diff options
Diffstat (limited to 'libc/stdlib/malloc-930716/realloc.c')
| -rw-r--r-- | libc/stdlib/malloc-930716/realloc.c | 142 |
1 files changed, 0 insertions, 142 deletions
diff --git a/libc/stdlib/malloc-930716/realloc.c b/libc/stdlib/malloc-930716/realloc.c deleted file mode 100644 index 397534a5a..000000000 --- a/libc/stdlib/malloc-930716/realloc.c +++ /dev/null @@ -1,142 +0,0 @@ -/* malloc.c - C standard library routine. - Copyright (c) 1989, 1993 Michael J. Haertel - You may redistribute this library under the terms of the - GNU Library General Public License (version 2 or any later - version) as published by the Free Software Foundation. - THIS SOFTWARE IS PROVIDED "AS IS" WITHOUT ANY EXPRESS OR IMPLIED - WARRANTY. IN PARTICULAR, THE AUTHOR MAKES NO REPRESENTATION OR - WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY OF THIS - SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE. */ - -#define _GNU_SOURCE -#include <features.h> -#include <limits.h> -#include <stddef.h> -#include <stdlib.h> -#include <string.h> -#include <unistd.h> -#include <errno.h> -#include "malloc.h" - -#ifdef __UCLIBC_HAS_THREADS__ -#include <pthread.h> -extern pthread_mutex_t __malloclock; -# define LOCK __pthread_mutex_lock(&__malloclock) -# define UNLOCK __pthread_mutex_unlock(&__malloclock); -#else -# define LOCK -# define UNLOCK -#endif - -/* Resize the given region to the new size, returning a pointer - to the (possibly moved) region. This is optimized for speed; - some benchmarks seem to indicate that greater compactness is - achieved by unconditionally allocating and copying to a - new region. */ -void * realloc (void *ptr, size_t size) -{ - void *result, *previous; - size_t block, blocks, type; - size_t oldlimit; - - if (!ptr) - return malloc(size); - if (!size) { - LOCK; - __free_unlocked(ptr); - result = __malloc_unlocked(0); - goto alldone; - } - - LOCK; - block = BLOCK(ptr); - - switch (type = _heapinfo[block].busy.type) { - case 0: - /* Maybe reallocate a large block to a small fragment. */ - if (size <= BLOCKSIZE / 2) { - if ((result = __malloc_unlocked(size)) != NULL) { - memcpy(result, ptr, size); - __free_unlocked(ptr); - } - goto alldone; - } - - /* The new size is a large allocation as well; see if - we can hold it in place. */ - blocks = BLOCKIFY(size); - if (blocks < _heapinfo[block].busy.info.size) { - /* The new size is smaller; return excess memory - to the free list. */ - _heapinfo[block + blocks].busy.type = 0; - _heapinfo[block + blocks].busy.info.size - = _heapinfo[block].busy.info.size - blocks; - _heapinfo[block].busy.info.size = blocks; - __free_unlocked(ADDRESS(block + blocks)); - result = ptr; - goto alldone; - } else if (blocks == _heapinfo[block].busy.info.size) { - /* No size change necessary. */ - result = ptr; - goto alldone; - } else { - /* Won't fit, so allocate a new region that will. Free - the old region first in case there is sufficient adjacent - free space to grow without moving. */ - blocks = _heapinfo[block].busy.info.size; - /* Prevent free from actually returning memory to the system. */ - oldlimit = _heaplimit; - _heaplimit = 0; - __free_unlocked(ptr); - _heaplimit = oldlimit; - result = __malloc_unlocked(size); - if (!result) { - /* Now we're really in trouble. We have to unfree - the thing we just freed. Unfortunately it might - have been coalesced with its neighbors. */ - if (_heapindex == block) - __malloc_unlocked(blocks * BLOCKSIZE); - else { - previous = __malloc_unlocked((block - _heapindex) * BLOCKSIZE); - __malloc_unlocked(blocks * BLOCKSIZE); - __free_unlocked(previous); - } - goto oom; - } - if (ptr != result) - memmove(result, ptr, blocks * BLOCKSIZE); - goto alldone; - } - break; - - default: - /* Old size is a fragment; type is logarithm to base two of - the fragment size. */ - if ((size > 1 << (type - 1)) && (size <= 1 << type)) { - /* New size is the same kind of fragment. */ - result = ptr; - goto alldone; - } - else { - /* New size is different; allocate a new space, and copy - the lesser of the new size and the old. */ - result = __malloc_unlocked(size); - if (!result) { - goto oom; - } - memcpy(result, ptr, MIN(size, (size_t)(1 << type))); - __free_unlocked(ptr); - goto alldone; - } - break; - } -alldone: - UNLOCK; - return result; - -oom: - UNLOCK; - __set_errno(ENOMEM); - return NULL; -} - |