sysdeps/mach/hurd/sbrk.c

   1 /* Copyright (C) 1991-2015 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <hurd.h>
  20 #include <unistd.h>
  21
  22 /* Extend the process's data space by INCREMENT.
  23    If INCREMENT is negative, shrink data space by - INCREMENT.
  24    Return the address of the start of the new data space, or -1 for errors.  */
  25 void *
  26 __sbrk (intptr_t increment)
  27 {
  28   void *result;
  29
  30   HURD_CRITICAL_BEGIN;
  31   __mutex_lock (&_hurd_brk_lock);
  32   result = (void *) _hurd_brk;
  33   if (increment != 0 && _hurd_set_brk (_hurd_brk + increment) < 0)
  34     result = (void *) -1;
  35   __mutex_unlock (&_hurd_brk_lock);
  36   HURD_CRITICAL_END;
  37
  38   return result;
  39 }
  40 libc_hidden_def (__sbrk)
  41 weak_alias (__sbrk, sbrk)