nuttx/mm/umm_malloc.c
2014-09-01 10:46:51 -06:00

125 lines
4.4 KiB
C

/****************************************************************************
* mm/umm_malloc.c
*
* Copyright (C) 2007, 2009, 2013-2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdlib.h>
#include <unistd.h>
#include <nuttx/mm.h>
#ifdef CONFIG_MM_USER_HEAP
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Type Definitions
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/************************************************************************
* Name: malloc
*
* Description:
* Allocate memory from the user heap.
*
* Parameters:
* size - Size (in bytes) of the memory region to be allocated.
*
* Return Value:
* The address of the allocated memory (NULL on failure to allocate)
*
************************************************************************/
FAR void *malloc(size_t size)
{
#ifdef CONFIG_ARCH_ADDRENV
FAR void *brkaddr;
FAR void *mem;
/* Loop until we successfully allocate the memory or until an error
* occurs. If we fail to allocate memory on the first pass, then call
* sbrk to extend the heap by one page. This may require several
* passes if more the size of the allocation is more than one page.
*
* An alternative would be to increase the size of the heap by the
* full requested allocation in sbrk(). Then the loop should never
* execute more than twice (but more memory than we need may be
* allocated).
*/
do
{
mem = mm_malloc(&g_mmheap, size);
if (!mem)
{
brkaddr = sbrk(size);
if (brkaddr == (FAR void *)-1)
{
return NULL;
}
}
}
while (mem == NULL);
return mem;
#else
return mm_malloc(&g_mmheap, size);
#endif
}
#endif /* CONFIG_MM_USER_HEAP */