* xact.c
* top level transaction system support routines
*
- * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
+ * See src/backend/access/transam/README for more information.
+ *
+ * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/access/transam/xact.c,v 1.173 2004/07/28 14:23:27 tgl Exp $
- *
- * NOTES
- * Transaction aborts can now occur two ways:
- *
- * 1) system dies from some internal cause (syntax error, etc..)
- * 2) user types ABORT
- *
- * These two cases used to be treated identically, but now
- * we need to distinguish them. Why? consider the following
- * two situations:
- *
- * case 1 case 2
- * ------ ------
- * 1) user types BEGIN 1) user types BEGIN
- * 2) user does something 2) user does something
- * 3) user does not like what 3) system aborts for some reason
- * she sees and types ABORT
- *
- * In case 1, we want to abort the transaction and return to the
- * default state. In case 2, there may be more commands coming
- * our way which are part of the same transaction block and we have
- * to ignore these commands until we see a COMMIT transaction or
- * ROLLBACK.
- *
- * Internal aborts are now handled by AbortTransactionBlock(), just as
- * they always have been, and user aborts are now handled by
- * UserAbortTransactionBlock(). Both of them rely on AbortTransaction()
- * to do all the real work. The only difference is what state we
- * enter after AbortTransaction() does its work:
- *
- * * AbortTransactionBlock() leaves us in TBLOCK_ABORT and
- * * UserAbortTransactionBlock() leaves us in TBLOCK_ENDABORT
- *
- * Low-level transaction abort handling is divided into two phases:
- * * AbortTransaction() executes as soon as we realize the transaction
- * has failed. It should release all shared resources (locks etc)
- * so that we do not delay other backends unnecessarily.
- * * CleanupTransaction() executes when we finally see a user COMMIT
- * or ROLLBACK command; it cleans things up and gets us out of
- * the transaction internally. In particular, we mustn't destroy
- * TopTransactionContext until this point.
- *
- * NOTES
- * The essential aspects of the transaction system are:
- *
- * o transaction id generation
- * o transaction log updating
- * o memory cleanup
- * o cache invalidation
- * o lock cleanup
- *
- * Hence, the functional division of the transaction code is
- * based on which of the above things need to be done during
- * a start/commit/abort transaction. For instance, the
- * routine AtCommit_Memory() takes care of all the memory
- * cleanup stuff done at commit time.
- *
- * The code is layered as follows:
- *
- * StartTransaction
- * CommitTransaction
- * AbortTransaction
- * CleanupTransaction
- *
- * are provided to do the lower level work like recording
- * the transaction status in the log and doing memory cleanup.
- * above these routines are another set of functions:
- *
- * StartTransactionCommand
- * CommitTransactionCommand
- * AbortCurrentTransaction
- *
- * These are the routines used in the postgres main processing
- * loop. They are sensitive to the current transaction block state
- * and make calls to the lower level routines appropriately.
- *
- * Support for transaction blocks is provided via the functions:
- *
- * BeginTransactionBlock
- * CommitTransactionBlock
- * AbortTransactionBlock
- *
- * These are invoked only in response to a user "BEGIN WORK", "COMMIT",
- * or "ROLLBACK" command. The tricky part about these functions
- * is that they are called within the postgres main loop, in between
- * the StartTransactionCommand() and CommitTransactionCommand().
- *
- * For example, consider the following sequence of user commands:
- *
- * 1) begin
- * 2) select * from foo
- * 3) insert into foo (bar = baz)
- * 4) commit
- *
- * in the main processing loop, this results in the following
- * transaction sequence:
- *
- * / StartTransactionCommand();
- * 1) / ProcessUtility(); << begin
- * \ BeginTransactionBlock();
- * \ CommitTransactionCommand();
- *
- * / StartTransactionCommand();
- * 2) < ProcessQuery(); << select * from foo
- * \ CommitTransactionCommand();
- *
- * / StartTransactionCommand();
- * 3) < ProcessQuery(); << insert into foo (bar = baz)
- * \ CommitTransactionCommand();
- *
- * / StartTransactionCommand();
- * 4) / ProcessUtility(); << commit
- * \ CommitTransactionBlock();
- * \ CommitTransactionCommand();
- *
- * The point of this example is to demonstrate the need for
- * StartTransactionCommand() and CommitTransactionCommand() to
- * be state smart -- they should do nothing in between the calls
- * to BeginTransactionBlock() and EndTransactionBlock() and
- * outside these calls they need to do normal start/commit
- * processing.
- *
- * Furthermore, suppose the "select * from foo" caused an abort
- * condition. We would then want to abort the transaction and
- * ignore all subsequent commands up to the "commit".
- * -cim 3/23/90
+ * $PostgreSQL: pgsql/src/backend/access/transam/xact.c,v 1.247 2007/09/03 00:39:13 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include <time.h>
#include <unistd.h>
+#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 "commands/trigger.h"
-#include "commands/user.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/sinval.h"
+#include "storage/lmgr.h"
+#include "storage/procarray.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/resowner.h"
-#include "pgstat.h"
+#include "utils/relcache.h"
+
+/*
+ * User-tweakable parameters
+ */
+int DefaultXactIsoLevel = XACT_READ_COMMITTED;
+int XactIsoLevel;
+
+bool DefaultXactReadOnly = false;
+bool XactReadOnly;
+
+bool XactSyncCommit = true;
+
+int CommitDelay = 0; /* precommit delay in microseconds */
+int CommitSiblings = 5; /* # concurrent xacts needed to sleep */
/*
*/
typedef enum TransState
{
- TRANS_DEFAULT,
- TRANS_START,
- TRANS_INPROGRESS,
- TRANS_COMMIT,
- TRANS_ABORT
+ 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;
/*
* transaction block states - transaction state of client queries
+ *
+ * Note: the subtransaction states are used only for non-topmost
+ * transactions; the others appear only in the topmost transaction.
*/
typedef enum TBlockState
{
/* not-in-transaction-block states */
- TBLOCK_DEFAULT,
- TBLOCK_STARTED,
+ TBLOCK_DEFAULT, /* idle */
+ TBLOCK_STARTED, /* running single-query transaction */
/* transaction block states */
- TBLOCK_BEGIN,
- TBLOCK_INPROGRESS,
- TBLOCK_END,
- TBLOCK_ABORT,
- TBLOCK_ENDABORT,
+ TBLOCK_BEGIN, /* starting transaction block */
+ TBLOCK_INPROGRESS, /* live transaction */
+ TBLOCK_END, /* COMMIT received */
+ TBLOCK_ABORT, /* failed xact, awaiting ROLLBACK */
+ TBLOCK_ABORT_END, /* failed xact, ROLLBACK received */
+ TBLOCK_ABORT_PENDING, /* live xact, ROLLBACK received */
+ TBLOCK_PREPARE, /* live xact, PREPARE received */
/* subtransaction states */
- TBLOCK_SUBBEGIN,
- TBLOCK_SUBINPROGRESS,
- TBLOCK_SUBEND,
- TBLOCK_SUBABORT,
- TBLOCK_SUBABORT_PENDING,
- TBLOCK_SUBENDABORT_ALL,
- TBLOCK_SUBENDABORT_RELEASE,
- TBLOCK_SUBENDABORT
+ TBLOCK_SUBBEGIN, /* starting a subtransaction */
+ TBLOCK_SUBINPROGRESS, /* live subtransaction */
+ TBLOCK_SUBEND, /* RELEASE received */
+ TBLOCK_SUBABORT, /* failed subxact, awaiting ROLLBACK */
+ TBLOCK_SUBABORT_END, /* failed subxact, ROLLBACK received */
+ TBLOCK_SUBABORT_PENDING, /* live subxact, ROLLBACK received */
+ TBLOCK_SUBRESTART, /* live subxact, ROLLBACK TO received */
+ TBLOCK_SUBABORT_RESTART /* failed subxact, ROLLBACK TO received */
} TBlockState;
/*
*/
typedef struct TransactionStateData
{
- TransactionId transactionIdData; /* my XID */
- char *name; /* savepoint name, if any */
- int savepointLevel; /* savepoint level */
- CommandId commandId; /* current CID */
- TransState state; /* low-level state */
- TBlockState blockState; /* high-level state */
- int nestingLevel; /* nest depth */
- MemoryContext curTransactionContext; /* my xact-lifetime context */
- ResourceOwner curTransactionOwner; /* my query resources */
- List *childXids; /* subcommitted child XIDs */
- AclId currentUser; /* subxact start current_user */
- bool prevXactReadOnly; /* entry-time xact r/o state */
- struct TransactionStateData *parent; /* back link to parent */
+ 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; /* 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 */
+ bool prevXactReadOnly; /* entry-time xact r/o state */
+ struct TransactionStateData *parent; /* back link to parent */
} TransactionStateData;
typedef TransactionStateData *TransactionState;
-
-static void AbortTransaction(void);
-static void AtAbort_Memory(void);
-static void AtCleanup_Memory(void);
-static void AtCommit_LocalCache(void);
-static void AtCommit_Memory(void);
-static void AtStart_Cache(void);
-static void AtStart_Memory(void);
-static void AtStart_ResourceOwner(void);
-static void CallEOXactCallbacks(bool isCommit);
-static void CleanupTransaction(void);
-static void CommitTransaction(void);
-static void RecordTransactionAbort(void);
-static void StartTransaction(void);
-
-static void RecordSubTransactionCommit(void);
-static void StartSubTransaction(void);
-static void CommitSubTransaction(void);
-static void AbortSubTransaction(void);
-static void CleanupSubTransaction(void);
-static void StartAbortedSubTransaction(void);
-static void PushTransaction(void);
-static void PopTransaction(void);
-static void CommitTransactionToLevel(int level);
-static char *CleanupAbortedSubTransactions(bool returnName);
-
-static void AtSubAbort_Memory(void);
-static void AtSubCleanup_Memory(void);
-static void AtSubCommit_Memory(void);
-static void AtSubStart_Memory(void);
-static void AtSubStart_ResourceOwner(void);
-
-static void ShowTransactionState(const char *str);
-static void ShowTransactionStateRec(TransactionState state);
-static const char *BlockStateAsString(TBlockState blockState);
-static const char *TransStateAsString(TransState state);
-
/*
* CurrentTransactionState always points to the current transaction state
* block. It will point to TopTransactionStateData when not in a
*/
static TransactionStateData TopTransactionStateData = {
0, /* transaction id */
+ 0, /* subtransaction id */
NULL, /* savepoint name */
0, /* savepoint level */
- FirstCommandId, /* command id */
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 */
static TransactionState CurrentTransactionState = &TopTransactionStateData;
/*
- * These vars hold 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.
+ * The subtransaction ID and command ID assignment counters are global
+ * to a whole transaction, so we do not keep them in the state stack.
*/
-static AbsoluteTime xactStartTime; /* integer part */
-static int xactStartTimeUsec; /* microsecond part */
+static SubTransactionId currentSubTransactionId;
+static CommandId currentCommandId;
+/*
+ * 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;
/*
- * User-tweakable parameters
+ * GID to be used for preparing the current transaction. This is also
+ * global to a whole transaction, so we don't keep it in the state stack.
*/
-int DefaultXactIsoLevel = XACT_READ_COMMITTED;
-int XactIsoLevel;
+static char *prepareGID;
-bool DefaultXactReadOnly = false;
-bool XactReadOnly;
+/*
+ * Some commands want to force synchronous commit.
+ */
+static bool forceSyncCommit = false;
-int CommitDelay = 0; /* precommit delay in microseconds */
-int CommitSiblings = 5; /* number of concurrent xacts needed to
- * sleep */
+/*
+ * 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
+ */
+typedef struct XactCallbackItem
+{
+ struct XactCallbackItem *next;
+ XactCallback callback;
+ void *arg;
+} XactCallbackItem;
+static XactCallbackItem *Xact_callbacks = NULL;
/*
- * List of add-on end-of-xact callbacks
+ * List of add-on start- and end-of-subxact callbacks
*/
-typedef struct EOXactCallbackItem
+typedef struct SubXactCallbackItem
{
- struct EOXactCallbackItem *next;
- EOXactCallback callback;
+ struct SubXactCallbackItem *next;
+ SubXactCallback callback;
void *arg;
-} EOXactCallbackItem;
+} SubXactCallbackItem;
+
+static SubXactCallbackItem *SubXact_callbacks = NULL;
+
-static EOXactCallbackItem *EOXact_callbacks = NULL;
+/* local function prototypes */
+static void AssignSubTransactionId(TransactionState s);
+static void AbortTransaction(void);
+static void AtAbort_Memory(void);
+static void AtCleanup_Memory(void);
+static void AtAbort_ResourceOwner(void);
+static void AtCommit_LocalCache(void);
+static void AtCommit_Memory(void);
+static void AtStart_Cache(void);
+static void AtStart_Memory(void);
+static void AtStart_ResourceOwner(void);
+static void CallXactCallbacks(XactEvent event);
+static void CallSubXactCallbacks(SubXactEvent event,
+ SubTransactionId mySubid,
+ SubTransactionId parentSubid);
+static void CleanupTransaction(void);
+static void CommitTransaction(void);
+static void RecordTransactionAbort(void);
+static void StartTransaction(void);
+
+static void RecordSubTransactionCommit(void);
+static void StartSubTransaction(void);
+static void CommitSubTransaction(void);
+static void AbortSubTransaction(void);
+static void CleanupSubTransaction(void);
+static void PushTransaction(void);
+static void PopTransaction(void);
+
+static void AtSubAbort_Memory(void);
+static void AtSubCleanup_Memory(void);
+static void AtSubAbort_ResourceOwner(void);
+static void AtSubCommit_Memory(void);
+static void AtSubStart_Memory(void);
+static void AtSubStart_ResourceOwner(void);
-static void (*_RollbackFunc) (void *) = NULL;
-static void *_RollbackData = NULL;
+static void ShowTransactionState(const char *str);
+static void ShowTransactionStateRec(TransactionState state);
+static const char *BlockStateAsString(TBlockState blockState);
+static const char *TransStateAsString(TransState state);
/* ----------------------------------------------------------------
/*
* 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;
- }
-
/*
- * Shouldn't get here, but lint is not happy with 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);
}
/*
{
TransactionState s = CurrentTransactionState;
- if (s->blockState == TBLOCK_ABORT ||
+ if (s->blockState == TBLOCK_ABORT ||
s->blockState == TBLOCK_SUBABORT)
return true;
* GetTopTransactionId
*
* Get the ID of the main transaction, even if we are currently inside
- * a subtransaction.
+ * a subtransaction. If we are not in a transaction at all, or if we
+ * are in transaction startup and haven't yet assigned an XID,
+ * InvalidTransactionId is returned.
*/
TransactionId
GetTopTransactionId(void)
{
- return TopTransactionStateData.transactionIdData;
+ 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).
*/
TransactionId
GetCurrentTransactionId(void)
{
TransactionState s = CurrentTransactionState;
- return s->transactionIdData;
+ if (!TransactionIdIsValid(s->transactionId))
+ AssignSubTransactionId(s);
+
+ return s->transactionId;
+}
+
+static void
+AssignSubTransactionId(TransactionState s)
+{
+ ResourceOwner currentOwner;
+
+ Assert(s->parent != NULL);
+ Assert(s->state == TRANS_INPROGRESS);
+ if (!TransactionIdIsValid(s->parent->transactionId))
+ AssignSubTransactionId(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.
+ */
+ s->transactionId = GetNewTransactionId(true);
+
+ 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
+ * ResourceOwner.
+ */
+ currentOwner = CurrentResourceOwner;
+ PG_TRY();
+ {
+ CurrentResourceOwner = s->curTransactionOwner;
+
+ XactLockTableInsert(s->transactionId);
+ }
+ PG_CATCH();
+ {
+ /* Ensure CurrentResourceOwner is restored on error */
+ CurrentResourceOwner = currentOwner;
+ PG_RE_THROW();
+ }
+ PG_END_TRY();
+ CurrentResourceOwner = currentOwner;
+}
+
+
+/*
+ * 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
+ */
+SubTransactionId
+GetCurrentSubTransactionId(void)
+{
+ TransactionState s = CurrentTransactionState;
+
+ return s->subTransactionId;
}
CommandId
GetCurrentCommandId(void)
{
- TransactionState s = CurrentTransactionState;
-
- return s->commandId;
+ /* this is global to a transaction, not subtransaction-local */
+ return currentCommandId;
}
+/*
+ * GetCurrentTransactionStartTimestamp
+ */
+TimestampTz
+GetCurrentTransactionStartTimestamp(void)
+{
+ return xactStartTimestamp;
+}
/*
- * GetCurrentTransactionStartTime
+ * GetCurrentStatementStartTimestamp
*/
-AbsoluteTime
-GetCurrentTransactionStartTime(void)
+TimestampTz
+GetCurrentStatementStartTimestamp(void)
{
- return xactStartTime;
+ 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();
+}
/*
- * GetCurrentTransactionStartTimeUsec
+ * SetCurrentStatementStartTimestamp
*/
-AbsoluteTime
-GetCurrentTransactionStartTimeUsec(int *msec)
+void
+SetCurrentStatementStartTimestamp(void)
{
- *msec = xactStartTimeUsec;
- return xactStartTime;
+ stmtStartTimestamp = GetCurrentTimestamp();
}
+/*
+ * SetCurrentTransactionStopTimestamp
+ */
+static inline void
+SetCurrentTransactionStopTimestamp(void)
+{
+ xactStopTimestamp = GetCurrentTimestamp();
+}
/*
* GetCurrentTransactionNestLevel
/*
* TransactionIdIsCurrentTransactionId
- *
- * During bootstrap, we cheat and say "it's not my transaction ID" even though
- * it is. Along with transam.c's cheat to say that the bootstrap XID is
- * already committed, this causes the tqual.c routines to see previously
- * inserted tuples as committed, which is what we need during bootstrap.
*/
bool
TransactionIdIsCurrentTransactionId(TransactionId xid)
{
- TransactionState s = CurrentTransactionState;
+ TransactionState s;
- if (AMI_OVERRIDE)
- {
- Assert(xid == BootstrapTransactionId);
+ /*
+ * We always say that BootstrapTransactionId is "not my transaction ID"
+ * even when it is (ie, during bootstrap). Along with the fact that
+ * transam.c always treats BootstrapTransactionId as already committed,
+ * this causes the tqual.c routines to see all tuples as committed, which
+ * is what we need during bootstrap. (Bootstrap mode only inserts tuples,
+ * it never updates or deletes them, so all tuples can be presumed good
+ * immediately.)
+ *
+ * Likewise, InvalidTransactionId and FrozenTransactionId are certainly
+ * not my transaction ID, so we can just return "false" immediately for
+ * any non-normal XID.
+ */
+ if (!TransactionIdIsNormal(xid))
return false;
- }
/*
- * We will return true for the Xid of the current subtransaction,
- * any of its subcommitted children, any of its parents, or any of
- * their previously subcommitted children.
+ * 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.
*/
- while (s != NULL)
+ for (s = CurrentTransactionState; s != NULL; s = s->parent)
{
- ListCell *cell;
+ ListCell *cell;
- if (TransactionIdEquals(xid, s->transactionIdData))
+ if (s->state == TRANS_ABORT)
+ continue;
+ if (!TransactionIdIsValid(s->transactionId))
+ continue; /* it can't have any child XIDs either */
+ if (TransactionIdEquals(xid, s->transactionId))
return true;
foreach(cell, s->childXids)
{
- if (TransactionIdEquals(xid, lfirst_int(cell)))
+ if (TransactionIdEquals(xid, lfirst_xid(cell)))
return true;
}
-
- s = s->parent;
}
return false;
void
CommandCounterIncrement(void)
{
- TransactionState s = CurrentTransactionState;
-
- s->commandId += 1;
- if (s->commandId == FirstCommandId) /* check for overflow */
+ 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")));
+ errmsg("cannot have more than 2^32-1 commands in a transaction")));
+ }
- /* Propagate new command ID into query snapshots, if set */
- if (QuerySnapshot)
- QuerySnapshot->curcid = s->commandId;
+ /* Propagate new command ID into static snapshots, if set */
if (SerializableSnapshot)
- SerializableSnapshot->curcid = s->commandId;
+ SerializableSnapshot->curcid = currentCommandId;
+ if (LatestSnapshot)
+ LatestSnapshot->curcid = currentCommandId;
/*
* make cache changes visible to me.
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(TopTransactionContext == NULL);
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(void)
{
int nrels;
- RelFileNode *rptr;
+ RelFileNode *rels;
int nchildren;
TransactionId *children;
/* Get data needed for commit record */
- nrels = smgrGetPendingDeletes(true, &rptr);
+ nrels = smgrGetPendingDeletes(true, &rels);
nchildren = xactGetCommittedChildren(&children);
/*
- * 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 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 (MyXactMadeXLogEntry || MyXactMadeTempRelUpdate || nrels > 0)
{
TransactionId xid = GetCurrentTransactionId();
bool madeTCentries;
+ bool isAsyncCommit = false;
XLogRecPtr recptr;
/* Tell bufmgr and smgr to prepare for commit */
START_CRIT_SECTION();
/*
- * We only need to log the commit 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 only need to log the commit in XLOG if the transaction made any
+ * transaction-controlled XLOG entries or will delete files.
*/
madeTCentries = (MyLastRecPtr.xrecoff != 0);
if (madeTCentries || nrels > 0)
int lastrdata = 0;
xl_xact_commit xlrec;
- xlrec.xtime = time(NULL);
+ /*
+ * Mark ourselves as within our "commit critical section". This
+ * forces any concurrent checkpoint to wait until we've updated
+ * pg_clog. Without this, it is possible for the checkpoint to
+ * set REDO after the XLOG record but fail to flush the pg_clog
+ * update to disk, leading to loss of the transaction commit if
+ * the system crashes a little later.
+ *
+ * Note: we could, but don't bother to, set this flag in
+ * RecordTransactionAbort. That's because loss of a transaction
+ * abort is noncritical; the presumption would be that it aborted,
+ * anyway.
+ *
+ * It's safe to change the 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.
+ */
+ MyProc->inCommit = true;
+
+ SetCurrentTransactionStopTimestamp();
+ xlrec.xact_time = xactStopTimestamp;
xlrec.nrels = nrels;
xlrec.nsubxacts = nchildren;
- rdata[0].buffer = InvalidBuffer;
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].buffer = InvalidBuffer;
- rdata[1].data = (char *) rptr;
+ 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].buffer = InvalidBuffer;
rdata[2].data = (char *) children;
rdata[2].len = nchildren * sizeof(TransactionId);
+ rdata[2].buffer = InvalidBuffer;
lastrdata = 2;
}
rdata[lastrdata].next = NULL;
}
/*
- * 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.
+ * 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.
*
* Note: if we generated a commit record above, MyXactMadeXLogEntry
* will certainly be set now.
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 the user has set synchronous_commit = off, and we're
+ * not doing cleanup of any rels nor committing any command
+ * that wanted to force sync commit, then we can defer fsync.
*/
- if (CommitDelay > 0 && enableFsync &&
- CountActiveBackends() >= CommitSiblings)
- pg_usleep(CommitDelay);
+ if (XactSyncCommit || forceSyncCommit || nrels > 0)
+ {
+ /*
+ * Synchronous commit case.
+ *
+ * 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);
+
+ XLogFlush(recptr);
+ }
+ else
+ {
+ /*
+ * Asynchronous commit case.
+ */
+ isAsyncCommit = true;
- XLogFlush(recptr);
+ /*
+ * Report the latest async commit LSN, so that
+ * the WAL writer knows to flush this commit.
+ */
+ XLogSetAsyncCommitLSN(recptr);
+ }
}
/*
- * 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.
+ * 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.
+ *
+ * The recptr here refers to the last xlog entry by this transaction
+ * so is the correct value to use for setting the clog.
*/
if (madeTCentries || MyXactMadeTempRelUpdate)
{
- TransactionIdCommit(xid);
- /* to avoid race conditions, the parent must commit first */
- TransactionIdCommitTree(nchildren, children);
+ if (isAsyncCommit)
+ {
+ TransactionIdAsyncCommit(xid, recptr);
+ /* to avoid race conditions, the parent must commit first */
+ TransactionIdAsyncCommitTree(nchildren, children, recptr);
+ }
+ else
+ {
+ TransactionIdCommit(xid);
+ /* to avoid race conditions, the parent must commit first */
+ TransactionIdCommitTree(nchildren, children);
+ }
}
+ /* Checkpoint can proceed now */
+ MyProc->inCommit = false;
+
END_CRIT_SECTION();
}
MyXactMadeXLogEntry = false;
MyXactMadeTempRelUpdate = false;
- /* Show myself as out of the transaction in PGPROC array */
- MyProc->logRec.xrecoff = 0;
-
/* And clean up local data */
- if (rptr)
- pfree(rptr);
+ if (rels)
+ pfree(rels);
if (children)
pfree(children);
}
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);
/*
* AtSubCommit_Memory
- *
- * We do not throw away the child's CurTransactionContext, since the data
- * it contains will be needed at upper commit.
*/
static void
AtSubCommit_Memory(void)
/* Return to parent transaction level's memory context. */
CurTransactionContext = s->parent->curTransactionContext;
MemoryContextSwitchTo(CurTransactionContext);
-}
-/*
- * AtSubCommit_childXids
+ /*
+ * Ordinarily we cannot throw away the child's CurTransactionContext,
+ * since the data it contains will be needed at upper commit. However, if
+ * there isn't actually anything in it, we can throw it away. This avoids
+ * a small memory leak in the common case of "trivial" subxacts.
+ */
+ if (MemoryContextIsEmpty(s->curTransactionContext))
+ {
+ MemoryContextDelete(s->curTransactionContext);
+ s->curTransactionContext = NULL;
+ }
+}
+
+/*
+ * AtSubCommit_childXids
*
* Pass my own XID and my child XIDs up to my parent as committed children.
*/
Assert(s->parent != NULL);
- old_cxt = MemoryContextSwitchTo(s->parent->curTransactionContext);
+ /*
+ * 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.
+ */
+ old_cxt = MemoryContextSwitchTo(TopTransactionContext);
- s->parent->childXids = list_concat(s->parent->childXids, s->childXids);
- s->childXids = NIL; /* ensure list not doubly referenced */
+ s->parent->childXids = lappend_xid(s->parent->childXids,
+ s->transactionId);
+
+ if (s->childXids != NIL)
+ {
+ s->parent->childXids = list_concat(s->parent->childXids,
+ s->childXids);
- s->parent->childXids = lappend_int(s->parent->childXids,
- s->transactionIdData);
+ /*
+ * list_concat doesn't free the list header for the second list; do so
+ * here to avoid memory leakage (kluge)
+ */
+ pfree(s->childXids);
+ s->childXids = NIL;
+ }
MemoryContextSwitchTo(old_cxt);
}
RecordSubTransactionCommit(void)
{
/*
- * We do not log the subcommit in XLOG; it doesn't matter until
- * the top-level transaction commits.
+ * 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 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...)
*/
if (MyLastRecPtr.xrecoff != 0 || MyXactMadeTempRelUpdate)
{
- TransactionId xid = GetCurrentTransactionId();
+ TransactionId xid = GetCurrentTransactionId();
/* XXX does this really need to be a critical section? */
START_CRIT_SECTION();
RecordTransactionAbort(void)
{
int nrels;
- RelFileNode *rptr;
- int nchildren;
- TransactionId *children;
+ RelFileNode *rels;
+ int nchildren;
+ TransactionId *children;
/* Get data needed for abort record */
- nrels = smgrGetPendingDeletes(false, &rptr);
+ 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.)
+ * recording the transaction abort at all. No one will ever care that it
+ * aborted. (These tests cover our whole transaction tree.)
*/
if (MyLastRecPtr.xrecoff != 0 || MyXactMadeTempRelUpdate || nrels > 0)
{
- TransactionId xid = GetCurrentTransactionId();
+ TransactionId xid = GetCurrentTransactionId();
/*
* Catch the scenario where we aborted partway through
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 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 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)
{
xl_xact_abort xlrec;
XLogRecPtr recptr;
- xlrec.xtime = time(NULL);
+ SetCurrentTransactionStopTimestamp();
+ xlrec.xact_time = xactStopTimestamp;
xlrec.nrels = nrels;
xlrec.nsubxacts = nchildren;
- rdata[0].buffer = InvalidBuffer;
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].buffer = InvalidBuffer;
- rdata[1].data = (char *) rptr;
+ 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].buffer = InvalidBuffer;
rdata[2].data = (char *) children;
rdata[2].len = nchildren * sizeof(TransactionId);
+ rdata[2].buffer = InvalidBuffer;
lastrdata = 2;
}
rdata[lastrdata].next = NULL;
* 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 last. That reduces the chance that concurrent
- * TransactionIdDidAbort calls will decide they need to do redundant
- * work.
+ * parent first. This assures an atomic transition of all the
+ * subtransactions to aborted state from the point of view of
+ * concurrent TransactionIdDidAbort calls.
*/
- TransactionIdAbortTree(nchildren, children);
TransactionIdAbort(xid);
+ TransactionIdAbortTree(nchildren, children);
END_CRIT_SECTION();
}
MyXactMadeXLogEntry = false;
MyXactMadeTempRelUpdate = false;
- /* Show myself as out of the transaction in PGPROC array */
- MyProc->logRec.xrecoff = 0;
-
/* And clean up local data */
- if (rptr)
- pfree(rptr);
+ if (rels)
+ pfree(rels);
if (children)
pfree(children);
}
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);
}
-
/*
* AtSubAbort_Memory
*/
static void
AtSubAbort_Memory(void)
{
- Assert(TopTransactionContext != NULL);
+ Assert(TransactionAbortContext != NULL);
+
+ MemoryContextSwitchTo(TransactionAbortContext);
+}
+
+
+/*
+ * AtAbort_ResourceOwner
+ */
+static void
+AtAbort_ResourceOwner(void)
+{
+ /*
+ * Make sure we have a valid ResourceOwner, if possible (else it will be
+ * NULL, which is OK)
+ */
+ CurrentResourceOwner = TopTransactionResourceOwner;
+}
+
+/*
+ * AtSubAbort_ResourceOwner
+ */
+static void
+AtSubAbort_ResourceOwner(void)
+{
+ TransactionState s = CurrentTransactionState;
+
+ /* Make sure we have a valid ResourceOwner */
+ CurrentResourceOwner = s->curTransactionOwner;
+}
+
+
+/*
+ * AtSubAbort_childXids
+ */
+static void
+AtSubAbort_childXids(void)
+{
+ TransactionState s = CurrentTransactionState;
- MemoryContextSwitchTo(TopTransactionContext);
+ /*
+ * We keep the child-XID lists in TopTransactionContext (see
+ * AtSubCommit_childXids). This means we'd better free the list
+ * explicitly at abort to avoid leakage.
+ */
+ list_free(s->childXids);
+ s->childXids = NIL;
}
/*
RecordSubTransactionAbort(void)
{
int nrels;
- RelFileNode *rptr;
- int nchildren;
- TransactionId *children;
+ RelFileNode *rels;
+ TransactionId xid = GetCurrentTransactionId();
+ int nchildren;
+ TransactionId *children;
/* Get data needed for abort record */
- nrels = smgrGetPendingDeletes(false, &rptr);
+ nrels = smgrGetPendingDeletes(false, &rels);
nchildren = xactGetCommittedChildren(&children);
/*
* 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.)
+ * 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
*/
if (MyLastRecPtr.xrecoff != 0 || MyXactMadeTempRelUpdate || nrels > 0)
{
- TransactionId xid = GetCurrentTransactionId();
-
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.
+ * 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;
+ int lastrdata = 0;
xl_xact_abort xlrec;
- XLogRecPtr recptr;
+ XLogRecPtr recptr;
- xlrec.xtime = time(NULL);
+ xlrec.xact_time = GetCurrentTimestamp();
xlrec.nrels = nrels;
xlrec.nsubxacts = nchildren;
- rdata[0].buffer = InvalidBuffer;
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].buffer = InvalidBuffer;
- rdata[1].data = (char *) rptr;
+ 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].buffer = InvalidBuffer;
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.
+ * necessary but XactLockTableWait makes use of it to avoid waiting
+ * for already-aborted subtransactions.
*/
- TransactionIdAbortTree(nchildren, children);
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 (rptr)
- pfree(rptr);
+ if (rels)
+ pfree(rels);
if (children)
pfree(children);
}
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).
*/
- MemoryContextDelete(s->curTransactionContext);
+ if (s->curTransactionContext)
+ MemoryContextDelete(s->curTransactionContext);
+ s->curTransactionContext = NULL;
}
/* ----------------------------------------------------------------
static void
StartTransaction(void)
{
- TransactionState s = CurrentTransactionState;
+ TransactionState s;
+
+ /*
+ * Let's just make sure the state stack is empty
+ */
+ s = &TopTransactionStateData;
+ CurrentTransactionState = s;
/*
* check the current transaction state
* start processing
*/
s->state = TRANS_START;
+ s->transactionId = InvalidTransactionId; /* until assigned */
/*
* Make sure we've freed any old snapshot, and reset xact state variables
FreeXactSnapshot();
XactIsoLevel = DefaultXactIsoLevel;
XactReadOnly = DefaultXactReadOnly;
+ forceSyncCommit = false;
+
+ /*
+ * reinitialize within-transaction counters
+ */
+ s->subTransactionId = TopSubTransactionId;
+ currentSubTransactionId = TopSubTransactionId;
+ currentCommandId = FirstCommandId;
/*
* must initialize resource-management stuff first
/*
* generate a new transaction id
*/
- s->transactionIdData = GetNewTransactionId(false);
+ s->transactionId = GetNewTransactionId(false);
+
+ XactLockTableInsert(s->transactionId);
- XactLockTableInsert(s->transactionIdData);
+ PG_TRACE1(transaction__start, s->transactionId);
/*
- * set now()
+ * 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.
*/
- xactStartTime = GetCurrentAbsoluteTimeUsec(&(xactStartTimeUsec));
+ xactStartTimestamp = stmtStartTimestamp;
+ xactStopTimestamp = 0;
+ pgstat_report_txn_timestamp(xactStartTimestamp);
/*
* initialize current transaction state fields
*/
- s->commandId = FirstCommandId;
s->nestingLevel = 1;
+ s->gucNestLevel = 1;
s->childXids = NIL;
/*
- * 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.
+ * 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.
*
* prevXactReadOnly is also valid only in sub-transactions.
*/
/*
* initialize other subsystems for new transaction
*/
+ AtStart_GUC();
AtStart_Inval();
AtStart_Cache();
- DeferredTriggerBeginXact();
+ AfterTriggerBeginXact();
/*
* done with start processing, set current transaction state to "in
ShowTransactionState("StartTransaction");
}
+
/*
* CommitTransaction
+ *
+ * NB: if you change this routine, better look at PrepareTransaction too!
*/
static void
CommitTransaction(void)
Assert(s->parent == NULL);
/*
- * Tell the trigger manager that this transaction is about to be
- * committed. He'll invoke all trigger deferred until XACT before we
- * really start on committing the transaction.
+ * 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.
*/
- DeferredTriggerEndXact();
+ for (;;)
+ {
+ /*
+ * Fire all currently pending deferred triggers.
+ */
+ AfterTriggerFireDeferred();
- /*
- * Similarly, let ON COMMIT management do its thing before we start to
- * commit.
- */
- PreCommit_on_commit_actions();
+ /*
+ * Convert any open holdable cursors into static portals. If there
+ * weren't any, we are done ... otherwise loop back to check if they
+ * queued deferred triggers. Lather, rinse, repeat.
+ */
+ if (!CommitHoldablePortals())
+ break;
+ }
- /* Prevent cancel/die interrupt while cleaning up */
- HOLD_INTERRUPTS();
+ /* Now we can shut down the deferred-trigger manager */
+ AfterTriggerEndXact(true);
- /*
- * set the current transaction state information appropriately during
- * the abort processing
- */
- s->state = TRANS_COMMIT;
+ /* Close any open regular cursors */
+ AtCommit_Portals();
/*
- * Do pre-commit processing (most of this stuff requires database
- * access, and in fact could still cause an error...)
+ * Let ON COMMIT management do its thing (must happen after closing
+ * cursors, to avoid dangling-reference problems)
*/
-
- AtCommit_Portals();
+ PreCommit_on_commit_actions();
/* close large objects before lower-level cleanup */
AtEOXact_LargeObject(true);
/* NOTIFY commit must come before lower-level cleanup */
AtCommit_Notify();
- /* Update the flat password file if we changed pg_shadow or pg_group */
- /* This should be the last step before commit */
- AtEOXact_UpdatePasswordFile(true);
+ /*
+ * Update flat files if we changed pg_database, pg_authid or
+ * pg_auth_members. This should be the last step before commit.
+ */
+ AtEOXact_UpdateFlatFiles(true);
+
+ /* Prevent cancel/die interrupt while cleaning up */
+ HOLD_INTERRUPTS();
+
+ /*
+ * set the current transaction state information appropriately during
+ * commit processing
+ */
+ s->state = TRANS_COMMIT;
/*
* Here is where we really truly commit.
*/
RecordTransactionCommit();
- /*
+ /*----------
* 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(SInvalLock) is required: UPDATE with xid 0 is blocked by
- * xid 1' UPDATE, xid 1 is doing commit while xid 2 gets snapshot - if
- * xid 2' GetSnapshotData sees xid 1 as running then it must see xid 0
- * as running as well or it will see two tuple versions - one deleted
- * by xid 1 and one inserted by xid 0. See notes in GetSnapshotData.
+ * 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 SInvalLock because that's what GetSnapshotData uses. */
- LWLockAcquire(SInvalLock, LW_EXCLUSIVE);
+ /* Lock ProcArrayLock because that's what GetSnapshotData uses. */
+ LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
MyProc->xid = InvalidTransactionId;
MyProc->xmin = InvalidTransactionId;
- LWLockRelease(SInvalLock);
+ MyProc->inVacuum = false; /* must be cleared with xid/xmin */
+
+ /* Clear the subtransaction-XID cache too while holding the lock */
+ MyProc->subxids.nxids = 0;
+ MyProc->subxids.overflowed = false;
+
+ LWLockRelease(ProcArrayLock);
}
+ PG_TRACE1(transaction__commit, s->transactionId);
+
/*
- * 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.
*/
- smgrDoPendingDeletes(true);
- /* smgrcommit already done */
+ CallXactCallbacks(XACT_EVENT_COMMIT);
ResourceOwnerRelease(TopTransactionResourceOwner,
RESOURCE_RELEASE_BEFORE_LOCKS,
true, true);
+ /* Check we've released all buffer pins */
+ AtEOXact_Buffers(true);
+
+ /* Clean up the relation cache */
+ AtEOXact_RelationCache(true);
+
/*
- * Make catalog changes visible to all backends. This has to happen
- * after relcache references are dropped (see comments for
- * AtEOXact_RelationCache), but before locks are released (if anyone
- * is waiting for lock on a relation we've modified, we want them to
- * know about the catalog change before they start using the relation).
+ * 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);
+ /*
+ * Likewise, dropping of files deleted during the transaction is best done
+ * after releasing relcache and buffer pins. (This is not strictly
+ * necessary during commit, since such pins should have been released
+ * already, but this ordering is definitely critical during abort.)
+ */
+ smgrDoPendingDeletes(true);
+
+ AtEOXact_MultiXact();
+
ResourceOwnerRelease(TopTransactionResourceOwner,
RESOURCE_RELEASE_LOCKS,
true, true);
RESOURCE_RELEASE_AFTER_LOCKS,
true, true);
- CallEOXactCallbacks(true);
- AtEOXact_GUC(true, false);
+ /* Check we've released all catcache entries */
+ AtEOXact_CatCache(true);
+
+ AtEOXact_GUC(true, 1);
AtEOXact_SPI(true);
- AtEOXact_on_commit_actions(true, s->transactionIdData);
+ 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_txn_timestamp(0);
CurrentResourceOwner = NULL;
ResourceOwnerDelete(TopTransactionResourceOwner);
AtCommit_Memory();
+ s->transactionId = InvalidTransactionId;
+ s->subTransactionId = InvalidSubTransactionId;
s->nestingLevel = 0;
+ s->gucNestLevel = 0;
s->childXids = NIL;
/*
RESUME_INTERRUPTS();
}
+
/*
- * AbortTransaction
+ * PrepareTransaction
+ *
+ * NB: if you change this routine, better look at CommitTransaction too!
*/
static void
-AbortTransaction(void)
+PrepareTransaction(void)
{
TransactionState s = CurrentTransactionState;
+ TransactionId xid = GetCurrentTransactionId();
+ GlobalTransaction gxact;
+ TimestampTz prepared_at;
- /* Prevent cancel/die interrupt while cleaning up */
- HOLD_INTERRUPTS();
+ ShowTransactionState("PrepareTransaction");
/*
- * 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!
+ * check the current transaction state
*/
- LWLockReleaseAll();
-
- /* Clean up buffer I/O and buffer context locks, too */
- AbortBufferIO();
- UnlockBuffers();
+ if (s->state != TRANS_INPROGRESS)
+ elog(WARNING, "PrepareTransaction while in %s state",
+ TransStateAsString(s->state));
+ Assert(s->parent == NULL);
/*
- * 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.
+ * 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.
*/
- LockWaitCancel();
+ for (;;)
+ {
+ /*
+ * Fire all currently pending deferred triggers.
+ */
+ AfterTriggerFireDeferred();
+
+ /*
+ * Convert any open holdable cursors into static portals. If there
+ * weren't any, we are done ... otherwise loop back to check if they
+ * queued deferred triggers. Lather, rinse, repeat.
+ */
+ if (!PrepareHoldablePortals())
+ break;
+ }
+
+ /* Now we can shut down the deferred-trigger manager */
+ AfterTriggerEndXact(true);
+
+ /* Close any open regular cursors */
+ AtCommit_Portals();
/*
- * check the current transaction state
+ * Let ON COMMIT management do its thing (must happen after closing
+ * cursors, to avoid dangling-reference problems)
*/
- if (s->state != TRANS_INPROGRESS)
- elog(WARNING, "AbortTransaction while in %s state",
- TransStateAsString(s->state));
- Assert(s->parent == NULL);
+ PreCommit_on_commit_actions();
+
+ /* close large objects before lower-level cleanup */
+ AtEOXact_LargeObject(true);
+
+ /* NOTIFY and flatfiles will be handled below */
+
+ /* Prevent cancel/die interrupt while cleaning up */
+ HOLD_INTERRUPTS();
/*
* set the current transaction state information appropriately during
- * the abort processing
+ * prepare processing
*/
- s->state = TRANS_ABORT;
+ s->state = TRANS_PREPARE;
- /* Make sure we are in a valid memory context */
- AtAbort_Memory();
+ prepared_at = GetCurrentTimestamp();
+
+ /* Tell bufmgr and smgr to prepare for commit */
+ BufmgrCommit();
+
+ /*
+ * Reserve the GID for this transaction. This could fail if the requested
+ * GID is invalid or already in use.
+ */
+ gxact = MarkAsPreparing(xid, prepareGID, prepared_at,
+ GetUserId(), MyDatabaseId);
+ prepareGID = NULL;
/*
- * Reset user id which might have been changed transiently. We cannot
- * use s->currentUser, but must get the session userid from miscinit.c.
+ * Collect data for the 2PC state file. Note that in general, no actual
+ * state change should happen in the called modules during this step,
+ * since it's still possible to fail before commit, and in that case we
+ * want transaction abort to be able to clean up. (In particular, the
+ * AtPrepare routines may error out if they find cases they cannot
+ * handle.) State cleanup should happen in the PostPrepare routines
+ * below. However, some modules can go ahead and clear state here because
+ * they wouldn't do anything with it during abort anyway.
*
- * (Note: 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: 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.
*/
- SetUserId(GetSessionUserId());
+ StartPrepare(gxact);
+
+ AtPrepare_Notify();
+ AtPrepare_UpdateFlatFiles();
+ AtPrepare_Inval();
+ AtPrepare_Locks();
+ AtPrepare_PgStat();
/*
- * do abort processing
+ * Here is where we really truly prepare.
+ *
+ * We have to record transaction prepares even if we didn't make any
+ * updates, because the transaction manager might get confused if we lose
+ * a global transaction.
+ */
+ EndPrepare(gxact);
+
+ /*
+ * Now we clean up backend-internal state and release internal resources.
*/
- DeferredTriggerAbortXact();
- AtAbort_Portals();
- AtEOXact_LargeObject(false); /* 'false' means it's abort */
- AtAbort_Notify();
- AtEOXact_UpdatePasswordFile(false);
- /* Advertise the fact that we aborted in pg_clog. */
- RecordTransactionAbort();
+ /* Break the chain of back-links in the XLOG records I output */
+ MyLastRecPtr.xrecoff = 0;
+ MyXactMadeXLogEntry = false;
+ MyXactMadeTempRelUpdate = false;
/*
- * Let others know about no transaction in progress by me. Note that
- * this must be done _before_ releasing locks we hold and _after_
- * RecordTransactionAbort.
+ * 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.
*/
- if (MyProc != NULL)
- {
- /* Lock SInvalLock because that's what GetSnapshotData uses. */
- LWLockAcquire(SInvalLock, LW_EXCLUSIVE);
- MyProc->xid = InvalidTransactionId;
- MyProc->xmin = InvalidTransactionId;
- LWLockRelease(SInvalLock);
- }
+
+ /* Lock ProcArrayLock because that's what GetSnapshotData uses. */
+ LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
+ MyProc->xid = InvalidTransactionId;
+ MyProc->xmin = InvalidTransactionId;
+ MyProc->inVacuum = false; /* must be cleared with xid/xmin */
+
+ /* Clear the subtransaction-XID cache too while holding the lock */
+ MyProc->subxids.nxids = 0;
+ MyProc->subxids.overflowed = false;
+
+ LWLockRelease(ProcArrayLock);
/*
- * Post-abort cleanup. See notes in CommitTransaction() concerning
- * ordering.
+ * 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.
*/
- smgrDoPendingDeletes(false);
- smgrabort();
+ CallXactCallbacks(XACT_EVENT_PREPARE);
ResourceOwnerRelease(TopTransactionResourceOwner,
RESOURCE_RELEASE_BEFORE_LOCKS,
- false, true);
- AtEOXact_Inval(false);
+ true, true);
+
+ /* 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();
+
+ AtEOXact_MultiXact();
+
+ PostPrepare_Locks(xid);
+
ResourceOwnerRelease(TopTransactionResourceOwner,
RESOURCE_RELEASE_LOCKS,
- false, true);
+ true, true);
ResourceOwnerRelease(TopTransactionResourceOwner,
RESOURCE_RELEASE_AFTER_LOCKS,
- false, true);
+ true, true);
- CallEOXactCallbacks(false);
- AtEOXact_GUC(false, false);
- AtEOXact_SPI(false);
- AtEOXact_on_commit_actions(false, s->transactionIdData);
- AtEOXact_Namespace(false);
+ /* Check we've released all catcache entries */
+ AtEOXact_CatCache(true);
+
+ /* PREPARE acts the same as COMMIT as far as GUC is concerned */
+ AtEOXact_GUC(true, 1);
+ AtEOXact_SPI(true);
+ AtEOXact_on_commit_actions(true);
+ AtEOXact_Namespace(true);
+ /* smgrcommit already done */
AtEOXact_Files();
- SetReindexProcessing(InvalidOid, InvalidOid);
- pgstat_count_xact_rollback();
+ AtEOXact_ComboCid();
+ AtEOXact_HashTables(true);
+ /* don't call AtEOXact_PgStat here */
- /*
+ CurrentResourceOwner = NULL;
+ ResourceOwnerDelete(TopTransactionResourceOwner);
+ s->curTransactionOwner = NULL;
+ CurTransactionResourceOwner = NULL;
+ TopTransactionResourceOwner = NULL;
+
+ AtCommit_Memory();
+
+ s->transactionId = InvalidTransactionId;
+ s->subTransactionId = InvalidSubTransactionId;
+ s->nestingLevel = 0;
+ s->gucNestLevel = 0;
+ s->childXids = NIL;
+
+ /*
+ * done with 1st phase commit processing, set current transaction state
+ * back to default
+ */
+ s->state = TRANS_DEFAULT;
+
+ RESUME_INTERRUPTS();
+}
+
+
+/*
+ * AbortTransaction
+ */
+static void
+AbortTransaction(void)
+{
+ TransactionState s = CurrentTransactionState;
+
+ /* Prevent cancel/die interrupt while cleaning up */
+ HOLD_INTERRUPTS();
+
+ /* Make sure we have a valid memory context and resource owner */
+ AtAbort_Memory();
+ AtAbort_ResourceOwner();
+
+ /*
+ * Release any LW locks we might be holding as quickly as possible.
+ * (Regular locks, however, must be held till we finish aborting.)
+ * Releasing LW locks is critical since we might try to grab them again
+ * while cleaning up!
+ */
+ LWLockReleaseAll();
+
+ /* Clean up buffer I/O and buffer context locks, too */
+ AbortBufferIO();
+ UnlockBuffers();
+
+ /*
+ * 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();
+
+ /*
+ * check the current transaction state
+ */
+ if (s->state != TRANS_INPROGRESS && s->state != TRANS_PREPARE)
+ elog(WARNING, "AbortTransaction while in %s state",
+ TransStateAsString(s->state));
+ Assert(s->parent == NULL);
+
+ /*
+ * set the current transaction state information appropriately during the
+ * abort processing
+ */
+ s->state = TRANS_ABORT;
+
+ /*
+ * Reset user id which might have been changed transiently. We cannot use
+ * s->currentUser, since it may not be set yet; instead rely on internal
+ * state of miscinit.c.
+ *
+ * (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.)
+ */
+ AtAbort_UserId();
+
+ /*
+ * do abort processing
+ */
+ AfterTriggerEndXact(false);
+ AtAbort_Portals();
+ AtEOXact_LargeObject(false); /* 'false' means it's abort */
+ AtAbort_Notify();
+ AtEOXact_UpdateFlatFiles(false);
+
+ /*
+ * 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();
+
+ /*
+ * 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;
+ MyProc->inVacuum = false; /* must be cleared with xid/xmin */
+ MyProc->inCommit = false; /* be sure this gets cleared */
+
+ /* Clear the subtransaction-XID cache too while holding the lock */
+ MyProc->subxids.nxids = 0;
+ MyProc->subxids.overflowed = false;
+
+ LWLockRelease(ProcArrayLock);
+ }
+
+ PG_TRACE1(transaction__abort, s->transactionId);
+
+ /*
+ * Post-abort cleanup. See notes in CommitTransaction() concerning
+ * ordering.
+ */
+
+ CallXactCallbacks(XACT_EVENT_ABORT);
+
+ ResourceOwnerRelease(TopTransactionResourceOwner,
+ RESOURCE_RELEASE_BEFORE_LOCKS,
+ false, true);
+ AtEOXact_Buffers(false);
+ AtEOXact_RelationCache(false);
+ AtEOXact_Inval(false);
+ smgrDoPendingDeletes(false);
+ AtEOXact_MultiXact();
+ ResourceOwnerRelease(TopTransactionResourceOwner,
+ RESOURCE_RELEASE_LOCKS,
+ false, true);
+ ResourceOwnerRelease(TopTransactionResourceOwner,
+ RESOURCE_RELEASE_AFTER_LOCKS,
+ false, true);
+ AtEOXact_CatCache(false);
+
+ AtEOXact_GUC(false, 1);
+ AtEOXact_SPI(false);
+ AtEOXact_on_commit_actions(false);
+ AtEOXact_Namespace(false);
+ smgrabort();
+ AtEOXact_Files();
+ AtEOXact_ComboCid();
+ AtEOXact_HashTables(false);
+ AtEOXact_PgStat(false);
+ pgstat_report_txn_timestamp(0);
+
+ /*
* State remains TRANS_ABORT until CleanupTransaction().
*/
RESUME_INTERRUPTS();
* State should still be TRANS_ABORT from AbortTransaction().
*/
if (s->state != TRANS_ABORT)
- elog(FATAL, "CleanupTransaction and not in abort state");
+ elog(FATAL, "CleanupTransaction: unexpected state %s",
+ TransStateAsString(s->state));
/*
* do abort cleanup processing
*/
AtCleanup_Portals(); /* now safe to release portal memory */
- CurrentResourceOwner = NULL; /* and resource owner */
- ResourceOwnerDelete(TopTransactionResourceOwner);
+ CurrentResourceOwner = NULL; /* and resource owner */
+ if (TopTransactionResourceOwner)
+ ResourceOwnerDelete(TopTransactionResourceOwner);
s->curTransactionOwner = NULL;
CurTransactionResourceOwner = NULL;
TopTransactionResourceOwner = NULL;
AtCleanup_Memory(); /* and transaction memory */
+ s->transactionId = InvalidTransactionId;
+ s->subTransactionId = InvalidSubTransactionId;
s->nestingLevel = 0;
+ s->gucNestLevel = 0;
s->childXids = NIL;
/*
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;
/*
- * This is the case when we are somewhere in a transaction block
- * and about to start a new command. For now we do nothing
- * but someday we may do command-local resource initialization.
+ * 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 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 to the "END
- * TRANSACTION" which will set things straight.
+ * 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:
case TBLOCK_SUBBEGIN:
case TBLOCK_END:
case TBLOCK_SUBEND:
- case TBLOCK_SUBENDABORT_ALL:
- case TBLOCK_SUBENDABORT:
+ case TBLOCK_ABORT_END:
+ case TBLOCK_SUBABORT_END:
+ case TBLOCK_ABORT_PENDING:
case TBLOCK_SUBABORT_PENDING:
- case TBLOCK_SUBENDABORT_RELEASE:
- case TBLOCK_ENDABORT:
- elog(FATAL, "StartTransactionCommand: unexpected state %s",
+ case TBLOCK_SUBRESTART:
+ case TBLOCK_SUBABORT_RESTART:
+ case TBLOCK_PREPARE:
+ elog(ERROR, "StartTransactionCommand: unexpected state %s",
BlockStateAsString(s->blockState));
break;
}
/*
* This shouldn't happen, because it means the previous
* StartTransactionCommand didn't set the STARTED state
- * appropriately, or we didn't manage previous pending
- * abort states.
+ * appropriately.
*/
case TBLOCK_DEFAULT:
- case TBLOCK_SUBABORT_PENDING:
elog(FATAL, "CommitTransactionCommand: unexpected state %s",
BlockStateAsString(s->blockState));
break;
/*
* If we aren't in a transaction block, just do our usual
- * transaction commit.
+ * transaction commit, and return to the idle state.
*/
case TBLOCK_STARTED:
CommitTransaction();
break;
/*
- * This is the case right after we get a "BEGIN TRANSACTION"
- * command, but the user hasn't done anything else yet, so we
- * change to the "transaction block in progress" state and
- * return.
+ * 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:
CommandCounterIncrement();
break;
/*
- * This is the case when we just got the "END TRANSACTION"
- * statement, so we commit the transaction and go back to the
- * default state.
+ * We are completing a "COMMIT" command. Do it and return to the
+ * idle state.
*/
case TBLOCK_END:
- /* commit all open subtransactions */
- if (s->nestingLevel > 1)
- CommitTransactionToLevel(2);
- s = CurrentTransactionState;
- Assert(s->parent == NULL);
- /* and now the outer transaction */
CommitTransaction();
s->blockState = TBLOCK_DEFAULT;
break;
/*
- * Here we are in the middle of a transaction block but one of
- * the commands caused an abort so we do nothing but remain in
- * the abort state. Eventually we will get to the "END
- * TRANSACTION" which will set things straight.
+ * 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 which just
- * processed the "END TRANSACTION" command from the user, so
- * clean up and return to the default state.
+ * 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_ENDABORT:
+ case TBLOCK_ABORT_END:
CleanupTransaction();
s->blockState = TBLOCK_DEFAULT;
break;
/*
- * Ditto, but in a subtransaction. AbortOutOfAnyTransaction
- * will do the dirty work.
+ * 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_SUBENDABORT_ALL:
- AbortOutOfAnyTransaction();
- s = CurrentTransactionState; /* changed by AbortOutOfAnyTransaction */
- /* AbortOutOfAnyTransaction sets the blockState */
+ case TBLOCK_ABORT_PENDING:
+ AbortTransaction();
+ CleanupTransaction();
+ s->blockState = TBLOCK_DEFAULT;
break;
/*
- * We were just issued a SAVEPOINT inside a transaction block.
- * Start a subtransaction. (BeginTransactionBlock already
- * did PushTransaction, so as to have someplace to put the
- * SUBBEGIN state.)
+ * We are completing a "PREPARE TRANSACTION" command. Do it and
+ * return to the idle state.
*/
- case TBLOCK_SUBBEGIN:
- StartSubTransaction();
- s->blockState = TBLOCK_SUBINPROGRESS;
+ case TBLOCK_PREPARE:
+ PrepareTransaction();
+ s->blockState = TBLOCK_DEFAULT;
break;
/*
- * Inside a subtransaction, increment the command counter.
+ * We were just issued a SAVEPOINT inside a transaction block.
+ * Start a subtransaction. (DefineSavepoint already did
+ * PushTransaction, so as to have someplace to put the SUBBEGIN
+ * state.)
*/
- case TBLOCK_SUBINPROGRESS:
- CommandCounterIncrement();
+ case TBLOCK_SUBBEGIN:
+ StartSubTransaction();
+ s->blockState = TBLOCK_SUBINPROGRESS;
break;
/*
- * We were issued a RELEASE command, so we end the current
- * subtransaction and return to the parent transaction.
+ * We were issued a COMMIT or RELEASE command, so we end the
+ * current subtransaction and return to the parent transaction.
+ * The parent might be ended too, so repeat till we are all the
+ * way out or find an INPROGRESS transaction.
*/
case TBLOCK_SUBEND:
- CommitSubTransaction();
- PopTransaction();
- s = CurrentTransactionState; /* changed by pop */
+ do
+ {
+ CommitSubTransaction();
+ s = CurrentTransactionState; /* changed by pop */
+ } while (s->blockState == TBLOCK_SUBEND);
+ /* If we had a COMMIT command, finish off the main xact too */
+ if (s->blockState == TBLOCK_END)
+ {
+ Assert(s->parent == NULL);
+ CommitTransaction();
+ s->blockState = TBLOCK_DEFAULT;
+ }
+ else if (s->blockState == TBLOCK_PREPARE)
+ {
+ Assert(s->parent == NULL);
+ PrepareTransaction();
+ s->blockState = TBLOCK_DEFAULT;
+ }
+ else
+ {
+ Assert(s->blockState == TBLOCK_INPROGRESS ||
+ s->blockState == TBLOCK_SUBINPROGRESS);
+ }
break;
/*
- * If we are in an aborted subtransaction, do nothing.
+ * The current already-failed subtransaction is ending due to a
+ * ROLLBACK or ROLLBACK TO command, so pop it and recursively
+ * examine the parent (which could be in any of several states).
*/
- case TBLOCK_SUBABORT:
+ case TBLOCK_SUBABORT_END:
+ CleanupSubTransaction();
+ CommitTransactionCommand();
break;
/*
- * The current subtransaction is ending. Do the equivalent
- * of a ROLLBACK TO followed by a RELEASE command.
+ * As above, but it's not dead yet, so abort first.
*/
- case TBLOCK_SUBENDABORT_RELEASE:
- CleanupAbortedSubTransactions(false);
+ case TBLOCK_SUBABORT_PENDING:
+ AbortSubTransaction();
+ CleanupSubTransaction();
+ CommitTransactionCommand();
break;
/*
- * The current subtransaction is ending due to a ROLLBACK
- * TO command, so close all savepoints up to the target
- * level. When finished, recreate the savepoint.
+ * The current subtransaction is the target of a ROLLBACK TO
+ * command. Abort and pop it, then start a new subtransaction
+ * with the same name.
*/
- case TBLOCK_SUBENDABORT:
+ case TBLOCK_SUBRESTART:
{
- char *name = CleanupAbortedSubTransactions(true);
+ char *name;
+ int savepointLevel;
+
+ /* save name and keep Cleanup from freeing it */
+ name = s->name;
+ s->name = NULL;
+ savepointLevel = s->savepointLevel;
+
+ AbortSubTransaction();
+ CleanupSubTransaction();
- Assert(PointerIsValid(name));
- DefineSavepoint(name);
- s = CurrentTransactionState; /* changed by DefineSavepoint */
- pfree(name);
+ DefineSavepoint(NULL);
+ s = CurrentTransactionState; /* changed by push */
+ s->name = name;
+ s->savepointLevel = savepointLevel;
/* This is the same as TBLOCK_SUBBEGIN case */
AssertState(s->blockState == TBLOCK_SUBBEGIN);
s->blockState = TBLOCK_SUBINPROGRESS;
}
break;
- }
-}
-
-/*
- * CleanupAbortedSubTransactions
- *
- * Helper function for CommitTransactionCommand. Aborts and cleans up
- * dead subtransactions after a ROLLBACK TO command. Optionally returns
- * the name of the last dead subtransaction so it can be reused to redefine
- * the savepoint. (Caller is responsible for pfree'ing the result.)
- */
-static char *
-CleanupAbortedSubTransactions(bool returnName)
-{
- TransactionState s = CurrentTransactionState;
- char *name = NULL;
-
- AssertState(PointerIsValid(s->parent));
- Assert(s->parent->blockState == TBLOCK_SUBINPROGRESS ||
- s->parent->blockState == TBLOCK_INPROGRESS ||
- s->parent->blockState == TBLOCK_SUBABORT_PENDING);
- /*
- * Abort everything up to the target level. The current
- * subtransaction only needs cleanup. If we need to save the name,
- * look for the last subtransaction in TBLOCK_SUBABORT_PENDING state.
- */
- if (returnName && s->parent->blockState != TBLOCK_SUBABORT_PENDING)
- name = MemoryContextStrdup(TopMemoryContext, s->name);
+ /*
+ * Same as above, but the subtransaction had already failed, so we
+ * don't need AbortSubTransaction.
+ */
+ case TBLOCK_SUBABORT_RESTART:
+ {
+ char *name;
+ int savepointLevel;
- CleanupSubTransaction();
- PopTransaction();
- s = CurrentTransactionState; /* changed by pop */
+ /* save name and keep Cleanup from freeing it */
+ name = s->name;
+ s->name = NULL;
+ savepointLevel = s->savepointLevel;
- while (s->blockState == TBLOCK_SUBABORT_PENDING)
- {
- AbortSubTransaction();
- if (returnName && s->parent->blockState != TBLOCK_SUBABORT_PENDING)
- name = MemoryContextStrdup(TopMemoryContext, s->name);
- CleanupSubTransaction();
- PopTransaction();
- s = CurrentTransactionState;
- }
+ CleanupSubTransaction();
- AssertState(s->blockState == TBLOCK_SUBINPROGRESS ||
- s->blockState == TBLOCK_INPROGRESS);
+ DefineSavepoint(NULL);
+ s = CurrentTransactionState; /* changed by push */
+ s->name = name;
+ s->savepointLevel = savepointLevel;
- return name;
+ /* This is the same as TBLOCK_SUBBEGIN case */
+ AssertState(s->blockState == TBLOCK_SUBBEGIN);
+ StartSubTransaction();
+ s->blockState = TBLOCK_SUBINPROGRESS;
+ }
+ break;
+ }
}
/*
switch (s->blockState)
{
- /*
- * we aren't in a transaction, so we do nothing.
- */
case TBLOCK_DEFAULT:
+ if (s->state == TRANS_DEFAULT)
+ {
+ /* we are idle, so nothing to do */
+ }
+ else
+ {
+ /*
+ * We can get here after an error during transaction start
+ * (state will be TRANS_START). Need to clean up the
+ * incompletely started transaction. First, adjust the
+ * low-level state to suppress warning message from
+ * AbortTransaction.
+ */
+ if (s->state == TRANS_START)
+ s->state = TRANS_INPROGRESS;
+ AbortTransaction();
+ CleanupTransaction();
+ }
break;
/*
- * if we aren't in a transaction block, we just do the basic
- * abort & cleanup transaction.
+ * 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" so we enter the
- * abort state. Eventually an "END TRANSACTION" will fix
- * things.
+ * 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();
- s->blockState = TBLOCK_ABORT;
- /* CleanupTransaction happens when we exit TBLOCK_ENDABORT */
+ CleanupTransaction();
+ s->blockState = TBLOCK_DEFAULT;
break;
/*
- * This is the case when we are somewhere in a transaction block
- * and we've gotten a failure, so we abort the transaction and
- * set up the persistent ABORT state. We will stay in ABORT
- * until we get an "END TRANSACTION".
+ * We are somewhere in a transaction block and we've gotten a
+ * failure, so we abort the transaction and set up the persistent
+ * ABORT state. We will stay in ABORT until we get a ROLLBACK.
*/
case TBLOCK_INPROGRESS:
AbortTransaction();
s->blockState = TBLOCK_ABORT;
- /* CleanupTransaction happens when we exit TBLOCK_ENDABORT */
+ /* CleanupTransaction happens when we exit TBLOCK_ABORT_END */
break;
/*
- * Here, the system was fouled up just after the user wanted
- * to end the transaction block so we abort the transaction
- * and return to the default state.
+ * 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 an "END TRANSACTION" to come along and lo
- * and behold, we abort 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:
break;
/*
- * Here we were in an aborted transaction block which just
- * processed the "END TRANSACTION" command but somehow aborted
- * again.. since we must have done the abort processing, we
- * clean up and return to the default state.
+ * We are in a failed transaction and we got the ROLLBACK command.
+ * We have already aborted, we just need to cleanup and go to idle
+ * state.
*/
- case TBLOCK_ENDABORT:
+ case TBLOCK_ABORT_END:
CleanupTransaction();
s->blockState = TBLOCK_DEFAULT;
break;
/*
- * If we are just starting a subtransaction, put it
- * in aborted state.
+ * We are in a live transaction and we got a ROLLBACK command.
+ * Abort, cleanup, go to idle state.
*/
- case TBLOCK_SUBBEGIN:
- StartAbortedSubTransaction();
- s->blockState = TBLOCK_SUBABORT;
+ case TBLOCK_ABORT_PENDING:
+ AbortTransaction();
+ CleanupTransaction();
+ s->blockState = TBLOCK_DEFAULT;
+ break;
+
+ /*
+ * Here, we failed while trying to PREPARE. Clean up the
+ * transaction and return to idle state (we do not want to stay in
+ * the transaction).
+ */
+ case TBLOCK_PREPARE:
+ AbortTransaction();
+ CleanupTransaction();
+ s->blockState = TBLOCK_DEFAULT;
break;
+ /*
+ * We got an error inside a subtransaction. Abort just the
+ * subtransaction, and go to the persistent SUBABORT state until
+ * we get ROLLBACK.
+ */
case TBLOCK_SUBINPROGRESS:
AbortSubTransaction();
s->blockState = TBLOCK_SUBABORT;
break;
/*
- * If we are aborting an ending transaction,
- * we have to abort the parent transaction too.
+ * If we failed while trying to create a subtransaction, clean up
+ * the broken subtransaction and abort the parent. The same
+ * applies if we get a failure while ending a subtransaction.
*/
+ case TBLOCK_SUBBEGIN:
case TBLOCK_SUBEND:
case TBLOCK_SUBABORT_PENDING:
+ case TBLOCK_SUBRESTART:
AbortSubTransaction();
CleanupSubTransaction();
- PopTransaction();
- s = CurrentTransactionState; /* changed by pop */
- Assert(s->blockState != TBLOCK_SUBEND &&
- s->blockState != TBLOCK_SUBENDABORT);
AbortCurrentTransaction();
break;
/*
* Same as above, except the Abort() was already done.
*/
- case TBLOCK_SUBENDABORT:
- case TBLOCK_SUBENDABORT_RELEASE:
+ case TBLOCK_SUBABORT_END:
+ case TBLOCK_SUBABORT_RESTART:
CleanupSubTransaction();
- PopTransaction();
- s = CurrentTransactionState; /* changed by pop */
- Assert(s->blockState != TBLOCK_SUBEND &&
- s->blockState != TBLOCK_SUBENDABORT);
AbortCurrentTransaction();
break;
-
- /*
- * We are already aborting the whole transaction tree.
- * Do nothing, CommitTransactionCommand will call
- * AbortOutOfAnyTransaction and set things straight.
- */
- case TBLOCK_SUBENDABORT_ALL:
- break;
}
}
* 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
if (IsSubTransaction())
return true;
- if (!MemoryContextContains(QueryContext, stmtNode))
+ if (!isTopLevel)
return true;
if (CurrentTransactionState->blockState != TBLOCK_DEFAULT &&
/*
- * Register or deregister callback functions for end-of-xact cleanup
+ * Register or deregister callback functions for start- and end-of-xact
+ * operations.
*
* These functions are intended for use by dynamically loaded modules.
* For built-in modules we generally just hardwire the appropriate calls
* (mainly because it's easier to control the order that way, where needed).
*
- * Note that the callback occurs post-commit or post-abort, so the callback
- * functions can only do noncritical cleanup.
+ * At transaction end, the callback occurs post-commit or post-abort, so the
+ * callback functions can only do noncritical cleanup.
*/
void
-RegisterEOXactCallback(EOXactCallback callback, void *arg)
+RegisterXactCallback(XactCallback callback, void *arg)
{
- EOXactCallbackItem *item;
+ XactCallbackItem *item;
- item = (EOXactCallbackItem *)
- MemoryContextAlloc(TopMemoryContext, sizeof(EOXactCallbackItem));
+ item = (XactCallbackItem *)
+ MemoryContextAlloc(TopMemoryContext, sizeof(XactCallbackItem));
item->callback = callback;
item->arg = arg;
- item->next = EOXact_callbacks;
- EOXact_callbacks = item;
+ item->next = Xact_callbacks;
+ Xact_callbacks = item;
}
void
-UnregisterEOXactCallback(EOXactCallback callback, void *arg)
+UnregisterXactCallback(XactCallback callback, void *arg)
{
- EOXactCallbackItem *item;
- EOXactCallbackItem *prev;
+ XactCallbackItem *item;
+ XactCallbackItem *prev;
prev = NULL;
- for (item = EOXact_callbacks; item; prev = item, item = item->next)
+ for (item = Xact_callbacks; item; prev = item, item = item->next)
{
if (item->callback == callback && item->arg == arg)
{
if (prev)
prev->next = item->next;
else
- EOXact_callbacks = item->next;
+ Xact_callbacks = item->next;
pfree(item);
break;
}
}
static void
-CallEOXactCallbacks(bool isCommit)
+CallXactCallbacks(XactEvent event)
+{
+ XactCallbackItem *item;
+
+ for (item = Xact_callbacks; item; item = item->next)
+ (*item->callback) (event, item->arg);
+}
+
+
+/*
+ * Register or deregister callback functions for start- and end-of-subxact
+ * operations.
+ *
+ * Pretty much same as above, but for subtransaction events.
+ *
+ * At subtransaction end, the callback occurs post-subcommit or post-subabort,
+ * so the callback functions can only do noncritical cleanup. At
+ * subtransaction start, the callback is called when the subtransaction has
+ * finished initializing.
+ */
+void
+RegisterSubXactCallback(SubXactCallback callback, void *arg)
+{
+ SubXactCallbackItem *item;
+
+ item = (SubXactCallbackItem *)
+ MemoryContextAlloc(TopMemoryContext, sizeof(SubXactCallbackItem));
+ item->callback = callback;
+ item->arg = arg;
+ item->next = SubXact_callbacks;
+ SubXact_callbacks = item;
+}
+
+void
+UnregisterSubXactCallback(SubXactCallback callback, void *arg)
{
- EOXactCallbackItem *item;
+ SubXactCallbackItem *item;
+ SubXactCallbackItem *prev;
- for (item = EOXact_callbacks; item; item = item->next)
+ prev = NULL;
+ for (item = SubXact_callbacks; item; prev = item, item = item->next)
{
- (*item->callback) (isCommit, item->arg);
+ if (item->callback == callback && item->arg == arg)
+ {
+ if (prev)
+ prev->next = item->next;
+ else
+ SubXact_callbacks = item->next;
+ pfree(item);
+ break;
+ }
}
}
+static void
+CallSubXactCallbacks(SubXactEvent event,
+ SubTransactionId mySubid,
+ SubTransactionId parentSubid)
+{
+ SubXactCallbackItem *item;
+
+ for (item = SubXact_callbacks; item; item = item->next)
+ (*item->callback) (event, mySubid, parentSubid, item->arg);
+}
+
/* ----------------------------------------------------------------
* transaction block support
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;
errmsg("there is already a transaction in progress")));
break;
- /* These cases are invalid. Reject them altogether. */
+ /* These cases are invalid. */
case TBLOCK_DEFAULT:
case TBLOCK_BEGIN:
case TBLOCK_SUBBEGIN:
- case TBLOCK_ENDABORT:
case TBLOCK_END:
- case TBLOCK_SUBENDABORT_ALL:
- case TBLOCK_SUBENDABORT:
- case TBLOCK_SUBABORT_PENDING:
- case TBLOCK_SUBENDABORT_RELEASE:
case TBLOCK_SUBEND:
+ case TBLOCK_ABORT_END:
+ case TBLOCK_SUBABORT_END:
+ case TBLOCK_ABORT_PENDING:
+ case TBLOCK_SUBABORT_PENDING:
+ case TBLOCK_SUBRESTART:
+ case TBLOCK_SUBABORT_RESTART:
+ case TBLOCK_PREPARE:
elog(FATAL, "BeginTransactionBlock: unexpected state %s",
BlockStateAsString(s->blockState));
break;
}
/*
- * EndTransactionBlock
- * This executes a COMMIT command.
+ * PrepareTransactionBlock
+ * This executes a PREPARE command.
*
- * Since COMMIT may actually do a ROLLBACK, the result indicates what
- * happened: TRUE for COMMIT, FALSE for ROLLBACK.
+ * Since PREPARE may actually do a ROLLBACK, the result indicates what
+ * happened: TRUE for PREPARE, FALSE for ROLLBACK.
+ *
+ * Note that we don't actually do anything here except change blockState.
+ * The real work will be done in the upcoming PrepareTransaction().
+ * We do it this way because it's not convenient to change memory context,
+ * resource owner, etc while executing inside a Portal.
*/
bool
-EndTransactionBlock(void)
+PrepareTransactionBlock(char *gid)
{
- TransactionState s = CurrentTransactionState;
+ TransactionState s;
+ bool result;
+
+ /* Set up to commit the current transaction */
+ result = EndTransactionBlock();
+
+ /* If successful, change outer tblock state to PREPARE */
+ if (result)
+ {
+ s = CurrentTransactionState;
+
+ while (s->parent != NULL)
+ s = s->parent;
+
+ if (s->blockState == TBLOCK_END)
+ {
+ /* Save GID where PrepareTransaction can find it again */
+ prepareGID = MemoryContextStrdup(TopTransactionContext, gid);
+
+ s->blockState = TBLOCK_PREPARE;
+ }
+ else
+ {
+ /*
+ * ignore case where we are not in a transaction;
+ * EndTransactionBlock already issued a warning.
+ */
+ Assert(s->blockState == TBLOCK_STARTED);
+ /* Don't send back a PREPARE result tag... */
+ result = false;
+ }
+ }
+
+ return result;
+}
+
+/*
+ * EndTransactionBlock
+ * This executes a COMMIT command.
+ *
+ * Since COMMIT may actually do a ROLLBACK, the result indicates what
+ * happened: TRUE for COMMIT, FALSE for ROLLBACK.
+ *
+ * Note that we don't actually do anything here except change blockState.
+ * The real work will be done in the upcoming CommitTransactionCommand().
+ * We do it this way because it's not convenient to change memory context,
+ * resource owner, etc while executing inside a Portal.
+ */
+bool
+EndTransactionBlock(void)
+{
+ TransactionState s = CurrentTransactionState;
bool result = false;
switch (s->blockState)
{
- /*
- * We are in a transaction block which should commit when we
- * get to the upcoming CommitTransactionCommand() so we set the
- * state to "END". CommitTransactionCommand() will recognize this
- * and commit the transaction and return us to the default state.
- */
+ /*
+ * We are in a transaction block, so tell CommitTransactionCommand
+ * to COMMIT.
+ */
case TBLOCK_INPROGRESS:
- case TBLOCK_SUBINPROGRESS:
s->blockState = TBLOCK_END;
result = true;
break;
/*
- * We are in a transaction block which aborted. Since the
- * AbortTransaction() was already done, we need only
- * change to the special "END ABORT" state. The upcoming
- * CommitTransactionCommand() will recognise this and then put us
- * back in the default state.
+ * We are in a failed transaction block. Tell
+ * CommitTransactionCommand it's time to exit the block.
*/
case TBLOCK_ABORT:
- s->blockState = TBLOCK_ENDABORT;
+ s->blockState = TBLOCK_ABORT_END;
+ break;
+
+ /*
+ * We are in a live subtransaction block. Set up to subcommit all
+ * open subtransactions and then commit the main transaction.
+ */
+ case TBLOCK_SUBINPROGRESS:
+ while (s->parent != NULL)
+ {
+ if (s->blockState == TBLOCK_SUBINPROGRESS)
+ s->blockState = TBLOCK_SUBEND;
+ else
+ elog(FATAL, "EndTransactionBlock: unexpected state %s",
+ BlockStateAsString(s->blockState));
+ s = s->parent;
+ }
+ if (s->blockState == TBLOCK_INPROGRESS)
+ s->blockState = TBLOCK_END;
+ else
+ elog(FATAL, "EndTransactionBlock: unexpected state %s",
+ BlockStateAsString(s->blockState));
+ result = true;
break;
/*
- * Here we are inside an aborted subtransaction. Go to the "abort
- * the whole tree" state so that CommitTransactionCommand() calls
- * AbortOutOfAnyTransaction.
+ * 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:
- s->blockState = TBLOCK_SUBENDABORT_ALL;
+ while (s->parent != NULL)
+ {
+ if (s->blockState == TBLOCK_SUBINPROGRESS)
+ s->blockState = TBLOCK_SUBABORT_PENDING;
+ else if (s->blockState == TBLOCK_SUBABORT)
+ s->blockState = TBLOCK_SUBABORT_END;
+ else
+ elog(FATAL, "EndTransactionBlock: unexpected state %s",
+ BlockStateAsString(s->blockState));
+ s = s->parent;
+ }
+ if (s->blockState == TBLOCK_INPROGRESS)
+ s->blockState = TBLOCK_ABORT_PENDING;
+ else if (s->blockState == TBLOCK_ABORT)
+ s->blockState = TBLOCK_ABORT_END;
+ else
+ elog(FATAL, "EndTransactionBlock: unexpected state %s",
+ BlockStateAsString(s->blockState));
break;
- case TBLOCK_STARTED:
/*
- * here, the user issued COMMIT 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.
+ * The user issued COMMIT when not inside a transaction. Issue a
+ * WARNING, staying in TBLOCK_STARTED state. The upcoming call to
+ * CommitTransactionCommand() will then close the transaction and
+ * put us back into the default state.
*/
+ case TBLOCK_STARTED:
ereport(WARNING,
(errcode(ERRCODE_NO_ACTIVE_SQL_TRANSACTION),
errmsg("there is no transaction in progress")));
- AbortTransaction();
- s->blockState = TBLOCK_ENDABORT;
+ result = true;
break;
- /* these cases are invalid. */
+ /* These cases are invalid. */
case TBLOCK_DEFAULT:
case TBLOCK_BEGIN:
- case TBLOCK_ENDABORT:
- case TBLOCK_END:
case TBLOCK_SUBBEGIN:
+ case TBLOCK_END:
case TBLOCK_SUBEND:
- case TBLOCK_SUBENDABORT_ALL:
- case TBLOCK_SUBENDABORT:
+ case TBLOCK_ABORT_END:
+ case TBLOCK_SUBABORT_END:
+ case TBLOCK_ABORT_PENDING:
case TBLOCK_SUBABORT_PENDING:
- case TBLOCK_SUBENDABORT_RELEASE:
+ case TBLOCK_SUBRESTART:
+ case TBLOCK_SUBABORT_RESTART:
+ case TBLOCK_PREPARE:
elog(FATAL, "EndTransactionBlock: unexpected state %s",
BlockStateAsString(s->blockState));
break;
/*
* UserAbortTransactionBlock
* This executes a ROLLBACK command.
+ *
+ * As above, we don't actually do anything here except change blockState.
*/
void
UserAbortTransactionBlock(void)
switch (s->blockState)
{
/*
- * We are inside a failed transaction block and we got an
- * abort command from the user. Abort processing is already
- * done, we just need to move to the ENDABORT state so we will
- * end up in the default state after the upcoming
- * CommitTransactionCommand().
- */
- case TBLOCK_ABORT:
- s->blockState = TBLOCK_ENDABORT;
- break;
-
- /*
- * We are inside a failed subtransaction and we got an
- * abort command from the user. Abort processing is already
- * done, so go to the "abort all" state and
- * CommitTransactionCommand will call AbortOutOfAnyTransaction
- * to set things straight.
+ * 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_SUBABORT:
- s->blockState = TBLOCK_SUBENDABORT_ALL;
+ case TBLOCK_INPROGRESS:
+ s->blockState = TBLOCK_ABORT_PENDING;
break;
/*
- * We are inside a transaction block and we got an abort
- * command from the user, so we move to the ENDABORT state and
- * do abort processing so we will end up in the default state
- * after the upcoming CommitTransactionCommand().
+ * We are inside a failed transaction block and we got a ROLLBACK
+ * command from the user. Abort processing is already done, so
+ * CommitTransactionCommand just has to cleanup and go back to
+ * idle state.
*/
- case TBLOCK_INPROGRESS:
- AbortTransaction();
- s->blockState = TBLOCK_ENDABORT;
+ case TBLOCK_ABORT:
+ s->blockState = TBLOCK_ABORT_END;
break;
/*
- * We are inside a subtransaction. Abort the current
- * subtransaction and go to the "abort all" state, so
- * CommitTransactionCommand will call AbortOutOfAnyTransaction
- * to set things straight.
+ * We are inside a subtransaction. Mark everything up to top
+ * level as exitable.
*/
case TBLOCK_SUBINPROGRESS:
- AbortSubTransaction();
- s->blockState = TBLOCK_SUBENDABORT_ALL;
+ case TBLOCK_SUBABORT:
+ while (s->parent != NULL)
+ {
+ if (s->blockState == TBLOCK_SUBINPROGRESS)
+ s->blockState = TBLOCK_SUBABORT_PENDING;
+ else if (s->blockState == TBLOCK_SUBABORT)
+ s->blockState = TBLOCK_SUBABORT_END;
+ else
+ elog(FATAL, "UserAbortTransactionBlock: unexpected state %s",
+ BlockStateAsString(s->blockState));
+ s = s->parent;
+ }
+ if (s->blockState == TBLOCK_INPROGRESS)
+ s->blockState = TBLOCK_ABORT_PENDING;
+ else if (s->blockState == TBLOCK_ABORT)
+ s->blockState = TBLOCK_ABORT_END;
+ else
+ elog(FATAL, "UserAbortTransactionBlock: unexpected state %s",
+ BlockStateAsString(s->blockState));
break;
/*
- * The user issued ABORT when not inside a transaction. Issue
- * a WARNING and go to abort state. The upcoming call to
+ * 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.
*/
ereport(WARNING,
(errcode(ERRCODE_NO_ACTIVE_SQL_TRANSACTION),
errmsg("there is no transaction in progress")));
- AbortTransaction();
- s->blockState = TBLOCK_ENDABORT;
+ s->blockState = TBLOCK_ABORT_PENDING;
break;
/* These cases are invalid. */
case TBLOCK_DEFAULT:
case TBLOCK_BEGIN:
+ case TBLOCK_SUBBEGIN:
case TBLOCK_END:
- case TBLOCK_ENDABORT:
case TBLOCK_SUBEND:
- case TBLOCK_SUBENDABORT_ALL:
- case TBLOCK_SUBENDABORT:
+ case TBLOCK_ABORT_END:
+ case TBLOCK_SUBABORT_END:
+ case TBLOCK_ABORT_PENDING:
case TBLOCK_SUBABORT_PENDING:
- case TBLOCK_SUBENDABORT_RELEASE:
- case TBLOCK_SUBBEGIN:
+ case TBLOCK_SUBRESTART:
+ case TBLOCK_SUBABORT_RESTART:
+ case TBLOCK_PREPARE:
elog(FATAL, "UserAbortTransactionBlock: unexpected state %s",
BlockStateAsString(s->blockState));
break;
void
DefineSavepoint(char *name)
{
- TransactionState s = CurrentTransactionState;
+ TransactionState s = CurrentTransactionState;
switch (s->blockState)
{
case TBLOCK_SUBINPROGRESS:
/* Normal subtransaction start */
PushTransaction();
- s = CurrentTransactionState; /* changed by push */
+ s = CurrentTransactionState; /* changed by push */
+
/*
- * Note that we are allocating the savepoint name in the
- * parent transaction's CurTransactionContext, since we
- * don't yet have a transaction context for the new guy.
+ * Savepoint names, like the TransactionState block itself, live
+ * in TopTransactionContext.
*/
- s->name = MemoryContextStrdup(CurTransactionContext, name);
- s->blockState = TBLOCK_SUBBEGIN;
+ if (name)
+ s->name = MemoryContextStrdup(TopTransactionContext, name);
break;
- /* These cases are invalid. Reject them altogether. */
+ /* These cases are invalid. */
case TBLOCK_DEFAULT:
case TBLOCK_STARTED:
case TBLOCK_BEGIN:
case TBLOCK_SUBBEGIN:
+ case TBLOCK_END:
+ case TBLOCK_SUBEND:
case TBLOCK_ABORT:
case TBLOCK_SUBABORT:
- case TBLOCK_ENDABORT:
- case TBLOCK_END:
- case TBLOCK_SUBENDABORT_ALL:
- case TBLOCK_SUBENDABORT:
+ case TBLOCK_ABORT_END:
+ case TBLOCK_SUBABORT_END:
+ case TBLOCK_ABORT_PENDING:
case TBLOCK_SUBABORT_PENDING:
- case TBLOCK_SUBENDABORT_RELEASE:
- case TBLOCK_SUBEND:
- elog(FATAL, "BeginTransactionBlock: unexpected state %s",
+ case TBLOCK_SUBRESTART:
+ case TBLOCK_SUBABORT_RESTART:
+ case TBLOCK_PREPARE:
+ elog(FATAL, "DefineSavepoint: unexpected state %s",
BlockStateAsString(s->blockState));
break;
}
/*
* ReleaseSavepoint
- * This executes a RELEASE command.
+ * This executes a RELEASE command.
+ *
+ * As above, we don't actually do anything here except change blockState.
*/
void
ReleaseSavepoint(List *options)
{
- TransactionState s = CurrentTransactionState;
- TransactionState target = s;
- char *name = NULL;
- ListCell *cell;
+ TransactionState s = CurrentTransactionState;
+ TransactionState target,
+ xact;
+ ListCell *cell;
+ char *name = NULL;
- /*
- * Check valid block state transaction status.
- */
switch (s->blockState)
{
+ /*
+ * We can't rollback to a savepoint if there is no savepoint
+ * defined.
+ */
case TBLOCK_INPROGRESS:
- case TBLOCK_ABORT:
ereport(ERROR,
(errcode(ERRCODE_S_E_INVALID_SPECIFICATION),
errmsg("no such savepoint")));
break;
/*
- * 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;
- /* these cases are invalid. */
+ /* These cases are invalid. */
case TBLOCK_DEFAULT:
case TBLOCK_STARTED:
case TBLOCK_BEGIN:
- case TBLOCK_ENDABORT:
- case TBLOCK_END:
- case TBLOCK_SUBABORT:
case TBLOCK_SUBBEGIN:
+ case TBLOCK_END:
case TBLOCK_SUBEND:
- case TBLOCK_SUBENDABORT_ALL:
- case TBLOCK_SUBENDABORT:
+ case TBLOCK_ABORT:
+ case TBLOCK_SUBABORT:
+ case TBLOCK_ABORT_END:
+ case TBLOCK_SUBABORT_END:
+ case TBLOCK_ABORT_PENDING:
case TBLOCK_SUBABORT_PENDING:
- case TBLOCK_SUBENDABORT_RELEASE:
+ case TBLOCK_SUBRESTART:
+ case TBLOCK_SUBABORT_RESTART:
+ case TBLOCK_PREPARE:
elog(FATAL, "ReleaseSavepoint: unexpected state %s",
BlockStateAsString(s->blockState));
break;
}
- foreach (cell, options)
+ foreach(cell, options)
{
- DefElem *elem = lfirst(cell);
+ DefElem *elem = lfirst(cell);
if (strcmp(elem->defname, "savepoint_name") == 0)
name = strVal(elem->arg);
Assert(PointerIsValid(name));
- while (target != NULL)
+ for (target = s; PointerIsValid(target); target = target->parent)
{
if (PointerIsValid(target->name) && strcmp(target->name, name) == 0)
break;
- target = target->parent;
}
if (!PointerIsValid(target))
(errcode(ERRCODE_S_E_INVALID_SPECIFICATION),
errmsg("no such savepoint")));
- CommitTransactionToLevel(target->nestingLevel);
+ /* disallow crossing savepoint level boundaries */
+ if (target->savepointLevel != s->savepointLevel)
+ ereport(ERROR,
+ (errcode(ERRCODE_S_E_INVALID_SPECIFICATION),
+ errmsg("no such savepoint")));
+
+ /*
+ * Mark "commit pending" all subtransactions up to the target
+ * subtransaction. The actual commits will happen when control gets to
+ * CommitTransactionCommand.
+ */
+ xact = CurrentTransactionState;
+ for (;;)
+ {
+ Assert(xact->blockState == TBLOCK_SUBINPROGRESS);
+ xact->blockState = TBLOCK_SUBEND;
+ if (xact == target)
+ break;
+ xact = xact->parent;
+ Assert(PointerIsValid(xact));
+ }
}
/*
* RollbackToSavepoint
- * This executes a ROLLBACK TO <savepoint> command.
+ * This executes a ROLLBACK TO <savepoint> command.
+ *
+ * As above, we don't actually do anything here except change blockState.
*/
void
RollbackToSavepoint(List *options)
{
TransactionState s = CurrentTransactionState;
TransactionState target,
- xact;
- ListCell *cell;
- char *name = NULL;
+ xact;
+ ListCell *cell;
+ char *name = NULL;
switch (s->blockState)
{
- /*
- * We can't rollback to a savepoint if there is no saveopint
- * defined.
- */
- case TBLOCK_ABORT:
+ /*
+ * We can't rollback to a savepoint if there is no savepoint
+ * defined.
+ */
case TBLOCK_INPROGRESS:
+ case TBLOCK_ABORT:
ereport(ERROR,
(errcode(ERRCODE_S_E_INVALID_SPECIFICATION),
errmsg("no such savepoint")));
/*
* There is at least one savepoint, so proceed.
*/
- case TBLOCK_SUBABORT:
case TBLOCK_SUBINPROGRESS:
- /*
- * Have to do AbortSubTransaction, but first check
- * if this is the right subtransaction
- */
+ case TBLOCK_SUBABORT:
break;
- /* these cases are invalid. */
+ /* These cases are invalid. */
case TBLOCK_DEFAULT:
case TBLOCK_STARTED:
case TBLOCK_BEGIN:
+ case TBLOCK_SUBBEGIN:
case TBLOCK_END:
- case TBLOCK_ENDABORT:
case TBLOCK_SUBEND:
- case TBLOCK_SUBENDABORT_ALL:
- case TBLOCK_SUBENDABORT:
+ case TBLOCK_ABORT_END:
+ case TBLOCK_SUBABORT_END:
+ case TBLOCK_ABORT_PENDING:
case TBLOCK_SUBABORT_PENDING:
- case TBLOCK_SUBENDABORT_RELEASE:
- case TBLOCK_SUBBEGIN:
+ case TBLOCK_SUBRESTART:
+ case TBLOCK_SUBABORT_RESTART:
+ case TBLOCK_PREPARE:
elog(FATAL, "RollbackToSavepoint: unexpected state %s",
BlockStateAsString(s->blockState));
break;
}
- foreach (cell, options)
+ foreach(cell, options)
{
- DefElem *elem = lfirst(cell);
+ DefElem *elem = lfirst(cell);
if (strcmp(elem->defname, "savepoint_name") == 0)
name = strVal(elem->arg);
Assert(PointerIsValid(name));
- target = CurrentTransactionState;
-
- while (target != NULL)
+ for (target = s; PointerIsValid(target); target = target->parent)
{
if (PointerIsValid(target->name) && strcmp(target->name, name) == 0)
break;
- target = target->parent;
-
- /* we don't cross savepoint level boundaries */
- if (target->savepointLevel != s->savepointLevel)
- ereport(ERROR,
- (errcode(ERRCODE_S_E_INVALID_SPECIFICATION),
- errmsg("no such savepoint")));
}
if (!PointerIsValid(target))
(errcode(ERRCODE_S_E_INVALID_SPECIFICATION),
errmsg("no such savepoint")));
- /*
- * Abort the current subtransaction, if needed. We can't Cleanup the
- * savepoint yet, so signal CommitTransactionCommand to do it and
- * close all savepoints up to the target level.
- */
- if (s->blockState == TBLOCK_SUBINPROGRESS)
- AbortSubTransaction();
- s->blockState = TBLOCK_SUBENDABORT;
+ /* disallow crossing savepoint level boundaries */
+ if (target->savepointLevel != s->savepointLevel)
+ ereport(ERROR,
+ (errcode(ERRCODE_S_E_INVALID_SPECIFICATION),
+ errmsg("no such savepoint")));
/*
* Mark "abort pending" all subtransactions up to the target
- * subtransaction. (Except the current subtransaction!)
+ * subtransaction. The actual aborts will happen when control gets to
+ * CommitTransactionCommand.
*/
xact = CurrentTransactionState;
-
- while (xact != target)
+ for (;;)
{
+ if (xact == target)
+ break;
+ if (xact->blockState == TBLOCK_SUBINPROGRESS)
+ xact->blockState = TBLOCK_SUBABORT_PENDING;
+ else if (xact->blockState == TBLOCK_SUBABORT)
+ xact->blockState = TBLOCK_SUBABORT_END;
+ else
+ elog(FATAL, "RollbackToSavepoint: unexpected state %s",
+ BlockStateAsString(xact->blockState));
xact = xact->parent;
Assert(PointerIsValid(xact));
- Assert(xact->blockState == TBLOCK_SUBINPROGRESS);
- xact->blockState = TBLOCK_SUBABORT_PENDING;
}
+
+ /* And mark the target as "restart pending" */
+ if (xact->blockState == TBLOCK_SUBINPROGRESS)
+ xact->blockState = TBLOCK_SUBRESTART;
+ else if (xact->blockState == TBLOCK_SUBABORT)
+ xact->blockState = TBLOCK_SUBABORT_RESTART;
+ else
+ elog(FATAL, "RollbackToSavepoint: unexpected state %s",
+ BlockStateAsString(xact->blockState));
+}
+
+/*
+ * BeginInternalSubTransaction
+ * This is the same as DefineSavepoint except it allows TBLOCK_STARTED,
+ * TBLOCK_END, and TBLOCK_PREPARE states, and therefore it can safely be
+ * used in functions that might be called when not inside a BEGIN block
+ * or when running deferred triggers at COMMIT/PREPARE time. Also, it
+ * automatically does CommitTransactionCommand/StartTransactionCommand
+ * instead of expecting the caller to do it.
+ */
+void
+BeginInternalSubTransaction(char *name)
+{
+ TransactionState s = CurrentTransactionState;
+
+ switch (s->blockState)
+ {
+ case TBLOCK_STARTED:
+ case TBLOCK_INPROGRESS:
+ case TBLOCK_END:
+ case TBLOCK_PREPARE:
+ case TBLOCK_SUBINPROGRESS:
+ /* Normal subtransaction start */
+ PushTransaction();
+ s = CurrentTransactionState; /* changed by push */
+
+ /*
+ * Savepoint names, like the TransactionState block itself, live
+ * in TopTransactionContext.
+ */
+ if (name)
+ s->name = MemoryContextStrdup(TopTransactionContext, name);
+ break;
+
+ /* These cases are invalid. */
+ case TBLOCK_DEFAULT:
+ case TBLOCK_BEGIN:
+ case TBLOCK_SUBBEGIN:
+ case TBLOCK_SUBEND:
+ case TBLOCK_ABORT:
+ case TBLOCK_SUBABORT:
+ case TBLOCK_ABORT_END:
+ case TBLOCK_SUBABORT_END:
+ case TBLOCK_ABORT_PENDING:
+ case TBLOCK_SUBABORT_PENDING:
+ case TBLOCK_SUBRESTART:
+ case TBLOCK_SUBABORT_RESTART:
+ elog(FATAL, "BeginInternalSubTransaction: unexpected state %s",
+ BlockStateAsString(s->blockState));
+ break;
+ }
+
+ CommitTransactionCommand();
+ StartTransactionCommand();
}
/*
- * RollbackAndReleaseSavepoint
+ * ReleaseCurrentSubTransaction
*
- * Executes a ROLLBACK TO command, immediately followed by a RELEASE
- * of the same savepoint.
+ * RELEASE (ie, commit) the innermost subtransaction, regardless of its
+ * savepoint name (if any).
+ * NB: do NOT use CommitTransactionCommand/StartTransactionCommand with this.
*/
void
-RollbackAndReleaseSavepoint(List *options)
+ReleaseCurrentSubTransaction(void)
{
- TransactionState s;
+ TransactionState s = CurrentTransactionState;
- RollbackToSavepoint(options);
- s = CurrentTransactionState;
- Assert(s->blockState == TBLOCK_SUBENDABORT);
- s->blockState = TBLOCK_SUBENDABORT_RELEASE;
+ if (s->blockState != TBLOCK_SUBINPROGRESS)
+ elog(ERROR, "ReleaseCurrentSubTransaction: unexpected state %s",
+ BlockStateAsString(s->blockState));
+ Assert(s->state == TRANS_INPROGRESS);
+ MemoryContextSwitchTo(CurTransactionContext);
+ CommitSubTransaction();
+ s = CurrentTransactionState; /* changed by pop */
+ Assert(s->state == TRANS_INPROGRESS);
+}
+
+/*
+ * RollbackAndReleaseCurrentSubTransaction
+ *
+ * ROLLBACK and RELEASE (ie, abort) the innermost subtransaction, regardless
+ * of its savepoint name (if any).
+ * NB: do NOT use CommitTransactionCommand/StartTransactionCommand with this.
+ */
+void
+RollbackAndReleaseCurrentSubTransaction(void)
+{
+ TransactionState s = CurrentTransactionState;
+
+ switch (s->blockState)
+ {
+ /* Must be in a subtransaction */
+ case TBLOCK_SUBINPROGRESS:
+ case TBLOCK_SUBABORT:
+ break;
+
+ /* These cases are invalid. */
+ case TBLOCK_DEFAULT:
+ case TBLOCK_STARTED:
+ case TBLOCK_BEGIN:
+ case TBLOCK_SUBBEGIN:
+ case TBLOCK_INPROGRESS:
+ case TBLOCK_END:
+ case TBLOCK_SUBEND:
+ case TBLOCK_ABORT:
+ case TBLOCK_ABORT_END:
+ case TBLOCK_SUBABORT_END:
+ case TBLOCK_ABORT_PENDING:
+ case TBLOCK_SUBABORT_PENDING:
+ case TBLOCK_SUBRESTART:
+ case TBLOCK_SUBABORT_RESTART:
+ case TBLOCK_PREPARE:
+ elog(FATAL, "RollbackAndReleaseCurrentSubTransaction: unexpected state %s",
+ BlockStateAsString(s->blockState));
+ break;
+ }
+
+ /*
+ * Abort the current subtransaction, if needed.
+ */
+ if (s->blockState == TBLOCK_SUBINPROGRESS)
+ AbortSubTransaction();
+
+ /* And clean it up, too */
+ CleanupSubTransaction();
+
+ s = CurrentTransactionState; /* changed by pop */
+ AssertState(s->blockState == TBLOCK_SUBINPROGRESS ||
+ s->blockState == TBLOCK_INPROGRESS ||
+ s->blockState == TBLOCK_STARTED);
}
/*
/*
* Get out of any transaction or nested transaction
*/
- do {
+ do
+ {
switch (s->blockState)
{
case TBLOCK_DEFAULT:
case TBLOCK_BEGIN:
case TBLOCK_INPROGRESS:
case TBLOCK_END:
+ case TBLOCK_ABORT_PENDING:
+ case TBLOCK_PREPARE:
/* In a transaction, so clean up */
AbortTransaction();
CleanupTransaction();
s->blockState = TBLOCK_DEFAULT;
break;
case TBLOCK_ABORT:
- case TBLOCK_ENDABORT:
+ case TBLOCK_ABORT_END:
/* AbortTransaction already done, still need Cleanup */
CleanupTransaction();
s->blockState = TBLOCK_DEFAULT;
break;
- case TBLOCK_SUBBEGIN:
+
/*
- * We didn't get as far as starting the subxact, so there's
- * nothing to abort. Just pop back to parent.
+ * In a subtransaction, so clean it up and abort parent too
*/
- PopTransaction();
- s = CurrentTransactionState; /* changed by pop */
- break;
+ case TBLOCK_SUBBEGIN:
case TBLOCK_SUBINPROGRESS:
case TBLOCK_SUBEND:
case TBLOCK_SUBABORT_PENDING:
- /* In a subtransaction, so clean it up and abort parent too */
+ case TBLOCK_SUBRESTART:
AbortSubTransaction();
CleanupSubTransaction();
- PopTransaction();
- s = CurrentTransactionState; /* changed by pop */
+ s = CurrentTransactionState; /* changed by pop */
break;
+
case TBLOCK_SUBABORT:
- case TBLOCK_SUBENDABORT_ALL:
- case TBLOCK_SUBENDABORT:
- case TBLOCK_SUBENDABORT_RELEASE:
+ case TBLOCK_SUBABORT_END:
+ case TBLOCK_SUBABORT_RESTART:
/* As above, but AbortSubTransaction already done */
CleanupSubTransaction();
- PopTransaction();
- s = CurrentTransactionState; /* changed by pop */
+ s = CurrentTransactionState; /* changed by pop */
break;
}
} while (s->blockState != TBLOCK_DEFAULT);
}
/*
- * CommitTransactionToLevel
- *
- * Commit everything from the current transaction level
- * up to the specified level (inclusive).
- */
-void
-CommitTransactionToLevel(int level)
-{
- TransactionState s = CurrentTransactionState;
-
- Assert(s->state == TRANS_INPROGRESS);
-
- while (s->nestingLevel >= level)
- {
- CommitSubTransaction();
- PopTransaction();
- s = CurrentTransactionState; /* changed by pop */
- Assert(s->state == TRANS_INPROGRESS);
- }
-}
-
-/*
* IsTransactionBlock --- are we within a transaction block?
*/
bool
/*
* IsTransactionOrTransactionBlock --- are we within either a transaction
- * or a transaction block? (The backend is only really "idle" when this
+ * or a transaction block? (The backend is only really "idle" when this
* returns false.)
*
* This should match up with IsTransactionBlock and IsTransactionState.
case TBLOCK_STARTED:
return 'I'; /* idle --- not in transaction */
case TBLOCK_BEGIN:
+ case TBLOCK_SUBBEGIN:
case TBLOCK_INPROGRESS:
- case TBLOCK_END:
case TBLOCK_SUBINPROGRESS:
- case TBLOCK_SUBBEGIN:
+ case TBLOCK_END:
case TBLOCK_SUBEND:
+ case TBLOCK_PREPARE:
return 'T'; /* in transaction */
case TBLOCK_ABORT:
- case TBLOCK_ENDABORT:
case TBLOCK_SUBABORT:
- case TBLOCK_SUBENDABORT_ALL:
- case TBLOCK_SUBENDABORT:
+ case TBLOCK_ABORT_END:
+ case TBLOCK_SUBABORT_END:
+ case TBLOCK_ABORT_PENDING:
case TBLOCK_SUBABORT_PENDING:
- case TBLOCK_SUBENDABORT_RELEASE:
+ case TBLOCK_SUBRESTART:
+ case TBLOCK_SUBABORT_RESTART:
return 'E'; /* in failed transaction */
}
IsSubTransaction(void)
{
TransactionState s = CurrentTransactionState;
-
- switch (s->blockState)
- {
- case TBLOCK_DEFAULT:
- case TBLOCK_STARTED:
- case TBLOCK_BEGIN:
- case TBLOCK_INPROGRESS:
- case TBLOCK_END:
- case TBLOCK_ABORT:
- case TBLOCK_ENDABORT:
- return false;
- case TBLOCK_SUBBEGIN:
- case TBLOCK_SUBINPROGRESS:
- case TBLOCK_SUBABORT:
- case TBLOCK_SUBEND:
- case TBLOCK_SUBENDABORT_ALL:
- case TBLOCK_SUBENDABORT:
- case TBLOCK_SUBABORT_PENDING:
- case TBLOCK_SUBENDABORT_RELEASE:
- return true;
- }
- /* should never get here */
- elog(FATAL, "invalid transaction block state: %s",
- BlockStateAsString(s->blockState));
- return false; /* keep compiler quiet */
+ if (s->nestingLevel >= 2)
+ return true;
+
+ return false;
}
/*
* StartSubTransaction
+ *
+ * If you're wondering why this is separate from PushTransaction: it's because
+ * we can't conveniently do this stuff right inside DefineSavepoint. The
+ * SAVEPOINT utility command will be executed inside a Portal, and if we
+ * muck with CurrentMemoryContext or CurrentResourceOwner then exit from
+ * the Portal will undo those settings. So we make DefineSavepoint just
+ * push a dummy transaction block, and when control returns to the main
+ * idle loop, CommitTransactionCommand will be called, and we'll come here
+ * to finish starting the subtransaction.
*/
static void
StartSubTransaction(void)
s->state = TRANS_START;
/*
+ * Initialize subsystems for new subtransaction
+ *
* must initialize resource-management stuff first
*/
AtSubStart_Memory();
AtSubStart_ResourceOwner();
-
- /*
- * Generate a new Xid and record it in pg_subtrans.
- */
- s->transactionIdData = GetNewTransactionId(true);
-
- SubTransSetParent(s->transactionIdData, s->parent->transactionIdData);
-
- XactLockTableInsert(s->transactionIdData);
-
- /*
- * Finish setup of other transaction state fields.
- */
- s->currentUser = GetUserId();
- s->prevXactReadOnly = XactReadOnly;
-
- /*
- * Initialize other subsystems for new subtransaction
- */
AtSubStart_Inval();
AtSubStart_Notify();
- DeferredTriggerBeginSubXact();
+ AfterTriggerBeginSubXact();
s->state = TRANS_INPROGRESS;
+ /*
+ * Call start-of-subxact callbacks
+ */
+ CallSubXactCallbacks(SUBXACT_EVENT_START_SUB, s->subTransactionId,
+ s->parent->subTransactionId);
+
ShowTransactionState("StartSubTransaction");
}
/*
* CommitSubTransaction
+ *
+ * The caller has to make sure to always reassign CurrentTransactionState
+ * if it has a local pointer to it after calling this function.
*/
static void
CommitSubTransaction(void)
elog(WARNING, "CommitSubTransaction while in %s state",
TransStateAsString(s->state));
- /* Pre-commit processing */
- AtSubCommit_Portals(s->parent->transactionIdData,
- s->parent->curTransactionOwner);
- DeferredTriggerEndSubXact(true);
+ /* Pre-commit processing goes here -- nothing to do at the moment */
s->state = TRANS_COMMIT;
- /* Mark subtransaction as subcommitted */
+ /* Must CCI to ensure commands of subtransaction are seen as done */
CommandCounterIncrement();
- RecordSubTransactionCommit();
- AtSubCommit_childXids();
+
+ /* Mark subtransaction as subcommitted */
+ if (TransactionIdIsValid(s->transactionId))
+ {
+ RecordSubTransactionCommit();
+ AtSubCommit_childXids();
+ }
/* Post-commit cleanup */
- AtSubCommit_smgr();
+ AfterTriggerEndSubXact(true);
+ AtSubCommit_Portals(s->subTransactionId,
+ s->parent->subTransactionId,
+ s->parent->curTransactionOwner);
+ AtEOSubXact_LargeObject(true, s->subTransactionId,
+ s->parent->subTransactionId);
+ AtSubCommit_Notify();
+ AtEOSubXact_UpdateFlatFiles(true, s->subTransactionId,
+ s->parent->subTransactionId);
- AtEOSubXact_Inval(true);
- AtEOSubXact_SPI(true, s->transactionIdData);
+ CallSubXactCallbacks(SUBXACT_EVENT_COMMIT_SUB, s->subTransactionId,
+ s->parent->subTransactionId);
- AtEOSubXact_LargeObject(true, s->transactionIdData,
- s->parent->transactionIdData);
- AtEOSubXact_UpdatePasswordFile(true, s->transactionIdData,
- s->parent->transactionIdData);
- AtEOSubXact_Files(true, s->transactionIdData,
- s->parent->transactionIdData);
- AtEOSubXact_Namespace(true, s->transactionIdData,
- s->parent->transactionIdData);
+ ResourceOwnerRelease(s->curTransactionOwner,
+ RESOURCE_RELEASE_BEFORE_LOCKS,
+ true, false);
+ AtEOSubXact_RelationCache(true, s->subTransactionId,
+ s->parent->subTransactionId);
+ AtEOSubXact_Inval(true);
+ AtSubCommit_smgr();
/*
- * Note that we just release the resource owner's resources and don't
- * delete it. This is because locks are not actually released here.
- * The owner object continues to exist as a child of its parent owner
- * (namely my parent transaction's resource owner), and the locks
- * effectively become that owner object's responsibility.
+ * The only lock we actually release here is the subtransaction XID lock.
+ * The rest just get transferred to the parent resource owner.
*/
+ CurrentResourceOwner = s->curTransactionOwner;
+ if (TransactionIdIsValid(s->transactionId))
+ XactLockTableDelete(s->transactionId);
+
ResourceOwnerRelease(s->curTransactionOwner,
- RESOURCE_RELEASE_BEFORE_LOCKS,
+ RESOURCE_RELEASE_LOCKS,
true, false);
- /* we can skip the LOCKS phase */
ResourceOwnerRelease(s->curTransactionOwner,
RESOURCE_RELEASE_AFTER_LOCKS,
true, false);
- AtSubCommit_Notify();
- AtEOXact_GUC(true, true);
- AtEOSubXact_on_commit_actions(true, s->transactionIdData,
- s->parent->transactionIdData);
+ AtEOXact_GUC(true, s->gucNestLevel);
+ AtEOSubXact_SPI(true, s->subTransactionId);
+ AtEOSubXact_on_commit_actions(true, s->subTransactionId,
+ s->parent->subTransactionId);
+ AtEOSubXact_Namespace(true, s->subTransactionId,
+ s->parent->subTransactionId);
+ AtEOSubXact_Files(true, s->subTransactionId,
+ s->parent->subTransactionId);
+ AtEOSubXact_HashTables(true, s->nestingLevel);
+ AtEOSubXact_PgStat(true, s->nestingLevel);
/*
- * 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;
CurrentResourceOwner = s->parent->curTransactionOwner;
CurTransactionResourceOwner = s->parent->curTransactionOwner;
+ ResourceOwnerDelete(s->curTransactionOwner);
s->curTransactionOwner = NULL;
AtSubCommit_Memory();
s->state = TRANS_DEFAULT;
+
+ PopTransaction();
}
/*
{
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();
- AtSubAbort_Memory();
-
/*
- * do abort processing
+ * check the current transaction state
*/
+ ShowTransactionState("AbortSubTransaction");
- RecordSubTransactionAbort();
-
- /* Post-abort cleanup */
- AtSubAbort_smgr();
-
- DeferredTriggerEndSubXact(false);
- AtEOSubXact_SPI(false, s->transactionIdData);
- AtSubAbort_Portals(s->parent->transactionIdData,
- s->parent->curTransactionOwner);
- AtEOSubXact_Inval(false);
+ if (s->state != TRANS_INPROGRESS)
+ elog(WARNING, "AbortSubTransaction while in %s state",
+ TransStateAsString(s->state));
- AtEOSubXact_LargeObject(false, s->transactionIdData,
- s->parent->transactionIdData);
- AtEOSubXact_UpdatePasswordFile(false, s->transactionIdData,
- s->parent->transactionIdData);
- AtEOSubXact_Files(false, s->transactionIdData,
- s->parent->transactionIdData);
- AtEOSubXact_Namespace(false, s->transactionIdData,
- s->parent->transactionIdData);
+ s->state = TRANS_ABORT;
- ResourceOwnerRelease(s->curTransactionOwner,
- RESOURCE_RELEASE_BEFORE_LOCKS,
- false, false);
- ResourceOwnerRelease(s->curTransactionOwner,
- RESOURCE_RELEASE_LOCKS,
- false, false);
- ResourceOwnerRelease(s->curTransactionOwner,
- RESOURCE_RELEASE_AFTER_LOCKS,
- false, false);
+ /*
+ * We can skip all this stuff if the subxact failed before creating a
+ * ResourceOwner...
+ */
+ if (s->curTransactionOwner)
+ {
+ AfterTriggerEndSubXact(false);
+ AtSubAbort_Portals(s->subTransactionId,
+ s->parent->subTransactionId,
+ s->parent->curTransactionOwner);
+ AtEOSubXact_LargeObject(false, s->subTransactionId,
+ s->parent->subTransactionId);
+ AtSubAbort_Notify();
+ AtEOSubXact_UpdateFlatFiles(false, s->subTransactionId,
+ s->parent->subTransactionId);
+
+ /* Advertise the fact that we aborted in pg_clog. */
+ if (TransactionIdIsValid(s->transactionId))
+ {
+ RecordSubTransactionAbort();
+ AtSubAbort_childXids();
+ }
- AtSubAbort_Notify();
- AtEOXact_GUC(false, true);
- AtEOSubXact_on_commit_actions(false, s->transactionIdData,
- s->parent->transactionIdData);
+ /* Post-abort cleanup */
+ CallSubXactCallbacks(SUBXACT_EVENT_ABORT_SUB, s->subTransactionId,
+ s->parent->subTransactionId);
+
+ ResourceOwnerRelease(s->curTransactionOwner,
+ RESOURCE_RELEASE_BEFORE_LOCKS,
+ false, false);
+ AtEOSubXact_RelationCache(false, s->subTransactionId,
+ s->parent->subTransactionId);
+ AtEOSubXact_Inval(false);
+ AtSubAbort_smgr();
+ ResourceOwnerRelease(s->curTransactionOwner,
+ RESOURCE_RELEASE_LOCKS,
+ false, false);
+ ResourceOwnerRelease(s->curTransactionOwner,
+ RESOURCE_RELEASE_AFTER_LOCKS,
+ false, false);
+
+ AtEOXact_GUC(false, s->gucNestLevel);
+ AtEOSubXact_SPI(false, s->subTransactionId);
+ AtEOSubXact_on_commit_actions(false, s->subTransactionId,
+ s->parent->subTransactionId);
+ AtEOSubXact_Namespace(false, s->subTransactionId,
+ s->parent->subTransactionId);
+ AtEOSubXact_Files(false, s->subTransactionId,
+ s->parent->subTransactionId);
+ AtEOSubXact_HashTables(false, s->nestingLevel);
+ AtEOSubXact_PgStat(false, s->nestingLevel);
+ }
/*
- * 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.)
+ * 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.
+ * 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;
- CommandCounterIncrement();
-
RESUME_INTERRUPTS();
}
/*
* CleanupSubTransaction
+ *
+ * The caller has to make sure to always reassign CurrentTransactionState
+ * if it has a local pointer to it after calling this function.
*/
static void
CleanupSubTransaction(void)
elog(WARNING, "CleanupSubTransaction while in %s state",
TransStateAsString(s->state));
- AtSubCleanup_Portals();
+ AtSubCleanup_Portals(s->subTransactionId);
CurrentResourceOwner = s->parent->curTransactionOwner;
CurTransactionResourceOwner = s->parent->curTransactionOwner;
- ResourceOwnerDelete(s->curTransactionOwner);
+ if (s->curTransactionOwner)
+ ResourceOwnerDelete(s->curTransactionOwner);
s->curTransactionOwner = NULL;
AtSubCleanup_Memory();
s->state = TRANS_DEFAULT;
-}
-
-/*
- * StartAbortedSubTransaction
- *
- * This function is used to start a subtransaction and put it immediately
- * into aborted state. The end result should be equivalent to
- * StartSubTransaction immediately followed by AbortSubTransaction.
- * The reason we don't implement it just that way is that many of the backend
- * modules aren't designed to handle starting a subtransaction when not
- * inside a valid transaction. Rather than making them all capable of
- * doing that, we just omit the paired start and abort calls in this path.
- */
-static void
-StartAbortedSubTransaction(void)
-{
- TransactionState s = CurrentTransactionState;
-
- if (s->state != TRANS_DEFAULT)
- elog(WARNING, "StartAbortedSubTransaction while in %s state",
- TransStateAsString(s->state));
-
- s->state = TRANS_START;
-
- /*
- * We don't bother to generate a new Xid, so the end state is not
- * *exactly* like we had done a full Start/AbortSubTransaction...
- */
- s->transactionIdData = InvalidTransactionId;
- /* Make sure currentUser is reasonably valid */
- Assert(s->parent != NULL);
- s->currentUser = s->parent->currentUser;
-
- /*
- * Initialize only what has to be there for CleanupSubTransaction to work.
- */
- AtSubStart_Memory();
- AtSubStart_ResourceOwner();
-
- s->state = TRANS_ABORT;
-
- AtSubAbort_Memory();
-
- ShowTransactionState("StartAbortedSubTransaction");
+ PopTransaction();
}
/*
* PushTransaction
- * Set up transaction state for a subtransaction
+ * Create transaction state stack entry for a subtransaction
*
* The caller has to make sure to always reassign CurrentTransactionState
* if it has a local pointer to it after calling this function.
static void
PushTransaction(void)
{
- TransactionState p = CurrentTransactionState;
- TransactionState s;
+ 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.
+ */
+ currentSubTransactionId += 1;
+ if (currentSubTransactionId == InvalidSubTransactionId)
+ {
+ currentSubTransactionId -= 1;
+ pfree(s);
+ ereport(ERROR,
+ (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+ errmsg("cannot have more than 2^32-1 subtransactions in a transaction")));
+ }
+
+ /*
+ * We can now stack a minimally valid subtransaction without fear of
+ * failure.
+ */
+ s->transactionId = InvalidTransactionId; /* until assigned */
+ s->subTransactionId = currentSubTransactionId;
s->parent = p;
s->nestingLevel = p->nestingLevel + 1;
+ s->gucNestLevel = NewGUCNestLevel();
s->savepointLevel = p->savepointLevel;
s->state = TRANS_DEFAULT;
s->blockState = TBLOCK_SUBBEGIN;
+ s->currentUser = currentUser;
+ s->prevXactReadOnly = XactReadOnly;
- /* Command IDs count in a continuous sequence through subtransactions */
- s->commandId = p->commandId;
+ CurrentTransactionState = s;
/*
- * Copy down some other data so that we will have valid state until
- * StartSubTransaction runs.
+ * 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.
*/
- s->transactionIdData = p->transactionIdData;
- s->curTransactionContext = p->curTransactionContext;
- s->curTransactionOwner = p->curTransactionOwner;
- s->currentUser = p->currentUser;
-
- CurrentTransactionState = s;
}
/*
if (s->parent == NULL)
elog(FATAL, "PopTransaction with no parent");
- /* Command IDs count in a continuous sequence through subtransactions */
- s->parent->commandId = s->commandId;
-
CurrentTransactionState = s->parent;
/* Let's just make sure CurTransactionContext is good */
ShowTransactionState(const char *str)
{
/* skip work if message will definitely not be printed */
- if (log_min_messages <= DEBUG2 || client_min_messages <= DEBUG2)
+ if (log_min_messages <= DEBUG3 || client_min_messages <= DEBUG3)
{
- elog(DEBUG2, "%s", str);
+ elog(DEBUG3, "%s", str);
ShowTransactionStateRec(CurrentTransactionState);
}
}
ShowTransactionStateRec(s->parent);
/* use ereport to suppress computation if msg will not be printed */
- ereport(DEBUG2,
- (errmsg_internal("name: %s; blockState: %13s; state: %7s, xid/cid: %u/%02u, nestlvl: %d, children: %s",
+ 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",
BlockStateAsString(s->blockState),
TransStateAsString(s->state),
- (unsigned int) s->transactionIdData,
- (unsigned int) s->commandId,
+ (unsigned int) s->transactionId,
+ (unsigned int) s->subTransactionId,
+ (unsigned int) currentCommandId,
s->nestingLevel,
nodeToString(s->childXids))));
}
return "END";
case TBLOCK_ABORT:
return "ABORT";
- case TBLOCK_ENDABORT:
- return "ENDABORT";
+ case TBLOCK_ABORT_END:
+ return "ABORT END";
+ case TBLOCK_ABORT_PENDING:
+ return "ABORT PEND";
+ case TBLOCK_PREPARE:
+ return "PREPARE";
case TBLOCK_SUBBEGIN:
return "SUB BEGIN";
case TBLOCK_SUBINPROGRESS:
return "SUB END";
case TBLOCK_SUBABORT:
return "SUB ABORT";
- case TBLOCK_SUBENDABORT_ALL:
- return "SUB ENDAB ALL";
- case TBLOCK_SUBENDABORT:
- return "SUB ENDAB";
+ case TBLOCK_SUBABORT_END:
+ return "SUB ABORT END";
case TBLOCK_SUBABORT_PENDING:
return "SUB ABRT PEND";
- case TBLOCK_SUBENDABORT_RELEASE:
- return "SUB ENDAB REL";
+ case TBLOCK_SUBRESTART:
+ return "SUB RESTART";
+ case TBLOCK_SUBABORT_RESTART:
+ return "SUB AB RESTRT";
}
return "UNRECOGNIZED";
}
return "DEFAULT";
case TRANS_START:
return "START";
+ case TRANS_INPROGRESS:
+ return "INPROGR";
case TRANS_COMMIT:
return "COMMIT";
case TRANS_ABORT:
return "ABORT";
- case TRANS_INPROGRESS:
- return "INPROGR";
+ case TRANS_PREPARE:
+ return "PREPARE";
}
return "UNRECOGNIZED";
}
/*
* xactGetCommittedChildren
*
- * Gets the list of committed children of the current transaction. The return
+ * 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.
int
xactGetCommittedChildren(TransactionId **ptr)
{
- TransactionState s = CurrentTransactionState;
- int nchildren;
- TransactionId *children;
- ListCell *p;
+ TransactionState s = CurrentTransactionState;
+ int nchildren;
+ TransactionId *children;
+ ListCell *p;
nchildren = list_length(s->childXids);
if (nchildren == 0)
foreach(p, s->childXids)
{
- TransactionId child = lfirst_int(p);
+ TransactionId child = lfirst_xid(p);
*children++ = child;
}
* XLOG support routines
*/
+static void
+xact_redo_commit(xl_xact_commit *xlrec, TransactionId xid)
+{
+ TransactionId *sub_xids;
+ TransactionId max_xid;
+ int i;
+
+ TransactionIdCommit(xid);
+
+ /* Mark committed subtransactions as committed */
+ sub_xids = (TransactionId *) &(xlrec->xnodes[xlrec->nrels]);
+ TransactionIdCommitTree(xlrec->nsubxacts, sub_xids);
+
+ /* Make sure nextXid is beyond any XID mentioned in the record */
+ max_xid = xid;
+ for (i = 0; i < xlrec->nsubxacts; i++)
+ {
+ if (TransactionIdPrecedes(max_xid, sub_xids[i]))
+ max_xid = sub_xids[i];
+ }
+ if (TransactionIdFollowsOrEquals(max_xid,
+ ShmemVariableCache->nextXid))
+ {
+ ShmemVariableCache->nextXid = max_xid;
+ TransactionIdAdvance(ShmemVariableCache->nextXid);
+ }
+
+ /* Make sure files supposed to be dropped are dropped */
+ for (i = 0; i < xlrec->nrels; i++)
+ {
+ XLogDropRelation(xlrec->xnodes[i]);
+ smgrdounlink(smgropen(xlrec->xnodes[i]), false, true);
+ }
+}
+
+static void
+xact_redo_abort(xl_xact_abort *xlrec, TransactionId xid)
+{
+ TransactionId *sub_xids;
+ TransactionId max_xid;
+ int i;
+
+ TransactionIdAbort(xid);
+
+ /* Mark subtransactions as aborted */
+ sub_xids = (TransactionId *) &(xlrec->xnodes[xlrec->nrels]);
+ TransactionIdAbortTree(xlrec->nsubxacts, sub_xids);
+
+ /* Make sure nextXid is beyond any XID mentioned in the record */
+ max_xid = xid;
+ for (i = 0; i < xlrec->nsubxacts; i++)
+ {
+ if (TransactionIdPrecedes(max_xid, sub_xids[i]))
+ max_xid = sub_xids[i];
+ }
+ if (TransactionIdFollowsOrEquals(max_xid,
+ ShmemVariableCache->nextXid))
+ {
+ ShmemVariableCache->nextXid = max_xid;
+ TransactionIdAdvance(ShmemVariableCache->nextXid);
+ }
+
+ /* Make sure files supposed to be dropped are dropped */
+ for (i = 0; i < xlrec->nrels; i++)
+ {
+ XLogDropRelation(xlrec->xnodes[i]);
+ smgrdounlink(smgropen(xlrec->xnodes[i]), false, true);
+ }
+}
+
void
xact_redo(XLogRecPtr lsn, XLogRecord *record)
{
if (info == XLOG_XACT_COMMIT)
{
xl_xact_commit *xlrec = (xl_xact_commit *) XLogRecGetData(record);
- int i;
- TransactionIdCommit(record->xl_xid);
- /* Mark committed subtransactions as committed */
- TransactionIdCommitTree(xlrec->nsubxacts,
- (TransactionId *) &(xlrec->xnodes[xlrec->nrels]));
- /* Make sure files supposed to be dropped are dropped */
- for (i = 0; i < xlrec->nrels; i++)
- {
- XLogCloseRelation(xlrec->xnodes[i]);
- smgrdounlink(smgropen(xlrec->xnodes[i]), false, true);
- }
+ xact_redo_commit(xlrec, record->xl_xid);
}
else if (info == XLOG_XACT_ABORT)
{
xl_xact_abort *xlrec = (xl_xact_abort *) XLogRecGetData(record);
- int i;
- TransactionIdAbort(record->xl_xid);
- /* mark subtransactions as aborted */
- TransactionIdAbortTree(xlrec->nsubxacts,
- (TransactionId *) &(xlrec->xnodes[xlrec->nrels]));
- /* Make sure files supposed to be dropped are dropped */
+ xact_redo_abort(xlrec, record->xl_xid);
+ }
+ else if (info == XLOG_XACT_PREPARE)
+ {
+ /* the record contents are exactly the 2PC file */
+ RecreateTwoPhaseFile(record->xl_xid,
+ XLogRecGetData(record), record->xl_len);
+ }
+ else if (info == XLOG_XACT_COMMIT_PREPARED)
+ {
+ xl_xact_commit_prepared *xlrec = (xl_xact_commit_prepared *) XLogRecGetData(record);
+
+ xact_redo_commit(&xlrec->crec, xlrec->xid);
+ RemoveTwoPhaseFile(xlrec->xid, false);
+ }
+ else if (info == XLOG_XACT_ABORT_PREPARED)
+ {
+ xl_xact_abort_prepared *xlrec = (xl_xact_abort_prepared *) XLogRecGetData(record);
+
+ xact_redo_abort(&xlrec->arec, xlrec->xid);
+ RemoveTwoPhaseFile(xlrec->xid, false);
+ }
+ else
+ elog(PANIC, "xact_redo: unknown op code %u", info);
+}
+
+static void
+xact_desc_commit(StringInfo buf, xl_xact_commit *xlrec)
+{
+ int i;
+
+ appendStringInfoString(buf, timestamptz_to_str(xlrec->xact_time));
+ if (xlrec->nrels > 0)
+ {
+ appendStringInfo(buf, "; rels:");
for (i = 0; i < xlrec->nrels; i++)
{
- XLogCloseRelation(xlrec->xnodes[i]);
- smgrdounlink(smgropen(xlrec->xnodes[i]), false, true);
+ RelFileNode rnode = xlrec->xnodes[i];
+
+ appendStringInfo(buf, " %u/%u/%u",
+ rnode.spcNode, rnode.dbNode, rnode.relNode);
}
}
- else
- elog(PANIC, "xact_redo: unknown op code %u", info);
+ if (xlrec->nsubxacts > 0)
+ {
+ TransactionId *xacts = (TransactionId *)
+ &xlrec->xnodes[xlrec->nrels];
+
+ appendStringInfo(buf, "; subxacts:");
+ for (i = 0; i < xlrec->nsubxacts; i++)
+ appendStringInfo(buf, " %u", xacts[i]);
+ }
}
-void
-xact_undo(XLogRecPtr lsn, XLogRecord *record)
+static void
+xact_desc_abort(StringInfo buf, xl_xact_abort *xlrec)
{
- uint8 info = record->xl_info & ~XLR_INFO_MASK;
+ int i;
- if (info == XLOG_XACT_COMMIT) /* shouldn't be called by XLOG */
- elog(PANIC, "xact_undo: can't undo committed xaction");
- else if (info != XLOG_XACT_ABORT)
- elog(PANIC, "xact_redo: unknown op code %u", info);
+ appendStringInfoString(buf, timestamptz_to_str(xlrec->xact_time));
+ if (xlrec->nrels > 0)
+ {
+ appendStringInfo(buf, "; rels:");
+ for (i = 0; i < xlrec->nrels; i++)
+ {
+ RelFileNode rnode = xlrec->xnodes[i];
+
+ appendStringInfo(buf, " %u/%u/%u",
+ rnode.spcNode, rnode.dbNode, rnode.relNode);
+ }
+ }
+ if (xlrec->nsubxacts > 0)
+ {
+ TransactionId *xacts = (TransactionId *)
+ &xlrec->xnodes[xlrec->nrels];
+
+ appendStringInfo(buf, "; subxacts:");
+ for (i = 0; i < xlrec->nsubxacts; 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;
- int i;
if (info == XLOG_XACT_COMMIT)
{
xl_xact_commit *xlrec = (xl_xact_commit *) rec;
- struct tm *tm = localtime(&xlrec->xtime);
-
- sprintf(buf + strlen(buf), "commit: %04u-%02u-%02u %02u:%02u:%02u",
- tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
- tm->tm_hour, tm->tm_min, tm->tm_sec);
- if (xlrec->nrels > 0)
- {
- sprintf(buf + strlen(buf), "; rels:");
- for (i = 0; i < xlrec->nrels; i++)
- {
- RelFileNode rnode = xlrec->xnodes[i];
- sprintf(buf + strlen(buf), " %u/%u/%u",
- rnode.spcNode, rnode.dbNode, rnode.relNode);
- }
- }
- if (xlrec->nsubxacts > 0)
- {
- TransactionId *xacts = (TransactionId *)
- &xlrec->xnodes[xlrec->nrels];
- sprintf(buf + strlen(buf), "; subxacts:");
- for (i = 0; i < xlrec->nsubxacts; i++)
- sprintf(buf + strlen(buf), " %u", xacts[i]);
- }
+ appendStringInfo(buf, "commit: ");
+ xact_desc_commit(buf, xlrec);
}
else if (info == XLOG_XACT_ABORT)
{
xl_xact_abort *xlrec = (xl_xact_abort *) rec;
- struct tm *tm = localtime(&xlrec->xtime);
- sprintf(buf + strlen(buf), "abort: %04u-%02u-%02u %02u:%02u:%02u",
- tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
- tm->tm_hour, tm->tm_min, tm->tm_sec);
- if (xlrec->nrels > 0)
- {
- sprintf(buf + strlen(buf), "; rels:");
- for (i = 0; i < xlrec->nrels; i++)
- {
- RelFileNode rnode = xlrec->xnodes[i];
- sprintf(buf + strlen(buf), " %u/%u/%u",
- rnode.spcNode, rnode.dbNode, rnode.relNode);
- }
- }
- if (xlrec->nsubxacts > 0)
- {
- TransactionId *xacts = (TransactionId *)
- &xlrec->xnodes[xlrec->nrels];
-
- sprintf(buf + strlen(buf), "; subxacts:");
- for (i = 0; i < xlrec->nsubxacts; i++)
- sprintf(buf + strlen(buf), " %u", xacts[i]);
- }
+ appendStringInfo(buf, "abort: ");
+ xact_desc_abort(buf, xlrec);
}
- else
- strcat(buf, "UNKNOWN");
-}
-
-void
-XactPushRollback(void (*func) (void *), void *data)
-{
-#ifdef XLOG_II
- if (_RollbackFunc != NULL)
- elog(PANIC, "XactPushRollback: already installed");
-#endif
+ else if (info == XLOG_XACT_PREPARE)
+ {
+ appendStringInfo(buf, "prepare");
+ }
+ else if (info == XLOG_XACT_COMMIT_PREPARED)
+ {
+ xl_xact_commit_prepared *xlrec = (xl_xact_commit_prepared *) rec;
- _RollbackFunc = func;
- _RollbackData = data;
-}
+ 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;
-void
-XactPopRollback(void)
-{
- _RollbackFunc = NULL;
+ appendStringInfo(buf, "abort %u: ", xlrec->xid);
+ xact_desc_abort(buf, &xlrec->arec);
+ }
+ else
+ appendStringInfo(buf, "UNKNOWN");
}
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