# concurrence.h

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    00001 // Support for concurrent programing -*- C++ -*-
    00002
    00003 // Copyright (C) 2003, 2004
    00004 // Free Software Foundation, Inc.
    00005 //
    00006 // This file is part of the GNU ISO C++ Library.  This library is free
    00007 // software; you can redistribute it and/or modify it under the
    00008 // terms of the GNU General Public License as published by the
    00009 // Free Software Foundation; either version 2, or (at your option)
    00010 // any later version.
    00011
    00012 // This library is distributed in the hope that it will be useful,
    00013 // but WITHOUT ANY WARRANTY; without even the implied warranty of
    00014 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    00015 // GNU General Public License for more details.
    00016
    00017 // You should have received a copy of the GNU General Public License along
    00018 // with this library; see the file COPYING.  If not, write to the Free
    00019 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
    00020 // USA.
    00021
    00022 // As a special exception, you may use this file as part of a free software
    00023 // library without restriction.  Specifically, if other files instantiate
    00024 // templates or use macros or inline functions from this file, or you compile
    00025 // this file and link it with other files to produce an executable, this
    00026 // file does not by itself cause the resulting executable to be covered by
    00027 // the GNU General Public License.  This exception does not however
    00028 // invalidate any other reasons why the executable file might be covered by
    00029 // the GNU General Public License.
    00030
    00031 /** @file concurrence.h
    00032  *  This is an internal header file, included by other library headers.
    00033  *  You should not attempt to use it directly.
    00034  */
    00035
    00036 #ifndef _CONCURRENCE_H
    00037 #define _CONCURRENCE_H 1
    00038
    00039 // GCC's thread abstraction layer
    00040 #include "bits/gthr.h"
    00041
    00042 #if __GTHREADS
    00043
    00044 # ifdef __GTHREAD_MUTEX_INIT
    00045 #  define __glibcxx_mutex_type __gthread_mutex_t
    00046 #  define __glibcxx_mutex_define_initialized(NAME) \
    00047 __gthread_mutex_t NAME = __GTHREAD_MUTEX_INIT
    00048 #  define __glibcxx_mutex_lock(NAME) \
    00049 __gthread_mutex_lock(&NAME)
    00050 # else
    00051 // Implies __GTHREAD_MUTEX_INIT_FUNCTION
    00052 struct __glibcxx_mutex : public __gthread_mutex_t
    00053 {
    00054    __glibcxx_mutex() { __GTHREAD_MUTEX_INIT_FUNCTION(this); }
    00055 };
    00056
    00057 #  define __glibcxx_mutex_type __glibcxx_mutex
    00058 #  define __glibcxx_mutex_define_initialized(NAME) \
    00059 __glibcxx_mutex NAME
    00060 # define __glibcxx_mutex_lock(NAME) \
    00061 __gthread_mutex_lock(&NAME)
    00062 # endif
    00063
    00064 # define __glibcxx_mutex_unlock(NAME) __gthread_mutex_unlock(&NAME)
    00065
    00066 #else
    00067
    00068 # define __glibcxx_mutex_type __gthread_mutex_t
    00069 # define __glibcxx_mutex_define_initialized(NAME) __gthread_mutex_t NAME
    00070 # define __glibcxx_mutex_lock(NAME)
    00071 # define __glibcxx_mutex_unlock(NAME)
    00072
    00073 #endif
    00074
    00075 namespace __gnu_cxx
    00076 {
    00077   typedef __glibcxx_mutex_type mutex_type;
    00078
    00079   /// @brief  Scoped lock idiom.
    00080   // Acquire the mutex here with a constructor call, then release with
    00081   // the destructor call in accordance with RAII style.
    00082   class lock
    00083   {
    00084     // Externally defined and initialized.
    00085     mutex_type& device;
    00086
    00087   public:
    00088     explicit lock(mutex_type& name) : device(name)
    00089     { __glibcxx_mutex_lock(device); }
    00090
    00091     ~lock() throw()
    00092     { __glibcxx_mutex_unlock(device); }
    00093
    00094   private:
    00095     lock(const lock&);
    00096     lock& operator=(const lock&);
    00097   };
    00098 }
    00099
    00100 #endif