atomicity.h revision 117397
1// Low-level functions for atomic operations: x86, x >= 4 version -*- C++ -*- 2 3// Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc. 4// 5// This file is part of the GNU ISO C++ Library. This library is free 6// software; you can redistribute it and/or modify it under the 7// terms of the GNU General Public License as published by the 8// Free Software Foundation; either version 2, or (at your option) 9// any later version. 10 11// This library is distributed in the hope that it will be useful, 12// but WITHOUT ANY WARRANTY; without even the implied warranty of 13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14// GNU General Public License for more details. 15 16// You should have received a copy of the GNU General Public License along 17// with this library; see the file COPYING. If not, write to the Free 18// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, 19// USA. 20 21// As a special exception, you may use this file as part of a free software 22// library without restriction. Specifically, if other files instantiate 23// templates or use macros or inline functions from this file, or you compile 24// this file and link it with other files to produce an executable, this 25// file does not by itself cause the resulting executable to be covered by 26// the GNU General Public License. This exception does not however 27// invalidate any other reasons why the executable file might be covered by 28// the GNU General Public License. 29 30#ifndef _BITS_ATOMICITY_H 31#define _BITS_ATOMICITY_H 1 32 33typedef int _Atomic_word; 34 35static inline _Atomic_word 36__attribute__ ((__unused__)) 37__exchange_and_add (volatile _Atomic_word *__mem, int __val) 38{ 39 register _Atomic_word __result; 40 __asm__ __volatile__ ("lock; xadd{l} {%0,%1|%1,%0}" 41 : "=r" (__result), "+m" (*__mem) 42 : "0" (__val) 43 : "memory"); 44 return __result; 45} 46 47static inline void 48__attribute__ ((__unused__)) 49__atomic_add (volatile _Atomic_word* __mem, int __val) 50{ 51 __asm__ __volatile__ ("lock; add{l} {%1,%0|%0,%1}" 52 : "+m" (*__mem) : "ir" (__val) : "memory"); 53} 54 55#endif /* atomicity.h */ 56 57 58