState->prepXacts[i] = TwoPhaseState->prepXacts[TwoPhaseState->numPrepXacts]; + /* and put it back in the freelist */ + gxact->proc.links.next = TwoPhaseState->freeGXacts; + TwoPhaseState->freeGXacts = MAKE_OFFSET(gxact); + /* Back up index count too, so we don't miss scanning one */ + i--; + } + } + + /* Check for conflicting GID */ + for (i = 0; i < TwoPhaseState->numPrepXacts; i++) + { + gxact = TwoPhaseState->prepXacts[i]; + if (strcmp(gxact->gid, gid) == 0) + { + ereport(ERROR, + (errcode(ERRCODE_DUPLICATE_OBJECT), + errmsg("global transaction identifier \"%s\" is already in use", + gid))); + } + } + + /* Get a free gxact from the freelist */ + if (TwoPhaseState->freeGXacts == INVALID_OFFSET) + ereport(ERROR, + (errcode(ERRCODE_OUT_OF_MEMORY), + errmsg("maximum number of prepared transactions reached"), + errhint("Increase max_prepared_transactions (currently %d).", + max_prepared_xacts))); + gxact = (GlobalTransaction) MAKE_PTR(TwoPhaseState->freeGXacts); + TwoPhaseState->freeGXacts = gxact->proc.links.next; + + /* Initialize it */ + MemSet(&gxact->proc, 0, sizeof(PGPROC)); + SHMQueueElemInit(&(gxact->proc.links)); + gxact->proc.waitStatus = STATUS_OK; + gxact->proc.xid = xid; + gxact->proc.xmin = InvalidTransactionId; + gxact->proc.pid = 0; + gxact->proc.databaseId = databaseid; + gxact->proc.lwWaiting = false; + gxact->proc.lwExclusive = false; + gxact->proc.lwWaitLink = NULL; + gxact->proc.waitLock = NULL; + gxact->proc.waitProcLock = NULL; + SHMQueueInit(&(gxact->proc.procLocks)); + /* subxid data must be filled later by GXactLoadSubxactData */ + gxact->proc.subxids.overflowed = false; + gxact->proc.subxids.nxids = 0; + + gxact->owner = owner; + gxact->locking_xid = xid; + gxact->valid = false; + strcpy(gxact->gid, gid); + + /* And insert it into the active array */ + Assert(TwoPhaseState->numPrepXacts < max_prepared_xacts); + TwoPhaseState->prepXacts[TwoPhaseState->numPrepXacts++] = gxact; + + LWLockRelease(TwoPhaseStateLock); + + return gxact; +} + +/* + * GXactLoadSubxactData + * + * If the transaction being persisted had any subtransactions, this must + * be called before MarkAsPrepared() to load information into the dummy + * PGPROC. + */ +static void +GXactLoadSubxactData(GlobalTransaction gxact, int nsubxacts, + TransactionId *children) +{ + /* We need no extra lock since the GXACT isn't valid yet */ + if (nsubxacts > PGPROC_MAX_CACHED_SUBXIDS) + { + gxact->proc.subxids.overflowed = true; + nsubxacts = PGPROC_MAX_CACHED_SUBXIDS; + } + if (nsubxacts > 0) + { + memcpy(gxact->proc.subxids.xids, children, + nsubxacts * sizeof(TransactionId)); + gxact->proc.subxids.nxids = nsubxacts; + } +} + +/* + * MarkAsPrepared + * Mark the GXACT as fully valid, and enter it into the global ProcArray. + */ +void +MarkAsPrepared(GlobalTransaction gxact) +{ + /* Lock here may be overkill, but I'm not convinced of that ... */ + LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE); + Assert(!gxact->valid); + gxact->valid = true; + LWLockRelease(TwoPhaseStateLock); + + /* + * Put it into the global ProcArray so TransactionIdInProgress considers + * the XID as still running. + */ + ProcArrayAdd(&gxact->proc); +} + +/* + * LockGXact + * Locate the prepared transaction and mark it busy for COMMIT or PREPARE. + */ +static GlobalTransaction +LockGXact(char *gid, AclId user) +{ + int i; + + LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE); + + for (i = 0; i < TwoPhaseState->numPrepXacts; i++) + { + GlobalTransaction gxact = TwoPhaseState->prepXacts[i]; + + /* Ignore not-yet-valid GIDs */ + if (!gxact->valid) + continue; + if (strcmp(gxact->gid, gid) != 0) + continue; + + /* Found it, but has someone else got it locked? */ + if (TransactionIdIsValid(gxact->locking_xid)) + { + if (TransactionIdIsActive(gxact->locking_xid)) + ereport(ERROR, + (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), + errmsg("prepared transaction with gid \"%s\" is busy", + gid))); + gxact->locking_xid = InvalidTransactionId; + } + + if (user != gxact->owner && !superuser_arg(user)) + ereport(ERROR, + (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), + errmsg("permission denied to finish prepared transaction"), + errhint("Must be superuser or the user that prepared the transaction."))); + + /* OK for me to lock it */ + gxact->locking_xid = GetTopTransactionId(); + + LWLockRelease(TwoPhaseStateLock); + + return gxact; + } + + LWLockRelease(TwoPhaseStateLock); + + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_OBJECT), + errmsg("prepared transaction with gid \"%s\" does not exist", + gid))); + + /* NOTREACHED */ + return NULL; +} + +/* + * RemoveGXact + * Remove the prepared transaction from the shared memory array. + * + * NB: caller should have already removed it from ProcArray + */ +static void +RemoveGXact(GlobalTransaction gxact) +{ + int i; + + LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE); + + for (i = 0; i < TwoPhaseState->numPrepXacts; i++) + { + if (gxact == TwoPhaseState->prepXacts[i]) + { + /* remove from the active array */ + TwoPhaseState->numPrepXacts--; + TwoPhaseState->prepXacts[i] = TwoPhaseState->prepXacts[TwoPhaseState->numPrepXacts]; + + /* and put it back in the freelist */ + gxact->proc.links.next = TwoPhaseState->freeGXacts; + TwoPhaseState->freeGXacts = MAKE_OFFSET(gxact); + + LWLockRelease(TwoPhaseStateLock); + + return; + } + } + + LWLockRelease(TwoPhaseStateLock); + + elog(ERROR, "failed to find %p in GlobalTransaction array", gxact); +} + +/* + * Returns an array of all prepared transactions for the user-level + * function pg_prepared_xact. + * + * The returned array and all its elements are copies of internal data + * structures, to minimize the time we need to hold the TwoPhaseStateLock. + * + * WARNING -- we return even those transactions that are not fully prepared + * yet. The caller should filter them out if he doesn't want them. + * + * The returned array is palloc'd. + */ +static int +GetPreparedTransactionList(GlobalTransaction *gxacts) +{ + GlobalTransaction array; + int num; + int i; + + LWLockAcquire(TwoPhaseStateLock, LW_SHARED); + + if (TwoPhaseState->numPrepXacts == 0) + { + LWLockRelease(TwoPhaseStateLock); + + *gxacts = NULL; + return 0; + } + + num = TwoPhaseState->numPrepXacts; + array = (GlobalTransaction) palloc(sizeof(GlobalTransactionData) * num); + *gxacts = array; + for (i = 0; i < num; i++) + memcpy(array + i, TwoPhaseState->prepXacts[i], + sizeof(GlobalTransactionData)); + + LWLockRelease(TwoPhaseStateLock); + + return num; +} + + +/* Working status for pg_prepared_xact */ +typedef struct +{ + GlobalTransaction array; + int ngxacts; + int currIdx; +} Working_State; + +/* + * pg_prepared_xact + * Produce a view with one row per prepared transaction. + * + * This function is here so we don't have to export the + * GlobalTransactionData struct definition. + */ +Datum +pg_prepared_xact(PG_FUNCTION_ARGS) +{ + FuncCallContext *funcctx; + Working_State *status; + + if (SRF_IS_FIRSTCALL()) + { + TupleDesc tupdesc; + MemoryContext oldcontext; + + /* create a function context for cross-call persistence */ + funcctx = SRF_FIRSTCALL_INIT(); + + /* + * Switch to memory context appropriate for multiple function + * calls + */ + oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx); + + /* build tupdesc for result tuples */ + /* this had better match pg_prepared_xacts view in system_views.sql */ + tupdesc = CreateTemplateTupleDesc(4, false); + TupleDescInitEntry(tupdesc, (AttrNumber) 1, "transaction", + XIDOID, -1, 0); + TupleDescInitEntry(tupdesc, (AttrNumber) 2, "gid", + TEXTOID, -1, 0); + TupleDescInitEntry(tupdesc, (AttrNumber) 3, "ownerid", + INT4OID, -1, 0); + TupleDescInitEntry(tupdesc, (AttrNumber) 4, "dbid", + OIDOID, -1, 0); + + funcctx->tuple_desc = BlessTupleDesc(tupdesc); + + /* + * Collect all the 2PC status information that we will format and + * send out as a result set. + */ + status = (Working_State *) palloc(sizeof(Working_State)); + funcctx->user_fctx = (void *) status; + + status->ngxacts = GetPreparedTransactionList(&status->array); + status->currIdx = 0; + + MemoryContextSwitchTo(oldcontext); + } + + funcctx = SRF_PERCALL_SETUP(); + status = (Working_State *) funcctx->user_fctx; + + while (status->array != NULL && status->currIdx < status->ngxacts) + { + GlobalTransaction gxact = &status->array[status->currIdx++]; + Datum values[4]; + bool nulls[4]; + HeapTuple tuple; + Datum result; + + if (!gxact->valid) + continue; + + /* + * Form tuple with appropriate data. + */ + MemSet(values, 0, sizeof(values)); + MemSet(nulls, 0, sizeof(nulls)); + + values[0] = TransactionIdGetDatum(gxact->proc.xid); + values[1] = DirectFunctionCall1(textin, CStringGetDatum(gxact->gid)); + values[2] = Int32GetDatum(gxact->owner); + values[3] = ObjectIdGetDatum(gxact->proc.databaseId); + + tuple = heap_form_tuple(funcctx->tuple_desc, values, nulls); + result = HeapTupleGetDatum(tuple); + SRF_RETURN_NEXT(funcctx, result); + } + + SRF_RETURN_DONE(funcctx); +} + +/* + * TwoPhaseGetDummyProc + * Get the PGPROC that represents a prepared transaction specified by XID + */ +PGPROC * +TwoPhaseGetDummyProc(TransactionId xid) +{ + PGPROC *result = NULL; + int i; + + static TransactionId cached_xid = InvalidTransactionId; + static PGPROC *cached_proc = NULL; + + /* + * During a recovery, COMMIT PREPARED, or ABORT PREPARED, we'll be called + * repeatedly for the same XID. We can save work with a simple cache. + */ + if (xid == cached_xid) + return cached_proc; + + LWLockAcquire(TwoPhaseStateLock, LW_SHARED); + + for (i = 0; i < TwoPhaseState->numPrepXacts; i++) + { + GlobalTransaction gxact = TwoPhaseState->prepXacts[i]; + + if (gxact->proc.xid == xid) + { + result = &gxact->proc; + break; + } + } + + LWLockRelease(TwoPhaseStateLock); + + if (result == NULL) /* should not happen */ + elog(ERROR, "failed to find dummy PGPROC for xid %u", xid); + + cached_xid = xid; + cached_proc = result; + + return result; +} + +/************************************************************************/ +/* State file support */ +/************************************************************************/ + +#define TwoPhaseFilePath(path, xid) \ + snprintf(path, MAXPGPATH, "%s/%s/%08X", DataDir, TWOPHASE_DIR, xid) + +/* + * 2PC state file format: + * + * 1. TwoPhaseFileHeader + * 2. TransactionId[] (subtransactions) + * 3. RelFileNode[] (files to be deleted at commit) + * 4. RelFileNode[] (files to be deleted at abort) + * 5. TwoPhaseRecordOnDisk + * 6. ... + * 7. TwoPhaseRecordOnDisk (end sentinel, rmid == TWOPHASE_RM_END_ID) + * 8. CRC32 + * + * Each segment except the final CRC32 is MAXALIGN'd. + */ + +/* + * Header for a 2PC state file + */ +#define TWOPHASE_MAGIC 0x57F94530 /* format identifier */ + +typedef struct TwoPhaseFileHeader +{ + uint32 magic; /* format identifier */ + uint32 total_len; /* actual file length */ + TransactionId xid; /* original transaction XID */ + Oid database; /* OID of database it was in */ + AclId owner; /* user running the transaction */ + int32 nsubxacts; /* number of following subxact XIDs */ + int32 ncommitrels; /* number of delete-on-commit rels */ + int32 nabortrels; /* number of delete-on-abort rels */ + char gid[GIDSIZE]; /* GID for transaction */ +} TwoPhaseFileHeader; + +/* + * Header for each record in a state file + * + * NOTE: len counts only the rmgr data, not the TwoPhaseRecordOnDisk header. + * The rmgr data will be stored starting on a MAXALIGN boundary. + */ +typedef struct TwoPhaseRecordOnDisk +{ + uint32 len; /* length of rmgr data */ + TwoPhaseRmgrId rmid; /* resource manager for this record */ + uint16 info; /* flag bits for use by rmgr */ +} TwoPhaseRecordOnDisk; + +/* + * During prepare, the state file is assembled in memory before writing it + * to WAL and the actual state file. We use a chain of XLogRecData blocks + * so that we will be able to pass the state file contents directly to + * XLogInsert. + */ +static struct xllist +{ + XLogRecData *head; /* first data block in the chain */ + XLogRecData *tail; /* last block in chain */ + uint32 bytes_free; /* free bytes left in tail block */ + uint32 total_len; /* total data bytes in chain */ +} records; + + +/* + * Append a block of data to records data structure. + * + * NB: each block is padded to a MAXALIGN multiple. This must be + * accounted for when the file is later read! + * + * The data is copied, so the caller is free to modify it afterwards. + */ +static void +save_state_data(const void *data, uint32 len) +{ + uint32 padlen = MAXALIGN(len); + + if (padlen > records.bytes_free) + { + records.tail->next = palloc0(sizeof(XLogRecData)); + records.tail = records.tail->next; + records.tail->buffer = InvalidBuffer; + records.tail->len = 0; + records.tail->next = NULL; + + records.bytes_free = Max(padlen, 512); + records.tail->data = palloc(records.bytes_free); + } + + memcpy(((char *) records.tail->data) + records.tail->len, data, len); + records.tail->len += padlen; + records.bytes_free -= padlen; + records.total_len += padlen; +} + +/* + * Start preparing a state file. + * + * Initializes data structure and inserts the 2PC file header record. + */ +void +StartPrepare(GlobalTransaction gxact) +{ + TransactionId xid = gxact->proc.xid; + TwoPhaseFileHeader hdr; + TransactionId *children; + RelFileNode *commitrels; + RelFileNode *abortrels; + + /* Initialize linked list */ + records.head = palloc0(sizeof(XLogRecData)); + records.head->buffer = InvalidBuffer; + records.head->len = 0; + records.head->next = NULL; + + records.bytes_free = Max(sizeof(TwoPhaseFileHeader), 512); + records.head->data = palloc(records.bytes_free); + + records.tail = records.head; + + records.total_len = 0; + + /* Create header */ + hdr.magic = TWOPHASE_MAGIC; + hdr.total_len = 0; /* EndPrepare will fill this in */ + hdr.xid = xid; + hdr.database = MyDatabaseId; + hdr.owner = GetUserId(); + hdr.nsubxacts = xactGetCommittedChildren(&children); + hdr.ncommitrels = smgrGetPendingDeletes(true, &commitrels); + hdr.nabortrels = smgrGetPendingDeletes(false, &abortrels); + StrNCpy(hdr.gid, gxact->gid, GIDSIZE); + + save_state_data(&hdr, sizeof(TwoPhaseFileHeader)); + + /* Add the additional info about subxacts and deletable files */ + if (hdr.nsubxacts > 0) + { + save_state_data(children, hdr.nsubxacts * sizeof(TransactionId)); + /* While we have the child-xact data, stuff it in the gxact too */ + GXactLoadSubxactData(gxact, hdr.nsubxacts, children); + pfree(children); + } + if (hdr.ncommitrels > 0) + { + save_state_data(commitrels, hdr.ncommitrels * sizeof(RelFileNode)); + pfree(commitrels); + } + if (hdr.nabortrels > 0) + { + save_state_data(abortrels, hdr.nabortrels * sizeof(RelFileNode)); + pfree(abortrels); + } +} + +/* + * Finish preparing state file. + * + * Calculates CRC and writes state file to WAL and in pg_twophase directory. + */ +void +EndPrepare(GlobalTransaction gxact) +{ + TransactionId xid = gxact->proc.xid; + TwoPhaseFileHeader *hdr; + char path[MAXPGPATH]; + XLogRecData *record; + XLogRecPtr recptr; + pg_crc32 statefile_crc; + pg_crc32 bogus_crc; + int fd; + + /* Add the end sentinel to the list of 2PC records */ + RegisterTwoPhaseRecord(TWOPHASE_RM_END_ID, 0, + NULL, 0); + + /* Go back and fill in total_len in the file header record */ + hdr = (TwoPhaseFileHeader *) records.head->data; + Assert(hdr->magic == TWOPHASE_MAGIC); + hdr->total_len = records.total_len + sizeof(pg_crc32); + + /* + * Create the 2PC state file. + * + * Note: because we use BasicOpenFile(), we are responsible for ensuring + * the FD gets closed in any error exit path. Once we get into the + * critical section, though, it doesn't matter since any failure causes + * PANIC anyway. + */ + TwoPhaseFilePath(path, xid); + + fd = BasicOpenFile(path, + O_CREAT | O_EXCL | O_WRONLY | PG_BINARY, + S_IRUSR | S_IWUSR); + if (fd < 0) + ereport(ERROR, + (errcode_for_file_access(), + errmsg("could not create twophase state file \"%s\": %m", + path))); + + /* Write data to file, and calculate CRC as we pass over it */ + INIT_CRC32(statefile_crc); + + for (record = records.head; record != NULL; record = record->next) + { + COMP_CRC32(statefile_crc, record->data, record->len); + if ((write(fd, record->data, record->len)) != record->len) + { + close(fd); + ereport(ERROR, + (errcode_for_file_access(), + errmsg("could not write twophase state file: %m"))); + } + } + + FIN_CRC32(statefile_crc); + + /* + * Write a deliberately bogus CRC to the state file, and flush it to disk. + * This is to minimize the odds of failure within the critical section + * below --- in particular, running out of disk space. + * + * On most filesystems, write() rather than fsync() detects out-of-space, + * so the fsync might be considered optional. Using it means there + * are three fsyncs not two associated with preparing a transaction; is + * the risk of an error from fsync high enough to justify that? + */ + bogus_crc = ~ statefile_crc; + + if ((write(fd, &bogus_crc, sizeof(pg_crc32))) != sizeof(pg_crc32)) + { + close(fd); + ereport(ERROR, + (errcode_for_file_access(), + errmsg("could not write twophase state file: %m"))); + } + + if (pg_fsync(fd) != 0) + { + close(fd); + ereport(ERROR, + (errcode_for_file_access(), + errmsg("could not fsync twophase state file: %m"))); + } + + /* Back up to prepare for rewriting the CRC */ + if (lseek(fd, -((off_t) sizeof(pg_crc32)), SEEK_CUR) < 0) + { + close(fd); + ereport(ERROR, + (errcode_for_file_access(), + errmsg("could not seek twophase state file: %m"))); + } + + /* + * The state file isn't valid yet, because we haven't written the correct + * CRC yet. Before we do that, insert entry in WAL and flush it to disk. + * + * Between the time we have written the WAL entry and the time we + * flush the correct state file CRC to disk, we have an inconsistency: + * the xact is prepared according to WAL but not according to our on-disk + * state. We use a critical section to force a PANIC if we are unable to + * complete the flush --- then, WAL replay should repair the + * inconsistency. + * + * We have to lock out checkpoint start here, too; otherwise a checkpoint + * starting immediately after the WAL record is inserted could complete + * before we've finished flushing, meaning that the WAL record would not + * get replayed if a crash follows. + */ + START_CRIT_SECTION(); + + LWLockAcquire(CheckpointStartLock, LW_SHARED); + + recptr = XLogInsert(RM_XACT_ID, XLOG_XACT_PREPARE, records.head); + XLogFlush(recptr); + + /* If we crash now, we have prepared: WAL replay will fix things */ + + /* write correct CRC, flush, and close file */ + if ((write(fd, &statefile_crc, sizeof(pg_crc32))) != sizeof(pg_crc32)) + { + close(fd); + ereport(ERROR, + (errcode_for_file_access(), + errmsg("could not write twophase state file: %m"))); + } + + if (pg_fsync(fd) != 0) + { + close(fd); + ereport(ERROR, + (errcode_for_file_access(), + errmsg("could not fsync twophase state file: %m"))); + } + + if (close(fd) != 0) + ereport(ERROR, + (errcode_for_file_access(), + errmsg("could not close twophase state file: %m"))); + + LWLockRelease(CheckpointStartLock); + + END_CRIT_SECTION(); + + records.tail = records.head = NULL; +} + +/* + * Register a 2PC record to be written to state file. + */ +void +RegisterTwoPhaseRecord(TwoPhaseRmgrId rmid, uint16 info, + const void *data, uint32 len) +{ + TwoPhaseRecordOnDisk record; + + record.rmid = rmid; + record.info = info; + record.len = len; + save_state_data(&record, sizeof(TwoPhaseRecordOnDisk)); + if (len > 0) + save_state_data(data, len); +} + + +/* + * Read and validate the state file for xid. + * + * If it looks OK (has a valid magic number and CRC), return the palloc'd + * contents of the file. Otherwise return NULL. + */ +static char * +ReadTwoPhaseFile(TransactionId xid) +{ + char path[MAXPGPATH]; + char *buf; + TwoPhaseFileHeader *hdr; + int fd; + struct stat stat; + uint32 crc_offset; + pg_crc32 calc_crc, file_crc; + + TwoPhaseFilePath(path, xid); + + fd = BasicOpenFile(path, O_RDONLY | PG_BINARY, 0); + if (fd < 0) + { + ereport(WARNING, + (errcode_for_file_access(), + errmsg("could not open twophase state file \"%s\": %m", + path))); + return NULL; + } + + /* + * Check file length. We can determine a lower bound pretty easily. + * We set an upper bound mainly to avoid palloc() failure on a corrupt + * file. + */ + if (fstat(fd, &stat)) + { + close(fd); + ereport(WARNING, + (errcode_for_file_access(), + errmsg("could not stat twophase state file \"%s\": %m", + path))); + return NULL; + } + + if (stat.st_size < (MAXALIGN(sizeof(TwoPhaseFileHeader)) + + MAXALIGN(sizeof(TwoPhaseRecordOnDisk)) + + sizeof(pg_crc32)) || + stat.st_size > 10000000) + { + close(fd); + return NULL; + } + + crc_offset = stat.st_size - sizeof(pg_crc32); + if (crc_offset != MAXALIGN(crc_offset)) + { + close(fd); + return NULL; + } + + /* + * OK, slurp in the file. + */ + buf = (char *) palloc(stat.st_size); + + if (read(fd, buf, stat.st_size) != stat.st_size) + { + close(fd); + ereport(WARNING, + (errcode_for_file_access(), + errmsg("could not read twophase state file \"%s\": %m", + path))); + pfree(buf); + return NULL; + } + + close(fd); + + hdr = (TwoPhaseFileHeader *) buf; + if (hdr->magic != TWOPHASE_MAGIC || hdr->total_len != stat.st_size) + { + pfree(buf); + return NULL; + } + + INIT_CRC32(calc_crc); + COMP_CRC32(calc_crc, buf, crc_offset); + FIN_CRC32(calc_crc); + + file_crc = *((pg_crc32 *) (buf + crc_offset)); + + if (!EQ_CRC32(calc_crc, file_crc)) + { + pfree(buf); + return NULL; + } + + return buf; +} + + +/* + * FinishPreparedTransaction: execute COMMIT PREPARED or ROLLBACK PREPARED + */ +void +FinishPreparedTransaction(char *gid, bool isCommit) +{ + GlobalTransaction gxact; + TransactionId xid; + char *buf; + char *bufptr; + TwoPhaseFileHeader *hdr; + TransactionId *children; + RelFileNode *commitrels; + RelFileNode *abortrels; + int i; + + /* + * Validate the GID, and lock the GXACT to ensure that two backends + * do not try to commit the same GID at once. + */ + gxact = LockGXact(gid, GetUserId()); + xid = gxact->proc.xid; + + /* + * Read and validate the state file + */ + buf = ReadTwoPhaseFile(xid); + if (buf == NULL) + ereport(ERROR, + (errcode(ERRCODE_DATA_CORRUPTED), + errmsg("twophase state file for transaction %u is corrupt", + xid))); + + /* + * Disassemble the header area + */ + hdr = (TwoPhaseFileHeader *) buf; + Assert(TransactionIdEquals(hdr->xid, xid)); + bufptr = buf + MAXALIGN(sizeof(TwoPhaseFileHeader)); + children = (TransactionId *) bufptr; + bufptr += MAXALIGN(hdr->nsubxacts * sizeof(TransactionId)); + commitrels = (RelFileNode *) bufptr; + bufptr += MAXALIGN(hdr->ncommitrels * sizeof(RelFileNode)); + abortrels = (RelFileNode *) bufptr; + bufptr += MAXALIGN(hdr->nabortrels * sizeof(RelFileNode)); + + /* + * The order of operations here is critical: make the XLOG entry for + * commit or abort, then mark the transaction committed or aborted in + * pg_clog, then remove its PGPROC from the global ProcArray (which + * means TransactionIdIsInProgress will stop saying the prepared xact + * is in progress), then run the post-commit or post-abort callbacks. + * The callbacks will release the locks the transaction held. + */ + if (isCommit) + RecordTransactionCommitPrepared(xid, + hdr->nsubxacts, children, + hdr->ncommitrels, commitrels); + else + RecordTransactionAbortPrepared(xid, + hdr->nsubxacts, children, + hdr->nabortrels, abortrels); + + ProcArrayRemove(&gxact->proc); + + /* + * In case we fail while running the callbacks, mark the gxact invalid + * so no one else will try to commit/rollback, and so it can be recycled + * properly later. It is still locked by our XID so it won't go away yet. + */ + gxact->valid = false; + + if (isCommit) + ProcessRecords(bufptr, xid, twophase_postcommit_callbacks); + else + ProcessRecords(bufptr, xid, twophase_postabort_callbacks); + + /* + * We also have to remove any files that were supposed to be dropped. + * NB: this code knows that we couldn't be dropping any temp rels ... + */ + if (isCommit) + { + for (i = 0; i < hdr->ncommitrels; i++) + smgrdounlink(smgropen(commitrels[i]), false, false); + } + else + { + for (i = 0; i < hdr->nabortrels; i++) + smgrdounlink(smgropen(abortrels[i]), false, false); + } + + pgstat_count_xact_commit(); + + /* + * And now we can clean up our mess. + */ + RemoveTwoPhaseFile(xid, true); + + RemoveGXact(gxact); + + pfree(buf); +} + +/* + * Scan a 2PC state file (already read into memory by ReadTwoPhaseFile) + * and call the indicated callbacks for each 2PC record. + */ +static void +ProcessRecords(char *bufptr, TransactionId xid, + const TwoPhaseCallback callbacks[]) +{ + for (;;) + { + TwoPhaseRecordOnDisk *record = (TwoPhaseRecordOnDisk *) bufptr; + + Assert(record->rmid <= TWOPHASE_RM_MAX_ID); + if (record->rmid == TWOPHASE_RM_END_ID) + break; + + bufptr += MAXALIGN(sizeof(TwoPhaseRecordOnDisk)); + + if (callbacks[record->rmid] != NULL) + callbacks[record->rmid](xid, record->info, + (void *) bufptr, record->len); + + bufptr += MAXALIGN(record->len); + } +} + +/* + * Remove the 2PC file for the specified XID. + * + * If giveWarning is false, do not complain about file-not-present; + * this is an expected case during WAL replay. + */ +void +RemoveTwoPhaseFile(TransactionId xid, bool giveWarning) +{ + char path[MAXPGPATH]; + + TwoPhaseFilePath(path, xid); + if (unlink(path)) + if (errno != ENOENT || giveWarning) + ereport(WARNING, + (errcode_for_file_access(), + errmsg("could not remove two-phase state file \"%s\": %m", + path))); +} + +/* + * Recreates a state file. This is used in WAL replay. + * + * Note: content and len don't include CRC. + */ +void +RecreateTwoPhaseFile(TransactionId xid, void *content, int len) +{ + char path[MAXPGPATH]; + pg_crc32 statefile_crc; + int fd; + + /* Recompute CRC */ + INIT_CRC32(statefile_crc); + COMP_CRC32(statefile_crc, content, len); + FIN_CRC32(statefile_crc); + + TwoPhaseFilePath(path, xid); + + fd = BasicOpenFile(path, + O_CREAT | O_TRUNC | O_WRONLY | PG_BINARY, + S_IRUSR | S_IWUSR); + if (fd < 0) + ereport(ERROR, + (errcode_for_file_access(), + errmsg("could not recreate twophase state file \"%s\": %m", + path))); + + /* Write content and CRC */ + if (write(fd, content, len) != len) + { + close(fd); + ereport(ERROR, + (errcode_for_file_access(), + errmsg("could not write twophase state file: %m"))); + } + if (write(fd, &statefile_crc, sizeof(pg_crc32)) != sizeof(pg_crc32)) + { + close(fd); + ereport(ERROR, + (errcode_for_file_access(), + errmsg("could not write twophase state file: %m"))); + } + + /* Sync and close the file */ + if (pg_fsync(fd) != 0) + { + close(fd); + ereport(ERROR, + (errcode_for_file_access(), + errmsg("could not fsync twophase state file: %m"))); + } + + if (close(fd) != 0) + ereport(ERROR, + (errcode_for_file_access(), + errmsg("could not close twophase state file: %m"))); +} + +/* + * PrescanPreparedTransactions + * + * Scan the pg_twophase directory and determine the range of valid XIDs + * present. This is run during database startup, after we have completed + * reading WAL. ShmemVariableCache->nextXid has been set to one more than + * the highest XID for which evidence exists in WAL. + * + * We throw away any prepared xacts with main XID beyond nextXid --- if any + * are present, it suggests that the DBA has done a PITR recovery to an + * earlier point in time without cleaning out pg_twophase. We dare not + * try to recover such prepared xacts since they likely depend on database + * state that doesn't exist now. + * + * However, we will advance nextXid beyond any subxact XIDs belonging to + * valid prepared xacts. We need to do this since subxact commit doesn't + * write a WAL entry, and so there might be no evidence in WAL of those + * subxact XIDs. + * + * Our other responsibility is to determine and return the oldest valid XID + * among the prepared xacts (if none, return ShmemVariableCache->nextXid). + * This is needed to synchronize pg_subtrans startup properly. + */ +TransactionId +PrescanPreparedTransactions(void) +{ + TransactionId origNextXid = ShmemVariableCache->nextXid; + TransactionId result = origNextXid; + char dir[MAXPGPATH]; + DIR *cldir; + struct dirent *clde; + + snprintf(dir, MAXPGPATH, "%s/%s", DataDir, TWOPHASE_DIR); + + cldir = AllocateDir(dir); + if (cldir == NULL) + ereport(ERROR, + (errcode_for_file_access(), + errmsg("could not open directory \"%s\": %m", dir))); + + errno = 0; + while ((clde = readdir(cldir)) != NULL) + { + if (strlen(clde->d_name) == 8 && + strspn(clde->d_name, "0123456789ABCDEF") == 8) + { + TransactionId xid; + char *buf; + TwoPhaseFileHeader *hdr; + TransactionId *subxids; + int i; + + xid = (TransactionId) strtoul(clde->d_name, NULL, 16); + + /* Reject XID if too new */ + if (TransactionIdFollowsOrEquals(xid, origNextXid)) + { + ereport(WARNING, + (errmsg("removing future twophase state file \"%s\"", + clde->d_name))); + RemoveTwoPhaseFile(xid, true); + errno = 0; + continue; + } + + /* + * Note: we can't check if already processed because clog + * subsystem isn't up yet. + */ + + /* Read and validate file */ + buf = ReadTwoPhaseFile(xid); + if (buf == NULL) + { + ereport(WARNING, + (errmsg("removing corrupt twophase state file \"%s\"", + clde->d_name))); + RemoveTwoPhaseFile(xid, true); + errno = 0; + continue; + } + + /* Deconstruct header */ + hdr = (TwoPhaseFileHeader *) buf; + if (!TransactionIdEquals(hdr->xid, xid)) + { + ereport(WARNING, + (errmsg("removing corrupt twophase state file \"%s\"", + clde->d_name))); + RemoveTwoPhaseFile(xid, true); + pfree(buf); + errno = 0; + continue; + } + + /* + * OK, we think this file is valid. Incorporate xid into the + * running-minimum result. + */ + if (TransactionIdPrecedes(xid, result)) + result = xid; + + /* + * Examine subtransaction XIDs ... they should all follow main + * XID, and they may force us to advance nextXid. + */ + subxids = (TransactionId *) + (buf + MAXALIGN(sizeof(TwoPhaseFileHeader))); + for (i = 0; i < hdr->nsubxacts; i++) + { + TransactionId subxid = subxids[i]; + + Assert(TransactionIdFollows(subxid, xid)); + if (TransactionIdFollowsOrEquals(subxid, + ShmemVariableCache->nextXid)) + { + ShmemVariableCache->nextXid = subxid; + TransactionIdAdvance(ShmemVariableCache->nextXid); + } + } + + pfree(buf); + } + errno = 0; + } +#ifdef WIN32 + + /* + * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but + * not in released version + */ + if (GetLastError() == ERROR_NO_MORE_FILES) + errno = 0; +#endif + if (errno) + ereport(ERROR, + (errcode_for_file_access(), + errmsg("could not read directory \"%s\": %m", dir))); + + FreeDir(cldir); + + return result; +} + +/* + * RecoverPreparedTransactions + * + * Scan the pg_twophase directory and reload shared-memory state for each + * prepared transaction (reacquire locks, etc). This is run during database + * startup. + */ +void +RecoverPreparedTransactions(void) +{ + char dir[MAXPGPATH]; + DIR *cldir; + struct dirent *clde; + + snprintf(dir, MAXPGPATH, "%s/%s", DataDir, TWOPHASE_DIR); + + cldir = AllocateDir(dir); + if (cldir == NULL) + ereport(ERROR, + (errcode_for_file_access(), + errmsg("could not open directory \"%s\": %m", dir))); + + errno = 0; + while ((clde = readdir(cldir)) != NULL) + { + if (strlen(clde->d_name) == 8 && + strspn(clde->d_name, "0123456789ABCDEF") == 8) + { + TransactionId xid; + char *buf; + char *bufptr; + TwoPhaseFileHeader *hdr; + TransactionId *subxids; + GlobalTransaction gxact; + int i; + + xid = (TransactionId) strtoul(clde->d_name, NULL, 16); + + /* Already processed? */ + if (TransactionIdDidCommit(xid) || TransactionIdDidAbort(xid)) + { + ereport(WARNING, + (errmsg("removing stale twophase state file \"%s\"", + clde->d_name))); + RemoveTwoPhaseFile(xid, true); + errno = 0; + continue; + } + + /* Read and validate file */ + buf = ReadTwoPhaseFile(xid); + if (buf == NULL) + { + ereport(WARNING, + (errmsg("removing corrupt twophase state file \"%s\"", + clde->d_name))); + RemoveTwoPhaseFile(xid, true); + errno = 0; + continue; + } + + ereport(LOG, + (errmsg("recovering prepared transaction %u", xid))); + + /* Deconstruct header */ + hdr = (TwoPhaseFileHeader *) buf; + Assert(TransactionIdEquals(hdr->xid, xid)); + bufptr = buf + MAXALIGN(sizeof(TwoPhaseFileHeader)); + subxids = (TransactionId *) bufptr; + bufptr += MAXALIGN(hdr->nsubxacts * sizeof(TransactionId)); + bufptr += MAXALIGN(hdr->ncommitrels * sizeof(RelFileNode)); + bufptr += MAXALIGN(hdr->nabortrels * sizeof(RelFileNode)); + + /* + * Reconstruct subtrans state for the transaction --- needed + * because pg_subtrans is not preserved over a restart + */ + for (i = 0; i < hdr->nsubxacts; i++) + SubTransSetParent(subxids[i], xid); + + /* + * Recreate its GXACT and dummy PGPROC + */ + gxact = MarkAsPreparing(xid, hdr->database, hdr->gid, hdr->owner); + GXactLoadSubxactData(gxact, hdr->nsubxacts, subxids); + MarkAsPrepared(gxact); + + /* + * Recover other state (notably locks) using resource managers + */ + ProcessRecords(bufptr, xid, twophase_recover_callbacks); + + pfree(buf); + } + errno = 0; + } +#ifdef WIN32 + + /* + * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but + * not in released version + */ + if (GetLastError() == ERROR_NO_MORE_FILES) + errno = 0; +#endif + if (errno) + ereport(ERROR, + (errcode_for_file_access(), + errmsg("could not read directory \"%s\": %m", dir))); + + FreeDir(cldir); +} + +/* + * RecordTransactionCommitPrepared + * + * This is basically the same as RecordTransactionCommit: in particular, + * we must take the CheckpointStartLock to avoid a race condition. + * + * We know the transaction made at least one XLOG entry (its PREPARE), + * so it is never possible to optimize out the commit record. + */ +static void +RecordTransactionCommitPrepared(TransactionId xid, + int nchildren, + TransactionId *children, + int nrels, + RelFileNode *rels) +{ + XLogRecData rdata[3]; + int lastrdata = 0; + xl_xact_commit_prepared xlrec; + XLogRecPtr recptr; + + START_CRIT_SECTION(); + + /* See notes in RecordTransactionCommit */ + LWLockAcquire(CheckpointStartLock, LW_SHARED); + + /* Emit the XLOG commit record */ + xlrec.xid = xid; + xlrec.crec.xtime = time(NULL); + xlrec.crec.nrels = nrels; + xlrec.crec.nsubxacts = nchildren; + rdata[0].data = (char *) (&xlrec); + rdata[0].len = MinSizeOfXactCommitPrepared; + rdata[0].buffer = InvalidBuffer; + /* dump rels to delete */ + if (nrels > 0) + { + rdata[0].next = &(rdata[1]); + rdata[1].data = (char *) rels; + rdata[1].len = nrels * sizeof(RelFileNode); + rdata[1].buffer = InvalidBuffer; + lastrdata = 1; + } + /* dump committed child Xids */ + if (nchildren > 0) + { + rdata[lastrdata].next = &(rdata[2]); + rdata[2].data = (char *) children; + rdata[2].len = nchildren * sizeof(TransactionId); + rdata[2].buffer = InvalidBuffer; + lastrdata = 2; + } + rdata[lastrdata].next = NULL; + + recptr = XLogInsert(RM_XACT_ID, + XLOG_XACT_COMMIT_PREPARED | XLOG_NO_TRAN, + rdata); + + /* we don't currently try to sleep before flush here ... */ + + /* Flush XLOG to disk */ + XLogFlush(recptr); + + /* Mark the transaction committed in pg_clog */ + TransactionIdCommit(xid); + /* to avoid race conditions, the parent must commit first */ + TransactionIdCommitTree(nchildren, children); + + /* Checkpoint is allowed again */ + LWLockRelease(CheckpointStartLock); + + END_CRIT_SECTION(); +} + +/* + * RecordTransactionAbortPrepared + * + * This is basically the same as RecordTransactionAbort. + * + * We know the transaction made at least one XLOG entry (its PREPARE), + * so it is never possible to optimize out the abort record. + */ +static void +RecordTransactionAbortPrepared(TransactionId xid, + int nchildren, + TransactionId *children, + int nrels, + RelFileNode *rels) +{ + XLogRecData rdata[3]; + int lastrdata = 0; + xl_xact_abort_prepared xlrec; + XLogRecPtr recptr; + + /* + * Catch the scenario where we aborted partway through + * RecordTransactionCommitPrepared ... + */ + if (TransactionIdDidCommit(xid)) + elog(PANIC, "cannot abort transaction %u, it was already committed", + xid); + + START_CRIT_SECTION(); + + /* Emit the XLOG abort record */ + xlrec.xid = xid; + xlrec.arec.xtime = time(NULL); + xlrec.arec.nrels = nrels; + xlrec.arec.nsubxacts = nchildren; + rdata[0].data = (char *) (&xlrec); + rdata[0].len = MinSizeOfXactAbortPrepared; + rdata[0].buffer = InvalidBuffer; + /* dump rels to delete */ + if (nrels > 0) + { + rdata[0].next = &(rdata[1]); + rdata[1].data = (char *) rels; + rdata[1].len = nrels * sizeof(RelFileNode); + rdata[1].buffer = InvalidBuffer; + lastrdata = 1; + } + /* dump committed child Xids */ + if (nchildren > 0) + { + rdata[lastrdata].next = &(rdata[2]); + rdata[2].data = (char *) children; + rdata[2].len = nchildren * sizeof(TransactionId); + rdata[2].buffer = InvalidBuffer; + lastrdata = 2; + } + rdata[lastrdata].next = NULL; + + recptr = XLogInsert(RM_XACT_ID, + XLOG_XACT_ABORT_PREPARED | XLOG_NO_TRAN, + rdata); + + /* Always flush, since we're about to remove the 2PC state file */ + XLogFlush(recptr); + + /* + * Mark the transaction aborted in clog. This is not absolutely + * necessary but we may as well do it while we are here. + */ + TransactionIdAbort(xid); + TransactionIdAbortTree(nchildren, children); + + END_CRIT_SECTION(); +} + diff --git a/src/backend/access/transam/twophase_rmgr.c b/src/backend/access/transam/twophase_rmgr.c new file mode 100644 index 00000000000..e78f8b2fbb3 --- /dev/null +++ b/src/backend/access/transam/twophase_rmgr.c @@ -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 */ +}; diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 040a4ab0b79..74163b7f576 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -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; @@ -1935,6 +2165,15 @@ CommitTransactionCommand(void) 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 * PushTransaction, so as to have someplace to put the @@ -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 || @@ -2156,6 +2401,17 @@ AbortCurrentTransaction(void) 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 * until we get ROLLBACK. @@ -2487,6 +2743,7 @@ 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; @@ -2494,6 +2751,57 @@ BeginTransactionBlock(void) } /* + * 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); + xact_redo_commit(xlrec, record->xl_xid); + } + else if (info == XLOG_XACT_ABORT) + { + xl_xact_abort *xlrec = (xl_xact_abort *) XLogRecGetData(record); - /* Mark committed subtransactions as committed */ - sub_xids = (TransactionId *) &(xlrec->xnodes[xlrec->nrels]); - TransactionIdCommitTree(xlrec->nsubxacts, sub_xids); + 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); - /* 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); - } + 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 files supposed to be dropped are dropped */ + 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++) { - XLogCloseRelation(xlrec->xnodes[i]); - smgrdounlink(smgropen(xlrec->xnodes[i]), false, true); + RelFileNode rnode = xlrec->xnodes[i]; + + sprintf(buf + strlen(buf), " %u/%u/%u", + rnode.spcNode, rnode.dbNode, rnode.relNode); } } - else if (info == XLOG_XACT_ABORT) + if (xlrec->nsubxacts > 0) { - xl_xact_abort *xlrec = (xl_xact_abort *) XLogRecGetData(record); - TransactionId *sub_xids; - TransactionId max_xid; - int i; - - TransactionIdAbort(record->xl_xid); - - /* Mark subtransactions as aborted */ - sub_xids = (TransactionId *) &(xlrec->xnodes[xlrec->nrels]); - TransactionIdAbortTree(xlrec->nsubxacts, sub_xids); + TransactionId *xacts = (TransactionId *) + &xlrec->xnodes[xlrec->nrels]; - /* Make sure nextXid is beyond any XID mentioned in the record */ - max_xid = record->xl_xid; + sprintf(buf + strlen(buf), "; subxacts:"); 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); - } + 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; - /* Make sure files supposed to be dropped are dropped */ + 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++) { - XLogCloseRelation(xlrec->xnodes[i]); - smgrdounlink(smgropen(xlrec->xnodes[i]), false, true); + RelFileNode rnode = xlrec->xnodes[i]; + + sprintf(buf + strlen(buf), " %u/%u/%u", + rnode.spcNode, rnode.dbNode, rnode.relNode); } } - else - elog(PANIC, "xact_redo: unknown op code %u", info); + 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"); diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index c5469d174f2..15b82ee9be8 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -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--; @@ -5096,31 +5065,6 @@ CreateCheckPoint(bool shutdown, bool force) } /* - * 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. diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index d66bb780b4f..2e9a3ecf7c7 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -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; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index 9914c724b71..142b02dfaf8 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -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); +} diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c index 25a7056500b..2e0d8dbc1a2 100644 --- a/src/backend/nodes/copyfuncs.c +++ b/src/backend/nodes/copyfuncs.c @@ -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; } diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c index e625ca7f32c..a991cf5eed3 100644 --- a/src/backend/nodes/equalfuncs.c +++ b/src/backend/nodes/equalfuncs.c @@ -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; } diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index 6ee53327865..d12fa9fa052 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -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 diff --git a/src/backend/parser/keywords.c b/src/backend/parser/keywords.c index 9296067dfae..1e0c63a9ce2 100644 --- a/src/backend/parser/keywords.c +++ b/src/backend/parser/keywords.c @@ -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}, diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c index 03057dbcb21..6ca13944f8a 100644 --- a/src/backend/postmaster/postmaster.c +++ b/src/backend/postmaster/postmaster.c @@ -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); diff --git a/src/backend/storage/ipc/ipci.c b/src/backend/storage/ipc/ipci.c index 22333a1f558..0761a8fdf51 100644 --- a/src/backend/storage/ipc/ipci.c +++ b/src/backend/storage/ipc/ipci.c @@ -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 diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c index 23b198b1497..7c2766e6285 100644 --- a/src/backend/storage/ipc/procarray.c +++ b/src/backend/storage/ipc/procarray.c @@ -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); } @@ -330,6 +331,55 @@ result_known: } /* + * 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 { \ diff --git a/src/backend/storage/lmgr/lmgr.c b/src/backend/storage/lmgr/lmgr.c index 351ef27bee7..91afd4ed9a5 100644 --- a/src/backend/storage/lmgr/lmgr.c +++ b/src/backend/storage/lmgr/lmgr.c @@ -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); diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 08e579486e0..22d389488d8 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -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); @@ -1606,13 +1614,261 @@ 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); +} diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index b62283cffb4..227c3694788 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -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; @@ -353,6 +351,35 @@ InitDummyProcess(int proctype) } /* + * 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. * * Returns true if we had been waiting for a lock, else false. @@ -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); diff --git a/src/backend/storage/smgr/smgr.c b/src/backend/storage/smgr/smgr.c index 13ad72a3755..2c8cf07eec8 100644 --- a/src/backend/storage/smgr/smgr.c +++ b/src/backend/storage/smgr/smgr.c @@ -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. * diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c index f1c65bacc43..454bc2577e1 100644 --- a/src/backend/tcop/postgres.c +++ b/src/backend/tcop/postgres.c @@ -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; diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c index 73be822a83e..f948b0f854e 100644 --- a/src/backend/tcop/utility.c +++ b/src/backend/tcop/utility.c @@ -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; diff --git a/src/backend/utils/cache/inval.c b/src/backend/utils/cache/inval.c index 61b7522f8c9..da0ffad16b2 100644 --- a/src/backend/utils/cache/inval.c +++ b/src/backend/utils/cache/inval.c @@ -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 @@ -637,6 +645,56 @@ AtStart_Inval(void) } /* + * 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. */ @@ -655,6 +713,47 @@ AtSubStart_Inval(void) } /* + * 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. * diff --git a/src/backend/utils/init/flatfiles.c b/src/backend/utils/init/flatfiles.c index 49495abfdd6..fcbc99189ff 100644 --- a/src/backend/utils/init/flatfiles.c +++ b/src/backend/utils/init/flatfiles.c @@ -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(); +} diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c index 7130365d4fd..72fba39df46 100644 --- a/src/backend/utils/init/postinit.c +++ b/src/backend/utils/init/postinit.c @@ -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"))); diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 8ee03e4d5e3..05ce93cf58f 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -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, diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample index 5d957ee247d..4c5a1ed59e3 100644 --- a/src/backend/utils/misc/postgresql.conf.sample +++ b/src/backend/utils/misc/postgresql.conf.sample @@ -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 diff --git a/src/backend/utils/mmgr/portalmem.c b/src/backend/utils/mmgr/portalmem.c index 26c5dd02a31..b55a3430256 100644 --- a/src/backend/utils/mmgr/portalmem.c +++ b/src/backend/utils/mmgr/portalmem.c @@ -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 $ * *------------------------------------------------------------------------- */ @@ -467,6 +467,48 @@ CommitHoldablePortals(void) } /* + * 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. * * Remove all non-holdable portals created in this transaction. diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c index f4951c3f1bb..9e42c902f1c 100644 --- a/src/bin/initdb/initdb.c +++ b/src/bin/initdb/initdb.c @@ -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", diff --git a/src/bin/psql/common.c b/src/bin/psql/common.c index df17d0404bc..fed2275f469 100644 --- a/src/bin/psql/common.c +++ b/src/bin/psql/common.c @@ -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 diff --git a/src/include/access/subtrans.h b/src/include/access/subtrans.h index ac884775a09..2810e438d54 100644 --- a/src/include/access/subtrans.h +++ b/src/include/access/subtrans.h @@ -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); diff --git a/src/include/access/twophase.h b/src/include/access/twophase.h new file mode 100644 index 00000000000..ac2e05f33ce --- /dev/null +++ b/src/include/access/twophase.h @@ -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 */ diff --git a/src/include/access/twophase_rmgr.h b/src/include/access/twophase_rmgr.h new file mode 100644 index 00000000000..f15233ba2f6 --- /dev/null +++ b/src/include/access/twophase_rmgr.h @@ -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 */ diff --git a/src/include/access/xact.h b/src/include/access/xact.h index 7c949899ac4..0c6b5580688 100644 --- a/src/include/access/xact.h +++ b/src/include/access/xact.h @@ -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); diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h index 535e5bb01ba..de422a41a9f 100644 --- a/src/include/catalog/catversion.h +++ b/src/include/catalog/catversion.h @@ -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 diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h index c06c4a7d41f..a05a4f3a62c 100644 --- a/src/include/catalog/pg_proc.h +++ b/src/include/catalog/pg_proc.h @@ -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?"); diff --git a/src/include/commands/async.h b/src/include/commands/async.h index 08855ea5403..b893771b0f7 100644 --- a/src/include/commands/async.h +++ b/src/include/commands/async.h @@ -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 */ diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h index 04b32082ebf..993a240faa1 100644 --- a/src/include/nodes/parsenodes.h +++ b/src/include/nodes/parsenodes.h @@ -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; /* ---------------------- diff --git a/src/include/storage/ipc.h b/src/include/storage/ipc.h index d08d0f10be0..3d325b10af6 100644 --- a/src/include/storage/ipc.h +++ b/src/include/storage/ipc.h @@ -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 */ diff --git a/src/include/storage/lmgr.h b/src/include/storage/lmgr.h index cdbf8ad406c..3a83c26c7df 100644 --- a/src/include/storage/lmgr.h +++ b/src/include/storage/lmgr.h @@ -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 */ diff --git a/src/include/storage/lock.h b/src/include/storage/lock.h index a471ff32a33..e434683d0e5 100644 --- a/src/include/storage/lock.h +++ b/src/include/storage/lock.h @@ -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 diff --git a/src/include/storage/lwlock.h b/src/include/storage/lwlock.h index eb45f3e39ae..b4ebdb85d59 100644 --- a/src/include/storage/lwlock.h +++ b/src/include/storage/lwlock.h @@ -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 */ diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h index f771d71933c..ece321028fc 100644 --- a/src/include/storage/proc.h +++ b/src/include/storage/proc.h @@ -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); diff --git a/src/include/storage/procarray.h b/src/include/storage/procarray.h index 437ac306e05..d1780bcca18 100644 --- a/src/include/storage/procarray.h +++ b/src/include/storage/procarray.h @@ -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); diff --git a/src/include/storage/smgr.h b/src/include/storage/smgr.h index f00a8aeb833..ab3c39fd1c6 100644 --- a/src/include/storage/smgr.h +++ b/src/include/storage/smgr.h @@ -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); diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h index b781a270c60..37423dc73c2 100644 --- a/src/include/utils/builtins.h +++ b/src/include/utils/builtins.h @@ -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); diff --git a/src/include/utils/flatfiles.h b/src/include/utils/flatfiles.h index 04a901ab008..939239aa1b9 100644 --- a/src/include/utils/flatfiles.h +++ b/src/include/utils/flatfiles.h @@ -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 */ diff --git a/src/include/utils/inval.h b/src/include/utils/inval.h index ac486e53ea0..372d34a22c3 100644 --- a/src/include/utils/inval.h +++ b/src/include/utils/inval.h @@ -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 */ diff --git a/src/include/utils/portal.h b/src/include/utils/portal.h index b8bcc33f583..33de53eee86 100644 --- a/src/include/utils/portal.h +++ b/src/include/utils/portal.h @@ -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); diff --git a/src/test/regress/expected/prepared_xacts.out b/src/test/regress/expected/prepared_xacts.out new file mode 100644 index 00000000000..d6a165e94e4 --- /dev/null +++ b/src/test/regress/expected/prepared_xacts.out @@ -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; diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index 5eccf2d44a0..acd2d25b35d 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -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; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index b3a4de3b56f..9a3f7927328 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -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 diff --git a/src/test/regress/serial_schedule b/src/test/regress/serial_schedule index f8621b404ac..bb60dc0a105 100644 --- a/src/test/regress/serial_schedule +++ b/src/test/regress/serial_schedule @@ -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 diff --git a/src/test/regress/sql/prepared_xacts.sql b/src/test/regress/sql/prepared_xacts.sql new file mode 100644 index 00000000000..39de88faab6 --- /dev/null +++ b/src/test/regress/sql/prepared_xacts.sql @@ -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; |