// Low-level functions for atomic operations -*- C++ -*- // Copyright (C) 2004 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 2, 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. // You should have received a copy of the GNU General Public License along // with this library; see the file COPYING. If not, write to the Free // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, // USA. // As a special exception, you may use this file as part of a free software // library without restriction. Specifically, if other files instantiate // templates or use macros or inline functions from this file, or you compile // this file and link it with other files to produce an executable, this // file does not by itself cause the resulting executable to be covered by // the GNU General Public License. This exception does not however // invalidate any other reasons why the executable file might be covered by // the GNU General Public License. /** @file atomicity.h * This is an internal header file, included by other library headers. * You should not attempt to use it directly. */ #ifndef _GLIBCXX_ATOMICITY_H #define _GLIBCXX_ATOMICITY_H 1 #include <bits/atomic_word.h> namespace __gnu_cxx { _Atomic_word __attribute__ ((__unused__)) __exchange_and_add(volatile _Atomic_word* __mem, int __val); void __attribute__ ((__unused__)) __atomic_add(volatile _Atomic_word* __mem, int __val); } // namespace __gnu_cxx /* Even if the CPU doesn't need a memory barrier, we need to ensure that the compiler doesn't reorder memory accesses across the barriers. */ #ifndef _GLIBCXX_READ_MEM_BARRIER #define _GLIBCXX_READ_MEM_BARRIER __asm __volatile ("":::"memory") #endif #ifndef _GLIBCXX_WRITE_MEM_BARRIER #define _GLIBCXX_WRITE_MEM_BARRIER __asm __volatile ("":::"memory") #endif #endif