Back to index

glibc  2.9
sbrk.c
Go to the documentation of this file.
00001 /* Copyright (C) 1991,94,95,97,98,2000,02 Free Software Foundation, Inc.
00002    This file is part of the GNU C Library.
00003 
00004    The GNU C Library is free software; you can redistribute it and/or
00005    modify it under the terms of the GNU Lesser General Public
00006    License as published by the Free Software Foundation; either
00007    version 2.1 of the License, or (at your option) any later version.
00008 
00009    The GNU C Library is distributed in the hope that it will be useful,
00010    but WITHOUT ANY WARRANTY; without even the implied warranty of
00011    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00012    Lesser General Public License for more details.
00013 
00014    You should have received a copy of the GNU Lesser General Public
00015    License along with the GNU C Library; if not, write to the Free
00016    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00017    02111-1307 USA.  */
00018 
00019 #include <errno.h>
00020 #include <hurd.h>
00021 #include <unistd.h>
00022 
00023 /* Extend the process's data space by INCREMENT.
00024    If INCREMENT is negative, shrink data space by - INCREMENT.
00025    Return the address of the start of the new data space, or -1 for errors.  */
00026 void *
00027 __sbrk (intptr_t increment)
00028 {
00029   void *result;
00030 
00031   HURD_CRITICAL_BEGIN;
00032   __mutex_lock (&_hurd_brk_lock);
00033   result = (void *) _hurd_brk;
00034   if (increment != 0 && _hurd_set_brk (_hurd_brk + increment) < 0)
00035     result = (void *) -1;
00036   __mutex_unlock (&_hurd_brk_lock);
00037   HURD_CRITICAL_END;
00038 
00039   return result;
00040 }
00041 libc_hidden_def (__sbrk)
00042 weak_alias (__sbrk, sbrk)