diff options
Diffstat (limited to 'src/backend/storage/lmgr/proc.c')
| -rw-r--r-- | src/backend/storage/lmgr/proc.c | 53 |
1 files changed, 40 insertions, 13 deletions
diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index b62283cffb4..227c3694788 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -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; @@ -353,6 +351,35 @@ InitDummyProcess(int proctype) } /* + * 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. * * Returns true if we had been waiting for a lock, else false. @@ -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); |