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- /****************************************************************************
- * mm/umm_heap/umm_realloc.c
- *
- * Copyright (C) 2007, 2009, 2013-2015 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/mm.h>
- #include "umm_heap/umm_heap.h"
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: realloc
- *
- * Description:
- * Re-allocate memory in the user heap.
- *
- * Input Parameters:
- * oldmem - The old memory allocated
- * newsize - Size (in bytes) of the new memory region to be re-allocated.
- *
- * Returned Value:
- * The address of the re-allocated memory (NULL on failure to re-allocate)
- *
- ****************************************************************************/
- FAR void *realloc(FAR void *oldmem, size_t size)
- {
- #if defined(CONFIG_ARCH_ADDRENV) && defined(CONFIG_BUILD_KERNEL)
- 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_realloc(USR_HEAP, oldmem, size);
- if (!mem)
- {
- brkaddr = sbrk(size);
- if (brkaddr == (FAR void *)-1)
- {
- return NULL;
- }
- }
- }
- while (mem == NULL);
- return mem;
- #else
- return mm_realloc(USR_HEAP, oldmem, size);
- #endif
- }
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