libstdc++
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00001 // Low-level type for atomic operations -*- C++ -*- 00002 00003 // Copyright (C) 2004, 2009 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 3, 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 // Under Section 7 of GPL version 3, you are granted additional 00017 // permissions described in the GCC Runtime Library Exception, version 00018 // 3.1, as published by the Free Software Foundation. 00019 00020 // You should have received a copy of the GNU General Public License and 00021 // a copy of the GCC Runtime Library Exception along with this program; 00022 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 00023 // <http://www.gnu.org/licenses/>. 00024 00025 /** @file atomic_word.h 00026 * This file is a GNU extension to the Standard C++ Library. 00027 */ 00028 00029 #ifndef _GLIBCXX_ATOMIC_WORD_H 00030 #define _GLIBCXX_ATOMIC_WORD_H 1 00031 00032 typedef int _Atomic_word; 00033 00034 // Define these two macros using the appropriate memory barrier for the target. 00035 // The commented out versions below are the defaults. 00036 // See ia64/atomic_word.h for an alternative approach. 00037 00038 // This one prevents loads from being hoisted across the barrier; 00039 // in other words, this is a Load-Load acquire barrier. 00040 // This is necessary iff TARGET_RELAXED_ORDERING is defined in tm.h. 00041 // #define _GLIBCXX_READ_MEM_BARRIER __asm __volatile ("":::"memory") 00042 00043 // This one prevents stores from being sunk across the barrier; in other 00044 // words, a Store-Store release barrier. 00045 // #define _GLIBCXX_WRITE_MEM_BARRIER __asm __volatile ("":::"memory") 00046 00047 #endif