diff options
Diffstat (limited to 'libc/stdlib/malloc')
| -rw-r--r-- | libc/stdlib/malloc/realloc.c | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/libc/stdlib/malloc/realloc.c b/libc/stdlib/malloc/realloc.c index 7a89712e3..34118ab5a 100644 --- a/libc/stdlib/malloc/realloc.c +++ b/libc/stdlib/malloc/realloc.c @@ -25,19 +25,22 @@ realloc (void *mem, size_t new_size) return malloc (new_size); else { - void *base_mem = mem - MALLOC_ALIGNMENT; - size_t size = *(size_t *)base_mem; + char *base_mem = MALLOC_BASE (mem); + size_t size = MALLOC_SIZE (mem); + + /* Make sure that we're dealing in a multiple of the heap allocation + unit (SIZE is already guaranteed to be so). */ + // new_size = HEAP_ADJUST_SIZE (new_size); MALLOC_DEBUG ("realloc: 0x%lx, %d (base = 0x%lx, total_size = %d)\n", (long)mem, new_size, (long)base_mem, size); - if (new_size <= size) - return mem; - else + if (new_size > size) + /* Grow the block. */ { void *new_mem = 0; size_t ext_size = new_size - size; - void *ext_addr = (char *)base_mem + ext_size; + void *ext_addr = base_mem + size; __malloc_lock (); ext_size = __heap_alloc_at (&__malloc_heap, ext_addr, ext_size); @@ -62,5 +65,15 @@ realloc (void *mem, size_t new_size) return new_mem; } + else if (new_size + HEAP_MIN_FREE_AREA_SIZE <= size) + /* Shrink the block. */ + { + __malloc_lock (); + __heap_free (&__malloc_heap, base_mem + new_size, new_size - size); + __malloc_unlock (); + } + else + /* Do nothing. */ + return mem; } } |