diff options
Diffstat (limited to 'Objects/obmalloc.c')
| -rw-r--r-- | Objects/obmalloc.c | 28 |
1 files changed, 16 insertions, 12 deletions
diff --git a/Objects/obmalloc.c b/Objects/obmalloc.c index fba03ea..cfcff2c 100644 --- a/Objects/obmalloc.c +++ b/Objects/obmalloc.c @@ -321,13 +321,14 @@ pymalloc strives at all levels (arena, pool, and block) never to touch a piece of memory until it's actually needed. So long as a pool is in the used state, we're certain there *is* a block -available for allocating. If pool->freeblock is NULL then, that means we -simply haven't yet gotten to one of the higher-address blocks. The offset -from the pool_header to the start of "the next" virgin block is stored in -the pool_header nextoffset member, and the largest value of nextoffset that -makes sense is stored in the maxnextoffset member when a pool is initialized. -All the blocks in a pool have been passed out at least once when and only -when nextoffset > maxnextoffset. +available for allocating, and pool->freeblock is not NULL. If pool->freeblock +points to the end of the free list before we've carved the entire pool into +blocks, that means we simply haven't yet gotten to one of the higher-address +blocks. The offset from the pool_header to the start of "the next" virgin +block is stored in the pool_header nextoffset member, and the largest value +of nextoffset that makes sense is stored in the maxnextoffset member when a +pool is initialized. All the blocks in a pool have been passed out at least +once when and only when nextoffset > maxnextoffset. Major obscurity: While the usedpools vector is declared to have poolp @@ -467,8 +468,7 @@ new_arena(void) maxarenas = 16; } else if (narenas == maxarenas) { - /* Grow arenas. Don't use realloc: if this fails, we - * don't want to lose the base addresses we already have. + /* Grow arenas. * * Exceedingly subtle: Someone may be calling the pymalloc * free via PyMem_{DEL, Del, FREE, Free} without holding the @@ -590,6 +590,7 @@ _PyMalloc_Malloc(size_t nbytes) */ ++pool->ref.count; bp = pool->freeblock; + assert(bp != NULL); if ((pool->freeblock = *(block **)bp) != NULL) { UNLOCK(); return (void *)bp; @@ -1057,12 +1058,15 @@ _PyMalloc_DebugRealloc(void *p, size_t nbytes) return p; } + assert(nbytes != 0); /* More memory is needed: get it, copy over the first original_nbytes of the original data, and free the original memory. */ fresh = _PyMalloc_DebugMalloc(nbytes); - if (fresh != NULL && original_nbytes > 0) - memcpy(fresh, p, original_nbytes); - _PyMalloc_DebugFree(p); + if (fresh != NULL) { + if (original_nbytes > 0) + memcpy(fresh, p, original_nbytes); + _PyMalloc_DebugFree(p); + } return fresh; } |