sysdeps/mach/hurd/sbrk.c

   1 /* Copyright (C) 1991,94,95,97,98,2000,02 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, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <errno.h>
  20 #include <hurd.h>
  21 #include <unistd.h>
  22
  23 /* Extend the process's data space by INCREMENT.
  24    If INCREMENT is negative, shrink data space by - INCREMENT.
  25    Return the address of the start of the new data space, or -1 for errors.  */
  26 void *
  27 __sbrk (intptr_t increment)
  28 {
  29   void *result;
  30
  31   HURD_CRITICAL_BEGIN;
  32   __mutex_lock (&_hurd_brk_lock);
  33   result = (void *) _hurd_brk;
  34   if (increment != 0 && _hurd_set_brk (_hurd_brk + increment) < 0)
  35     result = (void *) -1;
  36   __mutex_unlock (&_hurd_brk_lock);
  37   HURD_CRITICAL_END;
  38
  39   return result;
  40 }
  41 libc_hidden_def (__sbrk)
  42 weak_alias (__sbrk, sbrk)