View of xos/tests/sbrk.c

/* Copyright (C) 2008  Emmanuel Varoquaux
 
   This file is part of XOS.
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
 
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
 
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>. */
 
#include <unistd.h>
#include <stdio.h>
 
int main()
{
  void *_brk;
  volatile int *test_addr;
 
  printf("dummy printf to malloc memory.\n");
 
  _brk = sbrk(0);
  printf("brk=%p\n", _brk);
  test_addr = _brk + 4095;
 
  printf("increasing data segment...\n");
  sbrk(4096);
  _brk = sbrk(0);
  printf("brk=%p\n", _brk);
 
  printf("checking...\n");
  *test_addr = 0;
  printf("ok.\n");
 
  printf("decreasing data segment...\n");
  sbrk(-4096);
  _brk = sbrk(0);
  printf("brk=%p\n", _brk);
 
  printf("segfaulting...\n");
  *test_addr = 0;
 
  return 0;
}