diff options
Diffstat (limited to 'src/backend/storage/ipc/shmem.c')
| -rw-r--r-- | src/backend/storage/ipc/shmem.c | 155 |
1 files changed, 5 insertions, 150 deletions
diff --git a/src/backend/storage/ipc/shmem.c b/src/backend/storage/ipc/shmem.c index 685912e157a..b79f0f11913 100644 --- a/src/backend/storage/ipc/shmem.c +++ b/src/backend/storage/ipc/shmem.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/storage/ipc/shmem.c,v 1.97 2006/10/04 00:29:57 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/storage/ipc/shmem.c,v 1.98 2006/10/15 22:04:07 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -53,7 +53,7 @@ * postmaster. However, this does not work in the EXEC_BACKEND case. * In ports using EXEC_BACKEND, new backends have to set up their local * pointers using the method described in (b) above. - + * * (d) memory allocation model: shared memory can never be * freed, once allocated. Each hash table has its own free list, * so hash buckets can be reused when an item is deleted. However, @@ -61,15 +61,6 @@ * cannot be redistributed to other tables. We could build a simple * hash bucket garbage collector if need be. Right now, it seems * unnecessary. - * - * (e) Add-ins can request their own logical shared memory segments - * by calling RegisterAddinContext() from the preload-libraries hook. - * Each call establishes a uniquely named add-in shared memopry - * context which will be set up as part of postgres intialisation. - * Memory can be allocated from these contexts using - * ShmemAllocFromContext(), and can be reset to its initial condition - * using ShmemResetContext(). Also, RegisterAddinLWLock(LWLockid *lock_ptr) - * can be used to request that a LWLock be allocated, placed into *lock_ptr. */ #include "postgres.h" @@ -95,19 +86,6 @@ slock_t *ShmemLock; /* spinlock for shared memory and LWLock static HTAB *ShmemIndex = NULL; /* primary index hashtable for shmem */ -/* Structures and globals for managing add-in shared memory contexts */ -typedef struct context -{ - char *name; - Size size; - PGShmemHeader *seg_hdr; - struct context *next; -} ContextNode; - -static ContextNode *addin_contexts = NULL; -static Size addin_contexts_size = 0; - - /* * InitShmemAccess() --- set up basic pointers to shared memory. @@ -162,99 +140,7 @@ InitShmemAllocation(void) } /* - * RegisterAddinContext -- Register the requirement for a named shared - * memory context. - */ -void -RegisterAddinContext(const char *name, Size size) -{ - char *newstr = malloc(strlen(name) + 1); - ContextNode *node = malloc(sizeof(ContextNode)); - - strcpy(newstr, name); - node->name = newstr; - - /* Round up to typical page size */ - node->size = add_size(size, 8192 - (size % 8192)); - node->next = addin_contexts; - - addin_contexts = node; - addin_contexts_size = add_size(addin_contexts_size, node->size); -} - - -/* - * ContextFromName -- Return the ContextNode for the given named - * context, or NULL if not found. - */ -static ContextNode * -ContextFromName(const char *name) -{ - ContextNode *context = addin_contexts; - - while (context) - { - if (strcmp(name, context->name) == 0) - return context; - context = context->next; - } - return NULL; -} - -/* - * InitAddinContexts -- Initialise the registered addin shared memory - * contexts. - */ -void -InitAddinContexts(void *start) -{ - PGShmemHeader *next_segment = (PGShmemHeader *) start; - ContextNode *context = addin_contexts; - - while (context) - { - context->seg_hdr = next_segment; - - next_segment->totalsize = context->size; - next_segment->freeoffset = MAXALIGN(sizeof(PGShmemHeader)); - - next_segment = (PGShmemHeader *) - ((char *) next_segment + context->size); - context = context->next; - } -} - -/* - * ShmemResetContext -- Re-initialise the named addin shared memory context. - */ -void -ShmemResetContext(const char *name) -{ - PGShmemHeader *segment; - ContextNode *context = ContextFromName(name); - - if (!context) - ereport(ERROR, - (errcode(ERRCODE_INTERNAL_ERROR), - errmsg("cannot reset unknown shared memory context %s", - name))); - - segment = context->seg_hdr; - segment->freeoffset = MAXALIGN(sizeof(PGShmemHeader)); -} - -/* - * AddinShmemSize -- Report how much shared memory has been registered - * for add-ins. - */ -Size -AddinShmemSize(void) -{ - return addin_contexts_size; -} - -/* - * ShmemAllocFromContext -- allocate max-aligned chunk from shared memory + * ShmemAlloc -- allocate max-aligned chunk from shared memory * * Assumes ShmemLock and ShmemSegHdr are initialized. * @@ -263,31 +149,16 @@ AddinShmemSize(void) * to be compatible with malloc(). */ void * -ShmemAllocFromContext(Size size, const char *context_name) +ShmemAlloc(Size size) { Size newStart; Size newFree; void *newSpace; - ContextNode *context; /* use volatile pointer to prevent code rearrangement */ volatile PGShmemHeader *shmemseghdr = ShmemSegHdr; /* - * if context_name is provided, allocate from the named context - */ - if (context_name) - { - context = ContextFromName(context_name); - if (!context) - ereport(ERROR, - (errcode(ERRCODE_INTERNAL_ERROR), - errmsg("cannot reset unknown shared memory context %s", - context_name))); - shmemseghdr = context->seg_hdr; - } - - /* * ensure all space is adequately aligned. */ size = MAXALIGN(size); @@ -305,7 +176,7 @@ ShmemAllocFromContext(Size size, const char *context_name) newFree = newStart + size; if (newFree <= shmemseghdr->totalsize) { - newSpace = (void *) MAKE_PTRFROM((SHMEM_OFFSET) shmemseghdr, newStart); + newSpace = (void *) MAKE_PTR(newStart); shmemseghdr->freeoffset = newFree; } else @@ -322,22 +193,6 @@ ShmemAllocFromContext(Size size, const char *context_name) } /* - * ShmemAlloc -- allocate max-aligned chunk from shared memory - * - * Assumes ShmemLock and ShmemSegHdr are initialized. - * - * Returns: real pointer to memory or NULL if we are out - * of space. Has to return a real pointer in order - * to be compatible with malloc(). - */ - -void * -ShmemAlloc(Size size) -{ - return ShmemAllocFromContext(size, NULL); -} - -/* * ShmemIsValid -- test if an offset refers to valid shared memory * * Returns TRUE if the pointer is valid. |