00001 // Low-level type for atomic operations -*- C++ -*- 00002 00003 // Copyright (C) 2004 Free Software Foundation, Inc. 00004 // 00005 // This file is part of the GNU ISO C++ Library. This library is free 00006 // software; you can redistribute it and/or modify it under the 00007 // terms of the GNU General Public License as published by the 00008 // Free Software Foundation; either version 2, or (at your option) 00009 // any later version. 00010 00011 // This library is distributed in the hope that it will be useful, 00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00014 // GNU General Public License for more details. 00015 00016 // You should have received a copy of the GNU General Public License along 00017 // with this library; see the file COPYING. If not, write to the Free 00018 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 00019 // USA. 00020 00021 // As a special exception, you may use this file as part of a free software 00022 // library without restriction. Specifically, if other files instantiate 00023 // templates or use macros or inline functions from this file, or you compile 00024 // this file and link it with other files to produce an executable, this 00025 // file does not by itself cause the resulting executable to be covered by 00026 // the GNU General Public License. This exception does not however 00027 // invalidate any other reasons why the executable file might be covered by 00028 // the GNU General Public License. 00029 00030 #ifndef _GLIBCXX_ATOMIC_WORD_H 00031 #define _GLIBCXX_ATOMIC_WORD_H 1 00032 00033 typedef int _Atomic_word; 00034 00035 // Define these two macros using the appropriate memory barrier for the target. 00036 // The commented out versions below are the defaults. 00037 // See ia64/atomic_word.h for an alternative approach. 00038 00039 // This one prevents loads from being hoisted across the barrier; 00040 // in other words, this is a Load-Load acquire barrier. 00041 // This is necessary iff TARGET_RELAXED_ORDERING is defined in tm.h. 00042 // #define _GLIBCXX_READ_MEM_BARRIER __asm __volatile ("":::"memory") 00043 00044 // This one prevents stores from being sunk across the barrier; in other 00045 // words, a Store-Store release barrier. 00046 // #define _GLIBCXX_WRITE_MEM_BARRIER __asm __volatile ("":::"memory") 00047 00048 #endif