diff options
Diffstat (limited to 'src/backend/storage/lmgr/proc.c')
| -rw-r--r-- | src/backend/storage/lmgr/proc.c | 53 |
1 files changed, 28 insertions, 25 deletions
diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 4eb97b8a6a8..3c0b96713ad 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.55 1999/05/13 15:55:44 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.56 1999/05/25 16:11:23 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -46,7 +46,7 @@ * This is so that we can support more backends. (system-wide semaphore * sets run out pretty fast.) -ay 4/95 * - * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.55 1999/05/13 15:55:44 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.56 1999/05/25 16:11:23 momjian Exp $ */ #include <sys/time.h> #include <unistd.h> @@ -150,18 +150,20 @@ InitProcGlobal(IPCKey key, int maxBackends) for (i = 0; i < MAX_PROC_SEMS / PROC_NSEMS_PER_SET; i++) ProcGlobal->freeSemMap[i] = 0; - /* Arrange to delete semas on exit --- set this up now so that - * we will clean up if pre-allocation fails... + /* + * Arrange to delete semas on exit --- set this up now so that we + * will clean up if pre-allocation fails... */ on_shmem_exit(ProcFreeAllSemaphores, NULL); - /* Pre-create the semaphores for the first maxBackends processes, + /* + * Pre-create the semaphores for the first maxBackends processes, * unless we are running as a standalone backend. */ if (key != PrivateIPCKey) { for (i = 0; - i < (maxBackends+PROC_NSEMS_PER_SET-1) / PROC_NSEMS_PER_SET; + i < (maxBackends + PROC_NSEMS_PER_SET - 1) / PROC_NSEMS_PER_SET; i++) { IPCKey semKey = ProcGlobal->currKey + i; @@ -266,10 +268,11 @@ InitProcess(IPCKey key) ProcGetNewSemKeyAndNum(&semKey, &semNum); - /* Note: because of the pre-allocation done in InitProcGlobal, - * this call should always attach to an existing semaphore. - * It will (try to) create a new group of semaphores only if - * the postmaster tries to start more backends than it said it would. + /* + * Note: because of the pre-allocation done in InitProcGlobal, + * this call should always attach to an existing semaphore. It + * will (try to) create a new group of semaphores only if the + * postmaster tries to start more backends than it said it would. */ semId = IpcSemaphoreCreate(semKey, PROC_NSEMS_PER_SET, @@ -489,7 +492,7 @@ ProcQueueInit(PROC_QUEUE *queue) */ int ProcSleep(PROC_QUEUE *waitQueue,/* lock->waitProcs */ - LOCKMETHODCTL *lockctl, + LOCKMETHODCTL * lockctl, int token, /* lockmode */ LOCK *lock) { @@ -534,23 +537,22 @@ ProcSleep(PROC_QUEUE *waitQueue,/* lock->waitProcs */ } /* if he waits for me */ else if (lockctl->conflictTab[proc->token] & MyProc->holdLock) - { break; - } /* if conflicting locks requested */ else if (lockctl->conflictTab[proc->token] & myMask) { + /* - * If I request non self-conflicting lock and there - * are others requesting the same lock just before me - - * stay here. + * If I request non self-conflicting lock and there are others + * requesting the same lock just before me - stay here. */ if (!selfConflict && prevSame) break; } + /* - * Last attempt to don't move any more: if we don't conflict - * with rest waiters in queue. + * Last attempt to don't move any more: if we don't conflict with + * rest waiters in queue. */ else if (!(lockctl->conflictTab[token] & waitMask)) break; @@ -558,7 +560,7 @@ ProcSleep(PROC_QUEUE *waitQueue,/* lock->waitProcs */ prevSame = (proc->token == token); (aheadHolders[proc->token])++; if (aheadHolders[proc->token] == lock->holders[proc->token]) - waitMask &= ~ (1 << proc->token); + waitMask &= ~(1 << proc->token); proc = (PROC *) MAKE_PTR(proc->links.prev); } @@ -885,7 +887,7 @@ ProcGetNewSemKeyAndNum(IPCKey *key, int *semNum) { int i; int32 *freeSemMap = ProcGlobal->freeSemMap; - int32 fullmask = (1 << (PROC_NSEMS_PER_SET+1)) - 1; + int32 fullmask = (1 << (PROC_NSEMS_PER_SET + 1)) - 1; /* * we hold ProcStructLock when entering this routine. We scan through @@ -906,8 +908,8 @@ ProcGetNewSemKeyAndNum(IPCKey *key, int *semNum) { /* - * a free semaphore found. Mark it as allocated. - * Also set the bit indicating whole set is allocated. + * a free semaphore found. Mark it as allocated. Also set + * the bit indicating whole set is allocated. */ freeSemMap[i] |= mask + (1 << PROC_NSEMS_PER_SET); @@ -938,9 +940,10 @@ ProcFreeSem(IpcSemaphoreKey semKey, int semNum) mask = ~(1 << semNum); freeSemMap[i] &= mask; - /* Formerly we'd release a semaphore set if it was now completely unused, - * but now we keep the semaphores to ensure we won't run out when - * starting new backends --- cf. InitProcGlobal. Note that the + /* + * Formerly we'd release a semaphore set if it was now completely + * unused, but now we keep the semaphores to ensure we won't run out + * when starting new backends --- cf. InitProcGlobal. Note that the * PROC_NSEMS_PER_SET+1'st bit of the freeSemMap entry remains set to * indicate it is still allocated; ProcFreeAllSemaphores() needs that. */ |