sysdeps/mach/hurd/sbrk.c

   1 /* Copyright (C) 1991, 1994, 1995 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 Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 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 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <ansidecl.h>
  20 #include <errno.h>
  21 #include <hurd.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 PTR
  27 DEFUN(__sbrk, (increment), int increment)
  28 {
  29   PTR result;
  30
  31   HURD_CRITICAL_BEGIN;
  32   __mutex_lock (&_hurd_brk_lock);
  33   result = (PTR) _hurd_brk;
  34   if (increment != 0 && _hurd_set_brk (_hurd_brk + increment) < 0)
  35     result = (PTR) -1;
  36   __mutex_unlock (&_hurd_brk_lock);
  37   HURD_CRITICAL_END;
  38
  39   return result;
  40 }
  41
  42 weak_alias (__sbrk, sbrk)