diff options
| -rw-r--r-- | src/backend/utils/mmgr/aset.c | 48 |
1 files changed, 35 insertions, 13 deletions
diff --git a/src/backend/utils/mmgr/aset.c b/src/backend/utils/mmgr/aset.c index de56a2dc010..6c1b5f390da 100644 --- a/src/backend/utils/mmgr/aset.c +++ b/src/backend/utils/mmgr/aset.c @@ -11,7 +11,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/mmgr/aset.c,v 1.62 2005/06/04 22:57:22 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/utils/mmgr/aset.c,v 1.63 2005/09/01 18:15:42 tgl Exp $ * * NOTE: * This is a new (Feb. 05, 1999) implementation of the allocation set @@ -123,6 +123,12 @@ typedef void *AllocPointer; /* * AllocSetContext is our standard implementation of MemoryContext. + * + * Note: isReset means there is nothing for AllocSetReset to do. This is + * different from the aset being physically empty (empty blocks list) because + * we may still have a keeper block. It's also different from the set being + * logically empty, because we don't attempt to detect pfree'ing the last + * active chunk. */ typedef struct AllocSetContext { @@ -130,6 +136,7 @@ typedef struct AllocSetContext /* Info about storage allocated in this context: */ AllocBlock blocks; /* head of list of blocks in this set */ AllocChunk freelist[ALLOCSET_NUM_FREELISTS]; /* free chunk lists */ + bool isReset; /* T = no space alloced since last reset */ /* Allocation parameters for this context: */ Size initBlockSize; /* initial block size */ Size maxBlockSize; /* maximum block size */ @@ -347,6 +354,8 @@ AllocSetContextCreate(MemoryContext parent, context->keeper = block; } + context->isReset = true; + return (MemoryContext) context; } @@ -386,26 +395,28 @@ static void AllocSetReset(MemoryContext context) { AllocSet set = (AllocSet) context; - AllocBlock block = set->blocks; + AllocBlock block; AssertArg(AllocSetIsValid(set)); + /* Nothing to do if no pallocs since startup or last reset */ + if (set->isReset) + return; + #ifdef MEMORY_CONTEXT_CHECKING /* Check for corruption and leaks before freeing */ AllocSetCheck(context); #endif - /* Nothing to do if context has never contained any data */ - if (block == NULL) - return; - /* Clear chunk freelists */ MemSetAligned(set->freelist, 0, sizeof(set->freelist)); + block = set->blocks; + /* New blocks list is either empty or just the keeper block */ set->blocks = set->keeper; - do + while (block != NULL) { AllocBlock next = block->next; @@ -432,7 +443,8 @@ AllocSetReset(MemoryContext context) } block = next; } - while (block != NULL); + + set->isReset = true; } /* @@ -538,6 +550,8 @@ AllocSetAlloc(MemoryContext context, Size size) set->blocks = block; } + set->isReset = false; + AllocAllocInfo(set, chunk); return AllocChunkGetPointer(chunk); } @@ -576,6 +590,9 @@ AllocSetAlloc(MemoryContext context, Size size) ((char *) AllocChunkGetPointer(chunk))[size] = 0x7E; #endif + /* isReset must be false already */ + Assert(!set->isReset); + AllocAllocInfo(set, chunk); return AllocChunkGetPointer(chunk); } @@ -748,6 +765,8 @@ AllocSetAlloc(MemoryContext context, Size size) ((char *) AllocChunkGetPointer(chunk))[size] = 0x7E; #endif + set->isReset = false; + AllocAllocInfo(set, chunk); return AllocChunkGetPointer(chunk); } @@ -846,6 +865,9 @@ AllocSetRealloc(MemoryContext context, void *pointer, Size size) set->header.name, chunk); #endif + /* isReset must be false already */ + Assert(!set->isReset); + /* * Chunk sizes are aligned to power of 2 in AllocSetAlloc(). Maybe the * allocated area already is >= the new size. (In particular, we @@ -1009,12 +1031,12 @@ AllocSetIsEmpty(MemoryContext context) AllocSet set = (AllocSet) context; /* - * For now, we say "empty" only if the context never contained any - * space at all. We could examine the freelists to determine if all - * space has been freed, but it's not really worth the trouble for - * present uses of this functionality. + * For now, we say "empty" only if the context is new or just reset. + * We could examine the freelists to determine if all space has been + * freed, but it's not really worth the trouble for present uses of + * this functionality. */ - if (set->blocks == NULL) + if (set->isReset) return true; return false; } |