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Two-phase commit. Original patch by Heikki Linnakangas, with additional

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hacking by Alvaro Herrera and Tom Lane.
This commit is contained in:
Tom Lane
2005-06-17 22:32:51 +00:00
parent 5495575903
commit d0a89683a3
61 changed files with 4454 additions and 439 deletions
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53
src/backend/storage/lmgr/proc.c
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@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/storage/lmgr/proc.c,v 1.159 2005/06/14 22:15:32 tgl Exp $
* $PostgreSQL: pgsql/src/backend/storage/lmgr/proc.c,v 1.160 2005/06/17 22:32:45 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -92,13 +92,13 @@ static bool CheckStatementTimeout(void);
* Report shared-memory space needed by InitProcGlobal.
*/
int
ProcGlobalShmemSize(int maxBackends)
ProcGlobalShmemSize(void)
{
int size = 0;
size += MAXALIGN(sizeof(PROC_HDR)); /* ProcGlobal */
size += MAXALIGN(NUM_DUMMY_PROCS * sizeof(PGPROC)); /* DummyProcs */
size += MAXALIGN(maxBackends * sizeof(PGPROC)); /* MyProcs */
size += MAXALIGN(MaxBackends * sizeof(PGPROC)); /* MyProcs */
size += MAXALIGN(sizeof(slock_t)); /* ProcStructLock */
return size;
@@ -108,10 +108,10 @@ ProcGlobalShmemSize(int maxBackends)
* Report number of semaphores needed by InitProcGlobal.
*/
int
ProcGlobalSemas(int maxBackends)
ProcGlobalSemas(void)
{
/* We need a sema per backend, plus one for each dummy process. */
return maxBackends + NUM_DUMMY_PROCS;
return MaxBackends + NUM_DUMMY_PROCS;
}
/*
@@ -134,7 +134,7 @@ ProcGlobalSemas(int maxBackends)
* postmaster, not in backends.
*/
void
InitProcGlobal(int maxBackends)
InitProcGlobal(void)
{
bool foundProcGlobal,
foundDummy;
@@ -170,13 +170,13 @@ InitProcGlobal(int maxBackends)
* Pre-create the PGPROC structures and create a semaphore for
* each.
*/
procs = (PGPROC *) ShmemAlloc(maxBackends * sizeof(PGPROC));
procs = (PGPROC *) ShmemAlloc(MaxBackends * sizeof(PGPROC));
if (!procs)
ereport(FATAL,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of shared memory")));
MemSet(procs, 0, maxBackends * sizeof(PGPROC));
for (i = 0; i < maxBackends; i++)
MemSet(procs, 0, MaxBackends * sizeof(PGPROC));
for (i = 0; i < MaxBackends; i++)
{
PGSemaphoreCreate(&(procs[i].sem));
procs[i].links.next = ProcGlobal->freeProcs;
@@ -254,7 +254,6 @@ InitProcess(void)
MyProc->xmin = InvalidTransactionId;
MyProc->pid = MyProcPid;
MyProc->databaseId = MyDatabaseId;
MyProc->logRec.xrecoff = 0;
MyProc->lwWaiting = false;
MyProc->lwExclusive = false;
MyProc->lwWaitLink = NULL;
@@ -265,7 +264,7 @@ InitProcess(void)
/*
* Add our PGPROC to the PGPROC array in shared memory.
*/
ProcArrayAddMyself();
ProcArrayAdd(MyProc);
/*
* Arrange to clean up at backend exit.
@@ -332,7 +331,6 @@ InitDummyProcess(int proctype)
MyProc->xid = InvalidTransactionId;
MyProc->xmin = InvalidTransactionId;
MyProc->databaseId = MyDatabaseId;
MyProc->logRec.xrecoff = 0;
MyProc->lwWaiting = false;
MyProc->lwExclusive = false;
MyProc->lwWaitLink = NULL;
@@ -352,6 +350,35 @@ InitDummyProcess(int proctype)
PGSemaphoreReset(&MyProc->sem);
}
/*
* Check whether there are at least N free PGPROC objects.
*
* Note: this is designed on the assumption that N will generally be small.
*/
bool
HaveNFreeProcs(int n)
{
SHMEM_OFFSET offset;
PGPROC *proc;
/* use volatile pointer to prevent code rearrangement */
volatile PROC_HDR *procglobal = ProcGlobal;
SpinLockAcquire(ProcStructLock);
offset = procglobal->freeProcs;
while (n > 0 && offset != INVALID_OFFSET)
{
proc = (PGPROC *) MAKE_PTR(offset);
offset = proc->links.next;
n--;
}
SpinLockRelease(ProcStructLock);
return (n <= 0);
}
/*
* Cancel any pending wait for lock, when aborting a transaction.
*
@@ -478,7 +505,7 @@ ProcKill(int code, Datum arg)
#endif
/* Remove our PGPROC from the PGPROC array in shared memory */
ProcArrayRemoveMyself();
ProcArrayRemove(MyProc);
SpinLockAcquire(ProcStructLock);