*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.137 2002/11/11 22:19:20 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.138 2002/11/13 03:12:05 momjian Exp $
*
* NOTES
* Transaction aborts can now occur two ways:
*
- * 1) system dies from some internal cause (Assert, etc..)
- * 2) user types abort
+ * 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
* 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 an END transaction.
- * (or an ABORT! --djm)
+ * 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
* TransactionCommandContext until this point.
*
* NOTES
- * This file is an attempt at a redesign of the upper layer
- * of the V1 transaction system which was too poorly thought
- * out to describe. This new system hopes to be both simpler
- * in design, simpler to extend and needs to contain added
- * functionality to solve problems beyond the scope of the V1
- * system. (In particuler, communication of transaction
- * information between parallel backends has to be supported)
- *
* The essential aspects of the transaction system are:
*
* o transaction id generation
* o lock cleanup
*
* Hence, the functional division of the transaction code is
- * based on what of the above things need to be done during
+ * 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.
* CommitTransactionBlock
* AbortTransactionBlock
*
- * These are invoked only in responce to a user "BEGIN", "END",
- * or "ABORT" command. The tricky part about these functions
+ * These are invoked only in responce 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) retrieve (foo.all)
- * 3) append foo (bar = baz)
- * 4) end
+ * 2) select * from foo
+ * 3) insert into foo (bar = baz)
+ * 4) commit
*
* in the main processing loop, this results in the following
* transaction sequence:
* \ CommitTransactionCommand();
*
* / StartTransactionCommand();
- * 2) < ProcessQuery(); << retrieve (foo.all)
+ * 2) < ProcessQuery(); << select * from foo
* \ CommitTransactionCommand();
*
* / StartTransactionCommand();
- * 3) < ProcessQuery(); << append foo (bar = baz)
+ * 3) < ProcessQuery(); << insert into foo (bar = baz)
* \ CommitTransactionCommand();
*
* / StartTransactionCommand();
- * 4) / ProcessUtility(); << end
+ * 4) / ProcessUtility(); << commit
* \ CommitTransactionBlock();
* \ CommitTransactionCommand();
*
* outside these calls they need to do normal start/commit
* processing.
*
- * Furthermore, suppose the "retrieve (foo.all)" caused an abort
+ * 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 "end".
+ * ignore all subsequent commands up to the "commit".
* -cim 3/23/90
*
*-------------------------------------------------------------------------
*/
-/*
- * Large object clean up added in CommitTransaction() to prevent buffer leaks.
- * [PA, 7/17/98]
- * [PA] is Pascal André <andre@via.ecp.fr>
- */
#include "postgres.h"
#include <unistd.h>
static void RecordTransactionAbort(void);
static void StartTransaction(void);
-/* ----------------
- * global variables holding the current transaction state.
- * ----------------
+/*
+ * global variables holding the current transaction state.
*/
static TransactionStateData CurrentTransactionStateData = {
0, /* transaction id */
0, /* scan command id */
0x0, /* start time */
TRANS_DEFAULT, /* transaction state */
- TBLOCK_DEFAULT /* transaction block state */
+ TBLOCK_DEFAULT /* transaction block state of client queries */
};
TransactionState CurrentTransactionState = &CurrentTransactionStateData;
/*
- * User-tweakable parameters
+ * User-tweakable parameters
*/
int DefaultXactIsoLevel = XACT_READ_COMMITTED;
int XactIsoLevel;
/* ----------------------------------------------------------------
- * transaction state accessors
+ * transaction state accessors
* ----------------------------------------------------------------
*/
#ifdef NOT_USED
/* --------------------------------
- * TransactionFlushEnabled()
- * SetTransactionFlushEnabled()
+ * TransactionFlushEnabled()
+ * SetTransactionFlushEnabled()
*
- * These are used to test and set the "TransactionFlushState"
- * varable. If this variable is true (the default), then
- * the system will flush all dirty buffers to disk at the end
- * of each transaction. If false then we are assuming the
- * buffer pool resides in stable main memory, in which case we
- * only do writes as necessary.
+ * These are used to test and set the "TransactionFlushState"
+ * varable. If this variable is true (the default), then
+ * the system will flush all dirty buffers to disk at the end
+ * of each transaction. If false then we are assuming the
+ * buffer pool resides in stable main memory, in which case we
+ * only do writes as necessary.
* --------------------------------
*/
static int TransactionFlushState = 1;
/* --------------------------------
- * IsTransactionState
+ * IsTransactionState
*
- * This returns true if we are currently running a query
- * within an executing transaction.
+ * This returns true if we are currently running a query
+ * within an executing transaction.
* --------------------------------
*/
bool
}
/* --------------------------------
- * IsAbortedTransactionBlockState
+ * IsAbortedTransactionBlockState
*
- * This returns true if we are currently running a query
- * within an aborted transaction block.
+ * This returns true if we are currently running a query
+ * within an aborted transaction block.
* --------------------------------
*/
bool
/* --------------------------------
- * GetCurrentTransactionId
+ * GetCurrentTransactionId
* --------------------------------
*/
TransactionId
/* --------------------------------
- * GetCurrentCommandId
+ * GetCurrentCommandId
* --------------------------------
*/
CommandId
/* --------------------------------
- * GetCurrentTransactionStartTime
+ * GetCurrentTransactionStartTime
* --------------------------------
*/
AbsoluteTime
/* --------------------------------
- * GetCurrentTransactionStartTimeUsec
+ * GetCurrentTransactionStartTimeUsec
* --------------------------------
*/
AbsoluteTime
/* --------------------------------
- * TransactionIdIsCurrentTransactionId
+ * 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.
+ * 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
/* --------------------------------
- * CommandIdIsCurrentCommandId
+ * CommandIdIsCurrentCommandId
* --------------------------------
*/
bool
/* --------------------------------
- * CommandCounterIncrement
+ * CommandCounterIncrement
* --------------------------------
*/
void
*/
/* --------------------------------
- * AtStart_Cache
+ * AtStart_Cache
* --------------------------------
*/
static void
}
/* --------------------------------
- * AtStart_Memory
+ * AtStart_Memory
* --------------------------------
*/
static void
*/
/*
- * RecordTransactionCommit
+ * RecordTransactionCommit
*/
void
RecordTransactionCommit(void)
/* --------------------------------
- * AtCommit_Cache
+ * AtCommit_Cache
* --------------------------------
*/
static void
}
/* --------------------------------
- * AtCommit_LocalCache
+ * AtCommit_LocalCache
* --------------------------------
*/
static void
}
/* --------------------------------
- * AtCommit_Locks
+ * AtCommit_Locks
* --------------------------------
*/
static void
}
/* --------------------------------
- * AtCommit_Memory
+ * AtCommit_Memory
* --------------------------------
*/
static void
*/
/*
- * RecordTransactionAbort
+ * RecordTransactionAbort
*/
static void
RecordTransactionAbort(void)
}
/* --------------------------------
- * AtAbort_Cache
+ * AtAbort_Cache
* --------------------------------
*/
static void
}
/* --------------------------------
- * AtAbort_Locks
+ * AtAbort_Locks
* --------------------------------
*/
static void
/* --------------------------------
- * AtAbort_Memory
+ * AtAbort_Memory
* --------------------------------
*/
static void
*/
/* --------------------------------
- * AtCleanup_Memory
+ * AtCleanup_Memory
* --------------------------------
*/
static void
*/
/* --------------------------------
- * StartTransaction
- *
+ * StartTransaction
* --------------------------------
*/
static void
#endif
/* --------------------------------
- * CommitTransaction
- *
+ * CommitTransaction
* --------------------------------
*/
static void
}
/* --------------------------------
- * AbortTransaction
- *
+ * AbortTransaction
* --------------------------------
*/
static void
}
/* --------------------------------
- * CleanupTransaction
- *
+ * CleanupTransaction
* --------------------------------
*/
static void
}
/* --------------------------------
- * StartTransactionCommand
+ * StartTransactionCommand
*
- * preventChain, if true, forces autocommit behavior at the next
- * CommitTransactionCommand call.
+ * preventChain, if true, forces autocommit behavior at the next
+ * CommitTransactionCommand call.
* --------------------------------
*/
void
}
/* --------------------------------
- * CommitTransactionCommand
+ * CommitTransactionCommand
*
- * forceCommit = true forces autocommit behavior even when autocommit is off.
+ * forceCommit = true forces autocommit behavior even when autocommit is off.
* --------------------------------
*/
void
}
/* --------------------------------
- * AbortCurrentTransaction
+ * AbortCurrentTransaction
* --------------------------------
*/
void
}
/* --------------------------------
- * PreventTransactionChain
+ * PreventTransactionChain
*
- * This routine is to be called by statements that must not run inside
- * a transaction block, typically because they have non-rollback-able
- * side effects or do internal commits.
+ * This routine is to be called by statements that must not run inside
+ * a transaction block, typically because they have non-rollback-able
+ * side effects or do internal commits.
*
- * If we have already started a transaction block, issue an error; also issue
- * an error if we appear to be running inside a user-defined function (which
- * could issue more commands and possibly cause a failure after the statement
- * completes). In autocommit-off mode, we allow the statement if a block is
- * not already started, and force the statement to be autocommitted despite
- * the mode.
+ * If we have already started a transaction block, issue an error; also issue
+ * an error if we appear to be running inside a user-defined function (which
+ * could issue more commands and possibly cause a failure after the statement
+ * completes). In autocommit-off mode, we allow the statement if a block is
+ * not already started, and force the statement to be autocommitted despite
+ * the mode.
*
- * 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.
+ * 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.
* --------------------------------
*/
void
* ----------------------------------------------------------------
*/
/* --------------------------------
- * BeginTransactionBlock
+ * BeginTransactionBlock
* --------------------------------
*/
void
}
/* --------------------------------
- * EndTransactionBlock
+ * EndTransactionBlock
* --------------------------------
*/
void
}
/* --------------------------------
- * AbortTransactionBlock
+ * AbortTransactionBlock
* --------------------------------
*/
#ifdef NOT_USED
#endif
/* --------------------------------
- * UserAbortTransactionBlock
+ * UserAbortTransactionBlock
* --------------------------------
*/
void
}
/* --------------------------------
- * AbortOutOfAnyTransaction
+ * AbortOutOfAnyTransaction
*
- * This routine is provided for error recovery purposes. It aborts any
- * active transaction or transaction block, leaving the system in a known
- * idle state.
+ * This routine is provided for error recovery purposes. It aborts any
+ * active transaction or transaction block, leaving the system in a known
+ * idle state.
* --------------------------------
*/
void
return false;
}
+
+/*
+ * XLOG support routines
+ */
+
void
xact_redo(XLogRecPtr lsn, XLogRecord *record)
{
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