00001 // Low-level functions for atomic operations: x86, x >= 4 version -*- C++ -*- 00002 00003 // Copyright (C) 1999, 2000, 2001, 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, 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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 _BITS_ATOMICITY_H 00031 #define _BITS_ATOMICITY_H 1 00032 00033 typedef int _Atomic_word; 00034 00035 static inline _Atomic_word 00036 __attribute__ ((__unused__)) 00037 __exchange_and_add (volatile _Atomic_word *__mem, int __val) 00038 { 00039 register _Atomic_word __result; 00040 __asm__ __volatile__ ("lock; xadd{l} {%0,%1|%1,%0}" 00041 : "=r" (__result), "=m" (*__mem) 00042 : "0" (__val), "m"(*__mem) 00043 : "memory"); 00044 return __result; 00045 } 00046 00047 static inline void 00048 __attribute__ ((__unused__)) 00049 __atomic_add (volatile _Atomic_word* __mem, int __val) 00050 { 00051 __asm__ __volatile__ ("lock; add{l} {%1,%0|%0,%1}" 00052 : "=m" (*__mem) 00053 : "ir" (__val), "m"(*__mem) 00054 : "memory"); 00055 } 00056 00057 #endif /* atomicity.h */ 00058 00059