*
* See src/backend/access/transam/README for more information.
*
- * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/access/transam/xact.c,v 1.210 2005/07/13 22:46:09 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/access/transam/xact.c,v 1.260 2008/03/17 19:44:41 petere Exp $
*
*-------------------------------------------------------------------------
*/
#include "access/multixact.h"
#include "access/subtrans.h"
+#include "access/transam.h"
#include "access/twophase.h"
#include "access/xact.h"
-#include "catalog/heap.h"
-#include "catalog/index.h"
+#include "access/xlogutils.h"
#include "catalog/namespace.h"
#include "commands/async.h"
#include "commands/tablecmds.h"
#include "executor/spi.h"
#include "libpq/be-fsstubs.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "storage/fd.h"
-#include "storage/proc.h"
+#include "storage/lmgr.h"
#include "storage/procarray.h"
+#include "storage/sinvaladt.h"
#include "storage/smgr.h"
+#include "utils/combocid.h"
#include "utils/flatfiles.h"
#include "utils/guc.h"
#include "utils/inval.h"
#include "utils/memutils.h"
-#include "utils/portal.h"
#include "utils/relcache.h"
-#include "utils/resowner.h"
-#include "pgstat.h"
+#include "utils/xml.h"
+#include "pg_trace.h"
/*
bool DefaultXactReadOnly = false;
bool XactReadOnly;
+bool XactSyncCommit = true;
+
int CommitDelay = 0; /* precommit delay in microseconds */
int CommitSiblings = 5; /* # concurrent xacts needed to sleep */
+/*
+ * MyXactAccessedTempRel is set when a temporary relation is accessed.
+ * We don't allow PREPARE TRANSACTION in that case. (This is global
+ * so that it can be set from heapam.c.)
+ */
+bool MyXactAccessedTempRel = false;
+
/*
* transaction states - transaction state from server perspective
*/
typedef enum TransState
{
- TRANS_DEFAULT,
- TRANS_START,
- TRANS_INPROGRESS,
- TRANS_COMMIT,
- TRANS_ABORT,
- TRANS_PREPARE
+ TRANS_DEFAULT, /* idle */
+ TRANS_START, /* transaction starting */
+ TRANS_INPROGRESS, /* inside a valid transaction */
+ TRANS_COMMIT, /* commit in progress */
+ TRANS_ABORT, /* abort in progress */
+ TRANS_PREPARE /* prepare in progress */
} TransState;
/*
*/
typedef struct TransactionStateData
{
- TransactionId transactionId; /* my XID, or Invalid if none */
+ TransactionId transactionId; /* my XID, or Invalid if none */
SubTransactionId subTransactionId; /* my subxact ID */
char *name; /* savepoint name, if any */
int savepointLevel; /* savepoint level */
TransState state; /* low-level state */
TBlockState blockState; /* high-level state */
- int nestingLevel; /* nest depth */
- MemoryContext curTransactionContext; /* my xact-lifetime
- * context */
+ int nestingLevel; /* transaction nesting depth */
+ int gucNestLevel; /* GUC context nesting depth */
+ MemoryContext curTransactionContext; /* my xact-lifetime context */
ResourceOwner curTransactionOwner; /* my query resources */
- List *childXids; /* subcommitted child XIDs */
- Oid currentUser; /* subxact start current_user */
+ TransactionId *childXids; /* subcommitted child XIDs, in XID order */
+ int nChildXids; /* # of subcommitted child XIDs */
+ int maxChildXids; /* allocated size of childXids[] */
+ Oid prevUser; /* previous CurrentUserId setting */
+ bool prevSecDefCxt; /* previous SecurityDefinerContext setting */
bool prevXactReadOnly; /* entry-time xact r/o state */
struct TransactionStateData *parent; /* back link to parent */
} TransactionStateData;
typedef TransactionStateData *TransactionState;
-/*
- * childXids is currently implemented as an integer List, relying on the
- * assumption that TransactionIds are no wider than int. We use these
- * macros to provide some isolation in case that changes in the future.
- */
-#define lfirst_xid(lc) ((TransactionId) lfirst_int(lc))
-#define lappend_xid(list, datum) lappend_int(list, (int) (datum))
-
/*
* CurrentTransactionState always points to the current transaction state
* block. It will point to TopTransactionStateData when not in a
TRANS_DEFAULT, /* transaction state */
TBLOCK_DEFAULT, /* transaction block state from the client
* perspective */
- 0, /* nesting level */
+ 0, /* transaction nesting depth */
+ 0, /* GUC context nesting depth */
NULL, /* cur transaction context */
NULL, /* cur transaction resource owner */
- NIL, /* subcommitted child Xids */
- 0, /* entry-time current userid */
+ NULL, /* subcommitted child Xids */
+ 0, /* # of subcommitted child Xids */
+ 0, /* allocated size of childXids[] */
+ InvalidOid, /* previous CurrentUserId setting */
+ false, /* previous SecurityDefinerContext setting */
false, /* entry-time xact r/o state */
NULL /* link to parent state block */
};
*/
static SubTransactionId currentSubTransactionId;
static CommandId currentCommandId;
+static bool currentCommandIdUsed;
/*
- * This is the value of now(), ie, the transaction start time.
- * This does not change as we enter and exit subtransactions, so we don't
- * keep it inside the TransactionState stack.
+ * xactStartTimestamp is the value of transaction_timestamp().
+ * stmtStartTimestamp is the value of statement_timestamp().
+ * xactStopTimestamp is the time at which we log a commit or abort WAL record.
+ * These do not change as we enter and exit subtransactions, so we don't
+ * keep them inside the TransactionState stack.
*/
static TimestampTz xactStartTimestamp;
+static TimestampTz stmtStartTimestamp;
+static TimestampTz xactStopTimestamp;
/*
* GID to be used for preparing the current transaction. This is also
*/
static char *prepareGID;
+/*
+ * Some commands want to force synchronous commit.
+ */
+static bool forceSyncCommit = false;
+
+/*
+ * Private context for transaction-abort work --- we reserve space for this
+ * at startup to ensure that AbortTransaction and AbortSubTransaction can work
+ * when we've run out of memory.
+ */
+static MemoryContext TransactionAbortContext = NULL;
/*
* List of add-on start- and end-of-xact callbacks
/* local function prototypes */
-static void AssignSubTransactionId(TransactionState s);
+static void AssignTransactionId(TransactionState s);
static void AbortTransaction(void);
static void AtAbort_Memory(void);
static void AtCleanup_Memory(void);
static void AtStart_ResourceOwner(void);
static void CallXactCallbacks(XactEvent event);
static void CallSubXactCallbacks(SubXactEvent event,
- SubTransactionId mySubid,
- SubTransactionId parentSubid);
+ SubTransactionId mySubid,
+ SubTransactionId parentSubid);
static void CleanupTransaction(void);
static void CommitTransaction(void);
-static void RecordTransactionAbort(void);
+static TransactionId RecordTransactionAbort(bool isSubXact);
static void StartTransaction(void);
static void RecordSubTransactionCommit(void);
/*
* IsTransactionState
*
- * This returns true if we are currently running a query
- * within an executing transaction.
+ * This returns true if we are inside a valid transaction; that is,
+ * it is safe to initiate database access, take heavyweight locks, etc.
*/
bool
IsTransactionState(void)
{
TransactionState s = CurrentTransactionState;
- switch (s->state)
- {
- case TRANS_DEFAULT:
- return false;
- case TRANS_START:
- return true;
- case TRANS_INPROGRESS:
- return true;
- case TRANS_COMMIT:
- return true;
- case TRANS_ABORT:
- return true;
- case TRANS_PREPARE:
- return true;
- }
-
/*
- * Shouldn't get here, but lint is not happy without this...
+ * TRANS_DEFAULT and TRANS_ABORT are obviously unsafe states. However, we
+ * also reject the startup/shutdown states TRANS_START, TRANS_COMMIT,
+ * TRANS_PREPARE since it might be too soon or too late within those
+ * transition states to do anything interesting. Hence, the only "valid"
+ * state is TRANS_INPROGRESS.
*/
- return false;
+ return (s->state == TRANS_INPROGRESS);
}
/*
/*
* GetTopTransactionId
*
- * Get the ID of the main transaction, even if we are currently inside
- * a subtransaction.
+ * This will return the XID of the main transaction, assigning one if
+ * it's not yet set. Be careful to call this only inside a valid xact.
*/
TransactionId
GetTopTransactionId(void)
{
+ if (!TransactionIdIsValid(TopTransactionStateData.transactionId))
+ AssignTransactionId(&TopTransactionStateData);
return TopTransactionStateData.transactionId;
}
+/*
+ * GetTopTransactionIdIfAny
+ *
+ * This will return the XID of the main transaction, if one is assigned.
+ * It will return InvalidTransactionId if we are not currently inside a
+ * transaction, or inside a transaction that hasn't yet been assigned an XID.
+ */
+TransactionId
+GetTopTransactionIdIfAny(void)
+{
+ return TopTransactionStateData.transactionId;
+}
/*
* GetCurrentTransactionId
*
- * We do not assign XIDs to subtransactions until/unless this is called.
- * When we do assign an XID to a subtransaction, recursively make sure
- * its parent has one as well (this maintains the invariant that a child
- * transaction has an XID following its parent's).
+ * This will return the XID of the current transaction (main or sub
+ * transaction), assigning one if it's not yet set. Be careful to call this
+ * only inside a valid xact.
*/
TransactionId
GetCurrentTransactionId(void)
TransactionState s = CurrentTransactionState;
if (!TransactionIdIsValid(s->transactionId))
- AssignSubTransactionId(s);
-
+ AssignTransactionId(s);
return s->transactionId;
}
+/*
+ * GetCurrentTransactionIdIfAny
+ *
+ * This will return the XID of the current sub xact, if one is assigned.
+ * It will return InvalidTransactionId if we are not currently inside a
+ * transaction, or inside a transaction that hasn't been assigned an XID yet.
+ */
+TransactionId
+GetCurrentTransactionIdIfAny(void)
+{
+ return CurrentTransactionState->transactionId;
+}
+
+
+/*
+ * AssignTransactionId
+ *
+ * Assigns a new permanent XID to the given TransactionState.
+ * We do not assign XIDs to transactions until/unless this is called.
+ * Also, any parent TransactionStates that don't yet have XIDs are assigned
+ * one; this maintains the invariant that a child transaction has an XID
+ * following its parent's.
+ */
static void
-AssignSubTransactionId(TransactionState s)
+AssignTransactionId(TransactionState s)
{
+ bool isSubXact = (s->parent != NULL);
ResourceOwner currentOwner;
- Assert(s->parent != NULL);
+ /* Assert that caller didn't screw up */
+ Assert(!TransactionIdIsValid(s->transactionId));
Assert(s->state == TRANS_INPROGRESS);
- if (!TransactionIdIsValid(s->parent->transactionId))
- AssignSubTransactionId(s->parent);
+
+ /*
+ * Ensure parent(s) have XIDs, so that a child always has an XID later
+ * than its parent.
+ */
+ if (isSubXact && !TransactionIdIsValid(s->parent->transactionId))
+ AssignTransactionId(s->parent);
/*
* Generate a new Xid and record it in PG_PROC and pg_subtrans.
*
- * NB: we must make the subtrans entry BEFORE the Xid appears anywhere
- * in shared storage other than PG_PROC; because if there's no room for
- * it in PG_PROC, the subtrans entry is needed to ensure that other
- * backends see the Xid as "running". See GetNewTransactionId.
+ * NB: we must make the subtrans entry BEFORE the Xid appears anywhere in
+ * shared storage other than PG_PROC; because if there's no room for it in
+ * PG_PROC, the subtrans entry is needed to ensure that other backends see
+ * the Xid as "running". See GetNewTransactionId.
*/
- s->transactionId = GetNewTransactionId(true);
+ s->transactionId = GetNewTransactionId(isSubXact);
- SubTransSetParent(s->transactionId, s->parent->transactionId);
+ if (isSubXact)
+ SubTransSetParent(s->transactionId, s->parent->transactionId);
/*
- * Acquire lock on the transaction XID. (We assume this cannot block.)
- * We have to be sure that the lock is assigned to the transaction's
+ * Acquire lock on the transaction XID. (We assume this cannot block.) We
+ * have to ensure that the lock is assigned to the transaction's own
* ResourceOwner.
*/
currentOwner = CurrentResourceOwner;
PG_TRY();
{
CurrentResourceOwner = s->curTransactionOwner;
-
XactLockTableInsert(s->transactionId);
}
PG_CATCH();
}
-/*
- * GetCurrentTransactionIdIfAny
- *
- * Unlike GetCurrentTransactionId, this will return InvalidTransactionId
- * if we are currently not in a transaction, or in a transaction or
- * subtransaction that has not yet assigned itself an XID.
- */
-TransactionId
-GetCurrentTransactionIdIfAny(void)
-{
- TransactionState s = CurrentTransactionState;
-
- return s->transactionId;
-}
-
-
/*
* GetCurrentSubTransactionId
*/
/*
* 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(void)
+GetCurrentCommandId(bool used)
{
/* this is global to a transaction, not subtransaction-local */
+ if (used)
+ currentCommandIdUsed = true;
return currentCommandId;
}
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
*
/*
* We always say that BootstrapTransactionId is "not my transaction ID"
- * even when it is (ie, during bootstrap). Along with the fact that
+ * 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.)
+ * 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 (xid == BootstrapTransactionId)
+ 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.
+ * 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)
{
- ListCell *cell;
+ int low, high;
if (s->state == TRANS_ABORT)
continue;
continue; /* it can't have any child XIDs either */
if (TransactionIdEquals(xid, s->transactionId))
return true;
- foreach(cell, s->childXids)
+ /* As the childXids array is ordered, we can use binary search */
+ low = 0;
+ high = s->nChildXids - 1;
+ while (low <= high)
{
- if (TransactionIdEquals(xid, lfirst_xid(cell)))
+ 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;
}
}
void
CommandCounterIncrement(void)
{
- currentCommandId += 1;
- if (currentCommandId == FirstCommandId) /* check for overflow */
+ /*
+ * 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;
- ereport(ERROR,
- (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
- errmsg("cannot have more than 2^32-1 commands in a transaction")));
- }
+ currentCommandId += 1;
+ if (currentCommandId == FirstCommandId) /* check for overflow */
+ {
+ currentCommandId -= 1;
+ ereport(ERROR,
+ (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+ errmsg("cannot have more than 2^32-1 commands in a transaction")));
+ }
+ currentCommandIdUsed = false;
- /* Propagate new command ID into static snapshots, if set */
- if (SerializableSnapshot)
- SerializableSnapshot->curcid = currentCommandId;
- if (LatestSnapshot)
- LatestSnapshot->curcid = currentCommandId;
+ /* Propagate new command ID into static snapshots, if set */
+ if (SerializableSnapshot)
+ SerializableSnapshot->curcid = currentCommandId;
+ if (LatestSnapshot)
+ LatestSnapshot->curcid = 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.)
+ */
+ AtCommit_LocalCache();
+ }
/*
- * make cache changes visible to me.
+ * Make any other backends' catalog changes visible to me.
+ *
+ * XXX this is probably in the wrong place: CommandCounterIncrement
+ * should be purely a local operation, most likely. However fooling
+ * with this will affect asynchronous cross-backend interactions,
+ * which doesn't seem like a wise thing to do in late beta, so save
+ * improving this for another day - tgl 2007-11-30
*/
- AtCommit_LocalCache();
AtStart_Cache();
}
+/*
+ * ForceSyncCommit
+ *
+ * Interface routine to allow commands to force a synchronous commit of the
+ * current top-level transaction
+ */
+void
+ForceSyncCommit(void)
+{
+ forceSyncCommit = true;
+}
+
/* ----------------------------------------------------------------
* StartTransaction stuff
{
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(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.
+ * 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);
+ ALLOCSET_DEFAULT_MINSIZE,
+ ALLOCSET_DEFAULT_INITSIZE,
+ ALLOCSET_DEFAULT_MAXSIZE);
s->curTransactionContext = CurTransactionContext;
/* Make the CurTransactionContext active. */
Assert(s->parent != NULL);
/*
- * Create a resource owner for the subtransaction. We make it a child
- * of the immediate parent's resource owner.
+ * 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,
/*
* 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.)
+ *
+ * This is exported only to support an ugly hack in VACUUM FULL.
*/
-void
+TransactionId
RecordTransactionCommit(void)
{
+ TransactionId xid = GetTopTransactionIdIfAny();
+ bool markXidCommitted = TransactionIdIsValid(xid);
+ TransactionId latestXid = InvalidTransactionId;
int nrels;
RelFileNode *rels;
+ bool haveNonTemp;
int nchildren;
TransactionId *children;
/* Get data needed for commit record */
- nrels = smgrGetPendingDeletes(true, &rels);
+ nrels = smgrGetPendingDeletes(true, &rels, &haveNonTemp);
nchildren = xactGetCommittedChildren(&children);
/*
- * If we made neither any XLOG entries nor any temp-rel updates, and
- * have no files to be deleted, we can omit recording the transaction
- * commit at all. (This test includes the effects of subtransactions,
- * so the presence of committed subxacts need not alone force a
- * write.)
+ * If we haven't been assigned an XID yet, we neither can, nor do we want
+ * to write a COMMIT record.
*/
- if (MyXactMadeXLogEntry || MyXactMadeTempRelUpdate || nrels > 0)
+ if (!markXidCommitted)
{
- TransactionId xid = GetCurrentTransactionId();
- bool madeTCentries;
- XLogRecPtr recptr;
+ /*
+ * 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 (XactLastRecEnd.xrecoff == 0)
+ goto cleanup;
+ }
+ else
+ {
+ /*
+ * Begin commit critical section and insert the commit XLOG record.
+ */
+ XLogRecData rdata[3];
+ int lastrdata = 0;
+ xl_xact_commit xlrec;
/* Tell bufmgr and smgr to prepare for commit */
BufmgrCommit();
- START_CRIT_SECTION();
-
/*
- * If our transaction made any transaction-controlled XLOG
- * entries, we need to lock out checkpoint start between writing
- * our XLOG record and updating pg_clog. Otherwise 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 we crash a little later. Slightly klugy
- * fix for problem discovered 2004-08-10.
+ * 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.
*
- * (If it made no transaction-controlled XLOG entries, its XID
- * appears nowhere in permanent storage, so no one else will ever
- * care if it committed; so it doesn't matter if we lose the
- * commit flag.)
+ * 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.
*
- * Note we only need a shared lock.
+ * It's safe to change the inCommit 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 inCommit a
+ * bit fuzzy, but it doesn't matter.
*/
- madeTCentries = (MyLastRecPtr.xrecoff != 0);
- if (madeTCentries)
- LWLockAcquire(CheckpointStartLock, LW_SHARED);
-
- /*
- * We only need to log the commit in XLOG if the transaction made
- * any transaction-controlled XLOG entries or will delete files.
- */
- if (madeTCentries || nrels > 0)
+ START_CRIT_SECTION();
+ MyProc->inCommit = true;
+
+ SetCurrentTransactionStopTimestamp();
+ xlrec.xact_time = xactStopTimestamp;
+ xlrec.nrels = nrels;
+ xlrec.nsubxacts = nchildren;
+ rdata[0].data = (char *) (&xlrec);
+ rdata[0].len = MinSizeOfXactCommit;
+ rdata[0].buffer = InvalidBuffer;
+ /* dump rels to delete */
+ if (nrels > 0)
{
- XLogRecData rdata[3];
- int lastrdata = 0;
- xl_xact_commit xlrec;
-
- xlrec.xtime = time(NULL);
- xlrec.nrels = nrels;
- xlrec.nsubxacts = nchildren;
- rdata[0].data = (char *) (&xlrec);
- rdata[0].len = MinSizeOfXactCommit;
- rdata[0].buffer = InvalidBuffer;
- /* dump rels to delete */
- if (nrels > 0)
- {
- rdata[0].next = &(rdata[1]);
- rdata[1].data = (char *) rels;
- rdata[1].len = nrels * sizeof(RelFileNode);
- rdata[1].buffer = InvalidBuffer;
- lastrdata = 1;
- }
- /* dump committed child Xids */
- if (nchildren > 0)
- {
- rdata[lastrdata].next = &(rdata[2]);
- rdata[2].data = (char *) children;
- rdata[2].len = nchildren * sizeof(TransactionId);
- rdata[2].buffer = InvalidBuffer;
- lastrdata = 2;
- }
- rdata[lastrdata].next = NULL;
-
- recptr = XLogInsert(RM_XACT_ID, XLOG_XACT_COMMIT, rdata);
+ rdata[0].next = &(rdata[1]);
+ rdata[1].data = (char *) rels;
+ rdata[1].len = nrels * sizeof(RelFileNode);
+ rdata[1].buffer = InvalidBuffer;
+ lastrdata = 1;
}
- else
+ /* dump committed child Xids */
+ if (nchildren > 0)
{
- /* Just flush through last record written by me */
- recptr = ProcLastRecEnd;
+ rdata[lastrdata].next = &(rdata[2]);
+ rdata[2].data = (char *) children;
+ rdata[2].len = nchildren * sizeof(TransactionId);
+ rdata[2].buffer = InvalidBuffer;
+ lastrdata = 2;
}
+ rdata[lastrdata].next = NULL;
+
+ (void) XLogInsert(RM_XACT_ID, XLOG_XACT_COMMIT, rdata);
+ }
+ /*
+ * Check if we want to commit asynchronously. If the user has set
+ * synchronous_commit = off, and we're not doing cleanup of any non-temp
+ * rels nor committing any command that wanted to force sync commit, then
+ * we can defer flushing XLOG. (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 (XactSyncCommit || forceSyncCommit || haveNonTemp)
+ {
/*
- * We must flush our XLOG entries to disk if we made any XLOG
- * entries, whether in or out of transaction control. For
- * example, if we reported a nextval() result to the client, this
- * ensures that any XLOG record generated by nextval will hit the
- * disk before we report the transaction committed.
+ * Synchronous commit case.
*
- * Note: if we generated a commit record above, MyXactMadeXLogEntry
- * will certainly be set now.
+ * Sleep before flush! So we can flush more than one commit records
+ * per single fsync. (The idea is some other backend may do the
+ * XLogFlush while we're sleeping. This needs work still, because on
+ * most Unixen, the minimum select() delay is 10msec or more, which is
+ * way too long.)
+ *
+ * We do not sleep if enableFsync is not turned on, nor if there are
+ * fewer than CommitSiblings other backends with active transactions.
*/
- if (MyXactMadeXLogEntry)
- {
- /*
- * Sleep before flush! So we can flush more than one commit
- * records per single fsync. (The idea is some other backend
- * may do the XLogFlush while we're sleeping. This needs work
- * still, because on most Unixen, the minimum select() delay
- * is 10msec or more, which is way too long.)
- *
- * We do not sleep if enableFsync is not turned on, nor if there
- * are fewer than CommitSiblings other backends with active
- * transactions.
- */
- if (CommitDelay > 0 && enableFsync &&
- CountActiveBackends() >= CommitSiblings)
- pg_usleep(CommitDelay);
+ if (CommitDelay > 0 && enableFsync &&
+ CountActiveBackends() >= CommitSiblings)
+ pg_usleep(CommitDelay);
- XLogFlush(recptr);
- }
+ XLogFlush(XactLastRecEnd);
/*
- * We must mark the transaction committed in clog if its XID
- * appears either in permanent rels or in local temporary rels. We
- * test this by seeing if we made transaction-controlled entries
- * *OR* local-rel tuple updates. Note that if we made only the
- * latter, we have not emitted an XLOG record for our commit, and
- * so in the event of a crash the clog update might be lost. This
- * is okay because no one else will ever care whether we
- * committed.
+ * Now we may update the CLOG, if we wrote a COMMIT record above
*/
- if (madeTCentries || MyXactMadeTempRelUpdate)
+ if (markXidCommitted)
{
TransactionIdCommit(xid);
/* to avoid race conditions, the parent must commit first */
TransactionIdCommitTree(nchildren, children);
}
+ }
+ else
+ {
+ /*
+ * Asynchronous commit case.
+ *
+ * Report the latest async commit LSN, so that the WAL writer knows to
+ * flush this commit.
+ */
+ XLogSetAsyncCommitLSN(XactLastRecEnd);
- /* Unlock checkpoint lock if we acquired it */
- if (madeTCentries)
- LWLockRelease(CheckpointStartLock);
+ /*
+ * 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)
+ {
+ TransactionIdAsyncCommit(xid, XactLastRecEnd);
+ /* to avoid race conditions, the parent must commit first */
+ TransactionIdAsyncCommitTree(nchildren, children, XactLastRecEnd);
+ }
+ }
+ /*
+ * If we entered a commit critical section, leave it now, and let
+ * checkpoints proceed.
+ */
+ if (markXidCommitted)
+ {
+ MyProc->inCommit = false;
END_CRIT_SECTION();
}
- /* Break the chain of back-links in the XLOG records I output */
- MyLastRecPtr.xrecoff = 0;
- MyXactMadeXLogEntry = false;
- MyXactMadeTempRelUpdate = false;
+ /* Compute latestXid while we have the child XIDs handy */
+ latestXid = TransactionIdLatest(xid, nchildren, children);
- /* And clean up local data */
+ /* Reset XactLastRecEnd until the next transaction writes something */
+ XactLastRecEnd.xrecoff = 0;
+
+cleanup:
+ /* Clean up local data */
if (rels)
pfree(rels);
- if (children)
- pfree(children);
+
+ return latestXid;
}
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.
+ * 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);
/*
* 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.
+ * 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))
{
AtSubCommit_childXids(void)
{
TransactionState s = CurrentTransactionState;
- MemoryContext old_cxt;
+ int new_nChildXids;
Assert(s->parent != NULL);
/*
- * We keep the child-XID lists in TopTransactionContext; this avoids
- * setting up child-transaction contexts for what might be just a few
- * bytes of grandchild XIDs.
+ * The parent childXids array will need to hold my XID and all my
+ * childXids, in addition to the XIDs already there.
*/
- old_cxt = MemoryContextSwitchTo(TopTransactionContext);
+ new_nChildXids = s->parent->nChildXids + s->nChildXids + 1;
- s->parent->childXids = lappend_xid(s->parent->childXids,
- s->transactionId);
-
- if (s->childXids != NIL)
+ /* Allocate or enlarge the parent array if necessary */
+ if (s->parent->maxChildXids < new_nChildXids)
{
- s->parent->childXids = list_concat(s->parent->childXids,
- s->childXids);
+ int new_maxChildXids;
+ TransactionId *new_childXids;
+
/*
- * list_concat doesn't free the list header for the second list;
- * do so here to avoid memory leakage (kluge)
+ * 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.)
*/
- pfree(s->childXids);
- s->childXids = NIL;
+ 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;
}
- MemoryContextSwitchTo(old_cxt);
+ /*
+ * 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;
}
/*
static void
RecordSubTransactionCommit(void)
{
+ TransactionId xid = GetCurrentTransactionIdIfAny();
+
/*
* We do not log the subcommit in XLOG; it doesn't matter until the
* top-level transaction commits.
*
- * We must mark the subtransaction subcommitted in clog if its XID
- * appears either in permanent rels or in local temporary rels. We
- * test this by seeing if we made transaction-controlled entries *OR*
- * local-rel tuple updates. (The test here actually covers the entire
- * transaction tree so far, so it may mark subtransactions that don't
- * really need it, but it's probably not worth being tenser. Note that
- * if a prior subtransaction dirtied these variables, then
- * RecordTransactionCommit will have to do the full pushup anyway...)
+ * We must mark the subtransaction subcommitted in the CLOG if it had a
+ * valid XID assigned. If it did not, nobody else will ever know about
+ * the existence of this subxact. We don't have to deal with deletions
+ * scheduled for on-commit here, since they'll be reassigned to our parent
+ * (who might still abort).
*/
- if (MyLastRecPtr.xrecoff != 0 || MyXactMadeTempRelUpdate)
+ if (TransactionIdIsValid(xid))
{
- TransactionId xid = GetCurrentTransactionId();
-
/* XXX does this really need to be a critical section? */
START_CRIT_SECTION();
/*
* 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 void
-RecordTransactionAbort(void)
+static TransactionId
+RecordTransactionAbort(bool isSubXact)
{
+ TransactionId xid = GetCurrentTransactionIdIfAny();
+ TransactionId latestXid;
int nrels;
RelFileNode *rels;
int nchildren;
TransactionId *children;
-
- /* Get data needed for abort record */
- nrels = smgrGetPendingDeletes(false, &rels);
- nchildren = xactGetCommittedChildren(&children);
+ XLogRecData rdata[3];
+ int lastrdata = 0;
+ xl_xact_abort xlrec;
/*
- * If we made neither any transaction-controlled XLOG entries nor any
- * temp-rel updates, and are not going to delete any files, we can
- * omit recording the transaction abort at all. No one will ever care
- * that it aborted. (These tests cover our whole transaction tree.)
+ * 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 (MyLastRecPtr.xrecoff != 0 || MyXactMadeTempRelUpdate || nrels > 0)
+ if (!TransactionIdIsValid(xid))
{
- TransactionId xid = GetCurrentTransactionId();
+ /* Reset XactLastRecEnd until the next transaction writes something */
+ if (!isSubXact)
+ XactLastRecEnd.xrecoff = 0;
+ return InvalidTransactionId;
+ }
- /*
- * Catch the scenario where we aborted partway through
- * RecordTransactionCommit ...
- */
- if (TransactionIdDidCommit(xid))
- elog(PANIC, "cannot abort transaction %u, it was already committed", xid);
+ /*
+ * 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.
+ */
- START_CRIT_SECTION();
+ /*
+ * Check that we haven't aborted halfway through RecordTransactionCommit.
+ */
+ if (TransactionIdDidCommit(xid))
+ elog(PANIC, "cannot abort transaction %u, it was already committed",
+ xid);
- /*
- * We only need to log the abort in XLOG if the transaction made
- * any transaction-controlled XLOG entries or will delete files.
- * (If it made no transaction-controlled XLOG entries, its XID
- * appears nowhere in permanent storage, so no one else will ever
- * care if it committed.)
- *
- * We do not flush XLOG to disk unless deleting files, 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.
- */
- if (MyLastRecPtr.xrecoff != 0 || nrels > 0)
- {
- XLogRecData rdata[3];
- int lastrdata = 0;
- xl_xact_abort xlrec;
- XLogRecPtr recptr;
-
- xlrec.xtime = time(NULL);
- xlrec.nrels = nrels;
- xlrec.nsubxacts = nchildren;
- rdata[0].data = (char *) (&xlrec);
- rdata[0].len = MinSizeOfXactAbort;
- rdata[0].buffer = InvalidBuffer;
- /* dump rels to delete */
- if (nrels > 0)
- {
- rdata[0].next = &(rdata[1]);
- rdata[1].data = (char *) rels;
- rdata[1].len = nrels * sizeof(RelFileNode);
- rdata[1].buffer = InvalidBuffer;
- lastrdata = 1;
- }
- /* dump committed child Xids */
- if (nchildren > 0)
- {
- rdata[lastrdata].next = &(rdata[2]);
- rdata[2].data = (char *) children;
- rdata[2].len = nchildren * sizeof(TransactionId);
- rdata[2].buffer = InvalidBuffer;
- lastrdata = 2;
- }
- rdata[lastrdata].next = NULL;
+ /* Fetch the data we need for the abort record */
+ nrels = smgrGetPendingDeletes(false, &rels, NULL);
+ nchildren = xactGetCommittedChildren(&children);
- recptr = XLogInsert(RM_XACT_ID, XLOG_XACT_ABORT, rdata);
+ /* XXX do we really need a critical section here? */
+ START_CRIT_SECTION();
- /* Must flush if we are deleting files... */
- if (nrels > 0)
- XLogFlush(recptr);
- }
+ /* Write the ABORT record */
+ if (isSubXact)
+ xlrec.xact_time = GetCurrentTimestamp();
+ else
+ {
+ SetCurrentTransactionStopTimestamp();
+ xlrec.xact_time = xactStopTimestamp;
+ }
+ xlrec.nrels = nrels;
+ xlrec.nsubxacts = nchildren;
+ rdata[0].data = (char *) (&xlrec);
+ rdata[0].len = MinSizeOfXactAbort;
+ rdata[0].buffer = InvalidBuffer;
+ /* dump rels to delete */
+ if (nrels > 0)
+ {
+ rdata[0].next = &(rdata[1]);
+ rdata[1].data = (char *) rels;
+ rdata[1].len = nrels * sizeof(RelFileNode);
+ rdata[1].buffer = InvalidBuffer;
+ lastrdata = 1;
+ }
+ /* dump committed child Xids */
+ if (nchildren > 0)
+ {
+ rdata[lastrdata].next = &(rdata[2]);
+ rdata[2].data = (char *) children;
+ rdata[2].len = nchildren * sizeof(TransactionId);
+ rdata[2].buffer = InvalidBuffer;
+ lastrdata = 2;
+ }
+ rdata[lastrdata].next = NULL;
- /*
- * Mark the transaction aborted in clog. This is not absolutely
- * necessary but we may as well do it while we are here.
- *
- * The ordering here isn't critical but it seems best to mark the
- * parent first. This assures an atomic transition of all the
- * subtransactions to aborted state from the point of view of
- * concurrent TransactionIdDidAbort calls.
- */
- TransactionIdAbort(xid);
- TransactionIdAbortTree(nchildren, children);
+ (void) XLogInsert(RM_XACT_ID, XLOG_XACT_ABORT, rdata);
- END_CRIT_SECTION();
- }
+ /*
+ * 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.
+ *
+ * The ordering here isn't critical but it seems best to mark the parent
+ * first. This assures an atomic transition of all the subtransactions to
+ * aborted state from the point of view of concurrent
+ * TransactionIdDidAbort calls.
+ */
+ TransactionIdAbort(xid);
+ TransactionIdAbortTree(nchildren, children);
+
+ END_CRIT_SECTION();
- /* Break the chain of back-links in the XLOG records I output */
- MyLastRecPtr.xrecoff = 0;
- MyXactMadeXLogEntry = false;
- MyXactMadeTempRelUpdate = false;
+ /* 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.xrecoff = 0;
/* And clean up local data */
if (rels)
pfree(rels);
- if (children)
- pfree(children);
+
+ return latestXid;
}
/*
AtAbort_Memory(void)
{
/*
- * Make sure we are in a valid context (not a child of
- * TopTransactionContext...). Note that it is possible for this code
- * to be called when we aren't in a transaction at all; go directly to
- * TopMemoryContext in that case.
+ * 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 (TopTransactionContext != NULL)
- {
- MemoryContextSwitchTo(TopTransactionContext);
-
- /*
- * We do not want to destroy the transaction's global state yet,
- * so we can't free any memory here.
- */
- }
+ if (TransactionAbortContext != NULL)
+ MemoryContextSwitchTo(TransactionAbortContext);
else
MemoryContextSwitchTo(TopMemoryContext);
}
static void
AtSubAbort_Memory(void)
{
- Assert(TopTransactionContext != NULL);
+ Assert(TransactionAbortContext != NULL);
- MemoryContextSwitchTo(TopTransactionContext);
+ MemoryContextSwitchTo(TransactionAbortContext);
}
AtAbort_ResourceOwner(void)
{
/*
- * Make sure we have a valid ResourceOwner, if possible (else it
- * will be NULL, which is OK)
+ * Make sure we have a valid ResourceOwner, if possible (else it will be
+ * NULL, which is OK)
*/
CurrentResourceOwner = TopTransactionResourceOwner;
}
TransactionState s = CurrentTransactionState;
/*
- * We keep the child-XID lists in TopTransactionContext (see
- * AtSubCommit_childXids). This means we'd better free the list
+ * 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.
*/
- list_free(s->childXids);
- s->childXids = NIL;
-}
-
-/*
- * RecordSubTransactionAbort
- */
-static void
-RecordSubTransactionAbort(void)
-{
- int nrels;
- RelFileNode *rels;
- TransactionId xid = GetCurrentTransactionId();
- int nchildren;
- TransactionId *children;
-
- /* Get data needed for abort record */
- nrels = smgrGetPendingDeletes(false, &rels);
- nchildren = xactGetCommittedChildren(&children);
-
- /*
- * If we made neither any transaction-controlled XLOG entries nor any
- * temp-rel updates, and are not going to delete any files, we can
- * omit recording the transaction abort at all. No one will ever care
- * that it aborted. (These tests cover our whole transaction tree,
- * and therefore may mark subxacts that don't really need it, but it's
- * probably not worth being tenser.)
- *
- * In this case we needn't worry about marking subcommitted children as
- * aborted, because they didn't mark themselves as subcommitted in the
- * first place; see the optimization in RecordSubTransactionCommit.
- */
- if (MyLastRecPtr.xrecoff != 0 || MyXactMadeTempRelUpdate || nrels > 0)
- {
- START_CRIT_SECTION();
-
- /*
- * We only need to log the abort in XLOG if the transaction made
- * any transaction-controlled XLOG entries or will delete files.
- */
- if (MyLastRecPtr.xrecoff != 0 || nrels > 0)
- {
- XLogRecData rdata[3];
- int lastrdata = 0;
- xl_xact_abort xlrec;
- XLogRecPtr recptr;
-
- xlrec.xtime = time(NULL);
- xlrec.nrels = nrels;
- xlrec.nsubxacts = nchildren;
- rdata[0].data = (char *) (&xlrec);
- rdata[0].len = MinSizeOfXactAbort;
- rdata[0].buffer = InvalidBuffer;
- /* dump rels to delete */
- if (nrels > 0)
- {
- rdata[0].next = &(rdata[1]);
- rdata[1].data = (char *) rels;
- rdata[1].len = nrels * sizeof(RelFileNode);
- rdata[1].buffer = InvalidBuffer;
- lastrdata = 1;
- }
- /* dump committed child Xids */
- if (nchildren > 0)
- {
- rdata[lastrdata].next = &(rdata[2]);
- rdata[2].data = (char *) children;
- rdata[2].len = nchildren * sizeof(TransactionId);
- rdata[2].buffer = InvalidBuffer;
- lastrdata = 2;
- }
- rdata[lastrdata].next = NULL;
-
- recptr = XLogInsert(RM_XACT_ID, XLOG_XACT_ABORT, rdata);
-
- /* Must flush if we are deleting files... */
- if (nrels > 0)
- XLogFlush(recptr);
- }
-
- /*
- * Mark the transaction aborted in clog. This is not absolutely
- * necessary but XactLockTableWait makes use of it to avoid waiting
- * for already-aborted subtransactions.
- */
- TransactionIdAbort(xid);
- TransactionIdAbortTree(nchildren, children);
-
- END_CRIT_SECTION();
- }
-
- /*
- * We can immediately remove failed XIDs from PGPROC's cache of
- * running child XIDs. It's easiest to do it here while we have the
- * child XID array at hand, even though in the main-transaction case
- * the equivalent work happens just after return from
- * RecordTransactionAbort.
- */
- XidCacheRemoveRunningXids(xid, nchildren, children);
-
- /* And clean up local data */
- if (rels)
- pfree(rels);
- if (children)
- pfree(children);
+ if (s->childXids != NULL)
+ pfree(s->childXids);
+ s->childXids = NULL;
+ s->nChildXids = 0;
+ s->maxChildXids = 0;
}
/* ----------------------------------------------------------------
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.
+ * 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);
- Assert(CurrentTransactionState->parent == NULL);
+ /*
+ * Clear the special abort context for next time.
+ */
+ if (TransactionAbortContext != NULL)
+ MemoryContextResetAndDeleteChildren(TransactionAbortContext);
/*
* Release all transaction-local memory.
CurTransactionContext = s->parent->curTransactionContext;
/*
- * Delete the subxact local memory contexts. Its CurTransactionContext
- * can go too (note this also kills CurTransactionContexts from any
- * children of the subxact).
+ * 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);
StartTransaction(void)
{
TransactionState s;
+ VirtualTransactionId vxid;
/*
* Let's just make sure the state stack is empty
* start processing
*/
s->state = TRANS_START;
- s->transactionId = InvalidTransactionId; /* until assigned */
+ s->transactionId = InvalidTransactionId; /* until assigned */
/*
- * Make sure we've freed any old snapshot, and reset xact state
- * variables
+ * Make sure we've freed any old snapshot, and reset xact state variables
*/
FreeXactSnapshot();
XactIsoLevel = DefaultXactIsoLevel;
XactReadOnly = DefaultXactReadOnly;
+ forceSyncCommit = false;
+ MyXactAccessedTempRel = false;
/*
* reinitialize within-transaction counters
s->subTransactionId = TopSubTransactionId;
currentSubTransactionId = TopSubTransactionId;
currentCommandId = FirstCommandId;
+ currentCommandIdUsed = false;
/*
* must initialize resource-management stuff first
AtStart_ResourceOwner();
/*
- * generate a new transaction id
+ * Assign a new LocalTransactionId, and combine it with the backendId to
+ * form a virtual transaction id.
*/
- s->transactionId = GetNewTransactionId(false);
+ vxid.backendId = MyBackendId;
+ vxid.localTransactionId = GetNextLocalTransactionId();
- XactLockTableInsert(s->transactionId);
+ /*
+ * Lock the virtual transaction id before we announce it in the proc array
+ */
+ VirtualXactLockTableInsert(vxid);
/*
- * set now()
+ * Advertise it in the proc array. We assume assignment of
+ * LocalTransactionID is atomic, and the backendId should be set already.
*/
- xactStartTimestamp = GetCurrentTimestamp();
+ Assert(MyProc->backendId == vxid.backendId);
+ MyProc->lxid = vxid.localTransactionId;
+
+ TRACE_POSTGRESQL_TRANSACTION_START(vxid.localTransactionId);
/*
- * initialize current transaction state fields
+ * 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.
*/
- s->nestingLevel = 1;
- s->childXids = NIL;
+ xactStartTimestamp = stmtStartTimestamp;
+ xactStopTimestamp = 0;
+ pgstat_report_xact_timestamp(xactStartTimestamp);
/*
- * You might expect to see "s->currentUser = GetUserId();" here, but
- * you won't because it doesn't work during startup; the userid isn't
- * set yet during a backend's first transaction start. We only use
- * the currentUser field in sub-transaction state structs.
+ * initialize current transaction state fields
*
- * prevXactReadOnly is also valid only in sub-transactions.
+ * note: prevXactReadOnly is not used at the outermost level
*/
+ s->nestingLevel = 1;
+ s->gucNestLevel = 1;
+ s->childXids = NULL;
+ s->nChildXids = 0;
+ s->maxChildXids = 0;
+ GetUserIdAndContext(&s->prevUser, &s->prevSecDefCxt);
+ /* SecurityDefinerContext should never be set outside a transaction */
+ Assert(!s->prevSecDefCxt);
/*
* initialize other subsystems for new transaction
*/
+ AtStart_GUC();
AtStart_Inval();
AtStart_Cache();
AfterTriggerBeginXact();
CommitTransaction(void)
{
TransactionState s = CurrentTransactionState;
+ TransactionId latestXid;
ShowTransactionState("CommitTransaction");
Assert(s->parent == NULL);
/*
- * Do pre-commit processing (most of this stuff requires database
- * access, and in fact could still cause an error...)
+ * Do pre-commit processing (most of this stuff requires database access,
+ * and in fact could still cause an error...)
*
- * It is possible for CommitHoldablePortals to invoke functions that
- * queue deferred triggers, and it's also possible that triggers create
- * holdable cursors. So we have to loop until there's nothing left to
- * do.
+ * It is possible for CommitHoldablePortals to invoke functions that queue
+ * deferred triggers, and it's also possible that triggers create holdable
+ * cursors. So we have to loop until there's nothing left to do.
*/
for (;;)
{
/*
* Here is where we really truly commit.
*/
- RecordTransactionCommit();
+ 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_
+ /*
+ * Let others know about no transaction in progress by me. Note that this
+ * must be done _before_ releasing locks we hold and _after_
* RecordTransactionCommit.
- *
- * LWLockAcquire(ProcArrayLock) is required; consider this example:
- * UPDATE with xid 0 is blocked by xid 1's UPDATE.
- * xid 1 is doing commit while xid 2 gets snapshot.
- * If xid 2's GetSnapshotData sees xid 1 as running then it must see
- * xid 0 as running as well, or it will be able to see two tuple versions
- * - one deleted by xid 1 and one inserted by xid 0. See notes in
- * GetSnapshotData.
- *
- * Note: MyProc may be null during bootstrap.
- *----------
*/
- if (MyProc != NULL)
- {
- /* Lock ProcArrayLock because that's what GetSnapshotData uses. */
- LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
- MyProc->xid = InvalidTransactionId;
- MyProc->xmin = InvalidTransactionId;
-
- /* Clear the subtransaction-XID cache too while holding the lock */
- MyProc->subxids.nxids = 0;
- MyProc->subxids.overflowed = false;
-
- LWLockRelease(ProcArrayLock);
- }
+ 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
+ * 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.
+ * 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.
+ * 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);
/* 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).
+ * 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);
RESOURCE_RELEASE_AFTER_LOCKS,
true, true);
- AtEOXact_GUC(true, false);
+ /* Check we've released all catcache entries */
+ AtEOXact_CatCache(true);
+
+ AtEOXact_GUC(true, 1);
AtEOXact_SPI(true);
+ AtEOXact_xml();
AtEOXact_on_commit_actions(true);
AtEOXact_Namespace(true);
/* smgrcommit already done */
AtEOXact_Files();
- pgstat_count_xact_commit();
+ AtEOXact_ComboCid();
+ AtEOXact_HashTables(true);
+ AtEOXact_PgStat(true);
+ pgstat_report_xact_timestamp(0);
CurrentResourceOwner = NULL;
ResourceOwnerDelete(TopTransactionResourceOwner);
s->transactionId = InvalidTransactionId;
s->subTransactionId = InvalidSubTransactionId;
s->nestingLevel = 0;
- s->childXids = NIL;
+ s->gucNestLevel = 0;
+ s->childXids = NULL;
+ s->nChildXids = 0;
+ s->maxChildXids = 0;
/*
* done with commit processing, set current transaction state back to
static void
PrepareTransaction(void)
{
- TransactionState s = CurrentTransactionState;
- TransactionId xid = GetCurrentTransactionId();
- GlobalTransaction gxact;
- TimestampTz prepared_at;
+ TransactionState s = CurrentTransactionState;
+ TransactionId xid = GetCurrentTransactionId();
+ GlobalTransaction gxact;
+ TimestampTz prepared_at;
ShowTransactionState("PrepareTransaction");
Assert(s->parent == NULL);
/*
- * Do pre-commit processing (most of this stuff requires database
- * access, and in fact could still cause an error...)
+ * Do pre-commit processing (most of this stuff requires database access,
+ * and in fact could still cause an error...)
*
* It is possible for PrepareHoldablePortals to invoke functions that
* queue deferred triggers, and it's also possible that triggers create
- * holdable cursors. So we have to loop until there's nothing left to
- * do.
+ * holdable cursors. So we have to loop until there's nothing left to do.
*/
for (;;)
{
/* NOTIFY and flatfiles 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")));
+
/* Prevent cancel/die interrupt while cleaning up */
HOLD_INTERRUPTS();
BufmgrCommit();
/*
- * Reserve the GID for this transaction. This could fail if the
- * requested GID is invalid or already in use.
+ * 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);
* 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.
+ * 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.
+ * 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_UpdateFlatFiles();
AtPrepare_Inval();
AtPrepare_Locks();
+ AtPrepare_PgStat();
/*
* 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.
+ * 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.
+ * Now we clean up backend-internal state and release internal resources.
*/
- /* Break the chain of back-links in the XLOG records I output */
- MyLastRecPtr.xrecoff = 0;
- MyXactMadeXLogEntry = false;
- MyXactMadeTempRelUpdate = false;
+ /* Reset XactLastRecEnd until the next transaction writes something */
+ XactLastRecEnd.xrecoff = 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.
+ * Let others know about no transaction in progress by me. This has to be
+ * done *after* the prepared transaction has been marked valid, else
+ * someone may think it is unlocked and recyclable.
*/
-
- /* Lock ProcArrayLock because that's what GetSnapshotData uses. */
- LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
- MyProc->xid = InvalidTransactionId;
- MyProc->xmin = InvalidTransactionId;
-
- /* Clear the subtransaction-XID cache too while holding the lock */
- MyProc->subxids.nxids = 0;
- MyProc->subxids.overflowed = false;
-
- LWLockRelease(ProcArrayLock);
+ ProcArrayClearTransaction(MyProc);
/*
* This is all post-transaction cleanup. Note that if an error is raised
* here, it's too late to abort the transaction. This should be just
- * noncritical resource releasing. See notes in CommitTransaction.
+ * noncritical resource releasing. See notes in CommitTransaction.
*/
CallXactCallbacks(XACT_EVENT_PREPARE);
/* Check we've released all buffer pins */
AtEOXact_Buffers(true);
+ /* Clean up the relation cache */
+ AtEOXact_RelationCache(true);
+
/* notify and flatfiles don't need a postprepare call */
+ PostPrepare_PgStat();
+
PostPrepare_Inval();
PostPrepare_smgr();
RESOURCE_RELEASE_AFTER_LOCKS,
true, true);
+ /* 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, false);
+ AtEOXact_GUC(true, 1);
AtEOXact_SPI(true);
+ AtEOXact_xml();
AtEOXact_on_commit_actions(true);
AtEOXact_Namespace(true);
/* smgrcommit already done */
AtEOXact_Files();
+ AtEOXact_ComboCid();
+ AtEOXact_HashTables(true);
+ /* don't call AtEOXact_PgStat here */
CurrentResourceOwner = NULL;
ResourceOwnerDelete(TopTransactionResourceOwner);
s->transactionId = InvalidTransactionId;
s->subTransactionId = InvalidSubTransactionId;
s->nestingLevel = 0;
- s->childXids = NIL;
+ 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
+ * done with 1st phase commit processing, set current transaction state
+ * back to default
*/
s->state = TRANS_DEFAULT;
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!
+ * Releasing LW locks is critical since we might try to grab them again
+ * while cleaning up!
*/
LWLockReleaseAll();
UnlockBuffers();
/*
- * 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.
+ * 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.
*/
LockWaitCancel();
Assert(s->parent == NULL);
/*
- * set the current transaction state information appropriately during
- * the abort processing
+ * set the current transaction state information appropriately during the
+ * abort processing
*/
s->state = TRANS_ABORT;
- /* Make sure we have a valid memory context and resource owner */
- AtAbort_Memory();
- AtAbort_ResourceOwner();
-
/*
- * Reset user id which might have been changed transiently. We cannot
- * use s->currentUser, but must get the session userid from
- * miscinit.c.
+ * 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 SecurityDefinerContext also needs to be restored.
*
- * (Note: it is not necessary to restore session authorization here
- * because that can only be changed via GUC, and GUC will take care of
- * rolling it back if need be. However, an error within a SECURITY
- * DEFINER function could send control here with the wrong current
- * userid.)
+ * (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.)
*/
- SetUserId(GetSessionUserId());
+ SetUserIdAndContext(s->prevUser, s->prevSecDefCxt);
/*
* do abort processing
AtEOXact_UpdateFlatFiles(false);
/*
- * Advertise the fact that we aborted in pg_clog (assuming that we
- * got as far as assigning an XID to advertise).
+ * Advertise the fact that we aborted in pg_clog (assuming that we got as
+ * far as assigning an XID to advertise).
*/
- if (TransactionIdIsValid(s->transactionId))
- RecordTransactionAbort();
+ 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_
+ * Let others know about no transaction in progress by me. Note that this
+ * must be done _before_ releasing locks we hold and _after_
* RecordTransactionAbort.
*/
- if (MyProc != NULL)
- {
- /* Lock ProcArrayLock because that's what GetSnapshotData uses. */
- LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
- MyProc->xid = InvalidTransactionId;
- MyProc->xmin = InvalidTransactionId;
-
- /* Clear the subtransaction-XID cache too while holding the lock */
- MyProc->subxids.nxids = 0;
- MyProc->subxids.overflowed = false;
-
- LWLockRelease(ProcArrayLock);
- }
+ ProcArrayEndTransaction(MyProc, latestXid);
/*
* Post-abort cleanup. See notes in CommitTransaction() concerning
RESOURCE_RELEASE_BEFORE_LOCKS,
false, true);
AtEOXact_Buffers(false);
+ AtEOXact_RelationCache(false);
AtEOXact_Inval(false);
smgrDoPendingDeletes(false);
AtEOXact_MultiXact();
ResourceOwnerRelease(TopTransactionResourceOwner,
RESOURCE_RELEASE_AFTER_LOCKS,
false, true);
+ AtEOXact_CatCache(false);
- AtEOXact_GUC(false, false);
+ AtEOXact_GUC(false, 1);
AtEOXact_SPI(false);
+ AtEOXact_xml();
AtEOXact_on_commit_actions(false);
AtEOXact_Namespace(false);
smgrabort();
AtEOXact_Files();
- pgstat_count_xact_rollback();
+ AtEOXact_ComboCid();
+ AtEOXact_HashTables(false);
+ AtEOXact_PgStat(false);
+ pgstat_report_xact_timestamp(0);
/*
* State remains TRANS_ABORT until CleanupTransaction().
s->transactionId = InvalidTransactionId;
s->subTransactionId = InvalidSubTransactionId;
s->nestingLevel = 0;
- s->childXids = NIL;
+ s->gucNestLevel = 0;
+ s->childXids = NULL;
+ s->nChildXids = 0;
+ s->maxChildXids = 0;
/*
* done with abort processing, set current transaction state back to
switch (s->blockState)
{
/*
- * if we aren't in a transaction block, we just do our usual
- * start transaction.
+ * if we aren't in a transaction block, we just do our usual start
+ * transaction.
*/
case TBLOCK_DEFAULT:
StartTransaction();
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.)
+ * 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.)
+ * 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;
/*
- * 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.)
+ * 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;
/*
* This is the case when we have finished executing a command
- * someplace within a transaction block. We increment the
- * command counter and return.
+ * someplace within a transaction block. We increment the command
+ * counter and return.
*/
case TBLOCK_INPROGRESS:
case TBLOCK_SUBINPROGRESS:
break;
/*
- * We are completing a "COMMIT" command. Do it and return to
- * the idle state.
+ * We are completing a "COMMIT" command. Do it and return to the
+ * idle state.
*/
case TBLOCK_END:
CommitTransaction();
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.
+ * 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
+ * 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:
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.
+ * 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();
/*
* 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.)
+ * PushTransaction, so as to have someplace to put the SUBBEGIN
+ * state.)
*/
case TBLOCK_SUBBEGIN:
StartSubTransaction();
break;
/*
- * Same as above, but the subtransaction had already failed,
- * so we don't need AbortSubTransaction.
+ * Same as above, but the subtransaction had already failed, so we
+ * don't need AbortSubTransaction.
*/
case TBLOCK_SUBABORT_RESTART:
{
break;
/*
- * if we aren't in a transaction block, we just do the basic
- * abort & cleanup transaction.
+ * if we aren't in a transaction block, we just do the basic abort
+ * & cleanup transaction.
*/
case TBLOCK_STARTED:
AbortTransaction();
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.
+ * 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();
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).
+ * 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();
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.
+ * 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:
/*
* 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.
+ * We have already aborted, we just need to cleanup and go to idle
+ * state.
*/
case TBLOCK_ABORT_END:
CleanupTransaction();
/*
* 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).
+ * transaction and return to idle state (we do not want to stay in
+ * the transaction).
*/
case TBLOCK_PREPARE:
AbortTransaction();
/*
* We got an error inside a subtransaction. Abort just the
- * subtransaction, and go to the persistent SUBABORT state
- * until we get ROLLBACK.
+ * subtransaction, and go to the persistent SUBABORT state until
+ * we get ROLLBACK.
*/
case TBLOCK_SUBINPROGRESS:
AbortSubTransaction();
/*
* If we failed while trying to create a subtransaction, clean up
- * the broken subtransaction and abort the parent. The same
+ * the broken subtransaction and abort the parent. The same
* applies if we get a failure while ending a subtransaction.
*/
case TBLOCK_SUBBEGIN:
* could issue more commands and possibly cause a failure after the statement
* completes). Subtransactions are verboten too.
*
- * stmtNode: pointer to parameter block for statement; this is used in
- * a very klugy way to determine whether we are inside a function.
- * stmtType: statement type name for error messages.
+ * 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(void *stmtNode, const char *stmtType)
+PreventTransactionChain(bool isTopLevel, const char *stmtType)
{
/*
* xact block already started?
stmtType)));
/*
- * Are we inside a function call? If the statement's parameter block
- * was allocated in QueryContext, assume it is an interactive command.
- * Otherwise assume it is coming from a function.
+ * inside a function call?
*/
- if (!MemoryContextContains(QueryContext, stmtNode))
+ if (!isTopLevel)
ereport(ERROR,
(errcode(ERRCODE_ACTIVE_SQL_TRANSACTION),
/* translator: %s represents an SQL statement name */
- errmsg("%s cannot be executed from a function", stmtType)));
+ 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 &&
* use of the current statement's results. Likewise subtransactions.
* Thus this is an inverse for PreventTransactionChain.
*
- * stmtNode: pointer to parameter block for statement; this is used in
- * a very klugy way to determine whether we are inside a function.
- * stmtType: statement type name for error messages.
+ * isTopLevel: passed down from ProcessUtility to determine whether we are
+ * inside a function.
+ * stmtType: statement type name, for error messages.
*/
void
-RequireTransactionChain(void *stmtNode, const char *stmtType)
+RequireTransactionChain(bool isTopLevel, const char *stmtType)
{
/*
* xact block already started?
return;
/*
- * Are we inside a function call? If the statement's parameter block
- * was allocated in QueryContext, assume it is an interactive command.
- * Otherwise assume it is coming from a function.
+ * inside a function call?
*/
- if (!MemoryContextContains(QueryContext, stmtNode))
+ if (!isTopLevel)
return;
+
ereport(ERROR,
(errcode(ERRCODE_NO_ACTIVE_SQL_TRANSACTION),
/* translator: %s represents an SQL statement name */
- errmsg("%s may only be used in transaction blocks",
+ errmsg("%s can only be used in transaction blocks",
stmtType)));
}
* a transaction block than when running as single commands. ANALYZE is
* currently the only example.
*
- * stmtNode: pointer to parameter block for statement; this is used in
- * a very klugy way to determine whether we are inside a function.
+ * isTopLevel: passed down from ProcessUtility to determine whether we are
+ * inside a function.
*/
bool
-IsInTransactionChain(void *stmtNode)
+IsInTransactionChain(bool isTopLevel)
{
/*
- * Return true on same conditions that would make
- * PreventTransactionChain error out
+ * Return true on same conditions that would make PreventTransactionChain
+ * error out
*/
if (IsTransactionBlock())
return true;
if (IsSubTransaction())
return true;
- if (!MemoryContextContains(QueryContext, stmtNode))
+ if (!isTopLevel)
return true;
if (CurrentTransactionState->blockState != TBLOCK_DEFAULT &&
switch (s->blockState)
{
/*
- * We are not inside a transaction block, so allow one to
- * begin.
+ * We are not inside a transaction block, so allow one to begin.
*/
case TBLOCK_STARTED:
s->blockState = TBLOCK_BEGIN;
case TBLOCK_SUBABORT:
ereport(WARNING,
(errcode(ERRCODE_ACTIVE_SQL_TRANSACTION),
- errmsg("there is already a transaction in progress")));
+ errmsg("there is already a transaction in progress")));
break;
/* These cases are invalid. */
PrepareTransactionBlock(char *gid)
{
TransactionState s;
- bool result;
+ bool result;
/* Set up to commit the current transaction */
result = EndTransactionBlock();
break;
/*
- * We are in a live subtransaction block. Set up to subcommit
- * all open subtransactions and then commit the main transaction.
+ * 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)
break;
/*
- * Here we are inside an aborted subtransaction. Treat the
- * COMMIT as ROLLBACK: set up to abort everything and exit
- * the main transaction.
+ * 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)
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.
+ * 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;
/*
* 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.
+ * 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.
+ * We are inside a subtransaction. Mark everything up to top
+ * level as exitable.
*/
case TBLOCK_SUBINPROGRESS:
case TBLOCK_SUBABORT:
break;
/*
- * The user issued ABORT when not inside a transaction. Issue
- * a WARNING and go to abort state. The upcoming call to
+ * 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,
+ ereport(NOTICE,
(errcode(ERRCODE_NO_ACTIVE_SQL_TRANSACTION),
errmsg("there is no transaction in progress")));
s->blockState = TBLOCK_ABORT_PENDING;
s = CurrentTransactionState; /* changed by push */
/*
- * Savepoint names, like the TransactionState block itself,
- * live in TopTransactionContext.
+ * Savepoint names, like the TransactionState block itself, live
+ * in TopTransactionContext.
*/
if (name)
s->name = MemoryContextStrdup(TopTransactionContext, name);
break;
/*
- * We are in a non-aborted subtransaction. This is the only
- * valid case.
+ * We are in a non-aborted subtransaction. This is the only valid
+ * case.
*/
case TBLOCK_SUBINPROGRESS:
break;
/*
* Mark "commit pending" all subtransactions up to the target
- * subtransaction. The actual commits will happen when control gets
- * to CommitTransactionCommand.
+ * subtransaction. The actual commits will happen when control gets to
+ * CommitTransactionCommand.
*/
xact = CurrentTransactionState;
for (;;)
/*
* Mark "abort pending" all subtransactions up to the target
- * subtransaction. The actual aborts will happen when control gets
- * to CommitTransactionCommand.
+ * subtransaction. The actual aborts will happen when control gets to
+ * CommitTransactionCommand.
*/
xact = CurrentTransactionState;
for (;;)
/*
* BeginInternalSubTransaction
- * This is the same as DefineSavepoint except it allows TBLOCK_STARTED
- * state, and therefore it can safely be used in a function that might
- * be called when not inside a BEGIN block. Also, we automatically
- * cycle through CommitTransactionCommand/StartTransactionCommand
+ * 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
{
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.
+ * Savepoint names, like the TransactionState block itself, live
+ * in TopTransactionContext.
*/
if (name)
s->name = MemoryContextStrdup(TopTransactionContext, name);
case TBLOCK_DEFAULT:
case TBLOCK_BEGIN:
case TBLOCK_SUBBEGIN:
- case TBLOCK_END:
case TBLOCK_SUBEND:
case TBLOCK_ABORT:
case TBLOCK_SUBABORT:
case TBLOCK_SUBABORT_PENDING:
case TBLOCK_SUBRESTART:
case TBLOCK_SUBABORT_RESTART:
- case TBLOCK_PREPARE:
elog(FATAL, "BeginInternalSubTransaction: unexpected state %s",
BlockStateAsString(s->blockState));
break;
Assert(s->state == TRANS_INPROGRESS);
MemoryContextSwitchTo(CurTransactionContext);
CommitSubTransaction();
- s = CurrentTransactionState; /* changed by pop */
+ s = CurrentTransactionState; /* changed by pop */
Assert(s->state == TRANS_INPROGRESS);
}
break;
/*
- * In a subtransaction, so clean it up and abort parent
- * too
+ * In a subtransaction, so clean it up and abort parent too
*/
case TBLOCK_SUBBEGIN:
case TBLOCK_SUBINPROGRESS:
CommandCounterIncrement();
/* Mark subtransaction as subcommitted */
- if (TransactionIdIsValid(s->transactionId))
- {
- RecordSubTransactionCommit();
- AtSubCommit_childXids();
- }
+ RecordSubTransactionCommit();
/* Post-commit cleanup */
+ if (TransactionIdIsValid(s->transactionId))
+ AtSubCommit_childXids();
AfterTriggerEndSubXact(true);
AtSubCommit_Portals(s->subTransactionId,
s->parent->subTransactionId,
RESOURCE_RELEASE_AFTER_LOCKS,
true, false);
- AtEOXact_GUC(true, true);
+ AtEOXact_GUC(true, s->gucNestLevel);
AtEOSubXact_SPI(true, s->subTransactionId);
AtEOSubXact_on_commit_actions(true, s->subTransactionId,
s->parent->subTransactionId);
s->parent->subTransactionId);
AtEOSubXact_Files(true, s->subTransactionId,
s->parent->subTransactionId);
+ AtEOSubXact_HashTables(true, s->nestingLevel);
+ AtEOSubXact_PgStat(true, 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.
+ * 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;
{
TransactionState s = CurrentTransactionState;
- ShowTransactionState("AbortSubTransaction");
-
- if (s->state != TRANS_INPROGRESS)
- elog(WARNING, "AbortSubTransaction while in %s state",
- TransStateAsString(s->state));
-
+ /* Prevent cancel/die interrupt while cleaning up */
HOLD_INTERRUPTS();
- s->state = TRANS_ABORT;
+ /* 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!
+ * 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.
LockWaitCancel();
/*
- * do abort processing
+ * check the current transaction state
*/
- AtSubAbort_Memory();
- AtSubAbort_ResourceOwner();
+ ShowTransactionState("AbortSubTransaction");
+
+ if (s->state != TRANS_INPROGRESS)
+ elog(WARNING, "AbortSubTransaction while in %s state",
+ TransStateAsString(s->state));
+
+ s->state = TRANS_ABORT;
/*
- * We can skip all this stuff if the subxact failed before creating
- * a ResourceOwner...
+ * Reset user ID which might have been changed transiently. (See notes
+ * in AbortTransaction.)
+ */
+ SetUserIdAndContext(s->prevUser, s->prevSecDefCxt);
+
+ /*
+ * We can skip all this stuff if the subxact failed before creating a
+ * ResourceOwner...
*/
if (s->curTransactionOwner)
{
s->parent->subTransactionId);
/* Advertise the fact that we aborted in pg_clog. */
+ (void) RecordTransactionAbort(true);
+
+ /* Post-abort cleanup */
if (TransactionIdIsValid(s->transactionId))
- {
- RecordSubTransactionAbort();
AtSubAbort_childXids();
- }
- /* Post-abort cleanup */
CallSubXactCallbacks(SUBXACT_EVENT_ABORT_SUB, s->subTransactionId,
s->parent->subTransactionId);
RESOURCE_RELEASE_AFTER_LOCKS,
false, false);
- AtEOXact_GUC(false, true);
+ AtEOXact_GUC(false, s->gucNestLevel);
AtEOSubXact_SPI(false, s->subTransactionId);
+ AtEOXact_xml();
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);
}
/*
- * Reset user id which might have been changed transiently. Here we
- * want to restore to the userid that was current at subxact entry.
- * (As in AbortTransaction, we need not worry about the session
- * userid.)
- *
- * Must do this after AtEOXact_GUC to handle the case where we entered
- * the subxact inside a SECURITY DEFINER function (hence current and
- * session userids were different) and then session auth was changed
- * inside the subxact. GUC will reset both current and session
- * userids to the entry-time session userid. This is right in every
- * other scenario so it seems simplest to let GUC do that and fix it
- * here.
- */
- SetUserId(s->currentUser);
-
- /*
- * 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.
+ * 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;
{
TransactionState p = CurrentTransactionState;
TransactionState s;
- Oid currentUser;
-
- /*
- * At present, GetUserId cannot fail, but let's not assume that. Get
- * the ID before entering the critical code sequence.
- */
- currentUser = GetUserId();
/*
* We keep subtransaction state nodes in TopTransactionContext.
s = (TransactionState)
MemoryContextAllocZero(TopTransactionContext,
sizeof(TransactionStateData));
+
/*
* Assign a subtransaction ID, watching out for counter wraparound.
*/
(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->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;
- s->currentUser = currentUser;
+ GetUserIdAndContext(&s->prevUser, &s->prevSecDefCxt);
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.
+ * 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.
*/
}
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, nestlvl: %d, children: %s",
- PointerIsValid(s->name) ? s->name : "unnamed",
+ (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,
- s->nestingLevel,
- nodeToString(s->childXids))));
+ currentCommandIdUsed ? " (used)" : "",
+ s->nestingLevel, buf.data)));
+
+ pfree(buf.data);
}
/*
* xactGetCommittedChildren
*
* Gets the list of committed children of the current transaction. The return
- * value is the number of child transactions. *children is set to point to a
- * palloc'd array of TransactionIds. If there are no subxacts, *children is
- * set to NULL.
+ * 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;
- int nchildren;
- TransactionId *children;
- ListCell *p;
- nchildren = list_length(s->childXids);
- if (nchildren == 0)
- {
+ if (s->nChildXids == 0)
*ptr = NULL;
- return 0;
- }
-
- children = (TransactionId *) palloc(nchildren * sizeof(TransactionId));
- *ptr = children;
-
- foreach(p, s->childXids)
- {
- TransactionId child = lfirst_xid(p);
-
- *children++ = child;
- }
+ else
+ *ptr = s->childXids;
- return nchildren;
+ return s->nChildXids;
}
/*
/* Make sure files supposed to be dropped are dropped */
for (i = 0; i < xlrec->nrels; i++)
{
- XLogCloseRelation(xlrec->xnodes[i]);
+ XLogDropRelation(xlrec->xnodes[i]);
smgrdounlink(smgropen(xlrec->xnodes[i]), false, true);
}
}
/* Make sure files supposed to be dropped are dropped */
for (i = 0; i < xlrec->nrels; i++)
{
- XLogCloseRelation(xlrec->xnodes[i]);
+ XLogDropRelation(xlrec->xnodes[i]);
smgrdounlink(smgropen(xlrec->xnodes[i]), false, true);
}
}
}
static void
-xact_desc_commit(char *buf, xl_xact_commit *xlrec)
+xact_desc_commit(StringInfo buf, xl_xact_commit *xlrec)
{
- struct tm *tm = localtime(&xlrec->xtime);
int i;
- sprintf(buf + strlen(buf), "%04u-%02u-%02u %02u:%02u:%02u",
- tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
- tm->tm_hour, tm->tm_min, tm->tm_sec);
+ appendStringInfoString(buf, timestamptz_to_str(xlrec->xact_time));
if (xlrec->nrels > 0)
{
- sprintf(buf + strlen(buf), "; rels:");
+ appendStringInfo(buf, "; rels:");
for (i = 0; i < xlrec->nrels; i++)
{
RelFileNode rnode = xlrec->xnodes[i];
- sprintf(buf + strlen(buf), " %u/%u/%u",
- rnode.spcNode, rnode.dbNode, rnode.relNode);
+ appendStringInfo(buf, " %u/%u/%u",
+ rnode.spcNode, rnode.dbNode, rnode.relNode);
}
}
if (xlrec->nsubxacts > 0)
{
TransactionId *xacts = (TransactionId *)
- &xlrec->xnodes[xlrec->nrels];
+ &xlrec->xnodes[xlrec->nrels];
- sprintf(buf + strlen(buf), "; subxacts:");
+ appendStringInfo(buf, "; subxacts:");
for (i = 0; i < xlrec->nsubxacts; i++)
- sprintf(buf + strlen(buf), " %u", xacts[i]);
+ appendStringInfo(buf, " %u", xacts[i]);
}
}
static void
-xact_desc_abort(char *buf, xl_xact_abort *xlrec)
+xact_desc_abort(StringInfo buf, xl_xact_abort *xlrec)
{
- struct tm *tm = localtime(&xlrec->xtime);
int i;
- sprintf(buf + strlen(buf), "%04u-%02u-%02u %02u:%02u:%02u",
- tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
- tm->tm_hour, tm->tm_min, tm->tm_sec);
+ appendStringInfoString(buf, timestamptz_to_str(xlrec->xact_time));
if (xlrec->nrels > 0)
{
- sprintf(buf + strlen(buf), "; rels:");
+ appendStringInfo(buf, "; rels:");
for (i = 0; i < xlrec->nrels; i++)
{
RelFileNode rnode = xlrec->xnodes[i];
- sprintf(buf + strlen(buf), " %u/%u/%u",
- rnode.spcNode, rnode.dbNode, rnode.relNode);
+ appendStringInfo(buf, " %u/%u/%u",
+ rnode.spcNode, rnode.dbNode, rnode.relNode);
}
}
if (xlrec->nsubxacts > 0)
{
TransactionId *xacts = (TransactionId *)
- &xlrec->xnodes[xlrec->nrels];
+ &xlrec->xnodes[xlrec->nrels];
- sprintf(buf + strlen(buf), "; subxacts:");
+ appendStringInfo(buf, "; subxacts:");
for (i = 0; i < xlrec->nsubxacts; i++)
- sprintf(buf + strlen(buf), " %u", xacts[i]);
+ appendStringInfo(buf, " %u", xacts[i]);
}
}
void
-xact_desc(char *buf, uint8 xl_info, char *rec)
+xact_desc(StringInfo buf, uint8 xl_info, char *rec)
{
uint8 info = xl_info & ~XLR_INFO_MASK;
{
xl_xact_commit *xlrec = (xl_xact_commit *) rec;
- strcat(buf, "commit: ");
+ appendStringInfo(buf, "commit: ");
xact_desc_commit(buf, xlrec);
}
else if (info == XLOG_XACT_ABORT)
{
xl_xact_abort *xlrec = (xl_xact_abort *) rec;
- strcat(buf, "abort: ");
+ appendStringInfo(buf, "abort: ");
xact_desc_abort(buf, xlrec);
}
else if (info == XLOG_XACT_PREPARE)
{
- strcat(buf, "prepare");
+ appendStringInfo(buf, "prepare");
}
else if (info == XLOG_XACT_COMMIT_PREPARED)
{
xl_xact_commit_prepared *xlrec = (xl_xact_commit_prepared *) rec;
- sprintf(buf + strlen(buf), "commit %u: ", xlrec->xid);
+ appendStringInfo(buf, "commit %u: ", xlrec->xid);
xact_desc_commit(buf, &xlrec->crec);
}
else if (info == XLOG_XACT_ABORT_PREPARED)
{
xl_xact_abort_prepared *xlrec = (xl_xact_abort_prepared *) rec;
- sprintf(buf + strlen(buf), "abort %u: ", xlrec->xid);
+ appendStringInfo(buf, "abort %u: ", xlrec->xid);
xact_desc_abort(buf, &xlrec->arec);
}
else
- strcat(buf, "UNKNOWN");
+ appendStringInfo(buf, "UNKNOWN");
}
projects / postgresql / blobdiff