#include "postgres.h"
#include "access/clog.h"
#include "access/subtrans.h"
#include "access/transam.h"
#include "utils/snapmgr.h"

Include dependency graph for transam.c:

Functions
static XidStatus	TransactionLogFetch (TransactionId transactionId)

bool	TransactionIdDidCommit (TransactionId transactionId)

bool	TransactionIdDidAbort (TransactionId transactionId)

void	TransactionIdCommitTree (TransactionId xid, int nxids, TransactionId *xids)

void	TransactionIdAsyncCommitTree (TransactionId xid, int nxids, TransactionId *xids, XLogRecPtr lsn)

void	TransactionIdAbortTree (TransactionId xid, int nxids, TransactionId *xids)

TransactionId	TransactionIdLatest (TransactionId mainxid, int nxids, const TransactionId *xids)

XLogRecPtr	TransactionIdGetCommitLSN (TransactionId xid)

Variables
static TransactionId	cachedFetchXid = InvalidTransactionId

static XidStatus	cachedFetchXidStatus

static XLogRecPtr	cachedCommitLSN

Function Documentation

◆ TransactionIdAbortTree()

void TransactionIdAbortTree	(	TransactionId	xid,
		int	nxids,
		TransactionId *	xids
	)

Definition at line 270 of file transam.c.

{
    TransactionIdSetTreeStatus(xid, nxids, xids,
                               TRANSACTION_STATUS_ABORTED, InvalidXLogRecPtr);
}

References InvalidXLogRecPtr, TRANSACTION_STATUS_ABORTED, and TransactionIdSetTreeStatus().

Referenced by RecordTransactionAbort(), RecordTransactionAbortPrepared(), and xact_redo_abort().

◆ TransactionIdAsyncCommitTree()

void TransactionIdAsyncCommitTree	(	TransactionId	xid,
		int	nxids,
		TransactionId *	xids,
		XLogRecPtr	lsn
	)

Definition at line 252 of file transam.c.

{
    TransactionIdSetTreeStatus(xid, nxids, xids,
                               TRANSACTION_STATUS_COMMITTED, lsn);
}

References TRANSACTION_STATUS_COMMITTED, and TransactionIdSetTreeStatus().

Referenced by RecordTransactionCommit(), and xact_redo_commit().

◆ TransactionIdCommitTree()

void TransactionIdCommitTree	(	TransactionId	xid,
		int	nxids,
		TransactionId *	xids
	)

Definition at line 240 of file transam.c.

{
    TransactionIdSetTreeStatus(xid, nxids, xids,
                               TRANSACTION_STATUS_COMMITTED,
                               InvalidXLogRecPtr);
}

References InvalidXLogRecPtr, TRANSACTION_STATUS_COMMITTED, and TransactionIdSetTreeStatus().

Referenced by RecordTransactionCommit(), RecordTransactionCommitPrepared(), and xact_redo_commit().

◆ TransactionIdDidAbort()

bool TransactionIdDidAbort ( TransactionId transactionId )

Definition at line 188 of file transam.c.

{
    XidStatus   xidstatus;
 
    xidstatus = TransactionLogFetch(transactionId);
 
    /*
     * If it's marked aborted, it's aborted.
     */
    if (xidstatus == TRANSACTION_STATUS_ABORTED)
        return true;
 
    /*
     * If it's marked subcommitted, we have to check the parent recursively.
     * However, if it's older than TransactionXmin, we can't look at
     * pg_subtrans; instead assume that the parent crashed without cleaning up
     * its children.
     */
    if (xidstatus == TRANSACTION_STATUS_SUB_COMMITTED)
    {
        TransactionId parentXid;
 
        if (TransactionIdPrecedes(transactionId, TransactionXmin))
            return true;
        parentXid = SubTransGetParent(transactionId);
        if (!TransactionIdIsValid(parentXid))
        {
            /* see notes in TransactionIdDidCommit */
            elog(WARNING, "no pg_subtrans entry for subcommitted XID %u",
                 transactionId);
            return true;
        }
        return TransactionIdDidAbort(parentXid);
    }
 
    /*
     * It's not aborted.
     */
    return false;
}

References elog, SubTransGetParent(), TRANSACTION_STATUS_ABORTED, TRANSACTION_STATUS_SUB_COMMITTED, TransactionIdDidAbort(), TransactionIdIsValid, TransactionIdPrecedes(), TransactionLogFetch(), TransactionXmin, and WARNING.

Referenced by DoesMultiXactIdConflict(), heap_lock_updated_tuple_rec(), heap_update(), ProcArrayApplyRecoveryInfo(), ProcessTwoPhaseBuffer(), StandbyAcquireAccessExclusiveLock(), test_lockmode_for_conflict(), TransactionIdDidAbort(), and TransactionIdIsInProgress().

◆ TransactionIdDidCommit()

bool TransactionIdDidCommit ( TransactionId transactionId )

Definition at line 126 of file transam.c.

{
    XidStatus   xidstatus;
 
    xidstatus = TransactionLogFetch(transactionId);
 
    /*
     * If it's marked committed, it's committed.
     */
    if (xidstatus == TRANSACTION_STATUS_COMMITTED)
        return true;
 
    /*
     * If it's marked subcommitted, we have to check the parent recursively.
     * However, if it's older than TransactionXmin, we can't look at
     * pg_subtrans; instead assume that the parent crashed without cleaning up
     * its children.
     *
     * Originally we Assert'ed that the result of SubTransGetParent was not
     * zero. However with the introduction of prepared transactions, there can
     * be a window just after database startup where we do not have complete
     * knowledge in pg_subtrans of the transactions after TransactionXmin.
     * StartupSUBTRANS() has ensured that any missing information will be
     * zeroed.  Since this case should not happen under normal conditions, it
     * seems reasonable to emit a WARNING for it.
     */
    if (xidstatus == TRANSACTION_STATUS_SUB_COMMITTED)
    {
        TransactionId parentXid;
 
        if (TransactionIdPrecedes(transactionId, TransactionXmin))
            return false;
        parentXid = SubTransGetParent(transactionId);
        if (!TransactionIdIsValid(parentXid))
        {
            elog(WARNING, "no pg_subtrans entry for subcommitted XID %u",
                 transactionId);
            return false;
        }
        return TransactionIdDidCommit(parentXid);
    }
 
    /*
     * It's not committed.
     */
    return false;
}

References elog, SubTransGetParent(), TRANSACTION_STATUS_COMMITTED, TRANSACTION_STATUS_SUB_COMMITTED, TransactionIdDidCommit(), TransactionIdIsValid, TransactionIdPrecedes(), TransactionLogFetch(), TransactionXmin, and WARNING.

Referenced by AsyncNotifyFreezeXids(), asyncQueueProcessPageEntries(), check_safe_enum_use(), compute_new_xmax_infomask(), FreezeMultiXactId(), get_xid_status(), HandleConcurrentAbort(), heap_pre_freeze_checks(), HeapTupleHeaderAdvanceConflictHorizon(), HeapTupleHeaderIsOnlyLocked(), HeapTupleSatisfiesDirty(), HeapTupleSatisfiesHistoricMVCC(), HeapTupleSatisfiesMVCC(), HeapTupleSatisfiesSelf(), HeapTupleSatisfiesToast(), HeapTupleSatisfiesUpdate(), HeapTupleSatisfiesVacuumHorizon(), MultiXactIdExpand(), pg_xact_status(), ProcArrayApplyRecoveryInfo(), ProcessTwoPhaseBuffer(), RecordTransactionAbort(), RecordTransactionAbortPrepared(), ReorderBufferCheckAndTruncateAbortedTXN(), SetupCheckXidLive(), StandbyAcquireAccessExclusiveLock(), test_lockmode_for_conflict(), TransactionIdDidCommit(), UpdateLogicalMappings(), and UpdateXmaxHintBits().

◆ TransactionIdGetCommitLSN()

XLogRecPtr TransactionIdGetCommitLSN ( TransactionId xid )

Definition at line 318 of file transam.c.

{
    XLogRecPtr  result;
 
    /*
     * Currently, all uses of this function are for xids that were just
     * reported to be committed by TransactionLogFetch, so we expect that
     * checking TransactionLogFetch's cache will usually succeed and avoid an
     * extra trip to shared memory.
     */
    if (TransactionIdEquals(xid, cachedFetchXid))
        return cachedCommitLSN;
 
    /* Special XIDs are always known committed */
    if (!TransactionIdIsNormal(xid))
        return InvalidXLogRecPtr;
 
    /*
     * Get the transaction status.
     */
    (void) TransactionIdGetStatus(xid, &result);
 
    return result;
}

References cachedCommitLSN, cachedFetchXid, InvalidXLogRecPtr, TransactionIdEquals, TransactionIdGetStatus(), and TransactionIdIsNormal.

Referenced by SetHintBits().

◆ TransactionIdLatest()

TransactionId TransactionIdLatest	(	TransactionId	mainxid,
		int	nxids,
		const TransactionId *	xids
	)

Definition at line 281 of file transam.c.

{
    TransactionId result;
 
    /*
     * In practice it is highly likely that the xids[] array is sorted, and so
     * we could save some cycles by just taking the last child XID, but this
     * probably isn't so performance-critical that it's worth depending on
     * that assumption.  But just to show we're not totally stupid, scan the
     * array back-to-front to avoid useless assignments.
     */
    result = mainxid;
    while (--nxids >= 0)
    {
        if (TransactionIdPrecedes(result, xids[nxids]))
            result = xids[nxids];
    }
    return result;
}

References TransactionIdPrecedes().

Referenced by FinishPreparedTransaction(), ProcArrayApplyXidAssignment(), RecordTransactionAbort(), RecordTransactionCommit(), xact_redo_abort(), and xact_redo_commit().

◆ TransactionLogFetch()

static XidStatus TransactionLogFetch ( TransactionId transactionId )

static

Definition at line 52 of file transam.c.

{
    XidStatus   xidstatus;
    XLogRecPtr  xidlsn;
 
    /*
     * Before going to the commit log manager, check our single item cache to
     * see if we didn't just check the transaction status a moment ago.
     */
    if (TransactionIdEquals(transactionId, cachedFetchXid))
        return cachedFetchXidStatus;
 
    /*
     * Also, check to see if the transaction ID is a permanent one.
     */
    if (!TransactionIdIsNormal(transactionId))
    {
        if (TransactionIdEquals(transactionId, BootstrapTransactionId))
            return TRANSACTION_STATUS_COMMITTED;
        if (TransactionIdEquals(transactionId, FrozenTransactionId))
            return TRANSACTION_STATUS_COMMITTED;
        return TRANSACTION_STATUS_ABORTED;
    }
 
    /*
     * Get the transaction status.
     */
    xidstatus = TransactionIdGetStatus(transactionId, &xidlsn);
 
    /*
     * Cache it, but DO NOT cache status for unfinished or sub-committed
     * transactions!  We only cache status that is guaranteed not to change.
     */
    if (xidstatus != TRANSACTION_STATUS_IN_PROGRESS &&
        xidstatus != TRANSACTION_STATUS_SUB_COMMITTED)
    {
        cachedFetchXid = transactionId;
        cachedFetchXidStatus = xidstatus;
        cachedCommitLSN = xidlsn;
    }
 
    return xidstatus;
}