4981 lines
136 KiB
C
4981 lines
136 KiB
C
/*-------------------------------------------------------------------------
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*
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* xact.c
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* top level transaction system support routines
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*
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* See src/backend/access/transam/README for more information.
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*
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* Portions Copyright (c) 1996-2014, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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*
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* IDENTIFICATION
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* src/backend/access/transam/xact.c
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include <time.h>
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#include <unistd.h>
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#include "access/commit_ts.h"
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#include "access/multixact.h"
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#include "access/subtrans.h"
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#include "access/transam.h"
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#include "access/twophase.h"
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#include "access/xact.h"
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#include "access/xlog.h"
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#include "access/xloginsert.h"
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#include "access/xlogutils.h"
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#include "catalog/catalog.h"
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#include "catalog/namespace.h"
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#include "catalog/storage.h"
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#include "commands/async.h"
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#include "commands/tablecmds.h"
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#include "commands/trigger.h"
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#include "executor/spi.h"
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#include "libpq/be-fsstubs.h"
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#include "libpq/pqsignal.h"
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#include "miscadmin.h"
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#include "pgstat.h"
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#include "replication/walsender.h"
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#include "replication/syncrep.h"
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#include "storage/fd.h"
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#include "storage/lmgr.h"
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#include "storage/predicate.h"
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#include "storage/proc.h"
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#include "storage/procarray.h"
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#include "storage/sinvaladt.h"
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#include "storage/smgr.h"
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#include "utils/catcache.h"
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#include "utils/combocid.h"
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#include "utils/guc.h"
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#include "utils/inval.h"
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#include "utils/memutils.h"
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#include "utils/relmapper.h"
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#include "utils/snapmgr.h"
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#include "utils/timeout.h"
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#include "utils/timestamp.h"
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#include "pg_trace.h"
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/*
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* User-tweakable parameters
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*/
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int DefaultXactIsoLevel = XACT_READ_COMMITTED;
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int XactIsoLevel;
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bool DefaultXactReadOnly = false;
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bool XactReadOnly;
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bool DefaultXactDeferrable = false;
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bool XactDeferrable;
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int synchronous_commit = SYNCHRONOUS_COMMIT_ON;
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/*
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* MyXactAccessedTempRel is set when a temporary relation is accessed.
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* We don't allow PREPARE TRANSACTION in that case. (This is global
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* so that it can be set from heapam.c.)
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*/
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bool MyXactAccessedTempRel = false;
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/*
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* transaction states - transaction state from server perspective
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*/
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typedef enum TransState
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{
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TRANS_DEFAULT, /* idle */
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TRANS_START, /* transaction starting */
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TRANS_INPROGRESS, /* inside a valid transaction */
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TRANS_COMMIT, /* commit in progress */
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TRANS_ABORT, /* abort in progress */
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TRANS_PREPARE /* prepare in progress */
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} TransState;
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/*
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* transaction block states - transaction state of client queries
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*
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* Note: the subtransaction states are used only for non-topmost
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* transactions; the others appear only in the topmost transaction.
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*/
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typedef enum TBlockState
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{
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/* not-in-transaction-block states */
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TBLOCK_DEFAULT, /* idle */
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TBLOCK_STARTED, /* running single-query transaction */
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/* transaction block states */
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TBLOCK_BEGIN, /* starting transaction block */
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TBLOCK_INPROGRESS, /* live transaction */
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TBLOCK_END, /* COMMIT received */
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TBLOCK_ABORT, /* failed xact, awaiting ROLLBACK */
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TBLOCK_ABORT_END, /* failed xact, ROLLBACK received */
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TBLOCK_ABORT_PENDING, /* live xact, ROLLBACK received */
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TBLOCK_PREPARE, /* live xact, PREPARE received */
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/* subtransaction states */
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TBLOCK_SUBBEGIN, /* starting a subtransaction */
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TBLOCK_SUBINPROGRESS, /* live subtransaction */
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TBLOCK_SUBRELEASE, /* RELEASE received */
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TBLOCK_SUBCOMMIT, /* COMMIT received while TBLOCK_SUBINPROGRESS */
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TBLOCK_SUBABORT, /* failed subxact, awaiting ROLLBACK */
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TBLOCK_SUBABORT_END, /* failed subxact, ROLLBACK received */
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TBLOCK_SUBABORT_PENDING, /* live subxact, ROLLBACK received */
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TBLOCK_SUBRESTART, /* live subxact, ROLLBACK TO received */
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TBLOCK_SUBABORT_RESTART /* failed subxact, ROLLBACK TO received */
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} TBlockState;
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/*
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* transaction state structure
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*/
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typedef struct TransactionStateData
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{
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TransactionId transactionId; /* my XID, or Invalid if none */
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SubTransactionId subTransactionId; /* my subxact ID */
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char *name; /* savepoint name, if any */
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int savepointLevel; /* savepoint level */
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TransState state; /* low-level state */
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TBlockState blockState; /* high-level state */
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int nestingLevel; /* transaction nesting depth */
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int gucNestLevel; /* GUC context nesting depth */
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MemoryContext curTransactionContext; /* my xact-lifetime context */
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ResourceOwner curTransactionOwner; /* my query resources */
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TransactionId *childXids; /* subcommitted child XIDs, in XID order */
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int nChildXids; /* # of subcommitted child XIDs */
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int maxChildXids; /* allocated size of childXids[] */
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Oid prevUser; /* previous CurrentUserId setting */
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int prevSecContext; /* previous SecurityRestrictionContext */
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bool prevXactReadOnly; /* entry-time xact r/o state */
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bool startedInRecovery; /* did we start in recovery? */
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bool didLogXid; /* has xid been included in WAL record? */
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struct TransactionStateData *parent; /* back link to parent */
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} TransactionStateData;
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typedef TransactionStateData *TransactionState;
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/*
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* CurrentTransactionState always points to the current transaction state
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* block. It will point to TopTransactionStateData when not in a
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* transaction at all, or when in a top-level transaction.
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*/
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static TransactionStateData TopTransactionStateData = {
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0, /* transaction id */
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0, /* subtransaction id */
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NULL, /* savepoint name */
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0, /* savepoint level */
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TRANS_DEFAULT, /* transaction state */
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TBLOCK_DEFAULT, /* transaction block state from the client
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* perspective */
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0, /* transaction nesting depth */
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0, /* GUC context nesting depth */
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NULL, /* cur transaction context */
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NULL, /* cur transaction resource owner */
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NULL, /* subcommitted child Xids */
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0, /* # of subcommitted child Xids */
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0, /* allocated size of childXids[] */
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InvalidOid, /* previous CurrentUserId setting */
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0, /* previous SecurityRestrictionContext */
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false, /* entry-time xact r/o state */
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false, /* startedInRecovery */
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false, /* didLogXid */
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NULL /* link to parent state block */
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};
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/*
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* unreportedXids holds XIDs of all subtransactions that have not yet been
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* reported in a XLOG_XACT_ASSIGNMENT record.
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*/
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static int nUnreportedXids;
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static TransactionId unreportedXids[PGPROC_MAX_CACHED_SUBXIDS];
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static TransactionState CurrentTransactionState = &TopTransactionStateData;
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/*
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* The subtransaction ID and command ID assignment counters are global
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* to a whole transaction, so we do not keep them in the state stack.
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*/
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static SubTransactionId currentSubTransactionId;
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static CommandId currentCommandId;
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static bool currentCommandIdUsed;
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/*
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* xactStartTimestamp is the value of transaction_timestamp().
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* stmtStartTimestamp is the value of statement_timestamp().
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* xactStopTimestamp is the time at which we log a commit or abort WAL record.
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* These do not change as we enter and exit subtransactions, so we don't
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* keep them inside the TransactionState stack.
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*/
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static TimestampTz xactStartTimestamp;
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static TimestampTz stmtStartTimestamp;
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static TimestampTz xactStopTimestamp;
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/*
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* GID to be used for preparing the current transaction. This is also
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* global to a whole transaction, so we don't keep it in the state stack.
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*/
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static char *prepareGID;
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/*
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* Some commands want to force synchronous commit.
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*/
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static bool forceSyncCommit = false;
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/*
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* Private context for transaction-abort work --- we reserve space for this
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* at startup to ensure that AbortTransaction and AbortSubTransaction can work
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* when we've run out of memory.
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*/
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static MemoryContext TransactionAbortContext = NULL;
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/*
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* List of add-on start- and end-of-xact callbacks
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*/
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typedef struct XactCallbackItem
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{
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struct XactCallbackItem *next;
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XactCallback callback;
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void *arg;
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} XactCallbackItem;
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static XactCallbackItem *Xact_callbacks = NULL;
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/*
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* List of add-on start- and end-of-subxact callbacks
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*/
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typedef struct SubXactCallbackItem
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{
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struct SubXactCallbackItem *next;
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SubXactCallback callback;
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void *arg;
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} SubXactCallbackItem;
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static SubXactCallbackItem *SubXact_callbacks = NULL;
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/* local function prototypes */
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static void AssignTransactionId(TransactionState s);
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static void AbortTransaction(void);
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static void AtAbort_Memory(void);
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static void AtCleanup_Memory(void);
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static void AtAbort_ResourceOwner(void);
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static void AtCCI_LocalCache(void);
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static void AtCommit_Memory(void);
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static void AtStart_Cache(void);
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static void AtStart_Memory(void);
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static void AtStart_ResourceOwner(void);
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static void CallXactCallbacks(XactEvent event);
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static void CallSubXactCallbacks(SubXactEvent event,
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SubTransactionId mySubid,
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SubTransactionId parentSubid);
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static void CleanupTransaction(void);
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static void CheckTransactionChain(bool isTopLevel, bool throwError,
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const char *stmtType);
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static void CommitTransaction(void);
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static TransactionId RecordTransactionAbort(bool isSubXact);
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static void StartTransaction(void);
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static void StartSubTransaction(void);
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static void CommitSubTransaction(void);
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static void AbortSubTransaction(void);
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static void CleanupSubTransaction(void);
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static void PushTransaction(void);
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static void PopTransaction(void);
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static void AtSubAbort_Memory(void);
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static void AtSubCleanup_Memory(void);
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static void AtSubAbort_ResourceOwner(void);
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static void AtSubCommit_Memory(void);
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static void AtSubStart_Memory(void);
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static void AtSubStart_ResourceOwner(void);
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static void ShowTransactionState(const char *str);
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static void ShowTransactionStateRec(TransactionState state);
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static const char *BlockStateAsString(TBlockState blockState);
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static const char *TransStateAsString(TransState state);
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/* ----------------------------------------------------------------
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* transaction state accessors
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* ----------------------------------------------------------------
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*/
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/*
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* IsTransactionState
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*
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* This returns true if we are inside a valid transaction; that is,
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* it is safe to initiate database access, take heavyweight locks, etc.
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*/
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bool
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IsTransactionState(void)
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{
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TransactionState s = CurrentTransactionState;
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/*
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* TRANS_DEFAULT and TRANS_ABORT are obviously unsafe states. However, we
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* also reject the startup/shutdown states TRANS_START, TRANS_COMMIT,
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* TRANS_PREPARE since it might be too soon or too late within those
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* transition states to do anything interesting. Hence, the only "valid"
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* state is TRANS_INPROGRESS.
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*/
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return (s->state == TRANS_INPROGRESS);
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}
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/*
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* IsAbortedTransactionBlockState
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*
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* This returns true if we are within an aborted transaction block.
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*/
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bool
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IsAbortedTransactionBlockState(void)
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{
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TransactionState s = CurrentTransactionState;
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if (s->blockState == TBLOCK_ABORT ||
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s->blockState == TBLOCK_SUBABORT)
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return true;
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return false;
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}
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/*
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* GetTopTransactionId
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*
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* This will return the XID of the main transaction, assigning one if
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* it's not yet set. Be careful to call this only inside a valid xact.
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*/
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TransactionId
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GetTopTransactionId(void)
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{
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if (!TransactionIdIsValid(TopTransactionStateData.transactionId))
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AssignTransactionId(&TopTransactionStateData);
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return TopTransactionStateData.transactionId;
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}
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/*
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* GetTopTransactionIdIfAny
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*
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* This will return the XID of the main transaction, if one is assigned.
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* It will return InvalidTransactionId if we are not currently inside a
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* transaction, or inside a transaction that hasn't yet been assigned an XID.
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*/
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TransactionId
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GetTopTransactionIdIfAny(void)
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{
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return TopTransactionStateData.transactionId;
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}
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/*
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* GetCurrentTransactionId
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*
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* This will return the XID of the current transaction (main or sub
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* transaction), assigning one if it's not yet set. Be careful to call this
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* only inside a valid xact.
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*/
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TransactionId
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GetCurrentTransactionId(void)
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{
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TransactionState s = CurrentTransactionState;
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if (!TransactionIdIsValid(s->transactionId))
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AssignTransactionId(s);
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return s->transactionId;
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}
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/*
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* GetCurrentTransactionIdIfAny
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*
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* This will return the XID of the current sub xact, if one is assigned.
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* It will return InvalidTransactionId if we are not currently inside a
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* transaction, or inside a transaction that hasn't been assigned an XID yet.
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*/
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TransactionId
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GetCurrentTransactionIdIfAny(void)
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{
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return CurrentTransactionState->transactionId;
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}
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/*
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* MarkCurrentTransactionIdLoggedIfAny
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*
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* Remember that the current xid - if it is assigned - now has been wal logged.
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*/
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void
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MarkCurrentTransactionIdLoggedIfAny(void)
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{
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if (TransactionIdIsValid(CurrentTransactionState->transactionId))
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CurrentTransactionState->didLogXid = true;
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}
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/*
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* GetStableLatestTransactionId
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*
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* Get the transaction's XID if it has one, else read the next-to-be-assigned
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* XID. Once we have a value, return that same value for the remainder of the
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* current transaction. This is meant to provide the reference point for the
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* age(xid) function, but might be useful for other maintenance tasks as well.
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*/
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TransactionId
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GetStableLatestTransactionId(void)
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{
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static LocalTransactionId lxid = InvalidLocalTransactionId;
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static TransactionId stablexid = InvalidTransactionId;
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if (lxid != MyProc->lxid)
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{
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lxid = MyProc->lxid;
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stablexid = GetTopTransactionIdIfAny();
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if (!TransactionIdIsValid(stablexid))
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stablexid = ReadNewTransactionId();
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}
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Assert(TransactionIdIsValid(stablexid));
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return stablexid;
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}
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/*
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* AssignTransactionId
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*
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* Assigns a new permanent XID to the given TransactionState.
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* We do not assign XIDs to transactions until/unless this is called.
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* Also, any parent TransactionStates that don't yet have XIDs are assigned
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* one; this maintains the invariant that a child transaction has an XID
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* following its parent's.
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*/
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static void
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AssignTransactionId(TransactionState s)
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{
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bool isSubXact = (s->parent != NULL);
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ResourceOwner currentOwner;
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bool log_unknown_top = false;
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/* Assert that caller didn't screw up */
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Assert(!TransactionIdIsValid(s->transactionId));
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Assert(s->state == TRANS_INPROGRESS);
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/*
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* Ensure parent(s) have XIDs, so that a child always has an XID later
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* than its parent. Musn't recurse here, or we might get a stack overflow
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* if we're at the bottom of a huge stack of subtransactions none of which
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* have XIDs yet.
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*/
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if (isSubXact && !TransactionIdIsValid(s->parent->transactionId))
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{
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TransactionState p = s->parent;
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TransactionState *parents;
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size_t parentOffset = 0;
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parents = palloc(sizeof(TransactionState) * s->nestingLevel);
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while (p != NULL && !TransactionIdIsValid(p->transactionId))
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{
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parents[parentOffset++] = p;
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p = p->parent;
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}
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/*
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* This is technically a recursive call, but the recursion will never
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* be more than one layer deep.
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*/
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while (parentOffset != 0)
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AssignTransactionId(parents[--parentOffset]);
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pfree(parents);
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}
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/*
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* When wal_level=logical, guarantee that a subtransaction's xid can only
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* be seen in the WAL stream if its toplevel xid has been logged before.
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* If necessary we log a xact_assignment record with fewer than
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* PGPROC_MAX_CACHED_SUBXIDS. Note that it is fine if didLogXid isn't set
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* for a transaction even though it appears in a WAL record, we just might
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* superfluously log something. That can happen when an xid is included
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* somewhere inside a wal record, but not in XLogRecord->xl_xid, like in
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* xl_standby_locks.
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*/
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if (isSubXact && XLogLogicalInfoActive() &&
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!TopTransactionStateData.didLogXid)
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log_unknown_top = true;
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/*
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* Generate a new Xid and record it in PG_PROC and pg_subtrans.
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*
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* NB: we must make the subtrans entry BEFORE the Xid appears anywhere in
|
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* shared storage other than PG_PROC; because if there's no room for it in
|
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* PG_PROC, the subtrans entry is needed to ensure that other backends see
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* the Xid as "running". See GetNewTransactionId.
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*/
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s->transactionId = GetNewTransactionId(isSubXact);
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if (isSubXact)
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SubTransSetParent(s->transactionId, s->parent->transactionId, false);
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|
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/*
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* If it's a top-level transaction, the predicate locking system needs to
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* be told about it too.
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*/
|
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if (!isSubXact)
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RegisterPredicateLockingXid(s->transactionId);
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|
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/*
|
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* Acquire lock on the transaction XID. (We assume this cannot block.) We
|
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* have to ensure that the lock is assigned to the transaction's own
|
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* ResourceOwner.
|
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*/
|
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currentOwner = CurrentResourceOwner;
|
|
PG_TRY();
|
|
{
|
|
CurrentResourceOwner = s->curTransactionOwner;
|
|
XactLockTableInsert(s->transactionId);
|
|
}
|
|
PG_CATCH();
|
|
{
|
|
/* Ensure CurrentResourceOwner is restored on error */
|
|
CurrentResourceOwner = currentOwner;
|
|
PG_RE_THROW();
|
|
}
|
|
PG_END_TRY();
|
|
CurrentResourceOwner = currentOwner;
|
|
|
|
/*
|
|
* Every PGPROC_MAX_CACHED_SUBXIDS assigned transaction ids within each
|
|
* top-level transaction we issue a WAL record for the assignment. We
|
|
* include the top-level xid and all the subxids that have not yet been
|
|
* reported using XLOG_XACT_ASSIGNMENT records.
|
|
*
|
|
* This is required to limit the amount of shared memory required in a hot
|
|
* standby server to keep track of in-progress XIDs. See notes for
|
|
* RecordKnownAssignedTransactionIds().
|
|
*
|
|
* We don't keep track of the immediate parent of each subxid, only the
|
|
* top-level transaction that each subxact belongs to. This is correct in
|
|
* recovery only because aborted subtransactions are separately WAL
|
|
* logged.
|
|
*
|
|
* This is correct even for the case where several levels above us didn't
|
|
* have an xid assigned as we recursed up to them beforehand.
|
|
*/
|
|
if (isSubXact && XLogStandbyInfoActive())
|
|
{
|
|
unreportedXids[nUnreportedXids] = s->transactionId;
|
|
nUnreportedXids++;
|
|
|
|
/*
|
|
* ensure this test matches similar one in
|
|
* RecoverPreparedTransactions()
|
|
*/
|
|
if (nUnreportedXids >= PGPROC_MAX_CACHED_SUBXIDS ||
|
|
log_unknown_top)
|
|
{
|
|
xl_xact_assignment xlrec;
|
|
|
|
/*
|
|
* xtop is always set by now because we recurse up transaction
|
|
* stack to the highest unassigned xid and then come back down
|
|
*/
|
|
xlrec.xtop = GetTopTransactionId();
|
|
Assert(TransactionIdIsValid(xlrec.xtop));
|
|
xlrec.nsubxacts = nUnreportedXids;
|
|
|
|
XLogBeginInsert();
|
|
XLogRegisterData((char *) &xlrec, MinSizeOfXactAssignment);
|
|
XLogRegisterData((char *) unreportedXids,
|
|
nUnreportedXids * sizeof(TransactionId));
|
|
|
|
(void) XLogInsert(RM_XACT_ID, XLOG_XACT_ASSIGNMENT);
|
|
|
|
nUnreportedXids = 0;
|
|
/* mark top, not current xact as having been logged */
|
|
TopTransactionStateData.didLogXid = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* GetCurrentSubTransactionId
|
|
*/
|
|
SubTransactionId
|
|
GetCurrentSubTransactionId(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
return s->subTransactionId;
|
|
}
|
|
|
|
/*
|
|
* SubTransactionIsActive
|
|
*
|
|
* Test if the specified subxact ID is still active. Note caller is
|
|
* responsible for checking whether this ID is relevant to the current xact.
|
|
*/
|
|
bool
|
|
SubTransactionIsActive(SubTransactionId subxid)
|
|
{
|
|
TransactionState s;
|
|
|
|
for (s = CurrentTransactionState; s != NULL; s = s->parent)
|
|
{
|
|
if (s->state == TRANS_ABORT)
|
|
continue;
|
|
if (s->subTransactionId == subxid)
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
|
|
/*
|
|
* GetCurrentCommandId
|
|
*
|
|
* "used" must be TRUE if the caller intends to use the command ID to mark
|
|
* inserted/updated/deleted tuples. FALSE means the ID is being fetched
|
|
* for read-only purposes (ie, as a snapshot validity cutoff). See
|
|
* CommandCounterIncrement() for discussion.
|
|
*/
|
|
CommandId
|
|
GetCurrentCommandId(bool used)
|
|
{
|
|
/* this is global to a transaction, not subtransaction-local */
|
|
if (used)
|
|
currentCommandIdUsed = true;
|
|
return currentCommandId;
|
|
}
|
|
|
|
/*
|
|
* GetCurrentTransactionStartTimestamp
|
|
*/
|
|
TimestampTz
|
|
GetCurrentTransactionStartTimestamp(void)
|
|
{
|
|
return xactStartTimestamp;
|
|
}
|
|
|
|
/*
|
|
* GetCurrentStatementStartTimestamp
|
|
*/
|
|
TimestampTz
|
|
GetCurrentStatementStartTimestamp(void)
|
|
{
|
|
return stmtStartTimestamp;
|
|
}
|
|
|
|
/*
|
|
* GetCurrentTransactionStopTimestamp
|
|
*
|
|
* We return current time if the transaction stop time hasn't been set
|
|
* (which can happen if we decide we don't need to log an XLOG record).
|
|
*/
|
|
TimestampTz
|
|
GetCurrentTransactionStopTimestamp(void)
|
|
{
|
|
if (xactStopTimestamp != 0)
|
|
return xactStopTimestamp;
|
|
return GetCurrentTimestamp();
|
|
}
|
|
|
|
/*
|
|
* SetCurrentStatementStartTimestamp
|
|
*/
|
|
void
|
|
SetCurrentStatementStartTimestamp(void)
|
|
{
|
|
stmtStartTimestamp = GetCurrentTimestamp();
|
|
}
|
|
|
|
/*
|
|
* SetCurrentTransactionStopTimestamp
|
|
*/
|
|
static inline void
|
|
SetCurrentTransactionStopTimestamp(void)
|
|
{
|
|
xactStopTimestamp = GetCurrentTimestamp();
|
|
}
|
|
|
|
/*
|
|
* GetCurrentTransactionNestLevel
|
|
*
|
|
* Note: this will return zero when not inside any transaction, one when
|
|
* inside a top-level transaction, etc.
|
|
*/
|
|
int
|
|
GetCurrentTransactionNestLevel(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
return s->nestingLevel;
|
|
}
|
|
|
|
|
|
/*
|
|
* TransactionIdIsCurrentTransactionId
|
|
*/
|
|
bool
|
|
TransactionIdIsCurrentTransactionId(TransactionId xid)
|
|
{
|
|
TransactionState s;
|
|
|
|
/*
|
|
* We always say that BootstrapTransactionId is "not my transaction ID"
|
|
* even when it is (ie, during bootstrap). Along with the fact that
|
|
* transam.c always treats BootstrapTransactionId as already committed,
|
|
* this causes the tqual.c routines to see all tuples as committed, which
|
|
* is what we need during bootstrap. (Bootstrap mode only inserts tuples,
|
|
* it never updates or deletes them, so all tuples can be presumed good
|
|
* immediately.)
|
|
*
|
|
* Likewise, InvalidTransactionId and FrozenTransactionId are certainly
|
|
* not my transaction ID, so we can just return "false" immediately for
|
|
* any non-normal XID.
|
|
*/
|
|
if (!TransactionIdIsNormal(xid))
|
|
return false;
|
|
|
|
/*
|
|
* We will return true for the Xid of the current subtransaction, any of
|
|
* its subcommitted children, any of its parents, or any of their
|
|
* previously subcommitted children. However, a transaction being aborted
|
|
* is no longer "current", even though it may still have an entry on the
|
|
* state stack.
|
|
*/
|
|
for (s = CurrentTransactionState; s != NULL; s = s->parent)
|
|
{
|
|
int low,
|
|
high;
|
|
|
|
if (s->state == TRANS_ABORT)
|
|
continue;
|
|
if (!TransactionIdIsValid(s->transactionId))
|
|
continue; /* it can't have any child XIDs either */
|
|
if (TransactionIdEquals(xid, s->transactionId))
|
|
return true;
|
|
/* As the childXids array is ordered, we can use binary search */
|
|
low = 0;
|
|
high = s->nChildXids - 1;
|
|
while (low <= high)
|
|
{
|
|
int middle;
|
|
TransactionId probe;
|
|
|
|
middle = low + (high - low) / 2;
|
|
probe = s->childXids[middle];
|
|
if (TransactionIdEquals(probe, xid))
|
|
return true;
|
|
else if (TransactionIdPrecedes(probe, xid))
|
|
low = middle + 1;
|
|
else
|
|
high = middle - 1;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* TransactionStartedDuringRecovery
|
|
*
|
|
* Returns true if the current transaction started while recovery was still
|
|
* in progress. Recovery might have ended since so RecoveryInProgress() might
|
|
* return false already.
|
|
*/
|
|
bool
|
|
TransactionStartedDuringRecovery(void)
|
|
{
|
|
return CurrentTransactionState->startedInRecovery;
|
|
}
|
|
|
|
/*
|
|
* CommandCounterIncrement
|
|
*/
|
|
void
|
|
CommandCounterIncrement(void)
|
|
{
|
|
/*
|
|
* If the current value of the command counter hasn't been "used" to mark
|
|
* tuples, we need not increment it, since there's no need to distinguish
|
|
* a read-only command from others. This helps postpone command counter
|
|
* overflow, and keeps no-op CommandCounterIncrement operations cheap.
|
|
*/
|
|
if (currentCommandIdUsed)
|
|
{
|
|
currentCommandId += 1;
|
|
if (currentCommandId == InvalidCommandId)
|
|
{
|
|
currentCommandId -= 1;
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
|
|
errmsg("cannot have more than 2^32-2 commands in a transaction")));
|
|
}
|
|
currentCommandIdUsed = false;
|
|
|
|
/* Propagate new command ID into static snapshots */
|
|
SnapshotSetCommandId(currentCommandId);
|
|
|
|
/*
|
|
* Make any catalog changes done by the just-completed command visible
|
|
* in the local syscache. We obviously don't need to do this after a
|
|
* read-only command. (But see hacks in inval.c to make real sure we
|
|
* don't think a command that queued inval messages was read-only.)
|
|
*/
|
|
AtCCI_LocalCache();
|
|
}
|
|
}
|
|
|
|
/*
|
|
* ForceSyncCommit
|
|
*
|
|
* Interface routine to allow commands to force a synchronous commit of the
|
|
* current top-level transaction
|
|
*/
|
|
void
|
|
ForceSyncCommit(void)
|
|
{
|
|
forceSyncCommit = true;
|
|
}
|
|
|
|
|
|
/* ----------------------------------------------------------------
|
|
* StartTransaction stuff
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
|
|
/*
|
|
* AtStart_Cache
|
|
*/
|
|
static void
|
|
AtStart_Cache(void)
|
|
{
|
|
AcceptInvalidationMessages();
|
|
}
|
|
|
|
/*
|
|
* AtStart_Memory
|
|
*/
|
|
static void
|
|
AtStart_Memory(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
/*
|
|
* If this is the first time through, create a private context for
|
|
* AbortTransaction to work in. By reserving some space now, we can
|
|
* insulate AbortTransaction from out-of-memory scenarios. Like
|
|
* ErrorContext, we set it up with slow growth rate and a nonzero minimum
|
|
* size, so that space will be reserved immediately.
|
|
*/
|
|
if (TransactionAbortContext == NULL)
|
|
TransactionAbortContext =
|
|
AllocSetContextCreate(TopMemoryContext,
|
|
"TransactionAbortContext",
|
|
32 * 1024,
|
|
32 * 1024,
|
|
32 * 1024);
|
|
|
|
/*
|
|
* We shouldn't have a transaction context already.
|
|
*/
|
|
Assert(TopTransactionContext == NULL);
|
|
|
|
/*
|
|
* Create a toplevel context for the transaction.
|
|
*/
|
|
TopTransactionContext =
|
|
AllocSetContextCreate(TopMemoryContext,
|
|
"TopTransactionContext",
|
|
ALLOCSET_DEFAULT_MINSIZE,
|
|
ALLOCSET_DEFAULT_INITSIZE,
|
|
ALLOCSET_DEFAULT_MAXSIZE);
|
|
|
|
/*
|
|
* In a top-level transaction, CurTransactionContext is the same as
|
|
* TopTransactionContext.
|
|
*/
|
|
CurTransactionContext = TopTransactionContext;
|
|
s->curTransactionContext = CurTransactionContext;
|
|
|
|
/* Make the CurTransactionContext active. */
|
|
MemoryContextSwitchTo(CurTransactionContext);
|
|
}
|
|
|
|
/*
|
|
* AtStart_ResourceOwner
|
|
*/
|
|
static void
|
|
AtStart_ResourceOwner(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
/*
|
|
* We shouldn't have a transaction resource owner already.
|
|
*/
|
|
Assert(TopTransactionResourceOwner == NULL);
|
|
|
|
/*
|
|
* Create a toplevel resource owner for the transaction.
|
|
*/
|
|
s->curTransactionOwner = ResourceOwnerCreate(NULL, "TopTransaction");
|
|
|
|
TopTransactionResourceOwner = s->curTransactionOwner;
|
|
CurTransactionResourceOwner = s->curTransactionOwner;
|
|
CurrentResourceOwner = s->curTransactionOwner;
|
|
}
|
|
|
|
/* ----------------------------------------------------------------
|
|
* StartSubTransaction stuff
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
|
|
/*
|
|
* AtSubStart_Memory
|
|
*/
|
|
static void
|
|
AtSubStart_Memory(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
Assert(CurTransactionContext != NULL);
|
|
|
|
/*
|
|
* Create a CurTransactionContext, which will be used to hold data that
|
|
* survives subtransaction commit but disappears on subtransaction abort.
|
|
* We make it a child of the immediate parent's CurTransactionContext.
|
|
*/
|
|
CurTransactionContext = AllocSetContextCreate(CurTransactionContext,
|
|
"CurTransactionContext",
|
|
ALLOCSET_DEFAULT_MINSIZE,
|
|
ALLOCSET_DEFAULT_INITSIZE,
|
|
ALLOCSET_DEFAULT_MAXSIZE);
|
|
s->curTransactionContext = CurTransactionContext;
|
|
|
|
/* Make the CurTransactionContext active. */
|
|
MemoryContextSwitchTo(CurTransactionContext);
|
|
}
|
|
|
|
/*
|
|
* AtSubStart_ResourceOwner
|
|
*/
|
|
static void
|
|
AtSubStart_ResourceOwner(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
Assert(s->parent != NULL);
|
|
|
|
/*
|
|
* Create a resource owner for the subtransaction. We make it a child of
|
|
* the immediate parent's resource owner.
|
|
*/
|
|
s->curTransactionOwner =
|
|
ResourceOwnerCreate(s->parent->curTransactionOwner,
|
|
"SubTransaction");
|
|
|
|
CurTransactionResourceOwner = s->curTransactionOwner;
|
|
CurrentResourceOwner = s->curTransactionOwner;
|
|
}
|
|
|
|
/* ----------------------------------------------------------------
|
|
* CommitTransaction stuff
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
|
|
/*
|
|
* RecordTransactionCommit
|
|
*
|
|
* Returns latest XID among xact and its children, or InvalidTransactionId
|
|
* if the xact has no XID. (We compute that here just because it's easier.)
|
|
*/
|
|
static TransactionId
|
|
RecordTransactionCommit(void)
|
|
{
|
|
TransactionId xid = GetTopTransactionIdIfAny();
|
|
bool markXidCommitted = TransactionIdIsValid(xid);
|
|
TransactionId latestXid = InvalidTransactionId;
|
|
int nrels;
|
|
RelFileNode *rels;
|
|
int nchildren;
|
|
TransactionId *children;
|
|
int nmsgs = 0;
|
|
SharedInvalidationMessage *invalMessages = NULL;
|
|
bool RelcacheInitFileInval = false;
|
|
bool wrote_xlog;
|
|
|
|
/* Get data needed for commit record */
|
|
nrels = smgrGetPendingDeletes(true, &rels);
|
|
nchildren = xactGetCommittedChildren(&children);
|
|
if (XLogStandbyInfoActive())
|
|
nmsgs = xactGetCommittedInvalidationMessages(&invalMessages,
|
|
&RelcacheInitFileInval);
|
|
wrote_xlog = (XactLastRecEnd != 0);
|
|
|
|
/*
|
|
* If we haven't been assigned an XID yet, we neither can, nor do we want
|
|
* to write a COMMIT record.
|
|
*/
|
|
if (!markXidCommitted)
|
|
{
|
|
/*
|
|
* We expect that every smgrscheduleunlink is followed by a catalog
|
|
* update, and hence XID assignment, so we shouldn't get here with any
|
|
* pending deletes. Use a real test not just an Assert to check this,
|
|
* since it's a bit fragile.
|
|
*/
|
|
if (nrels != 0)
|
|
elog(ERROR, "cannot commit a transaction that deleted files but has no xid");
|
|
|
|
/* Can't have child XIDs either; AssignTransactionId enforces this */
|
|
Assert(nchildren == 0);
|
|
|
|
/*
|
|
* If we didn't create XLOG entries, we're done here; otherwise we
|
|
* should flush those entries the same as a commit record. (An
|
|
* example of a possible record that wouldn't cause an XID to be
|
|
* assigned is a sequence advance record due to nextval() --- we want
|
|
* to flush that to disk before reporting commit.)
|
|
*/
|
|
if (!wrote_xlog)
|
|
goto cleanup;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* Begin commit critical section and insert the commit XLOG record.
|
|
*/
|
|
/* Tell bufmgr and smgr to prepare for commit */
|
|
BufmgrCommit();
|
|
|
|
/*
|
|
* Mark ourselves as within our "commit critical section". This
|
|
* forces any concurrent checkpoint to wait until we've updated
|
|
* pg_clog. Without this, it is possible for the checkpoint to set
|
|
* REDO after the XLOG record but fail to flush the pg_clog update to
|
|
* disk, leading to loss of the transaction commit if the system
|
|
* crashes a little later.
|
|
*
|
|
* Note: we could, but don't bother to, set this flag in
|
|
* RecordTransactionAbort. That's because loss of a transaction abort
|
|
* is noncritical; the presumption would be that it aborted, anyway.
|
|
*
|
|
* It's safe to change the delayChkpt flag of our own backend without
|
|
* holding the ProcArrayLock, since we're the only one modifying it.
|
|
* This makes checkpoint's determination of which xacts are delayChkpt
|
|
* a bit fuzzy, but it doesn't matter.
|
|
*/
|
|
START_CRIT_SECTION();
|
|
MyPgXact->delayChkpt = true;
|
|
|
|
SetCurrentTransactionStopTimestamp();
|
|
|
|
/*
|
|
* Do we need the long commit record? If not, use the compact format.
|
|
*
|
|
* For now always use the non-compact version if wal_level=logical, so
|
|
* we can hide commits from other databases. TODO: In the future we
|
|
* should merge compact and non-compact commits and use a flags
|
|
* variable to determine if it contains subxacts, relations or
|
|
* invalidation messages, that's more extensible and degrades more
|
|
* gracefully. Till then, it's just 20 bytes of overhead.
|
|
*/
|
|
if (nrels > 0 || nmsgs > 0 || RelcacheInitFileInval || forceSyncCommit ||
|
|
XLogLogicalInfoActive())
|
|
{
|
|
xl_xact_commit xlrec;
|
|
|
|
/*
|
|
* Set flags required for recovery processing of commits.
|
|
*/
|
|
xlrec.xinfo = 0;
|
|
if (RelcacheInitFileInval)
|
|
xlrec.xinfo |= XACT_COMPLETION_UPDATE_RELCACHE_FILE;
|
|
if (forceSyncCommit)
|
|
xlrec.xinfo |= XACT_COMPLETION_FORCE_SYNC_COMMIT;
|
|
|
|
xlrec.dbId = MyDatabaseId;
|
|
xlrec.tsId = MyDatabaseTableSpace;
|
|
|
|
xlrec.xact_time = xactStopTimestamp;
|
|
xlrec.nrels = nrels;
|
|
xlrec.nsubxacts = nchildren;
|
|
xlrec.nmsgs = nmsgs;
|
|
|
|
XLogBeginInsert();
|
|
XLogRegisterData((char *) (&xlrec), MinSizeOfXactCommit);
|
|
/* dump rels to delete */
|
|
if (nrels > 0)
|
|
XLogRegisterData((char *) rels,
|
|
nrels * sizeof(RelFileNode));
|
|
/* dump committed child Xids */
|
|
if (nchildren > 0)
|
|
XLogRegisterData((char *) children,
|
|
nchildren * sizeof(TransactionId));
|
|
/* dump shared cache invalidation messages */
|
|
if (nmsgs > 0)
|
|
XLogRegisterData((char *) invalMessages,
|
|
nmsgs * sizeof(SharedInvalidationMessage));
|
|
(void) XLogInsert(RM_XACT_ID, XLOG_XACT_COMMIT);
|
|
}
|
|
else
|
|
{
|
|
xl_xact_commit_compact xlrec;
|
|
|
|
xlrec.xact_time = xactStopTimestamp;
|
|
xlrec.nsubxacts = nchildren;
|
|
|
|
XLogBeginInsert();
|
|
XLogRegisterData((char *) (&xlrec), MinSizeOfXactCommitCompact);
|
|
/* dump committed child Xids */
|
|
if (nchildren > 0)
|
|
XLogRegisterData((char *) children,
|
|
nchildren * sizeof(TransactionId));
|
|
|
|
(void) XLogInsert(RM_XACT_ID, XLOG_XACT_COMMIT_COMPACT);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We only need to log the commit timestamp separately if the node
|
|
* identifier is a valid value; the commit record above already contains
|
|
* the timestamp info otherwise, and will be used to load it.
|
|
*/
|
|
if (markXidCommitted)
|
|
{
|
|
CommitTsNodeId node_id;
|
|
|
|
node_id = CommitTsGetDefaultNodeId();
|
|
TransactionTreeSetCommitTsData(xid, nchildren, children,
|
|
xactStopTimestamp,
|
|
node_id, node_id != InvalidCommitTsNodeId);
|
|
}
|
|
|
|
/*
|
|
* Check if we want to commit asynchronously. We can allow the XLOG flush
|
|
* to happen asynchronously if synchronous_commit=off, or if the current
|
|
* transaction has not performed any WAL-logged operation. The latter
|
|
* case can arise if the current transaction wrote only to temporary
|
|
* and/or unlogged tables. In case of a crash, the loss of such a
|
|
* transaction will be irrelevant since temp tables will be lost anyway,
|
|
* and unlogged tables will be truncated. (Given the foregoing, you might
|
|
* think that it would be unnecessary to emit the XLOG record at all in
|
|
* this case, but we don't currently try to do that. It would certainly
|
|
* cause problems at least in Hot Standby mode, where the
|
|
* KnownAssignedXids machinery requires tracking every XID assignment. It
|
|
* might be OK to skip it only when wal_level < hot_standby, but for now
|
|
* we don't.)
|
|
*
|
|
* However, if we're doing cleanup of any non-temp rels or committing any
|
|
* command that wanted to force sync commit, then we must flush XLOG
|
|
* immediately. (We must not allow asynchronous commit if there are any
|
|
* non-temp tables to be deleted, because we might delete the files before
|
|
* the COMMIT record is flushed to disk. We do allow asynchronous commit
|
|
* if all to-be-deleted tables are temporary though, since they are lost
|
|
* anyway if we crash.)
|
|
*/
|
|
if ((wrote_xlog && synchronous_commit > SYNCHRONOUS_COMMIT_OFF) ||
|
|
forceSyncCommit || nrels > 0)
|
|
{
|
|
XLogFlush(XactLastRecEnd);
|
|
|
|
/*
|
|
* Now we may update the CLOG, if we wrote a COMMIT record above
|
|
*/
|
|
if (markXidCommitted)
|
|
TransactionIdCommitTree(xid, nchildren, children);
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* Asynchronous commit case:
|
|
*
|
|
* This enables possible committed transaction loss in the case of a
|
|
* postmaster crash because WAL buffers are left unwritten. Ideally we
|
|
* could issue the WAL write without the fsync, but some
|
|
* wal_sync_methods do not allow separate write/fsync.
|
|
*
|
|
* Report the latest async commit LSN, so that the WAL writer knows to
|
|
* flush this commit.
|
|
*/
|
|
XLogSetAsyncXactLSN(XactLastRecEnd);
|
|
|
|
/*
|
|
* We must not immediately update the CLOG, since we didn't flush the
|
|
* XLOG. Instead, we store the LSN up to which the XLOG must be
|
|
* flushed before the CLOG may be updated.
|
|
*/
|
|
if (markXidCommitted)
|
|
TransactionIdAsyncCommitTree(xid, nchildren, children, XactLastRecEnd);
|
|
}
|
|
|
|
/*
|
|
* If we entered a commit critical section, leave it now, and let
|
|
* checkpoints proceed.
|
|
*/
|
|
if (markXidCommitted)
|
|
{
|
|
MyPgXact->delayChkpt = false;
|
|
END_CRIT_SECTION();
|
|
}
|
|
|
|
/* Compute latestXid while we have the child XIDs handy */
|
|
latestXid = TransactionIdLatest(xid, nchildren, children);
|
|
|
|
/*
|
|
* Wait for synchronous replication, if required.
|
|
*
|
|
* Note that at this stage we have marked clog, but still show as running
|
|
* in the procarray and continue to hold locks.
|
|
*/
|
|
if (wrote_xlog)
|
|
SyncRepWaitForLSN(XactLastRecEnd);
|
|
|
|
/* Reset XactLastRecEnd until the next transaction writes something */
|
|
XactLastRecEnd = 0;
|
|
|
|
cleanup:
|
|
/* Clean up local data */
|
|
if (rels)
|
|
pfree(rels);
|
|
|
|
return latestXid;
|
|
}
|
|
|
|
|
|
/*
|
|
* AtCCI_LocalCache
|
|
*/
|
|
static void
|
|
AtCCI_LocalCache(void)
|
|
{
|
|
/*
|
|
* Make any pending relation map changes visible. We must do this before
|
|
* processing local sinval messages, so that the map changes will get
|
|
* reflected into the relcache when relcache invals are processed.
|
|
*/
|
|
AtCCI_RelationMap();
|
|
|
|
/*
|
|
* Make catalog changes visible to me for the next command.
|
|
*/
|
|
CommandEndInvalidationMessages();
|
|
}
|
|
|
|
/*
|
|
* AtCommit_Memory
|
|
*/
|
|
static void
|
|
AtCommit_Memory(void)
|
|
{
|
|
/*
|
|
* Now that we're "out" of a transaction, have the system allocate things
|
|
* in the top memory context instead of per-transaction contexts.
|
|
*/
|
|
MemoryContextSwitchTo(TopMemoryContext);
|
|
|
|
/*
|
|
* Release all transaction-local memory.
|
|
*/
|
|
Assert(TopTransactionContext != NULL);
|
|
MemoryContextDelete(TopTransactionContext);
|
|
TopTransactionContext = NULL;
|
|
CurTransactionContext = NULL;
|
|
CurrentTransactionState->curTransactionContext = NULL;
|
|
}
|
|
|
|
/* ----------------------------------------------------------------
|
|
* CommitSubTransaction stuff
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
|
|
/*
|
|
* AtSubCommit_Memory
|
|
*/
|
|
static void
|
|
AtSubCommit_Memory(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
Assert(s->parent != NULL);
|
|
|
|
/* Return to parent transaction level's memory context. */
|
|
CurTransactionContext = s->parent->curTransactionContext;
|
|
MemoryContextSwitchTo(CurTransactionContext);
|
|
|
|
/*
|
|
* Ordinarily we cannot throw away the child's CurTransactionContext,
|
|
* since the data it contains will be needed at upper commit. However, if
|
|
* there isn't actually anything in it, we can throw it away. This avoids
|
|
* a small memory leak in the common case of "trivial" subxacts.
|
|
*/
|
|
if (MemoryContextIsEmpty(s->curTransactionContext))
|
|
{
|
|
MemoryContextDelete(s->curTransactionContext);
|
|
s->curTransactionContext = NULL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* AtSubCommit_childXids
|
|
*
|
|
* Pass my own XID and my child XIDs up to my parent as committed children.
|
|
*/
|
|
static void
|
|
AtSubCommit_childXids(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
int new_nChildXids;
|
|
|
|
Assert(s->parent != NULL);
|
|
|
|
/*
|
|
* The parent childXids array will need to hold my XID and all my
|
|
* childXids, in addition to the XIDs already there.
|
|
*/
|
|
new_nChildXids = s->parent->nChildXids + s->nChildXids + 1;
|
|
|
|
/* Allocate or enlarge the parent array if necessary */
|
|
if (s->parent->maxChildXids < new_nChildXids)
|
|
{
|
|
int new_maxChildXids;
|
|
TransactionId *new_childXids;
|
|
|
|
/*
|
|
* Make it 2x what's needed right now, to avoid having to enlarge it
|
|
* repeatedly. But we can't go above MaxAllocSize. (The latter limit
|
|
* is what ensures that we don't need to worry about integer overflow
|
|
* here or in the calculation of new_nChildXids.)
|
|
*/
|
|
new_maxChildXids = Min(new_nChildXids * 2,
|
|
(int) (MaxAllocSize / sizeof(TransactionId)));
|
|
|
|
if (new_maxChildXids < new_nChildXids)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
|
|
errmsg("maximum number of committed subtransactions (%d) exceeded",
|
|
(int) (MaxAllocSize / sizeof(TransactionId)))));
|
|
|
|
/*
|
|
* We keep the child-XID arrays in TopTransactionContext; this avoids
|
|
* setting up child-transaction contexts for what might be just a few
|
|
* bytes of grandchild XIDs.
|
|
*/
|
|
if (s->parent->childXids == NULL)
|
|
new_childXids =
|
|
MemoryContextAlloc(TopTransactionContext,
|
|
new_maxChildXids * sizeof(TransactionId));
|
|
else
|
|
new_childXids = repalloc(s->parent->childXids,
|
|
new_maxChildXids * sizeof(TransactionId));
|
|
|
|
s->parent->childXids = new_childXids;
|
|
s->parent->maxChildXids = new_maxChildXids;
|
|
}
|
|
|
|
/*
|
|
* Copy all my XIDs to parent's array.
|
|
*
|
|
* Note: We rely on the fact that the XID of a child always follows that
|
|
* of its parent. By copying the XID of this subtransaction before the
|
|
* XIDs of its children, we ensure that the array stays ordered. Likewise,
|
|
* all XIDs already in the array belong to subtransactions started and
|
|
* subcommitted before us, so their XIDs must precede ours.
|
|
*/
|
|
s->parent->childXids[s->parent->nChildXids] = s->transactionId;
|
|
|
|
if (s->nChildXids > 0)
|
|
memcpy(&s->parent->childXids[s->parent->nChildXids + 1],
|
|
s->childXids,
|
|
s->nChildXids * sizeof(TransactionId));
|
|
|
|
s->parent->nChildXids = new_nChildXids;
|
|
|
|
/* Release child's array to avoid leakage */
|
|
if (s->childXids != NULL)
|
|
pfree(s->childXids);
|
|
/* We must reset these to avoid double-free if fail later in commit */
|
|
s->childXids = NULL;
|
|
s->nChildXids = 0;
|
|
s->maxChildXids = 0;
|
|
}
|
|
|
|
/* ----------------------------------------------------------------
|
|
* AbortTransaction stuff
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
|
|
/*
|
|
* RecordTransactionAbort
|
|
*
|
|
* Returns latest XID among xact and its children, or InvalidTransactionId
|
|
* if the xact has no XID. (We compute that here just because it's easier.)
|
|
*/
|
|
static TransactionId
|
|
RecordTransactionAbort(bool isSubXact)
|
|
{
|
|
TransactionId xid = GetCurrentTransactionIdIfAny();
|
|
TransactionId latestXid;
|
|
int nrels;
|
|
RelFileNode *rels;
|
|
int nchildren;
|
|
TransactionId *children;
|
|
xl_xact_abort xlrec;
|
|
|
|
/*
|
|
* If we haven't been assigned an XID, nobody will care whether we aborted
|
|
* or not. Hence, we're done in that case. It does not matter if we have
|
|
* rels to delete (note that this routine is not responsible for actually
|
|
* deleting 'em). We cannot have any child XIDs, either.
|
|
*/
|
|
if (!TransactionIdIsValid(xid))
|
|
{
|
|
/* Reset XactLastRecEnd until the next transaction writes something */
|
|
if (!isSubXact)
|
|
XactLastRecEnd = 0;
|
|
return InvalidTransactionId;
|
|
}
|
|
|
|
/*
|
|
* We have a valid XID, so we should write an ABORT record for it.
|
|
*
|
|
* We do not flush XLOG to disk here, since the default assumption after a
|
|
* crash would be that we aborted, anyway. For the same reason, we don't
|
|
* need to worry about interlocking against checkpoint start.
|
|
*/
|
|
|
|
/*
|
|
* Check that we haven't aborted halfway through RecordTransactionCommit.
|
|
*/
|
|
if (TransactionIdDidCommit(xid))
|
|
elog(PANIC, "cannot abort transaction %u, it was already committed",
|
|
xid);
|
|
|
|
/* Fetch the data we need for the abort record */
|
|
nrels = smgrGetPendingDeletes(false, &rels);
|
|
nchildren = xactGetCommittedChildren(&children);
|
|
|
|
/* XXX do we really need a critical section here? */
|
|
START_CRIT_SECTION();
|
|
|
|
/* Write the ABORT record */
|
|
if (isSubXact)
|
|
xlrec.xact_time = GetCurrentTimestamp();
|
|
else
|
|
{
|
|
SetCurrentTransactionStopTimestamp();
|
|
xlrec.xact_time = xactStopTimestamp;
|
|
}
|
|
xlrec.nrels = nrels;
|
|
xlrec.nsubxacts = nchildren;
|
|
|
|
XLogBeginInsert();
|
|
XLogRegisterData((char *) (&xlrec), MinSizeOfXactAbort);
|
|
|
|
/* dump rels to delete */
|
|
if (nrels > 0)
|
|
XLogRegisterData((char *) rels, nrels * sizeof(RelFileNode));
|
|
|
|
/* dump committed child Xids */
|
|
if (nchildren > 0)
|
|
XLogRegisterData((char *) children,
|
|
nchildren * sizeof(TransactionId));
|
|
|
|
(void) XLogInsert(RM_XACT_ID, XLOG_XACT_ABORT);
|
|
|
|
/*
|
|
* Report the latest async abort LSN, so that the WAL writer knows to
|
|
* flush this abort. There's nothing to be gained by delaying this, since
|
|
* WALWriter may as well do this when it can. This is important with
|
|
* streaming replication because if we don't flush WAL regularly we will
|
|
* find that large aborts leave us with a long backlog for when commits
|
|
* occur after the abort, increasing our window of data loss should
|
|
* problems occur at that point.
|
|
*/
|
|
if (!isSubXact)
|
|
XLogSetAsyncXactLSN(XactLastRecEnd);
|
|
|
|
/*
|
|
* Mark the transaction aborted in clog. This is not absolutely necessary
|
|
* but we may as well do it while we are here; also, in the subxact case
|
|
* it is helpful because XactLockTableWait makes use of it to avoid
|
|
* waiting for already-aborted subtransactions. It is OK to do it without
|
|
* having flushed the ABORT record to disk, because in event of a crash
|
|
* we'd be assumed to have aborted anyway.
|
|
*/
|
|
TransactionIdAbortTree(xid, nchildren, children);
|
|
|
|
END_CRIT_SECTION();
|
|
|
|
/* Compute latestXid while we have the child XIDs handy */
|
|
latestXid = TransactionIdLatest(xid, nchildren, children);
|
|
|
|
/*
|
|
* If we're aborting a subtransaction, we can immediately remove failed
|
|
* XIDs from PGPROC's cache of running child XIDs. We do that here for
|
|
* subxacts, because we already have the child XID array at hand. For
|
|
* main xacts, the equivalent happens just after this function returns.
|
|
*/
|
|
if (isSubXact)
|
|
XidCacheRemoveRunningXids(xid, nchildren, children, latestXid);
|
|
|
|
/* Reset XactLastRecEnd until the next transaction writes something */
|
|
if (!isSubXact)
|
|
XactLastRecEnd = 0;
|
|
|
|
/* And clean up local data */
|
|
if (rels)
|
|
pfree(rels);
|
|
|
|
return latestXid;
|
|
}
|
|
|
|
/*
|
|
* AtAbort_Memory
|
|
*/
|
|
static void
|
|
AtAbort_Memory(void)
|
|
{
|
|
/*
|
|
* Switch into TransactionAbortContext, which should have some free space
|
|
* even if nothing else does. We'll work in this context until we've
|
|
* finished cleaning up.
|
|
*
|
|
* It is barely possible to get here when we've not been able to create
|
|
* TransactionAbortContext yet; if so use TopMemoryContext.
|
|
*/
|
|
if (TransactionAbortContext != NULL)
|
|
MemoryContextSwitchTo(TransactionAbortContext);
|
|
else
|
|
MemoryContextSwitchTo(TopMemoryContext);
|
|
}
|
|
|
|
/*
|
|
* AtSubAbort_Memory
|
|
*/
|
|
static void
|
|
AtSubAbort_Memory(void)
|
|
{
|
|
Assert(TransactionAbortContext != NULL);
|
|
|
|
MemoryContextSwitchTo(TransactionAbortContext);
|
|
}
|
|
|
|
|
|
/*
|
|
* AtAbort_ResourceOwner
|
|
*/
|
|
static void
|
|
AtAbort_ResourceOwner(void)
|
|
{
|
|
/*
|
|
* Make sure we have a valid ResourceOwner, if possible (else it will be
|
|
* NULL, which is OK)
|
|
*/
|
|
CurrentResourceOwner = TopTransactionResourceOwner;
|
|
}
|
|
|
|
/*
|
|
* AtSubAbort_ResourceOwner
|
|
*/
|
|
static void
|
|
AtSubAbort_ResourceOwner(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
/* Make sure we have a valid ResourceOwner */
|
|
CurrentResourceOwner = s->curTransactionOwner;
|
|
}
|
|
|
|
|
|
/*
|
|
* AtSubAbort_childXids
|
|
*/
|
|
static void
|
|
AtSubAbort_childXids(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
/*
|
|
* We keep the child-XID arrays in TopTransactionContext (see
|
|
* AtSubCommit_childXids). This means we'd better free the array
|
|
* explicitly at abort to avoid leakage.
|
|
*/
|
|
if (s->childXids != NULL)
|
|
pfree(s->childXids);
|
|
s->childXids = NULL;
|
|
s->nChildXids = 0;
|
|
s->maxChildXids = 0;
|
|
|
|
/*
|
|
* We could prune the unreportedXids array here. But we don't bother. That
|
|
* would potentially reduce number of XLOG_XACT_ASSIGNMENT records but it
|
|
* would likely introduce more CPU time into the more common paths, so we
|
|
* choose not to do that.
|
|
*/
|
|
}
|
|
|
|
/* ----------------------------------------------------------------
|
|
* CleanupTransaction stuff
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
|
|
/*
|
|
* AtCleanup_Memory
|
|
*/
|
|
static void
|
|
AtCleanup_Memory(void)
|
|
{
|
|
Assert(CurrentTransactionState->parent == NULL);
|
|
|
|
/*
|
|
* Now that we're "out" of a transaction, have the system allocate things
|
|
* in the top memory context instead of per-transaction contexts.
|
|
*/
|
|
MemoryContextSwitchTo(TopMemoryContext);
|
|
|
|
/*
|
|
* Clear the special abort context for next time.
|
|
*/
|
|
if (TransactionAbortContext != NULL)
|
|
MemoryContextResetAndDeleteChildren(TransactionAbortContext);
|
|
|
|
/*
|
|
* Release all transaction-local memory.
|
|
*/
|
|
if (TopTransactionContext != NULL)
|
|
MemoryContextDelete(TopTransactionContext);
|
|
TopTransactionContext = NULL;
|
|
CurTransactionContext = NULL;
|
|
CurrentTransactionState->curTransactionContext = NULL;
|
|
}
|
|
|
|
|
|
/* ----------------------------------------------------------------
|
|
* CleanupSubTransaction stuff
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
|
|
/*
|
|
* AtSubCleanup_Memory
|
|
*/
|
|
static void
|
|
AtSubCleanup_Memory(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
Assert(s->parent != NULL);
|
|
|
|
/* Make sure we're not in an about-to-be-deleted context */
|
|
MemoryContextSwitchTo(s->parent->curTransactionContext);
|
|
CurTransactionContext = s->parent->curTransactionContext;
|
|
|
|
/*
|
|
* Clear the special abort context for next time.
|
|
*/
|
|
if (TransactionAbortContext != NULL)
|
|
MemoryContextResetAndDeleteChildren(TransactionAbortContext);
|
|
|
|
/*
|
|
* Delete the subxact local memory contexts. Its CurTransactionContext can
|
|
* go too (note this also kills CurTransactionContexts from any children
|
|
* of the subxact).
|
|
*/
|
|
if (s->curTransactionContext)
|
|
MemoryContextDelete(s->curTransactionContext);
|
|
s->curTransactionContext = NULL;
|
|
}
|
|
|
|
/* ----------------------------------------------------------------
|
|
* interface routines
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
|
|
/*
|
|
* StartTransaction
|
|
*/
|
|
static void
|
|
StartTransaction(void)
|
|
{
|
|
TransactionState s;
|
|
VirtualTransactionId vxid;
|
|
|
|
/*
|
|
* Let's just make sure the state stack is empty
|
|
*/
|
|
s = &TopTransactionStateData;
|
|
CurrentTransactionState = s;
|
|
|
|
/*
|
|
* check the current transaction state
|
|
*/
|
|
if (s->state != TRANS_DEFAULT)
|
|
elog(WARNING, "StartTransaction while in %s state",
|
|
TransStateAsString(s->state));
|
|
|
|
/*
|
|
* set the current transaction state information appropriately during
|
|
* start processing
|
|
*/
|
|
s->state = TRANS_START;
|
|
s->transactionId = InvalidTransactionId; /* until assigned */
|
|
|
|
/*
|
|
* Make sure we've reset xact state variables
|
|
*
|
|
* If recovery is still in progress, mark this transaction as read-only.
|
|
* We have lower level defences in XLogInsert and elsewhere to stop us
|
|
* from modifying data during recovery, but this gives the normal
|
|
* indication to the user that the transaction is read-only.
|
|
*/
|
|
if (RecoveryInProgress())
|
|
{
|
|
s->startedInRecovery = true;
|
|
XactReadOnly = true;
|
|
}
|
|
else
|
|
{
|
|
s->startedInRecovery = false;
|
|
XactReadOnly = DefaultXactReadOnly;
|
|
}
|
|
XactDeferrable = DefaultXactDeferrable;
|
|
XactIsoLevel = DefaultXactIsoLevel;
|
|
forceSyncCommit = false;
|
|
MyXactAccessedTempRel = false;
|
|
|
|
/*
|
|
* reinitialize within-transaction counters
|
|
*/
|
|
s->subTransactionId = TopSubTransactionId;
|
|
currentSubTransactionId = TopSubTransactionId;
|
|
currentCommandId = FirstCommandId;
|
|
currentCommandIdUsed = false;
|
|
|
|
/*
|
|
* initialize reported xid accounting
|
|
*/
|
|
nUnreportedXids = 0;
|
|
s->didLogXid = false;
|
|
|
|
/*
|
|
* must initialize resource-management stuff first
|
|
*/
|
|
AtStart_Memory();
|
|
AtStart_ResourceOwner();
|
|
|
|
/*
|
|
* Assign a new LocalTransactionId, and combine it with the backendId to
|
|
* form a virtual transaction id.
|
|
*/
|
|
vxid.backendId = MyBackendId;
|
|
vxid.localTransactionId = GetNextLocalTransactionId();
|
|
|
|
/*
|
|
* Lock the virtual transaction id before we announce it in the proc array
|
|
*/
|
|
VirtualXactLockTableInsert(vxid);
|
|
|
|
/*
|
|
* Advertise it in the proc array. We assume assignment of
|
|
* LocalTransactionID is atomic, and the backendId should be set already.
|
|
*/
|
|
Assert(MyProc->backendId == vxid.backendId);
|
|
MyProc->lxid = vxid.localTransactionId;
|
|
|
|
TRACE_POSTGRESQL_TRANSACTION_START(vxid.localTransactionId);
|
|
|
|
/*
|
|
* set transaction_timestamp() (a/k/a now()). We want this to be the same
|
|
* as the first command's statement_timestamp(), so don't do a fresh
|
|
* GetCurrentTimestamp() call (which'd be expensive anyway). Also, mark
|
|
* xactStopTimestamp as unset.
|
|
*/
|
|
xactStartTimestamp = stmtStartTimestamp;
|
|
xactStopTimestamp = 0;
|
|
pgstat_report_xact_timestamp(xactStartTimestamp);
|
|
|
|
/*
|
|
* initialize current transaction state fields
|
|
*
|
|
* note: prevXactReadOnly is not used at the outermost level
|
|
*/
|
|
s->nestingLevel = 1;
|
|
s->gucNestLevel = 1;
|
|
s->childXids = NULL;
|
|
s->nChildXids = 0;
|
|
s->maxChildXids = 0;
|
|
GetUserIdAndSecContext(&s->prevUser, &s->prevSecContext);
|
|
/* SecurityRestrictionContext should never be set outside a transaction */
|
|
Assert(s->prevSecContext == 0);
|
|
|
|
/*
|
|
* initialize other subsystems for new transaction
|
|
*/
|
|
AtStart_GUC();
|
|
AtStart_Cache();
|
|
AfterTriggerBeginXact();
|
|
|
|
/*
|
|
* done with start processing, set current transaction state to "in
|
|
* progress"
|
|
*/
|
|
s->state = TRANS_INPROGRESS;
|
|
|
|
ShowTransactionState("StartTransaction");
|
|
}
|
|
|
|
|
|
/*
|
|
* CommitTransaction
|
|
*
|
|
* NB: if you change this routine, better look at PrepareTransaction too!
|
|
*/
|
|
static void
|
|
CommitTransaction(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
TransactionId latestXid;
|
|
|
|
ShowTransactionState("CommitTransaction");
|
|
|
|
/*
|
|
* check the current transaction state
|
|
*/
|
|
if (s->state != TRANS_INPROGRESS)
|
|
elog(WARNING, "CommitTransaction while in %s state",
|
|
TransStateAsString(s->state));
|
|
Assert(s->parent == NULL);
|
|
|
|
/*
|
|
* Do pre-commit processing that involves calling user-defined code, such
|
|
* as triggers. Since closing cursors could queue trigger actions,
|
|
* triggers could open cursors, etc, we have to keep looping until there's
|
|
* nothing left to do.
|
|
*/
|
|
for (;;)
|
|
{
|
|
/*
|
|
* Fire all currently pending deferred triggers.
|
|
*/
|
|
AfterTriggerFireDeferred();
|
|
|
|
/*
|
|
* Close open portals (converting holdable ones 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 (!PreCommit_Portals(false))
|
|
break;
|
|
}
|
|
|
|
CallXactCallbacks(XACT_EVENT_PRE_COMMIT);
|
|
|
|
/*
|
|
* The remaining actions cannot call any user-defined code, so it's safe
|
|
* to start shutting down within-transaction services. But note that most
|
|
* of this stuff could still throw an error, which would switch us into
|
|
* the transaction-abort path.
|
|
*/
|
|
|
|
/* Shut down the deferred-trigger manager */
|
|
AfterTriggerEndXact(true);
|
|
|
|
/*
|
|
* 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);
|
|
|
|
/*
|
|
* Mark serializable transaction as complete for predicate locking
|
|
* purposes. This should be done as late as we can put it and still allow
|
|
* errors to be raised for failure patterns found at commit.
|
|
*/
|
|
PreCommit_CheckForSerializationFailure();
|
|
|
|
/*
|
|
* Insert notifications sent by NOTIFY commands into the queue. This
|
|
* should be late in the pre-commit sequence to minimize time spent
|
|
* holding the notify-insertion lock.
|
|
*/
|
|
PreCommit_Notify();
|
|
|
|
/* Prevent cancel/die interrupt while cleaning up */
|
|
HOLD_INTERRUPTS();
|
|
|
|
/* Commit updates to the relation map --- do this as late as possible */
|
|
AtEOXact_RelationMap(true);
|
|
|
|
/*
|
|
* set the current transaction state information appropriately during
|
|
* commit processing
|
|
*/
|
|
s->state = TRANS_COMMIT;
|
|
|
|
/*
|
|
* Here is where we really truly commit.
|
|
*/
|
|
latestXid = RecordTransactionCommit();
|
|
|
|
TRACE_POSTGRESQL_TRANSACTION_COMMIT(MyProc->lxid);
|
|
|
|
/*
|
|
* Let others know about no transaction in progress by me. Note that this
|
|
* must be done _before_ releasing locks we hold and _after_
|
|
* RecordTransactionCommit.
|
|
*/
|
|
ProcArrayEndTransaction(MyProc, latestXid);
|
|
|
|
/*
|
|
* This is all post-commit cleanup. Note that if an error is raised here,
|
|
* it's too late to abort the transaction. This should be just
|
|
* noncritical resource releasing.
|
|
*
|
|
* The ordering of operations is not entirely random. The idea is:
|
|
* release resources visible to other backends (eg, files, buffer pins);
|
|
* then release locks; then release backend-local resources. We want to
|
|
* release locks at the point where any backend waiting for us will see
|
|
* our transaction as being fully cleaned up.
|
|
*
|
|
* Resources that can be associated with individual queries are handled by
|
|
* the ResourceOwner mechanism. The other calls here are for backend-wide
|
|
* state.
|
|
*/
|
|
|
|
CallXactCallbacks(XACT_EVENT_COMMIT);
|
|
|
|
ResourceOwnerRelease(TopTransactionResourceOwner,
|
|
RESOURCE_RELEASE_BEFORE_LOCKS,
|
|
true, true);
|
|
|
|
/* Check we've released all buffer pins */
|
|
AtEOXact_Buffers(true);
|
|
|
|
/* Clean up the relation cache */
|
|
AtEOXact_RelationCache(true);
|
|
|
|
/*
|
|
* Make catalog changes visible to all backends. This has to happen after
|
|
* relcache references are dropped (see comments for
|
|
* AtEOXact_RelationCache), but before locks are released (if anyone is
|
|
* waiting for lock on a relation we've modified, we want them to know
|
|
* about the catalog change before they start using the relation).
|
|
*/
|
|
AtEOXact_Inval(true);
|
|
|
|
AtEOXact_MultiXact();
|
|
|
|
ResourceOwnerRelease(TopTransactionResourceOwner,
|
|
RESOURCE_RELEASE_LOCKS,
|
|
true, true);
|
|
ResourceOwnerRelease(TopTransactionResourceOwner,
|
|
RESOURCE_RELEASE_AFTER_LOCKS,
|
|
true, true);
|
|
|
|
/*
|
|
* Likewise, dropping of files deleted during the transaction is best done
|
|
* after releasing relcache and buffer pins. (This is not strictly
|
|
* necessary during commit, since such pins should have been released
|
|
* already, but this ordering is definitely critical during abort.) Since
|
|
* this may take many seconds, also delay until after releasing locks.
|
|
* Other backends will observe the attendant catalog changes and not
|
|
* attempt to access affected files.
|
|
*/
|
|
smgrDoPendingDeletes(true);
|
|
|
|
/* Check we've released all catcache entries */
|
|
AtEOXact_CatCache(true);
|
|
|
|
AtCommit_Notify();
|
|
AtEOXact_GUC(true, 1);
|
|
AtEOXact_SPI(true);
|
|
AtEOXact_on_commit_actions(true);
|
|
AtEOXact_Namespace(true);
|
|
AtEOXact_SMgr();
|
|
AtEOXact_Files();
|
|
AtEOXact_ComboCid();
|
|
AtEOXact_HashTables(true);
|
|
AtEOXact_PgStat(true);
|
|
AtEOXact_Snapshot(true);
|
|
pgstat_report_xact_timestamp(0);
|
|
|
|
CurrentResourceOwner = NULL;
|
|
ResourceOwnerDelete(TopTransactionResourceOwner);
|
|
s->curTransactionOwner = NULL;
|
|
CurTransactionResourceOwner = NULL;
|
|
TopTransactionResourceOwner = NULL;
|
|
|
|
AtCommit_Memory();
|
|
|
|
s->transactionId = InvalidTransactionId;
|
|
s->subTransactionId = InvalidSubTransactionId;
|
|
s->nestingLevel = 0;
|
|
s->gucNestLevel = 0;
|
|
s->childXids = NULL;
|
|
s->nChildXids = 0;
|
|
s->maxChildXids = 0;
|
|
|
|
/*
|
|
* done with commit processing, set current transaction state back to
|
|
* default
|
|
*/
|
|
s->state = TRANS_DEFAULT;
|
|
|
|
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;
|
|
TimestampTz prepared_at;
|
|
|
|
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 that involves calling user-defined code, such
|
|
* as triggers. Since closing cursors could queue trigger actions,
|
|
* triggers could open cursors, etc, we have to keep looping until there's
|
|
* nothing left to do.
|
|
*/
|
|
for (;;)
|
|
{
|
|
/*
|
|
* Fire all currently pending deferred triggers.
|
|
*/
|
|
AfterTriggerFireDeferred();
|
|
|
|
/*
|
|
* Close open portals (converting holdable ones 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 (!PreCommit_Portals(true))
|
|
break;
|
|
}
|
|
|
|
CallXactCallbacks(XACT_EVENT_PRE_PREPARE);
|
|
|
|
/*
|
|
* The remaining actions cannot call any user-defined code, so it's safe
|
|
* to start shutting down within-transaction services. But note that most
|
|
* of this stuff could still throw an error, which would switch us into
|
|
* the transaction-abort path.
|
|
*/
|
|
|
|
/* Shut down the deferred-trigger manager */
|
|
AfterTriggerEndXact(true);
|
|
|
|
/*
|
|
* 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);
|
|
|
|
/*
|
|
* Mark serializable transaction as complete for predicate locking
|
|
* purposes. This should be done as late as we can put it and still allow
|
|
* errors to be raised for failure patterns found at commit.
|
|
*/
|
|
PreCommit_CheckForSerializationFailure();
|
|
|
|
/* NOTIFY will be handled below */
|
|
|
|
/*
|
|
* Don't allow PREPARE TRANSACTION if we've accessed a temporary table in
|
|
* this transaction. Having the prepared xact hold locks on another
|
|
* backend's temp table seems a bad idea --- for instance it would prevent
|
|
* the backend from exiting. There are other problems too, such as how to
|
|
* clean up the source backend's local buffers and ON COMMIT state if the
|
|
* prepared xact includes a DROP of a temp table.
|
|
*
|
|
* We must check this after executing any ON COMMIT actions, because they
|
|
* might still access a temp relation.
|
|
*
|
|
* XXX In principle this could be relaxed to allow some useful special
|
|
* cases, such as a temp table created and dropped all within the
|
|
* transaction. That seems to require much more bookkeeping though.
|
|
*/
|
|
if (MyXactAccessedTempRel)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
|
|
errmsg("cannot PREPARE a transaction that has operated on temporary tables")));
|
|
|
|
/*
|
|
* Likewise, don't allow PREPARE after pg_export_snapshot. This could be
|
|
* supported if we added cleanup logic to twophase.c, but for now it
|
|
* doesn't seem worth the trouble.
|
|
*/
|
|
if (XactHasExportedSnapshots())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
|
|
errmsg("cannot PREPARE a transaction that has exported snapshots")));
|
|
|
|
/* Prevent cancel/die interrupt while cleaning up */
|
|
HOLD_INTERRUPTS();
|
|
|
|
/*
|
|
* set the current transaction state information appropriately during
|
|
* prepare processing
|
|
*/
|
|
s->state = TRANS_PREPARE;
|
|
|
|
prepared_at = GetCurrentTimestamp();
|
|
|
|
/* 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, prepareGID, prepared_at,
|
|
GetUserId(), MyDatabaseId);
|
|
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_Locks();
|
|
AtPrepare_PredicateLocks();
|
|
AtPrepare_PgStat();
|
|
AtPrepare_MultiXact();
|
|
AtPrepare_RelationMap();
|
|
|
|
/*
|
|
* 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);
|
|
|
|
/*
|
|
* Now we clean up backend-internal state and release internal resources.
|
|
*/
|
|
|
|
/* Reset XactLastRecEnd until the next transaction writes something */
|
|
XactLastRecEnd = 0;
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
ProcArrayClearTransaction(MyProc);
|
|
|
|
/*
|
|
* In normal commit-processing, this is all non-critical post-transaction
|
|
* cleanup. When the transaction is prepared, however, it's important that
|
|
* the locks and other per-backend resources are transfered to the
|
|
* prepared transaction's PGPROC entry. Note that if an error is raised
|
|
* here, it's too late to abort the transaction. XXX: This probably should
|
|
* be in a critical section, to force a PANIC if any of this fails, but
|
|
* that cure could be worse than the disease.
|
|
*/
|
|
|
|
CallXactCallbacks(XACT_EVENT_PREPARE);
|
|
|
|
ResourceOwnerRelease(TopTransactionResourceOwner,
|
|
RESOURCE_RELEASE_BEFORE_LOCKS,
|
|
true, true);
|
|
|
|
/* Check we've released all buffer pins */
|
|
AtEOXact_Buffers(true);
|
|
|
|
/* Clean up the relation cache */
|
|
AtEOXact_RelationCache(true);
|
|
|
|
/* notify doesn't need a postprepare call */
|
|
|
|
PostPrepare_PgStat();
|
|
|
|
PostPrepare_Inval();
|
|
|
|
PostPrepare_smgr();
|
|
|
|
PostPrepare_MultiXact(xid);
|
|
|
|
PostPrepare_Locks(xid);
|
|
PostPrepare_PredicateLocks(xid);
|
|
|
|
ResourceOwnerRelease(TopTransactionResourceOwner,
|
|
RESOURCE_RELEASE_LOCKS,
|
|
true, true);
|
|
ResourceOwnerRelease(TopTransactionResourceOwner,
|
|
RESOURCE_RELEASE_AFTER_LOCKS,
|
|
true, true);
|
|
|
|
/*
|
|
* Allow another backend to finish the transaction. After
|
|
* PostPrepare_Twophase(), the transaction is completely detached from
|
|
* our backend. The rest is just non-critical cleanup of backend-local
|
|
* state.
|
|
*/
|
|
PostPrepare_Twophase();
|
|
|
|
/* Check we've released all catcache entries */
|
|
AtEOXact_CatCache(true);
|
|
|
|
/* PREPARE acts the same as COMMIT as far as GUC is concerned */
|
|
AtEOXact_GUC(true, 1);
|
|
AtEOXact_SPI(true);
|
|
AtEOXact_on_commit_actions(true);
|
|
AtEOXact_Namespace(true);
|
|
AtEOXact_SMgr();
|
|
AtEOXact_Files();
|
|
AtEOXact_ComboCid();
|
|
AtEOXact_HashTables(true);
|
|
/* don't call AtEOXact_PgStat here; we fixed pgstat state above */
|
|
AtEOXact_Snapshot(true);
|
|
pgstat_report_xact_timestamp(0);
|
|
|
|
CurrentResourceOwner = NULL;
|
|
ResourceOwnerDelete(TopTransactionResourceOwner);
|
|
s->curTransactionOwner = NULL;
|
|
CurTransactionResourceOwner = NULL;
|
|
TopTransactionResourceOwner = NULL;
|
|
|
|
AtCommit_Memory();
|
|
|
|
s->transactionId = InvalidTransactionId;
|
|
s->subTransactionId = InvalidSubTransactionId;
|
|
s->nestingLevel = 0;
|
|
s->gucNestLevel = 0;
|
|
s->childXids = NULL;
|
|
s->nChildXids = 0;
|
|
s->maxChildXids = 0;
|
|
|
|
/*
|
|
* done with 1st phase commit processing, set current transaction state
|
|
* back to default
|
|
*/
|
|
s->state = TRANS_DEFAULT;
|
|
|
|
RESUME_INTERRUPTS();
|
|
}
|
|
|
|
|
|
/*
|
|
* AbortTransaction
|
|
*/
|
|
static void
|
|
AbortTransaction(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
TransactionId latestXid;
|
|
|
|
/* Prevent cancel/die interrupt while cleaning up */
|
|
HOLD_INTERRUPTS();
|
|
|
|
/* Make sure we have a valid memory context and resource owner */
|
|
AtAbort_Memory();
|
|
AtAbort_ResourceOwner();
|
|
|
|
/*
|
|
* Release any LW locks we might be holding as quickly as possible.
|
|
* (Regular locks, however, must be held till we finish aborting.)
|
|
* Releasing LW locks is critical since we might try to grab them again
|
|
* while cleaning up!
|
|
*/
|
|
LWLockReleaseAll();
|
|
|
|
/* Clean up buffer I/O and buffer context locks, too */
|
|
AbortBufferIO();
|
|
UnlockBuffers();
|
|
|
|
/* Reset WAL record construction state */
|
|
XLogResetInsertion();
|
|
|
|
/*
|
|
* Also clean up any open wait for lock, since the lock manager will choke
|
|
* if we try to wait for another lock before doing this.
|
|
*/
|
|
LockErrorCleanup();
|
|
|
|
/*
|
|
* If any timeout events are still active, make sure the timeout interrupt
|
|
* is scheduled. This covers possible loss of a timeout interrupt due to
|
|
* longjmp'ing out of the SIGINT handler (see notes in handle_sig_alarm).
|
|
* We delay this till after LockErrorCleanup so that we don't uselessly
|
|
* reschedule lock or deadlock check timeouts.
|
|
*/
|
|
reschedule_timeouts();
|
|
|
|
/*
|
|
* Re-enable signals, in case we got here by longjmp'ing out of a signal
|
|
* handler. We do this fairly early in the sequence so that the timeout
|
|
* infrastructure will be functional if needed while aborting.
|
|
*/
|
|
PG_SETMASK(&UnBlockSig);
|
|
|
|
/*
|
|
* check the current transaction state
|
|
*/
|
|
if (s->state != TRANS_INPROGRESS && s->state != TRANS_PREPARE)
|
|
elog(WARNING, "AbortTransaction while in %s state",
|
|
TransStateAsString(s->state));
|
|
Assert(s->parent == NULL);
|
|
|
|
/*
|
|
* set the current transaction state information appropriately during the
|
|
* abort processing
|
|
*/
|
|
s->state = TRANS_ABORT;
|
|
|
|
/*
|
|
* Reset user ID which might have been changed transiently. We need this
|
|
* to clean up in case control escaped out of a SECURITY DEFINER function
|
|
* or other local change of CurrentUserId; therefore, the prior value of
|
|
* SecurityRestrictionContext also needs to be restored.
|
|
*
|
|
* (Note: it is not necessary to restore session authorization or role
|
|
* settings here because those can only be changed via GUC, and GUC will
|
|
* take care of rolling them back if need be.)
|
|
*/
|
|
SetUserIdAndSecContext(s->prevUser, s->prevSecContext);
|
|
|
|
/*
|
|
* do abort processing
|
|
*/
|
|
AfterTriggerEndXact(false); /* 'false' means it's abort */
|
|
AtAbort_Portals();
|
|
AtEOXact_LargeObject(false);
|
|
AtAbort_Notify();
|
|
AtEOXact_RelationMap(false);
|
|
AtAbort_Twophase();
|
|
|
|
/*
|
|
* Advertise the fact that we aborted in pg_clog (assuming that we got as
|
|
* far as assigning an XID to advertise).
|
|
*/
|
|
latestXid = RecordTransactionAbort(false);
|
|
|
|
TRACE_POSTGRESQL_TRANSACTION_ABORT(MyProc->lxid);
|
|
|
|
/*
|
|
* Let others know about no transaction in progress by me. Note that this
|
|
* must be done _before_ releasing locks we hold and _after_
|
|
* RecordTransactionAbort.
|
|
*/
|
|
ProcArrayEndTransaction(MyProc, latestXid);
|
|
|
|
/*
|
|
* Post-abort cleanup. See notes in CommitTransaction() concerning
|
|
* ordering. We can skip all of it if the transaction failed before
|
|
* creating a resource owner.
|
|
*/
|
|
if (TopTransactionResourceOwner != NULL)
|
|
{
|
|
CallXactCallbacks(XACT_EVENT_ABORT);
|
|
|
|
ResourceOwnerRelease(TopTransactionResourceOwner,
|
|
RESOURCE_RELEASE_BEFORE_LOCKS,
|
|
false, true);
|
|
AtEOXact_Buffers(false);
|
|
AtEOXact_RelationCache(false);
|
|
AtEOXact_Inval(false);
|
|
AtEOXact_MultiXact();
|
|
ResourceOwnerRelease(TopTransactionResourceOwner,
|
|
RESOURCE_RELEASE_LOCKS,
|
|
false, true);
|
|
ResourceOwnerRelease(TopTransactionResourceOwner,
|
|
RESOURCE_RELEASE_AFTER_LOCKS,
|
|
false, true);
|
|
smgrDoPendingDeletes(false);
|
|
AtEOXact_CatCache(false);
|
|
|
|
AtEOXact_GUC(false, 1);
|
|
AtEOXact_SPI(false);
|
|
AtEOXact_on_commit_actions(false);
|
|
AtEOXact_Namespace(false);
|
|
AtEOXact_SMgr();
|
|
AtEOXact_Files();
|
|
AtEOXact_ComboCid();
|
|
AtEOXact_HashTables(false);
|
|
AtEOXact_PgStat(false);
|
|
pgstat_report_xact_timestamp(0);
|
|
}
|
|
|
|
/*
|
|
* State remains TRANS_ABORT until CleanupTransaction().
|
|
*/
|
|
RESUME_INTERRUPTS();
|
|
}
|
|
|
|
/*
|
|
* CleanupTransaction
|
|
*/
|
|
static void
|
|
CleanupTransaction(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
/*
|
|
* State should still be TRANS_ABORT from AbortTransaction().
|
|
*/
|
|
if (s->state != TRANS_ABORT)
|
|
elog(FATAL, "CleanupTransaction: unexpected state %s",
|
|
TransStateAsString(s->state));
|
|
|
|
/*
|
|
* do abort cleanup processing
|
|
*/
|
|
AtCleanup_Portals(); /* now safe to release portal memory */
|
|
AtEOXact_Snapshot(false); /* and release the transaction's snapshots */
|
|
|
|
CurrentResourceOwner = NULL; /* and resource owner */
|
|
if (TopTransactionResourceOwner)
|
|
ResourceOwnerDelete(TopTransactionResourceOwner);
|
|
s->curTransactionOwner = NULL;
|
|
CurTransactionResourceOwner = NULL;
|
|
TopTransactionResourceOwner = NULL;
|
|
|
|
AtCleanup_Memory(); /* and transaction memory */
|
|
|
|
s->transactionId = InvalidTransactionId;
|
|
s->subTransactionId = InvalidSubTransactionId;
|
|
s->nestingLevel = 0;
|
|
s->gucNestLevel = 0;
|
|
s->childXids = NULL;
|
|
s->nChildXids = 0;
|
|
s->maxChildXids = 0;
|
|
|
|
/*
|
|
* done with abort processing, set current transaction state back to
|
|
* default
|
|
*/
|
|
s->state = TRANS_DEFAULT;
|
|
}
|
|
|
|
/*
|
|
* StartTransactionCommand
|
|
*/
|
|
void
|
|
StartTransactionCommand(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
switch (s->blockState)
|
|
{
|
|
/*
|
|
* if we aren't in a transaction block, we just do our usual start
|
|
* transaction.
|
|
*/
|
|
case TBLOCK_DEFAULT:
|
|
StartTransaction();
|
|
s->blockState = TBLOCK_STARTED;
|
|
break;
|
|
|
|
/*
|
|
* We are somewhere in a transaction block or subtransaction and
|
|
* about to start a new command. For now we do nothing, but
|
|
* someday we may do command-local resource initialization. (Note
|
|
* that any needed CommandCounterIncrement was done by the
|
|
* previous CommitTransactionCommand.)
|
|
*/
|
|
case TBLOCK_INPROGRESS:
|
|
case TBLOCK_SUBINPROGRESS:
|
|
break;
|
|
|
|
/*
|
|
* Here we are in a failed transaction block (one of the commands
|
|
* caused an abort) so we do nothing but remain in the abort
|
|
* state. Eventually we will get a ROLLBACK command which will
|
|
* get us out of this state. (It is up to other code to ensure
|
|
* that no commands other than ROLLBACK will be processed in these
|
|
* states.)
|
|
*/
|
|
case TBLOCK_ABORT:
|
|
case TBLOCK_SUBABORT:
|
|
break;
|
|
|
|
/* These cases are invalid. */
|
|
case TBLOCK_STARTED:
|
|
case TBLOCK_BEGIN:
|
|
case TBLOCK_SUBBEGIN:
|
|
case TBLOCK_END:
|
|
case TBLOCK_SUBRELEASE:
|
|
case TBLOCK_SUBCOMMIT:
|
|
case TBLOCK_ABORT_END:
|
|
case TBLOCK_SUBABORT_END:
|
|
case TBLOCK_ABORT_PENDING:
|
|
case TBLOCK_SUBABORT_PENDING:
|
|
case TBLOCK_SUBRESTART:
|
|
case TBLOCK_SUBABORT_RESTART:
|
|
case TBLOCK_PREPARE:
|
|
elog(ERROR, "StartTransactionCommand: unexpected state %s",
|
|
BlockStateAsString(s->blockState));
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* We must switch to CurTransactionContext before returning. This is
|
|
* already done if we called StartTransaction, otherwise not.
|
|
*/
|
|
Assert(CurTransactionContext != NULL);
|
|
MemoryContextSwitchTo(CurTransactionContext);
|
|
}
|
|
|
|
/*
|
|
* CommitTransactionCommand
|
|
*/
|
|
void
|
|
CommitTransactionCommand(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
switch (s->blockState)
|
|
{
|
|
/*
|
|
* This shouldn't happen, because it means the previous
|
|
* StartTransactionCommand didn't set the STARTED state
|
|
* appropriately.
|
|
*/
|
|
case TBLOCK_DEFAULT:
|
|
elog(FATAL, "CommitTransactionCommand: unexpected state %s",
|
|
BlockStateAsString(s->blockState));
|
|
break;
|
|
|
|
/*
|
|
* If we aren't in a transaction block, just do our usual
|
|
* transaction commit, and return to the idle state.
|
|
*/
|
|
case TBLOCK_STARTED:
|
|
CommitTransaction();
|
|
s->blockState = TBLOCK_DEFAULT;
|
|
break;
|
|
|
|
/*
|
|
* We are completing a "BEGIN TRANSACTION" command, so we change
|
|
* to the "transaction block in progress" state and return. (We
|
|
* assume the BEGIN did nothing to the database, so we need no
|
|
* CommandCounterIncrement.)
|
|
*/
|
|
case TBLOCK_BEGIN:
|
|
s->blockState = TBLOCK_INPROGRESS;
|
|
break;
|
|
|
|
/*
|
|
* This is the case when we have finished executing a command
|
|
* someplace within a transaction block. We increment the command
|
|
* counter and return.
|
|
*/
|
|
case TBLOCK_INPROGRESS:
|
|
case TBLOCK_SUBINPROGRESS:
|
|
CommandCounterIncrement();
|
|
break;
|
|
|
|
/*
|
|
* We are completing a "COMMIT" command. Do it and return to the
|
|
* idle state.
|
|
*/
|
|
case TBLOCK_END:
|
|
CommitTransaction();
|
|
s->blockState = TBLOCK_DEFAULT;
|
|
break;
|
|
|
|
/*
|
|
* Here we are in the middle of a transaction block but one of the
|
|
* commands caused an abort so we do nothing but remain in the
|
|
* abort state. Eventually we will get a ROLLBACK comand.
|
|
*/
|
|
case TBLOCK_ABORT:
|
|
case TBLOCK_SUBABORT:
|
|
break;
|
|
|
|
/*
|
|
* Here we were in an aborted transaction block and we just got
|
|
* the ROLLBACK command from the user, so clean up the
|
|
* already-aborted transaction and return to the idle state.
|
|
*/
|
|
case TBLOCK_ABORT_END:
|
|
CleanupTransaction();
|
|
s->blockState = TBLOCK_DEFAULT;
|
|
break;
|
|
|
|
/*
|
|
* Here we were in a perfectly good transaction block but the user
|
|
* told us to ROLLBACK anyway. We have to abort the transaction
|
|
* and then clean up.
|
|
*/
|
|
case TBLOCK_ABORT_PENDING:
|
|
AbortTransaction();
|
|
CleanupTransaction();
|
|
s->blockState = TBLOCK_DEFAULT;
|
|
break;
|
|
|
|
/*
|
|
* We are completing a "PREPARE TRANSACTION" command. Do it and
|
|
* return to the idle state.
|
|
*/
|
|
case TBLOCK_PREPARE:
|
|
PrepareTransaction();
|
|
s->blockState = TBLOCK_DEFAULT;
|
|
break;
|
|
|
|
/*
|
|
* We were just issued a SAVEPOINT inside a transaction block.
|
|
* Start a subtransaction. (DefineSavepoint already did
|
|
* PushTransaction, so as to have someplace to put the SUBBEGIN
|
|
* state.)
|
|
*/
|
|
case TBLOCK_SUBBEGIN:
|
|
StartSubTransaction();
|
|
s->blockState = TBLOCK_SUBINPROGRESS;
|
|
break;
|
|
|
|
/*
|
|
* We were issued a RELEASE command, so we end the current
|
|
* subtransaction and return to the parent transaction. The parent
|
|
* might be ended too, so repeat till we find an INPROGRESS
|
|
* transaction or subtransaction.
|
|
*/
|
|
case TBLOCK_SUBRELEASE:
|
|
do
|
|
{
|
|
CommitSubTransaction();
|
|
s = CurrentTransactionState; /* changed by pop */
|
|
} while (s->blockState == TBLOCK_SUBRELEASE);
|
|
|
|
Assert(s->blockState == TBLOCK_INPROGRESS ||
|
|
s->blockState == TBLOCK_SUBINPROGRESS);
|
|
break;
|
|
|
|
/*
|
|
* We were issued a COMMIT, so we end the current subtransaction
|
|
* hierarchy and perform final commit. We do this by rolling up
|
|
* any subtransactions into their parent, which leads to O(N^2)
|
|
* operations with respect to resource owners - this isn't that
|
|
* bad until we approach a thousands of savepoints but is
|
|
* necessary for correctness should after triggers create new
|
|
* resource owners.
|
|
*/
|
|
case TBLOCK_SUBCOMMIT:
|
|
do
|
|
{
|
|
CommitSubTransaction();
|
|
s = CurrentTransactionState; /* changed by pop */
|
|
} while (s->blockState == TBLOCK_SUBCOMMIT);
|
|
/* If we had a COMMIT command, finish off the main xact too */
|
|
if (s->blockState == TBLOCK_END)
|
|
{
|
|
Assert(s->parent == NULL);
|
|
CommitTransaction();
|
|
s->blockState = TBLOCK_DEFAULT;
|
|
}
|
|
else if (s->blockState == TBLOCK_PREPARE)
|
|
{
|
|
Assert(s->parent == NULL);
|
|
PrepareTransaction();
|
|
s->blockState = TBLOCK_DEFAULT;
|
|
}
|
|
else
|
|
elog(ERROR, "CommitTransactionCommand: unexpected state %s",
|
|
BlockStateAsString(s->blockState));
|
|
break;
|
|
|
|
/*
|
|
* The current already-failed subtransaction is ending due to a
|
|
* ROLLBACK or ROLLBACK TO command, so pop it and recursively
|
|
* examine the parent (which could be in any of several states).
|
|
*/
|
|
case TBLOCK_SUBABORT_END:
|
|
CleanupSubTransaction();
|
|
CommitTransactionCommand();
|
|
break;
|
|
|
|
/*
|
|
* As above, but it's not dead yet, so abort first.
|
|
*/
|
|
case TBLOCK_SUBABORT_PENDING:
|
|
AbortSubTransaction();
|
|
CleanupSubTransaction();
|
|
CommitTransactionCommand();
|
|
break;
|
|
|
|
/*
|
|
* The current subtransaction is the target of a ROLLBACK TO
|
|
* command. Abort and pop it, then start a new subtransaction
|
|
* with the same name.
|
|
*/
|
|
case TBLOCK_SUBRESTART:
|
|
{
|
|
char *name;
|
|
int savepointLevel;
|
|
|
|
/* save name and keep Cleanup from freeing it */
|
|
name = s->name;
|
|
s->name = NULL;
|
|
savepointLevel = s->savepointLevel;
|
|
|
|
AbortSubTransaction();
|
|
CleanupSubTransaction();
|
|
|
|
DefineSavepoint(NULL);
|
|
s = CurrentTransactionState; /* changed by push */
|
|
s->name = name;
|
|
s->savepointLevel = savepointLevel;
|
|
|
|
/* This is the same as TBLOCK_SUBBEGIN case */
|
|
AssertState(s->blockState == TBLOCK_SUBBEGIN);
|
|
StartSubTransaction();
|
|
s->blockState = TBLOCK_SUBINPROGRESS;
|
|
}
|
|
break;
|
|
|
|
/*
|
|
* Same as above, but the subtransaction had already failed, so we
|
|
* don't need AbortSubTransaction.
|
|
*/
|
|
case TBLOCK_SUBABORT_RESTART:
|
|
{
|
|
char *name;
|
|
int savepointLevel;
|
|
|
|
/* save name and keep Cleanup from freeing it */
|
|
name = s->name;
|
|
s->name = NULL;
|
|
savepointLevel = s->savepointLevel;
|
|
|
|
CleanupSubTransaction();
|
|
|
|
DefineSavepoint(NULL);
|
|
s = CurrentTransactionState; /* changed by push */
|
|
s->name = name;
|
|
s->savepointLevel = savepointLevel;
|
|
|
|
/* This is the same as TBLOCK_SUBBEGIN case */
|
|
AssertState(s->blockState == TBLOCK_SUBBEGIN);
|
|
StartSubTransaction();
|
|
s->blockState = TBLOCK_SUBINPROGRESS;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* AbortCurrentTransaction
|
|
*/
|
|
void
|
|
AbortCurrentTransaction(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
switch (s->blockState)
|
|
{
|
|
case TBLOCK_DEFAULT:
|
|
if (s->state == TRANS_DEFAULT)
|
|
{
|
|
/* we are idle, so nothing to do */
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* We can get here after an error during transaction start
|
|
* (state will be TRANS_START). Need to clean up the
|
|
* incompletely started transaction. First, adjust the
|
|
* low-level state to suppress warning message from
|
|
* AbortTransaction.
|
|
*/
|
|
if (s->state == TRANS_START)
|
|
s->state = TRANS_INPROGRESS;
|
|
AbortTransaction();
|
|
CleanupTransaction();
|
|
}
|
|
break;
|
|
|
|
/*
|
|
* if we aren't in a transaction block, we just do the basic abort
|
|
* & cleanup transaction.
|
|
*/
|
|
case TBLOCK_STARTED:
|
|
AbortTransaction();
|
|
CleanupTransaction();
|
|
s->blockState = TBLOCK_DEFAULT;
|
|
break;
|
|
|
|
/*
|
|
* If we are in TBLOCK_BEGIN it means something screwed up right
|
|
* after reading "BEGIN TRANSACTION". We assume that the user
|
|
* will interpret the error as meaning the BEGIN failed to get him
|
|
* into a transaction block, so we should abort and return to idle
|
|
* state.
|
|
*/
|
|
case TBLOCK_BEGIN:
|
|
AbortTransaction();
|
|
CleanupTransaction();
|
|
s->blockState = TBLOCK_DEFAULT;
|
|
break;
|
|
|
|
/*
|
|
* We are somewhere in a transaction block and we've gotten a
|
|
* failure, so we abort the transaction and set up the persistent
|
|
* ABORT state. We will stay in ABORT until we get a ROLLBACK.
|
|
*/
|
|
case TBLOCK_INPROGRESS:
|
|
AbortTransaction();
|
|
s->blockState = TBLOCK_ABORT;
|
|
/* CleanupTransaction happens when we exit TBLOCK_ABORT_END */
|
|
break;
|
|
|
|
/*
|
|
* Here, we failed while trying to COMMIT. Clean up the
|
|
* transaction and return to idle state (we do not want to stay in
|
|
* the transaction).
|
|
*/
|
|
case TBLOCK_END:
|
|
AbortTransaction();
|
|
CleanupTransaction();
|
|
s->blockState = TBLOCK_DEFAULT;
|
|
break;
|
|
|
|
/*
|
|
* Here, we are already in an aborted transaction state and are
|
|
* waiting for a ROLLBACK, but for some reason we failed again! So
|
|
* we just remain in the abort state.
|
|
*/
|
|
case TBLOCK_ABORT:
|
|
case TBLOCK_SUBABORT:
|
|
break;
|
|
|
|
/*
|
|
* We are in a failed transaction and we got the ROLLBACK command.
|
|
* We have already aborted, we just need to cleanup and go to idle
|
|
* state.
|
|
*/
|
|
case TBLOCK_ABORT_END:
|
|
CleanupTransaction();
|
|
s->blockState = TBLOCK_DEFAULT;
|
|
break;
|
|
|
|
/*
|
|
* We are in a live transaction and we got a ROLLBACK command.
|
|
* Abort, cleanup, go to idle state.
|
|
*/
|
|
case TBLOCK_ABORT_PENDING:
|
|
AbortTransaction();
|
|
CleanupTransaction();
|
|
s->blockState = TBLOCK_DEFAULT;
|
|
break;
|
|
|
|
/*
|
|
* Here, we failed while trying to PREPARE. Clean up the
|
|
* transaction and return to idle state (we do not want to stay in
|
|
* the transaction).
|
|
*/
|
|
case TBLOCK_PREPARE:
|
|
AbortTransaction();
|
|
CleanupTransaction();
|
|
s->blockState = TBLOCK_DEFAULT;
|
|
break;
|
|
|
|
/*
|
|
* We got an error inside a subtransaction. Abort just the
|
|
* subtransaction, and go to the persistent SUBABORT state until
|
|
* we get ROLLBACK.
|
|
*/
|
|
case TBLOCK_SUBINPROGRESS:
|
|
AbortSubTransaction();
|
|
s->blockState = TBLOCK_SUBABORT;
|
|
break;
|
|
|
|
/*
|
|
* If we failed while trying to create a subtransaction, clean up
|
|
* the broken subtransaction and abort the parent. The same
|
|
* applies if we get a failure while ending a subtransaction.
|
|
*/
|
|
case TBLOCK_SUBBEGIN:
|
|
case TBLOCK_SUBRELEASE:
|
|
case TBLOCK_SUBCOMMIT:
|
|
case TBLOCK_SUBABORT_PENDING:
|
|
case TBLOCK_SUBRESTART:
|
|
AbortSubTransaction();
|
|
CleanupSubTransaction();
|
|
AbortCurrentTransaction();
|
|
break;
|
|
|
|
/*
|
|
* Same as above, except the Abort() was already done.
|
|
*/
|
|
case TBLOCK_SUBABORT_END:
|
|
case TBLOCK_SUBABORT_RESTART:
|
|
CleanupSubTransaction();
|
|
AbortCurrentTransaction();
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* PreventTransactionChain
|
|
*
|
|
* This routine is to be called by statements that must not run inside
|
|
* a transaction block, typically because they have non-rollback-able
|
|
* side effects or do internal commits.
|
|
*
|
|
* If we have already started a transaction block, issue an error; also issue
|
|
* an error if we appear to be running inside a user-defined function (which
|
|
* could issue more commands and possibly cause a failure after the statement
|
|
* completes). Subtransactions are verboten too.
|
|
*
|
|
* isTopLevel: passed down from ProcessUtility to determine whether we are
|
|
* inside a function or multi-query querystring. (We will always fail if
|
|
* this is false, but it's convenient to centralize the check here instead of
|
|
* making callers do it.)
|
|
* stmtType: statement type name, for error messages.
|
|
*/
|
|
void
|
|
PreventTransactionChain(bool isTopLevel, const char *stmtType)
|
|
{
|
|
/*
|
|
* xact block already started?
|
|
*/
|
|
if (IsTransactionBlock())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_ACTIVE_SQL_TRANSACTION),
|
|
/* translator: %s represents an SQL statement name */
|
|
errmsg("%s cannot run inside a transaction block",
|
|
stmtType)));
|
|
|
|
/*
|
|
* subtransaction?
|
|
*/
|
|
if (IsSubTransaction())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_ACTIVE_SQL_TRANSACTION),
|
|
/* translator: %s represents an SQL statement name */
|
|
errmsg("%s cannot run inside a subtransaction",
|
|
stmtType)));
|
|
|
|
/*
|
|
* inside a function call?
|
|
*/
|
|
if (!isTopLevel)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_ACTIVE_SQL_TRANSACTION),
|
|
/* translator: %s represents an SQL statement name */
|
|
errmsg("%s cannot be executed from a function or multi-command string",
|
|
stmtType)));
|
|
|
|
/* If we got past IsTransactionBlock test, should be in default state */
|
|
if (CurrentTransactionState->blockState != TBLOCK_DEFAULT &&
|
|
CurrentTransactionState->blockState != TBLOCK_STARTED)
|
|
elog(FATAL, "cannot prevent transaction chain");
|
|
/* all okay */
|
|
}
|
|
|
|
/*
|
|
* These two functions allow for warnings or errors if a command is
|
|
* executed outside of a transaction block.
|
|
*
|
|
* While top-level transaction control commands (BEGIN/COMMIT/ABORT) and
|
|
* SET that have no effect issue warnings, all other no-effect commands
|
|
* generate errors.
|
|
*/
|
|
void
|
|
WarnNoTransactionChain(bool isTopLevel, const char *stmtType)
|
|
{
|
|
CheckTransactionChain(isTopLevel, false, stmtType);
|
|
}
|
|
|
|
void
|
|
RequireTransactionChain(bool isTopLevel, const char *stmtType)
|
|
{
|
|
CheckTransactionChain(isTopLevel, true, stmtType);
|
|
}
|
|
|
|
/*
|
|
* RequireTransactionChain
|
|
*
|
|
* This routine is to be called by statements that must run inside
|
|
* a transaction block, because they have no effects that persist past
|
|
* transaction end (and so calling them outside a transaction block
|
|
* is presumably an error). DECLARE CURSOR is an example.
|
|
*
|
|
* If we appear to be running inside a user-defined function, we do not
|
|
* issue anything, since the function could issue more commands that make
|
|
* use of the current statement's results. Likewise subtransactions.
|
|
* Thus this is an inverse for PreventTransactionChain.
|
|
*
|
|
* isTopLevel: passed down from ProcessUtility to determine whether we are
|
|
* inside a function.
|
|
* stmtType: statement type name, for warning or error messages.
|
|
*/
|
|
static void
|
|
CheckTransactionChain(bool isTopLevel, bool throwError, const char *stmtType)
|
|
{
|
|
/*
|
|
* xact block already started?
|
|
*/
|
|
if (IsTransactionBlock())
|
|
return;
|
|
|
|
/*
|
|
* subtransaction?
|
|
*/
|
|
if (IsSubTransaction())
|
|
return;
|
|
|
|
/*
|
|
* inside a function call?
|
|
*/
|
|
if (!isTopLevel)
|
|
return;
|
|
|
|
ereport(throwError ? ERROR : WARNING,
|
|
(errcode(ERRCODE_NO_ACTIVE_SQL_TRANSACTION),
|
|
/* translator: %s represents an SQL statement name */
|
|
errmsg("%s can only be used in transaction blocks",
|
|
stmtType)));
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* IsInTransactionChain
|
|
*
|
|
* This routine is for statements that need to behave differently inside
|
|
* a transaction block than when running as single commands. ANALYZE is
|
|
* currently the only example.
|
|
*
|
|
* isTopLevel: passed down from ProcessUtility to determine whether we are
|
|
* inside a function.
|
|
*/
|
|
bool
|
|
IsInTransactionChain(bool isTopLevel)
|
|
{
|
|
/*
|
|
* Return true on same conditions that would make PreventTransactionChain
|
|
* error out
|
|
*/
|
|
if (IsTransactionBlock())
|
|
return true;
|
|
|
|
if (IsSubTransaction())
|
|
return true;
|
|
|
|
if (!isTopLevel)
|
|
return true;
|
|
|
|
if (CurrentTransactionState->blockState != TBLOCK_DEFAULT &&
|
|
CurrentTransactionState->blockState != TBLOCK_STARTED)
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
|
|
/*
|
|
* Register or deregister callback functions for start- and end-of-xact
|
|
* operations.
|
|
*
|
|
* These functions are intended for use by dynamically loaded modules.
|
|
* For built-in modules we generally just hardwire the appropriate calls
|
|
* (mainly because it's easier to control the order that way, where needed).
|
|
*
|
|
* At transaction end, the callback occurs post-commit or post-abort, so the
|
|
* callback functions can only do noncritical cleanup.
|
|
*/
|
|
void
|
|
RegisterXactCallback(XactCallback callback, void *arg)
|
|
{
|
|
XactCallbackItem *item;
|
|
|
|
item = (XactCallbackItem *)
|
|
MemoryContextAlloc(TopMemoryContext, sizeof(XactCallbackItem));
|
|
item->callback = callback;
|
|
item->arg = arg;
|
|
item->next = Xact_callbacks;
|
|
Xact_callbacks = item;
|
|
}
|
|
|
|
void
|
|
UnregisterXactCallback(XactCallback callback, void *arg)
|
|
{
|
|
XactCallbackItem *item;
|
|
XactCallbackItem *prev;
|
|
|
|
prev = NULL;
|
|
for (item = Xact_callbacks; item; prev = item, item = item->next)
|
|
{
|
|
if (item->callback == callback && item->arg == arg)
|
|
{
|
|
if (prev)
|
|
prev->next = item->next;
|
|
else
|
|
Xact_callbacks = item->next;
|
|
pfree(item);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
CallXactCallbacks(XactEvent event)
|
|
{
|
|
XactCallbackItem *item;
|
|
|
|
for (item = Xact_callbacks; item; item = item->next)
|
|
(*item->callback) (event, item->arg);
|
|
}
|
|
|
|
|
|
/*
|
|
* Register or deregister callback functions for start- and end-of-subxact
|
|
* operations.
|
|
*
|
|
* Pretty much same as above, but for subtransaction events.
|
|
*
|
|
* At subtransaction end, the callback occurs post-subcommit or post-subabort,
|
|
* so the callback functions can only do noncritical cleanup. At
|
|
* subtransaction start, the callback is called when the subtransaction has
|
|
* finished initializing.
|
|
*/
|
|
void
|
|
RegisterSubXactCallback(SubXactCallback callback, void *arg)
|
|
{
|
|
SubXactCallbackItem *item;
|
|
|
|
item = (SubXactCallbackItem *)
|
|
MemoryContextAlloc(TopMemoryContext, sizeof(SubXactCallbackItem));
|
|
item->callback = callback;
|
|
item->arg = arg;
|
|
item->next = SubXact_callbacks;
|
|
SubXact_callbacks = item;
|
|
}
|
|
|
|
void
|
|
UnregisterSubXactCallback(SubXactCallback callback, void *arg)
|
|
{
|
|
SubXactCallbackItem *item;
|
|
SubXactCallbackItem *prev;
|
|
|
|
prev = NULL;
|
|
for (item = SubXact_callbacks; item; prev = item, item = item->next)
|
|
{
|
|
if (item->callback == callback && item->arg == arg)
|
|
{
|
|
if (prev)
|
|
prev->next = item->next;
|
|
else
|
|
SubXact_callbacks = item->next;
|
|
pfree(item);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
CallSubXactCallbacks(SubXactEvent event,
|
|
SubTransactionId mySubid,
|
|
SubTransactionId parentSubid)
|
|
{
|
|
SubXactCallbackItem *item;
|
|
|
|
for (item = SubXact_callbacks; item; item = item->next)
|
|
(*item->callback) (event, mySubid, parentSubid, item->arg);
|
|
}
|
|
|
|
|
|
/* ----------------------------------------------------------------
|
|
* transaction block support
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
|
|
/*
|
|
* BeginTransactionBlock
|
|
* This executes a BEGIN command.
|
|
*/
|
|
void
|
|
BeginTransactionBlock(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
switch (s->blockState)
|
|
{
|
|
/*
|
|
* We are not inside a transaction block, so allow one to begin.
|
|
*/
|
|
case TBLOCK_STARTED:
|
|
s->blockState = TBLOCK_BEGIN;
|
|
break;
|
|
|
|
/*
|
|
* Already a transaction block in progress.
|
|
*/
|
|
case TBLOCK_INPROGRESS:
|
|
case TBLOCK_SUBINPROGRESS:
|
|
case TBLOCK_ABORT:
|
|
case TBLOCK_SUBABORT:
|
|
ereport(WARNING,
|
|
(errcode(ERRCODE_ACTIVE_SQL_TRANSACTION),
|
|
errmsg("there is already a transaction in progress")));
|
|
break;
|
|
|
|
/* These cases are invalid. */
|
|
case TBLOCK_DEFAULT:
|
|
case TBLOCK_BEGIN:
|
|
case TBLOCK_SUBBEGIN:
|
|
case TBLOCK_END:
|
|
case TBLOCK_SUBRELEASE:
|
|
case TBLOCK_SUBCOMMIT:
|
|
case TBLOCK_ABORT_END:
|
|
case TBLOCK_SUBABORT_END:
|
|
case TBLOCK_ABORT_PENDING:
|
|
case TBLOCK_SUBABORT_PENDING:
|
|
case TBLOCK_SUBRESTART:
|
|
case TBLOCK_SUBABORT_RESTART:
|
|
case TBLOCK_PREPARE:
|
|
elog(FATAL, "BeginTransactionBlock: unexpected state %s",
|
|
BlockStateAsString(s->blockState));
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* PrepareTransactionBlock
|
|
* This executes a PREPARE command.
|
|
*
|
|
* Since PREPARE may actually do a ROLLBACK, the result indicates what
|
|
* happened: TRUE for PREPARE, FALSE for ROLLBACK.
|
|
*
|
|
* Note that we don't actually do anything here except change blockState.
|
|
* The real work will be done in the upcoming PrepareTransaction().
|
|
* We do it this way because it's not convenient to change memory context,
|
|
* resource owner, etc while executing inside a Portal.
|
|
*/
|
|
bool
|
|
PrepareTransactionBlock(char *gid)
|
|
{
|
|
TransactionState s;
|
|
bool result;
|
|
|
|
/* Set up to commit the current transaction */
|
|
result = EndTransactionBlock();
|
|
|
|
/* If successful, change outer tblock state to PREPARE */
|
|
if (result)
|
|
{
|
|
s = CurrentTransactionState;
|
|
|
|
while (s->parent != NULL)
|
|
s = s->parent;
|
|
|
|
if (s->blockState == TBLOCK_END)
|
|
{
|
|
/* Save GID where PrepareTransaction can find it again */
|
|
prepareGID = MemoryContextStrdup(TopTransactionContext, gid);
|
|
|
|
s->blockState = TBLOCK_PREPARE;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* ignore case where we are not in a transaction;
|
|
* EndTransactionBlock already issued a warning.
|
|
*/
|
|
Assert(s->blockState == TBLOCK_STARTED);
|
|
/* Don't send back a PREPARE result tag... */
|
|
result = false;
|
|
}
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* EndTransactionBlock
|
|
* This executes a COMMIT command.
|
|
*
|
|
* Since COMMIT may actually do a ROLLBACK, the result indicates what
|
|
* happened: TRUE for COMMIT, FALSE for ROLLBACK.
|
|
*
|
|
* Note that we don't actually do anything here except change blockState.
|
|
* The real work will be done in the upcoming CommitTransactionCommand().
|
|
* We do it this way because it's not convenient to change memory context,
|
|
* resource owner, etc while executing inside a Portal.
|
|
*/
|
|
bool
|
|
EndTransactionBlock(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
bool result = false;
|
|
|
|
switch (s->blockState)
|
|
{
|
|
/*
|
|
* We are in a transaction block, so tell CommitTransactionCommand
|
|
* to COMMIT.
|
|
*/
|
|
case TBLOCK_INPROGRESS:
|
|
s->blockState = TBLOCK_END;
|
|
result = true;
|
|
break;
|
|
|
|
/*
|
|
* We are in a failed transaction block. Tell
|
|
* CommitTransactionCommand it's time to exit the block.
|
|
*/
|
|
case TBLOCK_ABORT:
|
|
s->blockState = TBLOCK_ABORT_END;
|
|
break;
|
|
|
|
/*
|
|
* We are in a live subtransaction block. Set up to subcommit all
|
|
* open subtransactions and then commit the main transaction.
|
|
*/
|
|
case TBLOCK_SUBINPROGRESS:
|
|
while (s->parent != NULL)
|
|
{
|
|
if (s->blockState == TBLOCK_SUBINPROGRESS)
|
|
s->blockState = TBLOCK_SUBCOMMIT;
|
|
else
|
|
elog(FATAL, "EndTransactionBlock: unexpected state %s",
|
|
BlockStateAsString(s->blockState));
|
|
s = s->parent;
|
|
}
|
|
if (s->blockState == TBLOCK_INPROGRESS)
|
|
s->blockState = TBLOCK_END;
|
|
else
|
|
elog(FATAL, "EndTransactionBlock: unexpected state %s",
|
|
BlockStateAsString(s->blockState));
|
|
result = true;
|
|
break;
|
|
|
|
/*
|
|
* Here we are inside an aborted subtransaction. Treat the COMMIT
|
|
* as ROLLBACK: set up to abort everything and exit the main
|
|
* transaction.
|
|
*/
|
|
case TBLOCK_SUBABORT:
|
|
while (s->parent != NULL)
|
|
{
|
|
if (s->blockState == TBLOCK_SUBINPROGRESS)
|
|
s->blockState = TBLOCK_SUBABORT_PENDING;
|
|
else if (s->blockState == TBLOCK_SUBABORT)
|
|
s->blockState = TBLOCK_SUBABORT_END;
|
|
else
|
|
elog(FATAL, "EndTransactionBlock: unexpected state %s",
|
|
BlockStateAsString(s->blockState));
|
|
s = s->parent;
|
|
}
|
|
if (s->blockState == TBLOCK_INPROGRESS)
|
|
s->blockState = TBLOCK_ABORT_PENDING;
|
|
else if (s->blockState == TBLOCK_ABORT)
|
|
s->blockState = TBLOCK_ABORT_END;
|
|
else
|
|
elog(FATAL, "EndTransactionBlock: unexpected state %s",
|
|
BlockStateAsString(s->blockState));
|
|
break;
|
|
|
|
/*
|
|
* The user issued COMMIT when not inside a transaction. Issue a
|
|
* WARNING, staying in TBLOCK_STARTED state. The upcoming call to
|
|
* CommitTransactionCommand() will then close the transaction and
|
|
* put us back into the default state.
|
|
*/
|
|
case TBLOCK_STARTED:
|
|
ereport(WARNING,
|
|
(errcode(ERRCODE_NO_ACTIVE_SQL_TRANSACTION),
|
|
errmsg("there is no transaction in progress")));
|
|
result = true;
|
|
break;
|
|
|
|
/* These cases are invalid. */
|
|
case TBLOCK_DEFAULT:
|
|
case TBLOCK_BEGIN:
|
|
case TBLOCK_SUBBEGIN:
|
|
case TBLOCK_END:
|
|
case TBLOCK_SUBRELEASE:
|
|
case TBLOCK_SUBCOMMIT:
|
|
case TBLOCK_ABORT_END:
|
|
case TBLOCK_SUBABORT_END:
|
|
case TBLOCK_ABORT_PENDING:
|
|
case TBLOCK_SUBABORT_PENDING:
|
|
case TBLOCK_SUBRESTART:
|
|
case TBLOCK_SUBABORT_RESTART:
|
|
case TBLOCK_PREPARE:
|
|
elog(FATAL, "EndTransactionBlock: unexpected state %s",
|
|
BlockStateAsString(s->blockState));
|
|
break;
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* UserAbortTransactionBlock
|
|
* This executes a ROLLBACK command.
|
|
*
|
|
* As above, we don't actually do anything here except change blockState.
|
|
*/
|
|
void
|
|
UserAbortTransactionBlock(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
switch (s->blockState)
|
|
{
|
|
/*
|
|
* We are inside a transaction block and we got a ROLLBACK command
|
|
* from the user, so tell CommitTransactionCommand to abort and
|
|
* exit the transaction block.
|
|
*/
|
|
case TBLOCK_INPROGRESS:
|
|
s->blockState = TBLOCK_ABORT_PENDING;
|
|
break;
|
|
|
|
/*
|
|
* We are inside a failed transaction block and we got a ROLLBACK
|
|
* command from the user. Abort processing is already done, so
|
|
* CommitTransactionCommand just has to cleanup and go back to
|
|
* idle state.
|
|
*/
|
|
case TBLOCK_ABORT:
|
|
s->blockState = TBLOCK_ABORT_END;
|
|
break;
|
|
|
|
/*
|
|
* We are inside a subtransaction. Mark everything up to top
|
|
* level as exitable.
|
|
*/
|
|
case TBLOCK_SUBINPROGRESS:
|
|
case TBLOCK_SUBABORT:
|
|
while (s->parent != NULL)
|
|
{
|
|
if (s->blockState == TBLOCK_SUBINPROGRESS)
|
|
s->blockState = TBLOCK_SUBABORT_PENDING;
|
|
else if (s->blockState == TBLOCK_SUBABORT)
|
|
s->blockState = TBLOCK_SUBABORT_END;
|
|
else
|
|
elog(FATAL, "UserAbortTransactionBlock: unexpected state %s",
|
|
BlockStateAsString(s->blockState));
|
|
s = s->parent;
|
|
}
|
|
if (s->blockState == TBLOCK_INPROGRESS)
|
|
s->blockState = TBLOCK_ABORT_PENDING;
|
|
else if (s->blockState == TBLOCK_ABORT)
|
|
s->blockState = TBLOCK_ABORT_END;
|
|
else
|
|
elog(FATAL, "UserAbortTransactionBlock: unexpected state %s",
|
|
BlockStateAsString(s->blockState));
|
|
break;
|
|
|
|
/*
|
|
* The user issued ABORT when not inside a transaction. Issue a
|
|
* WARNING and go to abort state. The upcoming call to
|
|
* CommitTransactionCommand() will then put us back into the
|
|
* default state.
|
|
*/
|
|
case TBLOCK_STARTED:
|
|
ereport(WARNING,
|
|
(errcode(ERRCODE_NO_ACTIVE_SQL_TRANSACTION),
|
|
errmsg("there is no transaction in progress")));
|
|
s->blockState = TBLOCK_ABORT_PENDING;
|
|
break;
|
|
|
|
/* These cases are invalid. */
|
|
case TBLOCK_DEFAULT:
|
|
case TBLOCK_BEGIN:
|
|
case TBLOCK_SUBBEGIN:
|
|
case TBLOCK_END:
|
|
case TBLOCK_SUBRELEASE:
|
|
case TBLOCK_SUBCOMMIT:
|
|
case TBLOCK_ABORT_END:
|
|
case TBLOCK_SUBABORT_END:
|
|
case TBLOCK_ABORT_PENDING:
|
|
case TBLOCK_SUBABORT_PENDING:
|
|
case TBLOCK_SUBRESTART:
|
|
case TBLOCK_SUBABORT_RESTART:
|
|
case TBLOCK_PREPARE:
|
|
elog(FATAL, "UserAbortTransactionBlock: unexpected state %s",
|
|
BlockStateAsString(s->blockState));
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* DefineSavepoint
|
|
* This executes a SAVEPOINT command.
|
|
*/
|
|
void
|
|
DefineSavepoint(char *name)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
switch (s->blockState)
|
|
{
|
|
case TBLOCK_INPROGRESS:
|
|
case TBLOCK_SUBINPROGRESS:
|
|
/* Normal subtransaction start */
|
|
PushTransaction();
|
|
s = CurrentTransactionState; /* changed by push */
|
|
|
|
/*
|
|
* Savepoint names, like the TransactionState block itself, live
|
|
* in TopTransactionContext.
|
|
*/
|
|
if (name)
|
|
s->name = MemoryContextStrdup(TopTransactionContext, name);
|
|
break;
|
|
|
|
/* These cases are invalid. */
|
|
case TBLOCK_DEFAULT:
|
|
case TBLOCK_STARTED:
|
|
case TBLOCK_BEGIN:
|
|
case TBLOCK_SUBBEGIN:
|
|
case TBLOCK_END:
|
|
case TBLOCK_SUBRELEASE:
|
|
case TBLOCK_SUBCOMMIT:
|
|
case TBLOCK_ABORT:
|
|
case TBLOCK_SUBABORT:
|
|
case TBLOCK_ABORT_END:
|
|
case TBLOCK_SUBABORT_END:
|
|
case TBLOCK_ABORT_PENDING:
|
|
case TBLOCK_SUBABORT_PENDING:
|
|
case TBLOCK_SUBRESTART:
|
|
case TBLOCK_SUBABORT_RESTART:
|
|
case TBLOCK_PREPARE:
|
|
elog(FATAL, "DefineSavepoint: unexpected state %s",
|
|
BlockStateAsString(s->blockState));
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* ReleaseSavepoint
|
|
* This executes a RELEASE command.
|
|
*
|
|
* As above, we don't actually do anything here except change blockState.
|
|
*/
|
|
void
|
|
ReleaseSavepoint(List *options)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
TransactionState target,
|
|
xact;
|
|
ListCell *cell;
|
|
char *name = NULL;
|
|
|
|
switch (s->blockState)
|
|
{
|
|
/*
|
|
* We can't rollback to a savepoint if there is no savepoint
|
|
* defined.
|
|
*/
|
|
case TBLOCK_INPROGRESS:
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_S_E_INVALID_SPECIFICATION),
|
|
errmsg("no such savepoint")));
|
|
break;
|
|
|
|
/*
|
|
* We are in a non-aborted subtransaction. This is the only valid
|
|
* case.
|
|
*/
|
|
case TBLOCK_SUBINPROGRESS:
|
|
break;
|
|
|
|
/* These cases are invalid. */
|
|
case TBLOCK_DEFAULT:
|
|
case TBLOCK_STARTED:
|
|
case TBLOCK_BEGIN:
|
|
case TBLOCK_SUBBEGIN:
|
|
case TBLOCK_END:
|
|
case TBLOCK_SUBRELEASE:
|
|
case TBLOCK_SUBCOMMIT:
|
|
case TBLOCK_ABORT:
|
|
case TBLOCK_SUBABORT:
|
|
case TBLOCK_ABORT_END:
|
|
case TBLOCK_SUBABORT_END:
|
|
case TBLOCK_ABORT_PENDING:
|
|
case TBLOCK_SUBABORT_PENDING:
|
|
case TBLOCK_SUBRESTART:
|
|
case TBLOCK_SUBABORT_RESTART:
|
|
case TBLOCK_PREPARE:
|
|
elog(FATAL, "ReleaseSavepoint: unexpected state %s",
|
|
BlockStateAsString(s->blockState));
|
|
break;
|
|
}
|
|
|
|
foreach(cell, options)
|
|
{
|
|
DefElem *elem = lfirst(cell);
|
|
|
|
if (strcmp(elem->defname, "savepoint_name") == 0)
|
|
name = strVal(elem->arg);
|
|
}
|
|
|
|
Assert(PointerIsValid(name));
|
|
|
|
for (target = s; PointerIsValid(target); target = target->parent)
|
|
{
|
|
if (PointerIsValid(target->name) && strcmp(target->name, name) == 0)
|
|
break;
|
|
}
|
|
|
|
if (!PointerIsValid(target))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_S_E_INVALID_SPECIFICATION),
|
|
errmsg("no such savepoint")));
|
|
|
|
/* disallow crossing savepoint level boundaries */
|
|
if (target->savepointLevel != s->savepointLevel)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_S_E_INVALID_SPECIFICATION),
|
|
errmsg("no such savepoint")));
|
|
|
|
/*
|
|
* Mark "commit pending" all subtransactions up to the target
|
|
* subtransaction. The actual commits will happen when control gets to
|
|
* CommitTransactionCommand.
|
|
*/
|
|
xact = CurrentTransactionState;
|
|
for (;;)
|
|
{
|
|
Assert(xact->blockState == TBLOCK_SUBINPROGRESS);
|
|
xact->blockState = TBLOCK_SUBRELEASE;
|
|
if (xact == target)
|
|
break;
|
|
xact = xact->parent;
|
|
Assert(PointerIsValid(xact));
|
|
}
|
|
}
|
|
|
|
/*
|
|
* RollbackToSavepoint
|
|
* This executes a ROLLBACK TO <savepoint> command.
|
|
*
|
|
* As above, we don't actually do anything here except change blockState.
|
|
*/
|
|
void
|
|
RollbackToSavepoint(List *options)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
TransactionState target,
|
|
xact;
|
|
ListCell *cell;
|
|
char *name = NULL;
|
|
|
|
switch (s->blockState)
|
|
{
|
|
/*
|
|
* We can't rollback to a savepoint if there is no savepoint
|
|
* defined.
|
|
*/
|
|
case TBLOCK_INPROGRESS:
|
|
case TBLOCK_ABORT:
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_S_E_INVALID_SPECIFICATION),
|
|
errmsg("no such savepoint")));
|
|
break;
|
|
|
|
/*
|
|
* There is at least one savepoint, so proceed.
|
|
*/
|
|
case TBLOCK_SUBINPROGRESS:
|
|
case TBLOCK_SUBABORT:
|
|
break;
|
|
|
|
/* These cases are invalid. */
|
|
case TBLOCK_DEFAULT:
|
|
case TBLOCK_STARTED:
|
|
case TBLOCK_BEGIN:
|
|
case TBLOCK_SUBBEGIN:
|
|
case TBLOCK_END:
|
|
case TBLOCK_SUBRELEASE:
|
|
case TBLOCK_SUBCOMMIT:
|
|
case TBLOCK_ABORT_END:
|
|
case TBLOCK_SUBABORT_END:
|
|
case TBLOCK_ABORT_PENDING:
|
|
case TBLOCK_SUBABORT_PENDING:
|
|
case TBLOCK_SUBRESTART:
|
|
case TBLOCK_SUBABORT_RESTART:
|
|
case TBLOCK_PREPARE:
|
|
elog(FATAL, "RollbackToSavepoint: unexpected state %s",
|
|
BlockStateAsString(s->blockState));
|
|
break;
|
|
}
|
|
|
|
foreach(cell, options)
|
|
{
|
|
DefElem *elem = lfirst(cell);
|
|
|
|
if (strcmp(elem->defname, "savepoint_name") == 0)
|
|
name = strVal(elem->arg);
|
|
}
|
|
|
|
Assert(PointerIsValid(name));
|
|
|
|
for (target = s; PointerIsValid(target); target = target->parent)
|
|
{
|
|
if (PointerIsValid(target->name) && strcmp(target->name, name) == 0)
|
|
break;
|
|
}
|
|
|
|
if (!PointerIsValid(target))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_S_E_INVALID_SPECIFICATION),
|
|
errmsg("no such savepoint")));
|
|
|
|
/* disallow crossing savepoint level boundaries */
|
|
if (target->savepointLevel != s->savepointLevel)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_S_E_INVALID_SPECIFICATION),
|
|
errmsg("no such savepoint")));
|
|
|
|
/*
|
|
* Mark "abort pending" all subtransactions up to the target
|
|
* subtransaction. The actual aborts will happen when control gets to
|
|
* CommitTransactionCommand.
|
|
*/
|
|
xact = CurrentTransactionState;
|
|
for (;;)
|
|
{
|
|
if (xact == target)
|
|
break;
|
|
if (xact->blockState == TBLOCK_SUBINPROGRESS)
|
|
xact->blockState = TBLOCK_SUBABORT_PENDING;
|
|
else if (xact->blockState == TBLOCK_SUBABORT)
|
|
xact->blockState = TBLOCK_SUBABORT_END;
|
|
else
|
|
elog(FATAL, "RollbackToSavepoint: unexpected state %s",
|
|
BlockStateAsString(xact->blockState));
|
|
xact = xact->parent;
|
|
Assert(PointerIsValid(xact));
|
|
}
|
|
|
|
/* And mark the target as "restart pending" */
|
|
if (xact->blockState == TBLOCK_SUBINPROGRESS)
|
|
xact->blockState = TBLOCK_SUBRESTART;
|
|
else if (xact->blockState == TBLOCK_SUBABORT)
|
|
xact->blockState = TBLOCK_SUBABORT_RESTART;
|
|
else
|
|
elog(FATAL, "RollbackToSavepoint: unexpected state %s",
|
|
BlockStateAsString(xact->blockState));
|
|
}
|
|
|
|
/*
|
|
* BeginInternalSubTransaction
|
|
* This is the same as DefineSavepoint except it allows TBLOCK_STARTED,
|
|
* TBLOCK_END, and TBLOCK_PREPARE states, and therefore it can safely be
|
|
* used in functions that might be called when not inside a BEGIN block
|
|
* or when running deferred triggers at COMMIT/PREPARE time. Also, it
|
|
* automatically does CommitTransactionCommand/StartTransactionCommand
|
|
* instead of expecting the caller to do it.
|
|
*/
|
|
void
|
|
BeginInternalSubTransaction(char *name)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
switch (s->blockState)
|
|
{
|
|
case TBLOCK_STARTED:
|
|
case TBLOCK_INPROGRESS:
|
|
case TBLOCK_END:
|
|
case TBLOCK_PREPARE:
|
|
case TBLOCK_SUBINPROGRESS:
|
|
/* Normal subtransaction start */
|
|
PushTransaction();
|
|
s = CurrentTransactionState; /* changed by push */
|
|
|
|
/*
|
|
* Savepoint names, like the TransactionState block itself, live
|
|
* in TopTransactionContext.
|
|
*/
|
|
if (name)
|
|
s->name = MemoryContextStrdup(TopTransactionContext, name);
|
|
break;
|
|
|
|
/* These cases are invalid. */
|
|
case TBLOCK_DEFAULT:
|
|
case TBLOCK_BEGIN:
|
|
case TBLOCK_SUBBEGIN:
|
|
case TBLOCK_SUBRELEASE:
|
|
case TBLOCK_SUBCOMMIT:
|
|
case TBLOCK_ABORT:
|
|
case TBLOCK_SUBABORT:
|
|
case TBLOCK_ABORT_END:
|
|
case TBLOCK_SUBABORT_END:
|
|
case TBLOCK_ABORT_PENDING:
|
|
case TBLOCK_SUBABORT_PENDING:
|
|
case TBLOCK_SUBRESTART:
|
|
case TBLOCK_SUBABORT_RESTART:
|
|
elog(FATAL, "BeginInternalSubTransaction: unexpected state %s",
|
|
BlockStateAsString(s->blockState));
|
|
break;
|
|
}
|
|
|
|
CommitTransactionCommand();
|
|
StartTransactionCommand();
|
|
}
|
|
|
|
/*
|
|
* ReleaseCurrentSubTransaction
|
|
*
|
|
* RELEASE (ie, commit) the innermost subtransaction, regardless of its
|
|
* savepoint name (if any).
|
|
* NB: do NOT use CommitTransactionCommand/StartTransactionCommand with this.
|
|
*/
|
|
void
|
|
ReleaseCurrentSubTransaction(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
if (s->blockState != TBLOCK_SUBINPROGRESS)
|
|
elog(ERROR, "ReleaseCurrentSubTransaction: unexpected state %s",
|
|
BlockStateAsString(s->blockState));
|
|
Assert(s->state == TRANS_INPROGRESS);
|
|
MemoryContextSwitchTo(CurTransactionContext);
|
|
CommitSubTransaction();
|
|
s = CurrentTransactionState; /* changed by pop */
|
|
Assert(s->state == TRANS_INPROGRESS);
|
|
}
|
|
|
|
/*
|
|
* RollbackAndReleaseCurrentSubTransaction
|
|
*
|
|
* ROLLBACK and RELEASE (ie, abort) the innermost subtransaction, regardless
|
|
* of its savepoint name (if any).
|
|
* NB: do NOT use CommitTransactionCommand/StartTransactionCommand with this.
|
|
*/
|
|
void
|
|
RollbackAndReleaseCurrentSubTransaction(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
switch (s->blockState)
|
|
{
|
|
/* Must be in a subtransaction */
|
|
case TBLOCK_SUBINPROGRESS:
|
|
case TBLOCK_SUBABORT:
|
|
break;
|
|
|
|
/* These cases are invalid. */
|
|
case TBLOCK_DEFAULT:
|
|
case TBLOCK_STARTED:
|
|
case TBLOCK_BEGIN:
|
|
case TBLOCK_SUBBEGIN:
|
|
case TBLOCK_INPROGRESS:
|
|
case TBLOCK_END:
|
|
case TBLOCK_SUBRELEASE:
|
|
case TBLOCK_SUBCOMMIT:
|
|
case TBLOCK_ABORT:
|
|
case TBLOCK_ABORT_END:
|
|
case TBLOCK_SUBABORT_END:
|
|
case TBLOCK_ABORT_PENDING:
|
|
case TBLOCK_SUBABORT_PENDING:
|
|
case TBLOCK_SUBRESTART:
|
|
case TBLOCK_SUBABORT_RESTART:
|
|
case TBLOCK_PREPARE:
|
|
elog(FATAL, "RollbackAndReleaseCurrentSubTransaction: unexpected state %s",
|
|
BlockStateAsString(s->blockState));
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Abort the current subtransaction, if needed.
|
|
*/
|
|
if (s->blockState == TBLOCK_SUBINPROGRESS)
|
|
AbortSubTransaction();
|
|
|
|
/* And clean it up, too */
|
|
CleanupSubTransaction();
|
|
|
|
s = CurrentTransactionState; /* changed by pop */
|
|
AssertState(s->blockState == TBLOCK_SUBINPROGRESS ||
|
|
s->blockState == TBLOCK_INPROGRESS ||
|
|
s->blockState == TBLOCK_STARTED);
|
|
}
|
|
|
|
/*
|
|
* AbortOutOfAnyTransaction
|
|
*
|
|
* This routine is provided for error recovery purposes. It aborts any
|
|
* active transaction or transaction block, leaving the system in a known
|
|
* idle state.
|
|
*/
|
|
void
|
|
AbortOutOfAnyTransaction(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
/*
|
|
* Get out of any transaction or nested transaction
|
|
*/
|
|
do
|
|
{
|
|
switch (s->blockState)
|
|
{
|
|
case TBLOCK_DEFAULT:
|
|
if (s->state == TRANS_DEFAULT)
|
|
{
|
|
/* Not in a transaction, do nothing */
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* We can get here after an error during transaction start
|
|
* (state will be TRANS_START). Need to clean up the
|
|
* incompletely started transaction. First, adjust the
|
|
* low-level state to suppress warning message from
|
|
* AbortTransaction.
|
|
*/
|
|
if (s->state == TRANS_START)
|
|
s->state = TRANS_INPROGRESS;
|
|
AbortTransaction();
|
|
CleanupTransaction();
|
|
}
|
|
break;
|
|
case TBLOCK_STARTED:
|
|
case TBLOCK_BEGIN:
|
|
case TBLOCK_INPROGRESS:
|
|
case TBLOCK_END:
|
|
case TBLOCK_ABORT_PENDING:
|
|
case TBLOCK_PREPARE:
|
|
/* In a transaction, so clean up */
|
|
AbortTransaction();
|
|
CleanupTransaction();
|
|
s->blockState = TBLOCK_DEFAULT;
|
|
break;
|
|
case TBLOCK_ABORT:
|
|
case TBLOCK_ABORT_END:
|
|
/* AbortTransaction already done, still need Cleanup */
|
|
CleanupTransaction();
|
|
s->blockState = TBLOCK_DEFAULT;
|
|
break;
|
|
|
|
/*
|
|
* In a subtransaction, so clean it up and abort parent too
|
|
*/
|
|
case TBLOCK_SUBBEGIN:
|
|
case TBLOCK_SUBINPROGRESS:
|
|
case TBLOCK_SUBRELEASE:
|
|
case TBLOCK_SUBCOMMIT:
|
|
case TBLOCK_SUBABORT_PENDING:
|
|
case TBLOCK_SUBRESTART:
|
|
AbortSubTransaction();
|
|
CleanupSubTransaction();
|
|
s = CurrentTransactionState; /* changed by pop */
|
|
break;
|
|
|
|
case TBLOCK_SUBABORT:
|
|
case TBLOCK_SUBABORT_END:
|
|
case TBLOCK_SUBABORT_RESTART:
|
|
/* As above, but AbortSubTransaction already done */
|
|
CleanupSubTransaction();
|
|
s = CurrentTransactionState; /* changed by pop */
|
|
break;
|
|
}
|
|
} while (s->blockState != TBLOCK_DEFAULT);
|
|
|
|
/* Should be out of all subxacts now */
|
|
Assert(s->parent == NULL);
|
|
}
|
|
|
|
/*
|
|
* IsTransactionBlock --- are we within a transaction block?
|
|
*/
|
|
bool
|
|
IsTransactionBlock(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
if (s->blockState == TBLOCK_DEFAULT || s->blockState == TBLOCK_STARTED)
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* IsTransactionOrTransactionBlock --- are we within either a transaction
|
|
* or a transaction block? (The backend is only really "idle" when this
|
|
* returns false.)
|
|
*
|
|
* This should match up with IsTransactionBlock and IsTransactionState.
|
|
*/
|
|
bool
|
|
IsTransactionOrTransactionBlock(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
if (s->blockState == TBLOCK_DEFAULT)
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* TransactionBlockStatusCode - return status code to send in ReadyForQuery
|
|
*/
|
|
char
|
|
TransactionBlockStatusCode(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
switch (s->blockState)
|
|
{
|
|
case TBLOCK_DEFAULT:
|
|
case TBLOCK_STARTED:
|
|
return 'I'; /* idle --- not in transaction */
|
|
case TBLOCK_BEGIN:
|
|
case TBLOCK_SUBBEGIN:
|
|
case TBLOCK_INPROGRESS:
|
|
case TBLOCK_SUBINPROGRESS:
|
|
case TBLOCK_END:
|
|
case TBLOCK_SUBRELEASE:
|
|
case TBLOCK_SUBCOMMIT:
|
|
case TBLOCK_PREPARE:
|
|
return 'T'; /* in transaction */
|
|
case TBLOCK_ABORT:
|
|
case TBLOCK_SUBABORT:
|
|
case TBLOCK_ABORT_END:
|
|
case TBLOCK_SUBABORT_END:
|
|
case TBLOCK_ABORT_PENDING:
|
|
case TBLOCK_SUBABORT_PENDING:
|
|
case TBLOCK_SUBRESTART:
|
|
case TBLOCK_SUBABORT_RESTART:
|
|
return 'E'; /* in failed transaction */
|
|
}
|
|
|
|
/* should never get here */
|
|
elog(FATAL, "invalid transaction block state: %s",
|
|
BlockStateAsString(s->blockState));
|
|
return 0; /* keep compiler quiet */
|
|
}
|
|
|
|
/*
|
|
* IsSubTransaction
|
|
*/
|
|
bool
|
|
IsSubTransaction(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
if (s->nestingLevel >= 2)
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* StartSubTransaction
|
|
*
|
|
* If you're wondering why this is separate from PushTransaction: it's because
|
|
* we can't conveniently do this stuff right inside DefineSavepoint. The
|
|
* SAVEPOINT utility command will be executed inside a Portal, and if we
|
|
* muck with CurrentMemoryContext or CurrentResourceOwner then exit from
|
|
* the Portal will undo those settings. So we make DefineSavepoint just
|
|
* push a dummy transaction block, and when control returns to the main
|
|
* idle loop, CommitTransactionCommand will be called, and we'll come here
|
|
* to finish starting the subtransaction.
|
|
*/
|
|
static void
|
|
StartSubTransaction(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
if (s->state != TRANS_DEFAULT)
|
|
elog(WARNING, "StartSubTransaction while in %s state",
|
|
TransStateAsString(s->state));
|
|
|
|
s->state = TRANS_START;
|
|
|
|
/*
|
|
* Initialize subsystems for new subtransaction
|
|
*
|
|
* must initialize resource-management stuff first
|
|
*/
|
|
AtSubStart_Memory();
|
|
AtSubStart_ResourceOwner();
|
|
AtSubStart_Notify();
|
|
AfterTriggerBeginSubXact();
|
|
|
|
s->state = TRANS_INPROGRESS;
|
|
|
|
/*
|
|
* Call start-of-subxact callbacks
|
|
*/
|
|
CallSubXactCallbacks(SUBXACT_EVENT_START_SUB, s->subTransactionId,
|
|
s->parent->subTransactionId);
|
|
|
|
ShowTransactionState("StartSubTransaction");
|
|
}
|
|
|
|
/*
|
|
* CommitSubTransaction
|
|
*
|
|
* The caller has to make sure to always reassign CurrentTransactionState
|
|
* if it has a local pointer to it after calling this function.
|
|
*/
|
|
static void
|
|
CommitSubTransaction(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
ShowTransactionState("CommitSubTransaction");
|
|
|
|
if (s->state != TRANS_INPROGRESS)
|
|
elog(WARNING, "CommitSubTransaction while in %s state",
|
|
TransStateAsString(s->state));
|
|
|
|
/* Pre-commit processing goes here */
|
|
|
|
CallSubXactCallbacks(SUBXACT_EVENT_PRE_COMMIT_SUB, s->subTransactionId,
|
|
s->parent->subTransactionId);
|
|
|
|
/* Do the actual "commit", such as it is */
|
|
s->state = TRANS_COMMIT;
|
|
|
|
/* Must CCI to ensure commands of subtransaction are seen as done */
|
|
CommandCounterIncrement();
|
|
|
|
/*
|
|
* Prior to 8.4 we marked subcommit in clog at this point. We now only
|
|
* perform that step, if required, as part of the atomic update of the
|
|
* whole transaction tree at top level commit or abort.
|
|
*/
|
|
|
|
/* Post-commit cleanup */
|
|
if (TransactionIdIsValid(s->transactionId))
|
|
AtSubCommit_childXids();
|
|
AfterTriggerEndSubXact(true);
|
|
AtSubCommit_Portals(s->subTransactionId,
|
|
s->parent->subTransactionId,
|
|
s->parent->curTransactionOwner);
|
|
AtEOSubXact_LargeObject(true, s->subTransactionId,
|
|
s->parent->subTransactionId);
|
|
AtSubCommit_Notify();
|
|
|
|
CallSubXactCallbacks(SUBXACT_EVENT_COMMIT_SUB, s->subTransactionId,
|
|
s->parent->subTransactionId);
|
|
|
|
ResourceOwnerRelease(s->curTransactionOwner,
|
|
RESOURCE_RELEASE_BEFORE_LOCKS,
|
|
true, false);
|
|
AtEOSubXact_RelationCache(true, s->subTransactionId,
|
|
s->parent->subTransactionId);
|
|
AtEOSubXact_Inval(true);
|
|
AtSubCommit_smgr();
|
|
|
|
/*
|
|
* The only lock we actually release here is the subtransaction XID lock.
|
|
*/
|
|
CurrentResourceOwner = s->curTransactionOwner;
|
|
if (TransactionIdIsValid(s->transactionId))
|
|
XactLockTableDelete(s->transactionId);
|
|
|
|
/*
|
|
* Other locks should get transferred to their parent resource owner.
|
|
*/
|
|
ResourceOwnerRelease(s->curTransactionOwner,
|
|
RESOURCE_RELEASE_LOCKS,
|
|
true, false);
|
|
ResourceOwnerRelease(s->curTransactionOwner,
|
|
RESOURCE_RELEASE_AFTER_LOCKS,
|
|
true, false);
|
|
|
|
AtEOXact_GUC(true, s->gucNestLevel);
|
|
AtEOSubXact_SPI(true, s->subTransactionId);
|
|
AtEOSubXact_on_commit_actions(true, s->subTransactionId,
|
|
s->parent->subTransactionId);
|
|
AtEOSubXact_Namespace(true, s->subTransactionId,
|
|
s->parent->subTransactionId);
|
|
AtEOSubXact_Files(true, s->subTransactionId,
|
|
s->parent->subTransactionId);
|
|
AtEOSubXact_HashTables(true, s->nestingLevel);
|
|
AtEOSubXact_PgStat(true, s->nestingLevel);
|
|
AtSubCommit_Snapshot(s->nestingLevel);
|
|
|
|
/*
|
|
* We need to restore the upper transaction's read-only state, in case the
|
|
* upper is read-write while the child is read-only; GUC will incorrectly
|
|
* think it should leave the child state in place.
|
|
*/
|
|
XactReadOnly = s->prevXactReadOnly;
|
|
|
|
CurrentResourceOwner = s->parent->curTransactionOwner;
|
|
CurTransactionResourceOwner = s->parent->curTransactionOwner;
|
|
ResourceOwnerDelete(s->curTransactionOwner);
|
|
s->curTransactionOwner = NULL;
|
|
|
|
AtSubCommit_Memory();
|
|
|
|
s->state = TRANS_DEFAULT;
|
|
|
|
PopTransaction();
|
|
}
|
|
|
|
/*
|
|
* AbortSubTransaction
|
|
*/
|
|
static void
|
|
AbortSubTransaction(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
/* Prevent cancel/die interrupt while cleaning up */
|
|
HOLD_INTERRUPTS();
|
|
|
|
/* Make sure we have a valid memory context and resource owner */
|
|
AtSubAbort_Memory();
|
|
AtSubAbort_ResourceOwner();
|
|
|
|
/*
|
|
* Release any LW locks we might be holding as quickly as possible.
|
|
* (Regular locks, however, must be held till we finish aborting.)
|
|
* Releasing LW locks is critical since we might try to grab them again
|
|
* while cleaning up!
|
|
*
|
|
* FIXME This may be incorrect --- Are there some locks we should keep?
|
|
* Buffer locks, for example? I don't think so but I'm not sure.
|
|
*/
|
|
LWLockReleaseAll();
|
|
|
|
AbortBufferIO();
|
|
UnlockBuffers();
|
|
|
|
/* Reset WAL record construction state */
|
|
XLogResetInsertion();
|
|
|
|
/*
|
|
* Also clean up any open wait for lock, since the lock manager will choke
|
|
* if we try to wait for another lock before doing this.
|
|
*/
|
|
LockErrorCleanup();
|
|
|
|
/*
|
|
* If any timeout events are still active, make sure the timeout interrupt
|
|
* is scheduled. This covers possible loss of a timeout interrupt due to
|
|
* longjmp'ing out of the SIGINT handler (see notes in handle_sig_alarm).
|
|
* We delay this till after LockErrorCleanup so that we don't uselessly
|
|
* reschedule lock or deadlock check timeouts.
|
|
*/
|
|
reschedule_timeouts();
|
|
|
|
/*
|
|
* Re-enable signals, in case we got here by longjmp'ing out of a signal
|
|
* handler. We do this fairly early in the sequence so that the timeout
|
|
* infrastructure will be functional if needed while aborting.
|
|
*/
|
|
PG_SETMASK(&UnBlockSig);
|
|
|
|
/*
|
|
* check the current transaction state
|
|
*/
|
|
ShowTransactionState("AbortSubTransaction");
|
|
|
|
if (s->state != TRANS_INPROGRESS)
|
|
elog(WARNING, "AbortSubTransaction while in %s state",
|
|
TransStateAsString(s->state));
|
|
|
|
s->state = TRANS_ABORT;
|
|
|
|
/*
|
|
* Reset user ID which might have been changed transiently. (See notes in
|
|
* AbortTransaction.)
|
|
*/
|
|
SetUserIdAndSecContext(s->prevUser, s->prevSecContext);
|
|
|
|
/*
|
|
* We can skip all this stuff if the subxact failed before creating a
|
|
* ResourceOwner...
|
|
*/
|
|
if (s->curTransactionOwner)
|
|
{
|
|
AfterTriggerEndSubXact(false);
|
|
AtSubAbort_Portals(s->subTransactionId,
|
|
s->parent->subTransactionId,
|
|
s->parent->curTransactionOwner);
|
|
AtEOSubXact_LargeObject(false, s->subTransactionId,
|
|
s->parent->subTransactionId);
|
|
AtSubAbort_Notify();
|
|
|
|
/* Advertise the fact that we aborted in pg_clog. */
|
|
(void) RecordTransactionAbort(true);
|
|
|
|
/* Post-abort cleanup */
|
|
if (TransactionIdIsValid(s->transactionId))
|
|
AtSubAbort_childXids();
|
|
|
|
CallSubXactCallbacks(SUBXACT_EVENT_ABORT_SUB, s->subTransactionId,
|
|
s->parent->subTransactionId);
|
|
|
|
ResourceOwnerRelease(s->curTransactionOwner,
|
|
RESOURCE_RELEASE_BEFORE_LOCKS,
|
|
false, false);
|
|
AtEOSubXact_RelationCache(false, s->subTransactionId,
|
|
s->parent->subTransactionId);
|
|
AtEOSubXact_Inval(false);
|
|
ResourceOwnerRelease(s->curTransactionOwner,
|
|
RESOURCE_RELEASE_LOCKS,
|
|
false, false);
|
|
ResourceOwnerRelease(s->curTransactionOwner,
|
|
RESOURCE_RELEASE_AFTER_LOCKS,
|
|
false, false);
|
|
AtSubAbort_smgr();
|
|
|
|
AtEOXact_GUC(false, s->gucNestLevel);
|
|
AtEOSubXact_SPI(false, s->subTransactionId);
|
|
AtEOSubXact_on_commit_actions(false, s->subTransactionId,
|
|
s->parent->subTransactionId);
|
|
AtEOSubXact_Namespace(false, s->subTransactionId,
|
|
s->parent->subTransactionId);
|
|
AtEOSubXact_Files(false, s->subTransactionId,
|
|
s->parent->subTransactionId);
|
|
AtEOSubXact_HashTables(false, s->nestingLevel);
|
|
AtEOSubXact_PgStat(false, s->nestingLevel);
|
|
AtSubAbort_Snapshot(s->nestingLevel);
|
|
}
|
|
|
|
/*
|
|
* Restore the upper transaction's read-only state, too. This should be
|
|
* redundant with GUC's cleanup but we may as well do it for consistency
|
|
* with the commit case.
|
|
*/
|
|
XactReadOnly = s->prevXactReadOnly;
|
|
|
|
RESUME_INTERRUPTS();
|
|
}
|
|
|
|
/*
|
|
* CleanupSubTransaction
|
|
*
|
|
* The caller has to make sure to always reassign CurrentTransactionState
|
|
* if it has a local pointer to it after calling this function.
|
|
*/
|
|
static void
|
|
CleanupSubTransaction(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
ShowTransactionState("CleanupSubTransaction");
|
|
|
|
if (s->state != TRANS_ABORT)
|
|
elog(WARNING, "CleanupSubTransaction while in %s state",
|
|
TransStateAsString(s->state));
|
|
|
|
AtSubCleanup_Portals(s->subTransactionId);
|
|
|
|
CurrentResourceOwner = s->parent->curTransactionOwner;
|
|
CurTransactionResourceOwner = s->parent->curTransactionOwner;
|
|
if (s->curTransactionOwner)
|
|
ResourceOwnerDelete(s->curTransactionOwner);
|
|
s->curTransactionOwner = NULL;
|
|
|
|
AtSubCleanup_Memory();
|
|
|
|
s->state = TRANS_DEFAULT;
|
|
|
|
PopTransaction();
|
|
}
|
|
|
|
/*
|
|
* PushTransaction
|
|
* Create transaction state stack entry for a subtransaction
|
|
*
|
|
* The caller has to make sure to always reassign CurrentTransactionState
|
|
* if it has a local pointer to it after calling this function.
|
|
*/
|
|
static void
|
|
PushTransaction(void)
|
|
{
|
|
TransactionState p = CurrentTransactionState;
|
|
TransactionState s;
|
|
|
|
/*
|
|
* We keep subtransaction state nodes in TopTransactionContext.
|
|
*/
|
|
s = (TransactionState)
|
|
MemoryContextAllocZero(TopTransactionContext,
|
|
sizeof(TransactionStateData));
|
|
|
|
/*
|
|
* Assign a subtransaction ID, watching out for counter wraparound.
|
|
*/
|
|
currentSubTransactionId += 1;
|
|
if (currentSubTransactionId == InvalidSubTransactionId)
|
|
{
|
|
currentSubTransactionId -= 1;
|
|
pfree(s);
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
|
|
errmsg("cannot have more than 2^32-1 subtransactions in a transaction")));
|
|
}
|
|
|
|
/*
|
|
* We can now stack a minimally valid subtransaction without fear of
|
|
* failure.
|
|
*/
|
|
s->transactionId = InvalidTransactionId; /* until assigned */
|
|
s->subTransactionId = currentSubTransactionId;
|
|
s->parent = p;
|
|
s->nestingLevel = p->nestingLevel + 1;
|
|
s->gucNestLevel = NewGUCNestLevel();
|
|
s->savepointLevel = p->savepointLevel;
|
|
s->state = TRANS_DEFAULT;
|
|
s->blockState = TBLOCK_SUBBEGIN;
|
|
GetUserIdAndSecContext(&s->prevUser, &s->prevSecContext);
|
|
s->prevXactReadOnly = XactReadOnly;
|
|
|
|
CurrentTransactionState = s;
|
|
|
|
/*
|
|
* AbortSubTransaction and CleanupSubTransaction have to be able to cope
|
|
* with the subtransaction from here on out; in particular they should not
|
|
* assume that it necessarily has a transaction context, resource owner,
|
|
* or XID.
|
|
*/
|
|
}
|
|
|
|
/*
|
|
* PopTransaction
|
|
* Pop back to parent transaction state
|
|
*
|
|
* The caller has to make sure to always reassign CurrentTransactionState
|
|
* if it has a local pointer to it after calling this function.
|
|
*/
|
|
static void
|
|
PopTransaction(void)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
if (s->state != TRANS_DEFAULT)
|
|
elog(WARNING, "PopTransaction while in %s state",
|
|
TransStateAsString(s->state));
|
|
|
|
if (s->parent == NULL)
|
|
elog(FATAL, "PopTransaction with no parent");
|
|
|
|
CurrentTransactionState = s->parent;
|
|
|
|
/* Let's just make sure CurTransactionContext is good */
|
|
CurTransactionContext = s->parent->curTransactionContext;
|
|
MemoryContextSwitchTo(CurTransactionContext);
|
|
|
|
/* Ditto for ResourceOwner links */
|
|
CurTransactionResourceOwner = s->parent->curTransactionOwner;
|
|
CurrentResourceOwner = s->parent->curTransactionOwner;
|
|
|
|
/* Free the old child structure */
|
|
if (s->name)
|
|
pfree(s->name);
|
|
pfree(s);
|
|
}
|
|
|
|
/*
|
|
* ShowTransactionState
|
|
* Debug support
|
|
*/
|
|
static void
|
|
ShowTransactionState(const char *str)
|
|
{
|
|
/* skip work if message will definitely not be printed */
|
|
if (log_min_messages <= DEBUG3 || client_min_messages <= DEBUG3)
|
|
{
|
|
elog(DEBUG3, "%s", str);
|
|
ShowTransactionStateRec(CurrentTransactionState);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* ShowTransactionStateRec
|
|
* Recursive subroutine for ShowTransactionState
|
|
*/
|
|
static void
|
|
ShowTransactionStateRec(TransactionState s)
|
|
{
|
|
StringInfoData buf;
|
|
|
|
initStringInfo(&buf);
|
|
|
|
if (s->nChildXids > 0)
|
|
{
|
|
int i;
|
|
|
|
appendStringInfo(&buf, "%u", s->childXids[0]);
|
|
for (i = 1; i < s->nChildXids; i++)
|
|
appendStringInfo(&buf, " %u", s->childXids[i]);
|
|
}
|
|
|
|
if (s->parent)
|
|
ShowTransactionStateRec(s->parent);
|
|
|
|
/* use ereport to suppress computation if msg will not be printed */
|
|
ereport(DEBUG3,
|
|
(errmsg_internal("name: %s; blockState: %13s; state: %7s, xid/subid/cid: %u/%u/%u%s, nestlvl: %d, children: %s",
|
|
PointerIsValid(s->name) ? s->name : "unnamed",
|
|
BlockStateAsString(s->blockState),
|
|
TransStateAsString(s->state),
|
|
(unsigned int) s->transactionId,
|
|
(unsigned int) s->subTransactionId,
|
|
(unsigned int) currentCommandId,
|
|
currentCommandIdUsed ? " (used)" : "",
|
|
s->nestingLevel, buf.data)));
|
|
|
|
pfree(buf.data);
|
|
}
|
|
|
|
/*
|
|
* BlockStateAsString
|
|
* Debug support
|
|
*/
|
|
static const char *
|
|
BlockStateAsString(TBlockState blockState)
|
|
{
|
|
switch (blockState)
|
|
{
|
|
case TBLOCK_DEFAULT:
|
|
return "DEFAULT";
|
|
case TBLOCK_STARTED:
|
|
return "STARTED";
|
|
case TBLOCK_BEGIN:
|
|
return "BEGIN";
|
|
case TBLOCK_INPROGRESS:
|
|
return "INPROGRESS";
|
|
case TBLOCK_END:
|
|
return "END";
|
|
case TBLOCK_ABORT:
|
|
return "ABORT";
|
|
case TBLOCK_ABORT_END:
|
|
return "ABORT END";
|
|
case TBLOCK_ABORT_PENDING:
|
|
return "ABORT PEND";
|
|
case TBLOCK_PREPARE:
|
|
return "PREPARE";
|
|
case TBLOCK_SUBBEGIN:
|
|
return "SUB BEGIN";
|
|
case TBLOCK_SUBINPROGRESS:
|
|
return "SUB INPROGRS";
|
|
case TBLOCK_SUBRELEASE:
|
|
return "SUB RELEASE";
|
|
case TBLOCK_SUBCOMMIT:
|
|
return "SUB COMMIT";
|
|
case TBLOCK_SUBABORT:
|
|
return "SUB ABORT";
|
|
case TBLOCK_SUBABORT_END:
|
|
return "SUB ABORT END";
|
|
case TBLOCK_SUBABORT_PENDING:
|
|
return "SUB ABRT PEND";
|
|
case TBLOCK_SUBRESTART:
|
|
return "SUB RESTART";
|
|
case TBLOCK_SUBABORT_RESTART:
|
|
return "SUB AB RESTRT";
|
|
}
|
|
return "UNRECOGNIZED";
|
|
}
|
|
|
|
/*
|
|
* TransStateAsString
|
|
* Debug support
|
|
*/
|
|
static const char *
|
|
TransStateAsString(TransState state)
|
|
{
|
|
switch (state)
|
|
{
|
|
case TRANS_DEFAULT:
|
|
return "DEFAULT";
|
|
case TRANS_START:
|
|
return "START";
|
|
case TRANS_INPROGRESS:
|
|
return "INPROGR";
|
|
case TRANS_COMMIT:
|
|
return "COMMIT";
|
|
case TRANS_ABORT:
|
|
return "ABORT";
|
|
case TRANS_PREPARE:
|
|
return "PREPARE";
|
|
}
|
|
return "UNRECOGNIZED";
|
|
}
|
|
|
|
/*
|
|
* xactGetCommittedChildren
|
|
*
|
|
* Gets the list of committed children of the current transaction. The return
|
|
* value is the number of child transactions. *ptr is set to point to an
|
|
* array of TransactionIds. The array is allocated in TopTransactionContext;
|
|
* the caller should *not* pfree() it (this is a change from pre-8.4 code!).
|
|
* If there are no subxacts, *ptr is set to NULL.
|
|
*/
|
|
int
|
|
xactGetCommittedChildren(TransactionId **ptr)
|
|
{
|
|
TransactionState s = CurrentTransactionState;
|
|
|
|
if (s->nChildXids == 0)
|
|
*ptr = NULL;
|
|
else
|
|
*ptr = s->childXids;
|
|
|
|
return s->nChildXids;
|
|
}
|
|
|
|
/*
|
|
* XLOG support routines
|
|
*/
|
|
|
|
/*
|
|
* Before 9.0 this was a fairly short function, but now it performs many
|
|
* actions for which the order of execution is critical.
|
|
*/
|
|
static void
|
|
xact_redo_commit_internal(TransactionId xid, XLogRecPtr lsn,
|
|
TimestampTz commit_time,
|
|
TransactionId *sub_xids, int nsubxacts,
|
|
SharedInvalidationMessage *inval_msgs, int nmsgs,
|
|
RelFileNode *xnodes, int nrels,
|
|
Oid dbId, Oid tsId,
|
|
uint32 xinfo)
|
|
{
|
|
TransactionId max_xid;
|
|
int i;
|
|
|
|
max_xid = TransactionIdLatest(xid, nsubxacts, sub_xids);
|
|
|
|
/*
|
|
* Make sure nextXid is beyond any XID mentioned in the record.
|
|
*
|
|
* We don't expect anyone else to modify nextXid, hence we don't need to
|
|
* hold a lock while checking this. We still acquire the lock to modify
|
|
* it, though.
|
|
*/
|
|
if (TransactionIdFollowsOrEquals(max_xid,
|
|
ShmemVariableCache->nextXid))
|
|
{
|
|
LWLockAcquire(XidGenLock, LW_EXCLUSIVE);
|
|
ShmemVariableCache->nextXid = max_xid;
|
|
TransactionIdAdvance(ShmemVariableCache->nextXid);
|
|
LWLockRelease(XidGenLock);
|
|
}
|
|
|
|
/* Set the transaction commit timestamp and metadata */
|
|
TransactionTreeSetCommitTsData(xid, nsubxacts, sub_xids,
|
|
commit_time, InvalidCommitTsNodeId, false);
|
|
|
|
if (standbyState == STANDBY_DISABLED)
|
|
{
|
|
/*
|
|
* Mark the transaction committed in pg_clog.
|
|
*/
|
|
TransactionIdCommitTree(xid, nsubxacts, sub_xids);
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* If a transaction completion record arrives that has as-yet
|
|
* unobserved subtransactions then this will not have been fully
|
|
* handled by the call to RecordKnownAssignedTransactionIds() in the
|
|
* main recovery loop in xlog.c. So we need to do bookkeeping again to
|
|
* cover that case. This is confusing and it is easy to think this
|
|
* call is irrelevant, which has happened three times in development
|
|
* already. Leave it in.
|
|
*/
|
|
RecordKnownAssignedTransactionIds(max_xid);
|
|
|
|
/*
|
|
* Mark the transaction committed in pg_clog. We use async commit
|
|
* protocol during recovery to provide information on database
|
|
* consistency for when users try to set hint bits. It is important
|
|
* that we do not set hint bits until the minRecoveryPoint is past
|
|
* this commit record. This ensures that if we crash we don't see hint
|
|
* bits set on changes made by transactions that haven't yet
|
|
* recovered. It's unlikely but it's good to be safe.
|
|
*/
|
|
TransactionIdAsyncCommitTree(xid, nsubxacts, sub_xids, lsn);
|
|
|
|
/*
|
|
* We must mark clog before we update the ProcArray.
|
|
*/
|
|
ExpireTreeKnownAssignedTransactionIds(xid, nsubxacts, sub_xids, max_xid);
|
|
|
|
/*
|
|
* Send any cache invalidations attached to the commit. We must
|
|
* maintain the same order of invalidation then release locks as
|
|
* occurs in CommitTransaction().
|
|
*/
|
|
ProcessCommittedInvalidationMessages(inval_msgs, nmsgs,
|
|
XactCompletionRelcacheInitFileInval(xinfo),
|
|
dbId, tsId);
|
|
|
|
/*
|
|
* Release locks, if any. We do this for both two phase and normal one
|
|
* phase transactions. In effect we are ignoring the prepare phase and
|
|
* just going straight to lock release. At commit we release all locks
|
|
* via their top-level xid only, so no need to provide subxact list,
|
|
* which will save time when replaying commits.
|
|
*/
|
|
StandbyReleaseLockTree(xid, 0, NULL);
|
|
}
|
|
|
|
/* Make sure files supposed to be dropped are dropped */
|
|
if (nrels > 0)
|
|
{
|
|
/*
|
|
* First update minimum recovery point to cover this WAL record. Once
|
|
* a relation is deleted, there's no going back. The buffer manager
|
|
* enforces the WAL-first rule for normal updates to relation files,
|
|
* so that the minimum recovery point is always updated before the
|
|
* corresponding change in the data file is flushed to disk, but we
|
|
* have to do the same here since we're bypassing the buffer manager.
|
|
*
|
|
* Doing this before deleting the files means that if a deletion fails
|
|
* for some reason, you cannot start up the system even after restart,
|
|
* until you fix the underlying situation so that the deletion will
|
|
* succeed. Alternatively, we could update the minimum recovery point
|
|
* after deletion, but that would leave a small window where the
|
|
* WAL-first rule would be violated.
|
|
*/
|
|
XLogFlush(lsn);
|
|
|
|
for (i = 0; i < nrels; i++)
|
|
{
|
|
SMgrRelation srel = smgropen(xnodes[i], InvalidBackendId);
|
|
ForkNumber fork;
|
|
|
|
for (fork = 0; fork <= MAX_FORKNUM; fork++)
|
|
XLogDropRelation(xnodes[i], fork);
|
|
smgrdounlink(srel, true);
|
|
smgrclose(srel);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We issue an XLogFlush() for the same reason we emit ForceSyncCommit()
|
|
* in normal operation. For example, in CREATE DATABASE, we copy all files
|
|
* from the template database, and then commit the transaction. If we
|
|
* crash after all the files have been copied but before the commit, you
|
|
* have files in the data directory without an entry in pg_database. To
|
|
* minimize the window for that, we use ForceSyncCommit() to rush the
|
|
* commit record to disk as quick as possible. We have the same window
|
|
* during recovery, and forcing an XLogFlush() (which updates
|
|
* minRecoveryPoint during recovery) helps to reduce that problem window,
|
|
* for any user that requested ForceSyncCommit().
|
|
*/
|
|
if (XactCompletionForceSyncCommit(xinfo))
|
|
XLogFlush(lsn);
|
|
|
|
}
|
|
|
|
/*
|
|
* Utility function to call xact_redo_commit_internal after breaking down xlrec
|
|
*/
|
|
static void
|
|
xact_redo_commit(xl_xact_commit *xlrec,
|
|
TransactionId xid, XLogRecPtr lsn)
|
|
{
|
|
TransactionId *subxacts;
|
|
SharedInvalidationMessage *inval_msgs;
|
|
|
|
/* subxid array follows relfilenodes */
|
|
subxacts = (TransactionId *) &(xlrec->xnodes[xlrec->nrels]);
|
|
/* invalidation messages array follows subxids */
|
|
inval_msgs = (SharedInvalidationMessage *) &(subxacts[xlrec->nsubxacts]);
|
|
|
|
xact_redo_commit_internal(xid, lsn, xlrec->xact_time,
|
|
subxacts, xlrec->nsubxacts,
|
|
inval_msgs, xlrec->nmsgs,
|
|
xlrec->xnodes, xlrec->nrels,
|
|
xlrec->dbId,
|
|
xlrec->tsId,
|
|
xlrec->xinfo);
|
|
}
|
|
|
|
/*
|
|
* Utility function to call xact_redo_commit_internal for compact form of message.
|
|
*/
|
|
static void
|
|
xact_redo_commit_compact(xl_xact_commit_compact *xlrec,
|
|
TransactionId xid, XLogRecPtr lsn)
|
|
{
|
|
xact_redo_commit_internal(xid, lsn, xlrec->xact_time,
|
|
xlrec->subxacts, xlrec->nsubxacts,
|
|
NULL, 0, /* inval msgs */
|
|
NULL, 0, /* relfilenodes */
|
|
InvalidOid, /* dbId */
|
|
InvalidOid, /* tsId */
|
|
0); /* xinfo */
|
|
}
|
|
|
|
/*
|
|
* Be careful with the order of execution, as with xact_redo_commit().
|
|
* The two functions are similar but differ in key places.
|
|
*
|
|
* Note also that an abort can be for a subtransaction and its children,
|
|
* not just for a top level abort. That means we have to consider
|
|
* topxid != xid, whereas in commit we would find topxid == xid always
|
|
* because subtransaction commit is never WAL logged.
|
|
*/
|
|
static void
|
|
xact_redo_abort(xl_xact_abort *xlrec, TransactionId xid)
|
|
{
|
|
TransactionId *sub_xids;
|
|
TransactionId max_xid;
|
|
int i;
|
|
|
|
sub_xids = (TransactionId *) &(xlrec->xnodes[xlrec->nrels]);
|
|
max_xid = TransactionIdLatest(xid, xlrec->nsubxacts, sub_xids);
|
|
|
|
/*
|
|
* Make sure nextXid is beyond any XID mentioned in the record.
|
|
*
|
|
* We don't expect anyone else to modify nextXid, hence we don't need to
|
|
* hold a lock while checking this. We still acquire the lock to modify
|
|
* it, though.
|
|
*/
|
|
if (TransactionIdFollowsOrEquals(max_xid,
|
|
ShmemVariableCache->nextXid))
|
|
{
|
|
LWLockAcquire(XidGenLock, LW_EXCLUSIVE);
|
|
ShmemVariableCache->nextXid = max_xid;
|
|
TransactionIdAdvance(ShmemVariableCache->nextXid);
|
|
LWLockRelease(XidGenLock);
|
|
}
|
|
|
|
if (standbyState == STANDBY_DISABLED)
|
|
{
|
|
/* Mark the transaction aborted in pg_clog, no need for async stuff */
|
|
TransactionIdAbortTree(xid, xlrec->nsubxacts, sub_xids);
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* If a transaction completion record arrives that has as-yet
|
|
* unobserved subtransactions then this will not have been fully
|
|
* handled by the call to RecordKnownAssignedTransactionIds() in the
|
|
* main recovery loop in xlog.c. So we need to do bookkeeping again to
|
|
* cover that case. This is confusing and it is easy to think this
|
|
* call is irrelevant, which has happened three times in development
|
|
* already. Leave it in.
|
|
*/
|
|
RecordKnownAssignedTransactionIds(max_xid);
|
|
|
|
/* Mark the transaction aborted in pg_clog, no need for async stuff */
|
|
TransactionIdAbortTree(xid, xlrec->nsubxacts, sub_xids);
|
|
|
|
/*
|
|
* We must update the ProcArray after we have marked clog.
|
|
*/
|
|
ExpireTreeKnownAssignedTransactionIds(xid, xlrec->nsubxacts, sub_xids, max_xid);
|
|
|
|
/*
|
|
* There are no flat files that need updating, nor invalidation
|
|
* messages to send or undo.
|
|
*/
|
|
|
|
/*
|
|
* Release locks, if any. There are no invalidations to send.
|
|
*/
|
|
StandbyReleaseLockTree(xid, xlrec->nsubxacts, sub_xids);
|
|
}
|
|
|
|
/* Make sure files supposed to be dropped are dropped */
|
|
for (i = 0; i < xlrec->nrels; i++)
|
|
{
|
|
SMgrRelation srel = smgropen(xlrec->xnodes[i], InvalidBackendId);
|
|
ForkNumber fork;
|
|
|
|
for (fork = 0; fork <= MAX_FORKNUM; fork++)
|
|
XLogDropRelation(xlrec->xnodes[i], fork);
|
|
smgrdounlink(srel, true);
|
|
smgrclose(srel);
|
|
}
|
|
}
|
|
|
|
void
|
|
xact_redo(XLogReaderState *record)
|
|
{
|
|
uint8 info = XLogRecGetInfo(record) & ~XLR_INFO_MASK;
|
|
|
|
/* Backup blocks are not used in xact records */
|
|
Assert(!XLogRecHasAnyBlockRefs(record));
|
|
|
|
if (info == XLOG_XACT_COMMIT_COMPACT)
|
|
{
|
|
xl_xact_commit_compact *xlrec = (xl_xact_commit_compact *) XLogRecGetData(record);
|
|
|
|
xact_redo_commit_compact(xlrec, XLogRecGetXid(record), record->EndRecPtr);
|
|
}
|
|
else if (info == XLOG_XACT_COMMIT)
|
|
{
|
|
xl_xact_commit *xlrec = (xl_xact_commit *) XLogRecGetData(record);
|
|
|
|
xact_redo_commit(xlrec, XLogRecGetXid(record), record->EndRecPtr);
|
|
}
|
|
else if (info == XLOG_XACT_ABORT)
|
|
{
|
|
xl_xact_abort *xlrec = (xl_xact_abort *) XLogRecGetData(record);
|
|
|
|
xact_redo_abort(xlrec, XLogRecGetXid(record));
|
|
}
|
|
else if (info == XLOG_XACT_PREPARE)
|
|
{
|
|
/* the record contents are exactly the 2PC file */
|
|
RecreateTwoPhaseFile(XLogRecGetXid(record),
|
|
XLogRecGetData(record), XLogRecGetDataLen(record));
|
|
}
|
|
else if (info == XLOG_XACT_COMMIT_PREPARED)
|
|
{
|
|
xl_xact_commit_prepared *xlrec = (xl_xact_commit_prepared *) XLogRecGetData(record);
|
|
|
|
xact_redo_commit(&xlrec->crec, xlrec->xid, record->EndRecPtr);
|
|
RemoveTwoPhaseFile(xlrec->xid, false);
|
|
}
|
|
else if (info == XLOG_XACT_ABORT_PREPARED)
|
|
{
|
|
xl_xact_abort_prepared *xlrec = (xl_xact_abort_prepared *) XLogRecGetData(record);
|
|
|
|
xact_redo_abort(&xlrec->arec, xlrec->xid);
|
|
RemoveTwoPhaseFile(xlrec->xid, false);
|
|
}
|
|
else if (info == XLOG_XACT_ASSIGNMENT)
|
|
{
|
|
xl_xact_assignment *xlrec = (xl_xact_assignment *) XLogRecGetData(record);
|
|
|
|
if (standbyState >= STANDBY_INITIALIZED)
|
|
ProcArrayApplyXidAssignment(xlrec->xtop,
|
|
xlrec->nsubxacts, xlrec->xsub);
|
|
}
|
|
else
|
|
elog(PANIC, "xact_redo: unknown op code %u", info);
|
|
}
|