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- /****************************************************************************
- * mm/umm_heap/umm_sbrk.c
- *
- * Copyright (C) 2014-2015 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 <unistd.h>
- #include <nuttx/mm/mm.h>
- #include <nuttx/addrenv.h>
- #include <nuttx/pgalloc.h>
- #include "umm_heap/umm_heap.h"
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: sbrk
- *
- * Description:
- * The sbrk() function is used to change the amount of space allocated
- * for the calling process. The change is made by resetting the process'
- * break value and allocating the appropriate amount of space. The amount
- * of allocated space increases as the break value increases.
- *
- * The sbrk() function adds 'incr' bytes to the break value and changes
- * the allocated space accordingly. If incr is negative, the amount of
- * allocated space is decreased by incr bytes. The current value of the
- * program break is returned by sbrk(0).
- *
- * Input Parameters:
- * incr - Specifies the number of bytes to add or to remove from the
- * space allocated for the process.
- *
- * Returned Value:
- * Upon successful completion, sbrk() returns the prior break value.
- * Otherwise, it returns (void *)-1 and sets errno to indicate the
- * error:
- *
- * ENOMEM - The requested change would allocate more space than
- * allowed under system limits.
- * EAGAIN - The total amount of system memory available for allocation
- * to this process is temporarily insufficient. This may occur even
- * though the space requested was less than the maximum data segment
- * size.
- *
- ****************************************************************************/
- FAR void *sbrk(intptr_t incr)
- {
- return mm_sbrk(USR_HEAP, incr, ARCH_HEAP_VEND);
- }
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