/* * libc/stdlib/malloc/heap_alloc.c -- allocate memory from a heap * * Copyright (C) 2002 NEC Corporation * Copyright (C) 2002 Miles Bader <miles@gnu.org> * * This file is subject to the terms and conditions of the GNU Lesser * General Public License. See the file COPYING.LIB in the main * directory of this archive for more details. * * Written by Miles Bader <miles@gnu.org> */ #include <stdlib.h> #include "heap.h" /* Allocate and return a block at least *SIZE bytes long from HEAP. *SIZE is adjusted to reflect the actual amount allocated (which may be greater than requested). */ void * __heap_alloc (struct heap_free_area **heap, size_t *size) { struct heap_free_area *fa; size_t _size = *size; void *mem = 0; _size = HEAP_ADJUST_SIZE (_size); if (_size < sizeof (struct heap_free_area)) /* Because we sometimes must use a freed block to hold a free-area node, we must make sure that every allocated block can hold one. */ _size = HEAP_ADJUST_SIZE (sizeof (struct heap_free_area)); HEAP_DEBUG (*heap, "before __heap_alloc"); /* Look for a free area that can contain _SIZE bytes. */ for (fa = *heap; fa; fa = fa->next) if (fa->size >= _size) { /* Found one! */ mem = HEAP_FREE_AREA_START (fa); *size = __heap_free_area_alloc (heap, fa, _size); break; } HEAP_DEBUG (*heap, "after __heap_alloc"); return mem; }