1 /* 2 * libc/stdlib/malloc/heap_alloc.c -- allocate memory from a heap 3 * 4 * Copyright (C) 2002 NEC Corporation 5 * Copyright (C) 2002 Miles Bader <miles@gnu.org> 6 * 7 * This file is subject to the terms and conditions of the GNU Lesser 8 * General Public License. See the file COPYING.LIB in the main 9 * directory of this archive for more details. 10 * 11 * Written by Miles Bader <miles@gnu.org> 12 */ 13 14 #include <stdlib.h> 15 16 #include "heap.h" 17 18 19 /* Allocate and return a block at least *SIZE bytes long from HEAP. 20 *SIZE is adjusted to reflect the actual amount allocated (which may be 21 greater than requested). */ 22 void * __heap_alloc(struct heap_free_area ** heap,size_t * size)23__heap_alloc (struct heap_free_area **heap, size_t *size) 24 { 25 struct heap_free_area *fa; 26 size_t _size = *size; 27 void *mem = 0; 28 29 _size = HEAP_ADJUST_SIZE (_size); 30 31 if (_size < sizeof (struct heap_free_area)) 32 /* Because we sometimes must use a freed block to hold a free-area node, 33 we must make sure that every allocated block can hold one. */ 34 _size = HEAP_ADJUST_SIZE (sizeof (struct heap_free_area)); 35 36 HEAP_DEBUG (*heap, "before __heap_alloc"); 37 38 /* Look for a free area that can contain _SIZE bytes. */ 39 for (fa = *heap; fa; fa = fa->next) 40 if (fa->size >= _size) 41 { 42 /* Found one! */ 43 mem = HEAP_FREE_AREA_START (fa); 44 *size = __heap_free_area_alloc (heap, fa, _size); 45 break; 46 } 47 48 HEAP_DEBUG (*heap, "after __heap_alloc"); 49 50 return mem; 51 } 52