diff options
Diffstat (limited to 'src/backend/storage/ipc/ipci.c')
| -rw-r--r-- | src/backend/storage/ipc/ipci.c | 131 |
1 files changed, 57 insertions, 74 deletions
diff --git a/src/backend/storage/ipc/ipci.c b/src/backend/storage/ipc/ipci.c index f95b1b34410..ac738d8f77a 100644 --- a/src/backend/storage/ipc/ipci.c +++ b/src/backend/storage/ipc/ipci.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/storage/ipc/ipci.c,v 1.64 2004/02/10 01:55:25 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/storage/ipc/ipci.c,v 1.65 2004/02/25 19:41:22 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -36,8 +36,10 @@ * Creates and initializes shared memory and semaphores. * * This is called by the postmaster or by a standalone backend. - * It is NEVER called by a backend forked from the postmaster; - * for such a backend, the shared memory is already ready-to-go. + * It is also called by a backend forked from the postmaster under + * the EXEC_BACKEND case + * + * In the non EXEC_BACKEND case, backends already have shared memory ready-to-go. * * If "makePrivate" is true then we only need private memory, not shared * memory. This is true for a standalone backend, false for a postmaster. @@ -47,53 +49,68 @@ CreateSharedMemoryAndSemaphores(bool makePrivate, int maxBackends, int port) { - int size; - int numSemas; - PGShmemHeader *seghdr; - - /* - * Size of the Postgres shared-memory block is estimated via - * moderately-accurate estimates for the big hogs, plus 100K for the - * stuff that's too small to bother with estimating. - */ - size = BufferShmemSize(); - size += LockShmemSize(maxBackends); - size += XLOGShmemSize(); - size += CLOGShmemSize(); - size += LWLockShmemSize(); - size += SInvalShmemSize(maxBackends); - size += FreeSpaceShmemSize(); + PGShmemHeader *seghdr = NULL; + if (!IsUnderPostmaster) + { + int size; + int numSemas; + + /* + * Size of the Postgres shared-memory block is estimated via + * moderately-accurate estimates for the big hogs, plus 100K for the + * stuff that's too small to bother with estimating. + */ + size = BufferShmemSize(); + size += LockShmemSize(maxBackends); + size += XLOGShmemSize(); + size += CLOGShmemSize(); + size += LWLockShmemSize(); + size += SInvalShmemSize(maxBackends); + size += FreeSpaceShmemSize(); #ifdef EXEC_BACKEND - size += ShmemBackendArraySize(); + size += ShmemBackendArraySize(); #endif - size += 100000; - /* might as well round it off to a multiple of a typical page size */ - size += 8192 - (size % 8192); - - elog(DEBUG3, "invoking IpcMemoryCreate(size=%d)", size); + size += 100000; + /* might as well round it off to a multiple of a typical page size */ + size += 8192 - (size % 8192); + + elog(DEBUG3, "invoking IpcMemoryCreate(size=%d)", size); + + /* + * Create the shmem segment + */ + seghdr = PGSharedMemoryCreate(size, makePrivate, port); + + /* + * Create semaphores + */ + numSemas = ProcGlobalSemas(maxBackends); + numSemas += SpinlockSemas(); + PGReserveSemaphores(numSemas, port); + } + else + { + /* + * Attach to the shmem segment. + * (this should only ever be reached by EXEC_BACKEND code, + * and only then with makePrivate == false) + */ + Assert(ExecBackend && !makePrivate); + seghdr = PGSharedMemoryCreate(-1, makePrivate, 0); + } - /* - * Create the shmem segment - */ - seghdr = PGSharedMemoryCreate(size, makePrivate, port); - - /* - * Create semaphores - */ - numSemas = ProcGlobalSemas(maxBackends); - numSemas += SpinlockSemas(); - PGReserveSemaphores(numSemas, port); /* * Set up shared memory allocation mechanism */ - InitShmemAllocation(seghdr, true); + InitShmemAllocation(seghdr, !IsUnderPostmaster); /* * Now initialize LWLocks, which do shared memory allocation and are * needed for InitShmemIndex. */ - CreateLWLocks(); + if (!IsUnderPostmaster) + CreateLWLocks(); /* * Set up shmem.c index hashtable @@ -137,41 +154,7 @@ CreateSharedMemoryAndSemaphores(bool makePrivate, /* * Alloc the win32 shared backend array */ - ShmemBackendArrayAllocation(); + if (!IsUnderPostmaster) + ShmemBackendArrayAllocation(); #endif } - - -#ifdef EXEC_BACKEND -/* - * AttachSharedMemoryAndSemaphores - * Attaches to the existing shared resources. - */ - -/* FIXME: [fork/exec] This function is starting to look pretty much like - CreateSharedMemoryAndSemaphores. Refactor? */ -void -AttachSharedMemoryAndSemaphores(void) -{ - PGShmemHeader *seghdr = PGSharedMemoryCreate(-1,false,-1); - - InitShmemAllocation(seghdr, false); - - InitShmemIndex(); - - XLOGShmemInit(); - CLOGShmemInit(); - InitBufferPool(); - - InitLocks(); - InitLockTable(MaxBackends); - - InitProcGlobal(MaxBackends); - - CreateSharedInvalidationState(MaxBackends); - - InitFreeSpaceMap(); - - PMSignalInit(); -} -#endif |