# atomicity.h

    00001 // Low-level functions for atomic operations: x86, x >= 4 version  -*- C++ -*-
    00002
    00003 // Copyright (C) 1999, 2000, 2001 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; xaddl %0,%2"
    00041             : "=r" (__result)
    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; addl %0,%1"
    00052             : : "ir" (__val), "m" (*__mem) : "memory");
    00053 }
    00054
    00055 #endif /* atomicity.h */
    00056
    00057