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authorMiles Bader <miles@lsi.nec.co.jp>2002-08-14 06:16:41 +0000
committerMiles Bader <miles@lsi.nec.co.jp>2002-08-14 06:16:41 +0000
commitcb6fdcff807a2d2c22cb3a5be03118d5d3695e10 (patch)
treeaff81aedfe6293eef54a25a6243a3c33c316b130 /libc/stdlib/malloc/realloc.c
parent8dc7fc0d12563a0a1b4c2cdb21e0734764d09c2c (diff)
Handle zero NEW_SIZE case.
Diffstat (limited to 'libc/stdlib/malloc/realloc.c')
-rw-r--r--libc/stdlib/malloc/realloc.c99
1 files changed, 54 insertions, 45 deletions
diff --git a/libc/stdlib/malloc/realloc.c b/libc/stdlib/malloc/realloc.c
index 7188bc897..31639d7fe 100644
--- a/libc/stdlib/malloc/realloc.c
+++ b/libc/stdlib/malloc/realloc.c
@@ -21,60 +21,69 @@
void *
realloc (void *mem, size_t new_size)
{
- if (! mem)
- return malloc (new_size);
- else
+ size_t size;
+ char *base_mem;
+
+ /* Check for special cases. */
+ if (! new_size)
{
- char *base_mem = MALLOC_BASE (mem);
- size_t size = MALLOC_SIZE (mem);
+ free (mem);
+ return 0;
+ }
+ else if (! mem)
+ return malloc (new_size);
- /* Include extra space to record the size of the allocated block.
- Also 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_HEADER_SIZE);
+ /* Normal realloc. */
- MALLOC_DEBUG ("realloc: 0x%lx, %d (base = 0x%lx, total_size = %d)\n",
- (long)mem, new_size, (long)base_mem, size);
+ base_mem = MALLOC_BASE (mem);
+ size = MALLOC_SIZE (mem);
- if (new_size > size)
- /* Grow the block. */
- {
- size_t extra = new_size - size;
+ /* Include extra space to record the size of the allocated block.
+ Also 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_HEADER_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)
+ /* Grow the block. */
+ {
+ size_t extra = new_size - size;
- __malloc_lock ();
- extra = __heap_alloc_at (&__malloc_heap, base_mem + size, extra);
- __malloc_unlock ();
+ __malloc_lock ();
+ extra = __heap_alloc_at (&__malloc_heap, base_mem + size, extra);
+ __malloc_unlock ();
- if (extra)
- /* Record the changed size. */
- MALLOC_SET_SIZE (mem, new_size);
- else
- /* Our attempts to extend MEM in place failed, just
- allocate-and-copy. */
+ if (extra)
+ /* Record the changed size. */
+ MALLOC_SET_SIZE (mem, new_size);
+ else
+ /* Our attempts to extend MEM in place failed, just
+ allocate-and-copy. */
+ {
+ void *new_mem = malloc (new_size - MALLOC_HEADER_SIZE);
+ if (new_mem)
{
- void *new_mem = malloc (new_size - MALLOC_HEADER_SIZE);
- if (new_mem)
- {
- memcpy (new_mem, mem, size - MALLOC_HEADER_SIZE);
- free (mem);
- }
- mem = new_mem;
+ memcpy (new_mem, mem, size - MALLOC_HEADER_SIZE);
+ free (mem);
}
+ mem = new_mem;
}
- else if (new_size + MALLOC_REALLOC_MIN_FREE_SIZE <= size)
- /* Shrink the block. */
- {
- __malloc_lock ();
- __heap_free (&__malloc_heap, base_mem + new_size, size - new_size);
- __malloc_unlock ();
- MALLOC_SET_SIZE (mem, new_size);
- }
+ }
+ else if (new_size + MALLOC_REALLOC_MIN_FREE_SIZE <= size)
+ /* Shrink the block. */
+ {
+ __malloc_lock ();
+ __heap_free (&__malloc_heap, base_mem + new_size, size - new_size);
+ __malloc_unlock ();
+ MALLOC_SET_SIZE (mem, new_size);
+ }
- if (mem)
- MALLOC_DEBUG (" realloc: returning 0x%lx"
- " (base:0x%lx, total_size:%d)\n",
- (long)mem, (long)MALLOC_BASE(mem), (long)MALLOC_SIZE(mem));
+ if (mem)
+ MALLOC_DEBUG (" realloc: returning 0x%lx"
+ " (base:0x%lx, total_size:%d)\n",
+ (long)mem, (long)MALLOC_BASE(mem), (long)MALLOC_SIZE(mem));
- return mem;
- }
+ return mem;
}