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Diffstat (limited to 'gnu/lib/libmalloc/realloc.c')
-rw-r--r-- | gnu/lib/libmalloc/realloc.c | 146 |
1 files changed, 0 insertions, 146 deletions
diff --git a/gnu/lib/libmalloc/realloc.c b/gnu/lib/libmalloc/realloc.c deleted file mode 100644 index 2d31766..0000000 --- a/gnu/lib/libmalloc/realloc.c +++ /dev/null @@ -1,146 +0,0 @@ -/* Change the size of a block allocated by `malloc'. - Copyright 1990, 1991, 1992, 1993 Free Software Foundation, Inc. - Written May 1989 by Mike Haertel. - -This library is free software; you can redistribute it and/or -modify it under the terms of the GNU Library General Public License as -published by the Free Software Foundation; either version 2 of the -License, or (at your option) any later version. - -This library is distributed in the hope that it will be useful, -but WITHOUT ANY WARRANTY; without even the implied warranty of -MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU -Library General Public License for more details. - -You should have received a copy of the GNU Library General Public -License along with this library; see the file COPYING.LIB. If -not, write to the Free Software Foundation, Inc., 675 Mass Ave, -Cambridge, MA 02139, USA. - - The author may be reached (Email) at the address mike@ai.mit.edu, - or (US mail) as Mike Haertel c/o Free Software Foundation. */ - -#ifndef _MALLOC_INTERNAL -#define _MALLOC_INTERNAL -#include <malloc.h> -#endif - -#define min(A, B) ((A) < (B) ? (A) : (B)) - -/* Debugging hook for realloc. */ -__ptr_t (*__realloc_hook) __P ((__ptr_t __ptr, size_t __size)); - -/* 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. This module has incestuous knowledge of the - internals of both free and malloc. */ -__ptr_t -realloc (ptr, size) - __ptr_t ptr; - size_t size; -{ - __ptr_t result; - int type; - size_t block, blocks, oldlimit; - - if (size == 0) - { - free (ptr); - return malloc (0); - } - else if (ptr == NULL) - return malloc (size); - - if (__realloc_hook != NULL) - return (*__realloc_hook) (ptr, size); - - block = BLOCK (ptr); - - type = _heapinfo[block].busy.type; - switch (type) - { - case 0: - /* Maybe reallocate a large block to a small fragment. */ - if (size <= BLOCKSIZE / 2) - { - result = malloc (size); - if (result != NULL) - { - memcpy (result, ptr, size); - free (ptr); - return result; - } - } - - /* 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 (ADDRESS (block + blocks)); - result = ptr; - } - else if (blocks == _heapinfo[block].busy.info.size) - /* No size change necessary. */ - result = ptr; - 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 (ptr); - _heaplimit = oldlimit; - result = malloc (size); - if (result == NULL) - { - /* 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) - (void) malloc (blocks * BLOCKSIZE); - else - { - __ptr_t previous = malloc ((block - _heapindex) * BLOCKSIZE); - (void) malloc (blocks * BLOCKSIZE); - free (previous); - } - return NULL; - } - if (ptr != result) - memmove (result, ptr, blocks * BLOCKSIZE); - } - break; - - default: - /* Old size is a fragment; type is logarithm - to base two of the fragment size. */ - if (size > (size_t) (1 << (type - 1)) && size <= (size_t) (1 << type)) - /* The new size is the same kind of fragment. */ - result = ptr; - else - { - /* The new size is different; allocate a new space, - and copy the lesser of the new size and the old. */ - result = malloc (size); - if (result == NULL) - return NULL; - memcpy (result, ptr, min (size, (size_t) 1 << type)); - free (ptr); - } - break; - } - - return result; -} |