incubator-nuttx/mm/mm_heap/mm_malloc_size.c

59 lines
1.9 KiB
C

/****************************************************************************
* mm/mm_heap/mm_malloc_size.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <assert.h>
#include <debug.h>
#include <nuttx/mm/mm.h>
#include "mm_heap/mm.h"
/****************************************************************************
* Public Functions
****************************************************************************/
size_t mm_malloc_size(FAR void *mem)
{
FAR struct mm_freenode_s *node;
/* Protect against attempts to query a NULL reference */
if (!mem)
{
return 0;
}
/* Map the memory chunk into a free node */
node = (FAR struct mm_freenode_s *)((FAR char *)mem - SIZEOF_MM_ALLOCNODE);
/* Sanity check against double-frees */
DEBUGASSERT(node->preceding & MM_ALLOC_BIT);
return node->size - SIZEOF_MM_ALLOCNODE;
}