Subversion Repositories openrisc_2011-10-31

// Low-level functions for atomic operations: Generic version  -*- C++ -*-

// Copyright (C) 1999, 2001, 2002, 2003, 2004, 2005, 2006, 2009

// Free Software Foundation, Inc.

//

// This file is part of the GNU ISO C++ Library.  This library 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, or (at your option)

// any later version.

// This 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 General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional

// permissions described in the GCC Runtime Library Exception, version

// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and

// a copy of the GCC Runtime Library Exception along with this program;

// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see

// <http://www.gnu.org/licenses/>.

/** @file ext/atomicity.h

 *  This file is a GNU extension to the Standard C++ Library.

 */

#include <ext/atomicity.h>

#include <ext/concurrence.h>

namespace

{

  __gnu_cxx::__mutex&

  get_atomic_mutex()

  {

    static __gnu_cxx::__mutex atomic_mutex;

    return atomic_mutex;

  }

} // anonymous namespace

_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)

  _Atomic_word

  __attribute__ ((__unused__))

  __exchange_and_add(volatile _Atomic_word* __mem, int __val) throw ()

  {

    __gnu_cxx::__scoped_lock sentry(get_atomic_mutex());

    _Atomic_word __result;

    __result = *__mem;

    *__mem += __val;

    return __result;

  }

  void

  __attribute__ ((__unused__))

  __atomic_add(volatile _Atomic_word* __mem, int __val) throw ()

  { __exchange_and_add(__mem, __val); }

_GLIBCXX_END_NAMESPACE