__sbrk.c

来自「一个C源代码分析器」· C语言 代码 · 共 41 行

/* Copyright (C) 1991, 1994 Free Software Foundation, Inc.
This file is part of the GNU C Library.

The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.

The GNU C Library 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
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB.  If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA.  */

#include <ansidecl.h>
#include <errno.h>
#include <hurd.h>

/* Extend the process's data space by INCREMENT.
   If INCREMENT is negative, shrink data space by - INCREMENT.
   Return the address of the start of the new data space, or -1 for errors.  */
PTR
DEFUN(__sbrk, (increment), int increment)
{
  PTR result;

  HURD_CRITICAL_BEGIN;
  __mutex_lock (&_hurd_brk_lock);
  result = (PTR) _hurd_brk;
  if (increment != 0 && _hurd_set_brk (_hurd_brk + increment) < 0)
    result = (PTR) -1;
  __mutex_unlock (&_hurd_brk_lock);
  HURD_CRITICAL_END;

  return result;
}