atomicity.h revision 169691
1// Low-level functions for atomic operations: Generic version -*- C++ -*- 2 3// Copyright (C) 1999, 2001, 2002, 2003, 2004, 2005, 2006 4// Free Software Foundation, Inc. 5// 6// This file is part of the GNU ISO C++ Library. This library is free 7// software; you can redistribute it and/or modify it under the 8// terms of the GNU General Public License as published by the 9// Free Software Foundation; either version 2, or (at your option) 10// any later version. 11 12// This library is distributed in the hope that it will be useful, 13// but WITHOUT ANY WARRANTY; without even the implied warranty of 14// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15// GNU General Public License for more details. 16 17// You should have received a copy of the GNU General Public License along 18// with this library; see the file COPYING. If not, write to the Free 19// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 20// USA. 21 22// As a special exception, you may use this file as part of a free software 23// library without restriction. Specifically, if other files instantiate 24// templates or use macros or inline functions from this file, or you compile 25// this file and link it with other files to produce an executable, this 26// file does not by itself cause the resulting executable to be covered by 27// the GNU General Public License. This exception does not however 28// invalidate any other reasons why the executable file might be covered by 29// the GNU General Public License. 30 31/** @file ext/atomicity.h 32 * This file is a GNU extension to the Standard C++ Library. 33 */ 34 35#include <ext/atomicity.h> 36#include <ext/concurrence.h> 37 38namespace 39{ 40 __gnu_cxx::__mutex atomic_mutex; 41} // anonymous namespace 42 43_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx) 44 45 _Atomic_word 46 __attribute__ ((__unused__)) 47 __exchange_and_add(volatile _Atomic_word* __mem, int __val) 48 { 49 __gnu_cxx::__scoped_lock sentry(atomic_mutex); 50 _Atomic_word __result; 51 __result = *__mem; 52 *__mem += __val; 53 return __result; 54 } 55 56 void 57 __attribute__ ((__unused__)) 58 __atomic_add(volatile _Atomic_word* __mem, int __val) 59 { __exchange_and_add(__mem, __val); } 60 61_GLIBCXX_END_NAMESPACE 62