diff options
Diffstat (limited to 'src/backend/storage/lmgr/spin.c')
| -rw-r--r-- | src/backend/storage/lmgr/spin.c | 29 |
1 files changed, 19 insertions, 10 deletions
diff --git a/src/backend/storage/lmgr/spin.c b/src/backend/storage/lmgr/spin.c index 5039141430..f7b1ac04f9 100644 --- a/src/backend/storage/lmgr/spin.c +++ b/src/backend/storage/lmgr/spin.c @@ -11,7 +11,7 @@ * is too slow to be very useful :-( * * - * Portions Copyright (c) 1996-2016, PostgreSQL Global Development Group + * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * @@ -23,11 +23,12 @@ #include "postgres.h" #include "storage/pg_sema.h" +#include "storage/shmem.h" #include "storage/spin.h" #ifndef HAVE_SPINLOCKS -PGSemaphore SpinlockSemaArray; +PGSemaphore *SpinlockSemaArray; #endif /* @@ -37,7 +38,7 @@ PGSemaphore SpinlockSemaArray; Size SpinlockSemaSize(void) { - return SpinlockSemas() * sizeof(PGSemaphoreData); + return SpinlockSemas() * sizeof(PGSemaphore); } #ifdef HAVE_SPINLOCKS @@ -67,16 +68,24 @@ SpinlockSemas(void) } /* - * Initialize semaphores. + * Initialize spinlock emulation. + * + * This must be called after PGReserveSemaphores(). */ -extern void -SpinlockSemaInit(PGSemaphore spinsemas) +void +SpinlockSemaInit(void) { - int i; + PGSemaphore *spinsemas; int nsemas = SpinlockSemas(); + int i; + /* + * We must use ShmemAllocUnlocked(), since the spinlock protecting + * ShmemAlloc() obviously can't be ready yet. + */ + spinsemas = (PGSemaphore *) ShmemAllocUnlocked(SpinlockSemaSize()); for (i = 0; i < nsemas; ++i) - PGSemaphoreCreate(&spinsemas[i]); + spinsemas[i] = PGSemaphoreCreate(); SpinlockSemaArray = spinsemas; } @@ -109,7 +118,7 @@ s_unlock_sema(volatile slock_t *lock) if (lockndx <= 0 || lockndx > NUM_SPINLOCK_SEMAPHORES) elog(ERROR, "invalid spinlock number: %d", lockndx); - PGSemaphoreUnlock(&SpinlockSemaArray[lockndx - 1]); + PGSemaphoreUnlock(SpinlockSemaArray[lockndx - 1]); } bool @@ -128,7 +137,7 @@ tas_sema(volatile slock_t *lock) if (lockndx <= 0 || lockndx > NUM_SPINLOCK_SEMAPHORES) elog(ERROR, "invalid spinlock number: %d", lockndx); /* Note that TAS macros return 0 if *success* */ - return !PGSemaphoreTryLock(&SpinlockSemaArray[lockndx - 1]); + return !PGSemaphoreTryLock(SpinlockSemaArray[lockndx - 1]); } #endif /* !HAVE_SPINLOCKS */ |