diff options
Diffstat (limited to 'src/backend/utils/hash/dynahash.c')
| -rw-r--r-- | src/backend/utils/hash/dynahash.c | 83 |
1 files changed, 73 insertions, 10 deletions
diff --git a/src/backend/utils/hash/dynahash.c b/src/backend/utils/hash/dynahash.c index b3a991fdc52..fd9b11ba98e 100644 --- a/src/backend/utils/hash/dynahash.c +++ b/src/backend/utils/hash/dynahash.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/utils/hash/dynahash.c,v 1.35 2001/03/22 03:59:59 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/utils/hash/dynahash.c,v 1.36 2001/06/22 19:16:23 wieck Exp $ * *------------------------------------------------------------------------- */ @@ -82,18 +82,13 @@ static int init_htab(HTAB *hashp, int nelem); * ---------------- */ static MemoryContext DynaHashCxt = NULL; +static MemoryContext CurrentDynaHashCxt = NULL; static void * DynaHashAlloc(Size size) { - if (!DynaHashCxt) - DynaHashCxt = AllocSetContextCreate(TopMemoryContext, - "DynaHash", - ALLOCSET_DEFAULT_MINSIZE, - ALLOCSET_DEFAULT_INITSIZE, - ALLOCSET_DEFAULT_MAXSIZE); - - return MemoryContextAlloc(DynaHashCxt, size); + Assert(MemoryContextIsValid(CurrentDynaHashCxt)); + return MemoryContextAlloc(CurrentDynaHashCxt, size); } #define MEM_ALLOC DynaHashAlloc @@ -133,6 +128,17 @@ hash_create(int nelem, HASHCTL *info, int flags) HHDR *hctl; HTAB *hashp; + if (!DynaHashCxt) + DynaHashCxt = AllocSetContextCreate(TopMemoryContext, + "DynaHash", + ALLOCSET_DEFAULT_MINSIZE, + ALLOCSET_DEFAULT_INITSIZE, + ALLOCSET_DEFAULT_MAXSIZE); + + if (flags & HASH_CONTEXT) + CurrentDynaHashCxt = info->hcxt; + else + CurrentDynaHashCxt = DynaHashCxt; hashp = (HTAB *) MEM_ALLOC(sizeof(HTAB)); MemSet(hashp, 0, sizeof(HTAB)); @@ -157,6 +163,7 @@ hash_create(int nelem, HASHCTL *info, int flags) hashp->segbase = (char *) info->segbase; hashp->alloc = info->alloc; hashp->dir = (SEG_OFFSET *) info->dir; + hashp->hcxt = NULL; /* hash table already exists, we're just attaching to it */ if (flags & HASH_ATTACH) @@ -171,12 +178,13 @@ hash_create(int nelem, HASHCTL *info, int flags) hashp->alloc = MEM_ALLOC; hashp->dir = NULL; hashp->segbase = NULL; + hashp->hcxt = DynaHashCxt; } if (!hashp->hctl) { - hashp->hctl = (HHDR *) hashp->alloc(sizeof(HHDR)); + hashp->hctl = (HHDR *) hashp->alloc(sizeof(HHDR)); if (!hashp->hctl) return 0; } @@ -218,6 +226,28 @@ hash_create(int nelem, HASHCTL *info, int flags) } if (flags & HASH_ALLOC) hashp->alloc = info->alloc; + else + { + if (flags & HASH_CONTEXT) + { + CurrentDynaHashCxt = AllocSetContextCreate(info->hcxt, + "DynaHashTable", + ALLOCSET_DEFAULT_MINSIZE, + ALLOCSET_DEFAULT_INITSIZE, + ALLOCSET_DEFAULT_MAXSIZE); + + hashp->hcxt = CurrentDynaHashCxt; + } + else + { + CurrentDynaHashCxt = AllocSetContextCreate(DynaHashCxt, + "DynaHashTable", + ALLOCSET_DEFAULT_MINSIZE, + ALLOCSET_DEFAULT_INITSIZE, + ALLOCSET_DEFAULT_MAXSIZE); + hashp->hcxt = CurrentDynaHashCxt; + } + } if (init_htab(hashp, nelem)) { @@ -305,6 +335,7 @@ init_htab(HTAB *hashp, int nelem) /* Allocate a directory */ if (!(hashp->dir)) { + CurrentDynaHashCxt = hashp->hcxt; hashp->dir = (SEG_OFFSET *) hashp->alloc(hctl->dsize * sizeof(SEG_OFFSET)); if (!hashp->dir) @@ -414,6 +445,14 @@ hash_select_dirsize(long num_entries) * allocated individually, see bucket_alloc!! Why doesn't it crash? * ANSWER: it probably does crash, but is never invoked in normal * operations... + * + * Thomas is right, it does crash. Therefore I changed the code + * to use a separate memory context which is a child of the DynaHashCxt + * by default. And the HASHCTL structure got extended with a hcxt + * field, where someone can specify an explicit context (giving new + * flag HASH_CONTEXT) and forget about hash_destroy() completely. + * The shmem operations aren't changed, but in shmem mode a destroy + * doesn't work anyway. Jan Wieck 03/2001. */ void @@ -421,6 +460,7 @@ hash_destroy(HTAB *hashp) { if (hashp != NULL) { +#if 0 SEG_OFFSET segNum; SEGMENT segp; int nsegs = hashp->hctl->nsegs; @@ -429,14 +469,27 @@ hash_destroy(HTAB *hashp) p, q; ELEMENT *curr; +#endif /* cannot destroy a shared memory hash table */ Assert(!hashp->segbase); /* allocation method must be one we know how to free, too */ Assert(hashp->alloc == MEM_ALLOC); + /* so this hashtable must have it's own context */ + Assert(hashp->hcxt != NULL); hash_stats("destroy", hashp); + /* + * Free buckets, dir etc. by destroying the hash tables + * memory context. + */ + MemoryContextDelete(hashp->hcxt); + +#if 0 + /* + * Dead code - replaced by MemoryContextDelete() above + */ for (segNum = 0; nsegs > 0; nsegs--, segNum++) { @@ -453,6 +506,13 @@ hash_destroy(HTAB *hashp) MEM_FREE((char *) segp); } MEM_FREE((char *) hashp->dir); +#endif + + /* + * Free the HTAB and control structure, which are allocated + * in the parent context (DynaHashCxt or the context given + * by the caller of hash_create(). + */ MEM_FREE((char *) hashp->hctl); MEM_FREE((char *) hashp); } @@ -876,6 +936,7 @@ dir_realloc(HTAB *hashp) old_dirsize = hashp->hctl->dsize * sizeof(SEG_OFFSET); new_dirsize = new_dsize * sizeof(SEG_OFFSET); + CurrentDynaHashCxt = hashp->hcxt; old_p = (char *) hashp->dir; p = (char *) hashp->alloc((Size) new_dirsize); @@ -898,6 +959,7 @@ seg_alloc(HTAB *hashp) SEGMENT segp; SEG_OFFSET segOffset; + CurrentDynaHashCxt = hashp->hcxt; segp = (SEGMENT) hashp->alloc(sizeof(BUCKET_INDEX) * hashp->hctl->ssize); if (!segp) @@ -928,6 +990,7 @@ bucket_alloc(HTAB *hashp) /* make sure its aligned correctly */ bucketSize = MAXALIGN(bucketSize); + CurrentDynaHashCxt = hashp->hcxt; tmpBucket = (ELEMENT *) hashp->alloc(BUCKET_ALLOC_INCR * bucketSize); if (!tmpBucket) |