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			319 lines
		
	
	
		
			7.4 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			319 lines
		
	
	
		
			7.4 KiB
		
	
	
	
		
			C++
		
	
	
	
| // Support for concurrent programing -*- C++ -*-
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| 
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| // Copyright (C) 2003-2018 Free Software Foundation, Inc.
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| //
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| // This file is part of the GNU ISO C++ Library.  This library is free
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| // software; you can redistribute it and/or modify it under the
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| // terms of the GNU General Public License as published by the
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| // Free Software Foundation; either version 3, or (at your option)
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| // any later version.
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| 
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| // This library is distributed in the hope that it will be useful,
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| // but WITHOUT ANY WARRANTY; without even the implied warranty of
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| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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| // GNU General Public License for more details.
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| 
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| // Under Section 7 of GPL version 3, you are granted additional
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| // permissions described in the GCC Runtime Library Exception, version
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| // 3.1, as published by the Free Software Foundation.
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| 
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| // You should have received a copy of the GNU General Public License and
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| // a copy of the GCC Runtime Library Exception along with this program;
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| // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
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| // <http://www.gnu.org/licenses/>.
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| 
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| /** @file ext/concurrence.h
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|  *  This file is a GNU extension to the Standard C++ Library.
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|  */
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| 
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| #ifndef _CONCURRENCE_H
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| #define _CONCURRENCE_H 1
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| 
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| #pragma GCC system_header
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| 
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| #include <exception>
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| #include <bits/gthr.h> 
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| #include <bits/functexcept.h>
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| #include <bits/cpp_type_traits.h>
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| #include <ext/type_traits.h>
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| 
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| namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
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| {
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| _GLIBCXX_BEGIN_NAMESPACE_VERSION
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| 
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|   // Available locking policies:
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|   // _S_single    single-threaded code that doesn't need to be locked.
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|   // _S_mutex     multi-threaded code that requires additional support
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|   //              from gthr.h or abstraction layers in concurrence.h.
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|   // _S_atomic    multi-threaded code using atomic operations.
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|   enum _Lock_policy { _S_single, _S_mutex, _S_atomic }; 
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| 
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|   // Compile time constant that indicates prefered locking policy in
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|   // the current configuration.
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|   static const _Lock_policy __default_lock_policy = 
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| #ifdef __GTHREADS
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| #if (defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_2) \
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|      && defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4))
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|   _S_atomic;
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| #else
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|   _S_mutex;
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| #endif
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| #else
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|   _S_single;
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| #endif
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| 
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|   // NB: As this is used in libsupc++, need to only depend on
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|   // exception. No stdexception classes, no use of std::string.
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|   class __concurrence_lock_error : public std::exception
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|   {
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|   public:
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|     virtual char const*
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|     what() const throw()
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|     { return "__gnu_cxx::__concurrence_lock_error"; }
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|   };
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| 
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|   class __concurrence_unlock_error : public std::exception
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|   {
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|   public:
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|     virtual char const*
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|     what() const throw()
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|     { return "__gnu_cxx::__concurrence_unlock_error"; }
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|   };
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| 
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|   class __concurrence_broadcast_error : public std::exception
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|   {
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|   public:
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|     virtual char const*
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|     what() const throw()
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|     { return "__gnu_cxx::__concurrence_broadcast_error"; }
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|   };
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| 
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|   class __concurrence_wait_error : public std::exception
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|   {
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|   public:
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|     virtual char const*
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|     what() const throw()
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|     { return "__gnu_cxx::__concurrence_wait_error"; }
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|   };
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| 
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|   // Substitute for concurrence_error object in the case of -fno-exceptions.
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|   inline void
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|   __throw_concurrence_lock_error()
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|   { _GLIBCXX_THROW_OR_ABORT(__concurrence_lock_error()); }
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| 
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|   inline void
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|   __throw_concurrence_unlock_error()
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|   { _GLIBCXX_THROW_OR_ABORT(__concurrence_unlock_error()); }
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| 
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| #ifdef __GTHREAD_HAS_COND
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|   inline void
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|   __throw_concurrence_broadcast_error()
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|   { _GLIBCXX_THROW_OR_ABORT(__concurrence_broadcast_error()); }
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| 
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|   inline void
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|   __throw_concurrence_wait_error()
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|   { _GLIBCXX_THROW_OR_ABORT(__concurrence_wait_error()); }
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| #endif
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|  
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|   class __mutex 
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|   {
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|   private:
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| #if __GTHREADS && defined __GTHREAD_MUTEX_INIT
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|     __gthread_mutex_t _M_mutex = __GTHREAD_MUTEX_INIT;
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| #else
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|     __gthread_mutex_t _M_mutex;
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| #endif
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| 
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|     __mutex(const __mutex&);
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|     __mutex& operator=(const __mutex&);
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| 
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|   public:
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|     __mutex() 
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|     { 
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| #if __GTHREADS && ! defined __GTHREAD_MUTEX_INIT
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|       if (__gthread_active_p())
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| 	__GTHREAD_MUTEX_INIT_FUNCTION(&_M_mutex);
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| #endif
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|     }
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| 
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| #if __GTHREADS && ! defined __GTHREAD_MUTEX_INIT
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|     ~__mutex() 
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|     { 
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|       if (__gthread_active_p())
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| 	__gthread_mutex_destroy(&_M_mutex); 
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|     }
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| #endif 
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| 
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|     void lock()
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|     {
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| #if __GTHREADS
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|       if (__gthread_active_p())
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| 	{
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| 	  if (__gthread_mutex_lock(&_M_mutex) != 0)
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| 	    __throw_concurrence_lock_error();
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| 	}
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| #endif
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|     }
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|     
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|     void unlock()
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|     {
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| #if __GTHREADS
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|       if (__gthread_active_p())
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| 	{
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| 	  if (__gthread_mutex_unlock(&_M_mutex) != 0)
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| 	    __throw_concurrence_unlock_error();
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| 	}
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| #endif
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|     }
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| 
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|     __gthread_mutex_t* gthread_mutex(void)
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|       { return &_M_mutex; }
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|   };
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| 
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|   class __recursive_mutex 
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|   {
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|   private:
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| #if __GTHREADS && defined __GTHREAD_RECURSIVE_MUTEX_INIT
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|     __gthread_recursive_mutex_t _M_mutex = __GTHREAD_RECURSIVE_MUTEX_INIT;
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| #else
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|     __gthread_recursive_mutex_t _M_mutex;
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| #endif
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| 
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|     __recursive_mutex(const __recursive_mutex&);
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|     __recursive_mutex& operator=(const __recursive_mutex&);
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| 
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|   public:
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|     __recursive_mutex() 
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|     { 
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| #if __GTHREADS && ! defined __GTHREAD_RECURSIVE_MUTEX_INIT
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|       if (__gthread_active_p())
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| 	__GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION(&_M_mutex);
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| #endif
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|     }
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| 
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| #if __GTHREADS && ! defined __GTHREAD_RECURSIVE_MUTEX_INIT
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|     ~__recursive_mutex()
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|     {
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|       if (__gthread_active_p())
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| 	__gthread_recursive_mutex_destroy(&_M_mutex);
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|     }
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| #endif
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| 
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|     void lock()
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|     { 
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| #if __GTHREADS
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|       if (__gthread_active_p())
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| 	{
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| 	  if (__gthread_recursive_mutex_lock(&_M_mutex) != 0)
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| 	    __throw_concurrence_lock_error();
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| 	}
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| #endif
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|     }
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|     
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|     void unlock()
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|     { 
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| #if __GTHREADS
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|       if (__gthread_active_p())
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| 	{
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| 	  if (__gthread_recursive_mutex_unlock(&_M_mutex) != 0)
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| 	    __throw_concurrence_unlock_error();
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| 	}
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| #endif
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|     }
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| 
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|     __gthread_recursive_mutex_t* gthread_recursive_mutex(void)
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|     { return &_M_mutex; }
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|   };
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| 
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|   /// Scoped lock idiom.
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|   // Acquire the mutex here with a constructor call, then release with
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|   // the destructor call in accordance with RAII style.
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|   class __scoped_lock
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|   {
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|   public:
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|     typedef __mutex __mutex_type;
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| 
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|   private:
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|     __mutex_type& _M_device;
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| 
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|     __scoped_lock(const __scoped_lock&);
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|     __scoped_lock& operator=(const __scoped_lock&);
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| 
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|   public:
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|     explicit __scoped_lock(__mutex_type& __name) : _M_device(__name)
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|     { _M_device.lock(); }
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| 
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|     ~__scoped_lock() throw()
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|     { _M_device.unlock(); }
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|   };
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| 
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| #ifdef __GTHREAD_HAS_COND
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|   class __cond
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|   {
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|   private:
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| #if __GTHREADS && defined __GTHREAD_COND_INIT
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|     __gthread_cond_t _M_cond = __GTHREAD_COND_INIT;
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| #else
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|     __gthread_cond_t _M_cond;
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| #endif
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| 
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|     __cond(const __cond&);
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|     __cond& operator=(const __cond&);
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| 
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|   public:
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|     __cond() 
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|     { 
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| #if __GTHREADS && ! defined __GTHREAD_COND_INIT
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|       if (__gthread_active_p())
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| 	__GTHREAD_COND_INIT_FUNCTION(&_M_cond);
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| #endif
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|     }
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| 
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| #if __GTHREADS && ! defined __GTHREAD_COND_INIT
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|     ~__cond() 
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|     { 
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|       if (__gthread_active_p())
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| 	__gthread_cond_destroy(&_M_cond); 
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|     }
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| #endif 
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| 
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|     void broadcast()
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|     {
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| #if __GTHREADS
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|       if (__gthread_active_p())
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| 	{
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| 	  if (__gthread_cond_broadcast(&_M_cond) != 0)
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| 	    __throw_concurrence_broadcast_error();
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| 	}
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| #endif
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|     }
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| 
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|     void wait(__mutex *mutex)
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|     {
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| #if __GTHREADS
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|       {
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| 	  if (__gthread_cond_wait(&_M_cond, mutex->gthread_mutex()) != 0)
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| 	    __throw_concurrence_wait_error();
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|       }
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| #endif
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|     }
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| 
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|     void wait_recursive(__recursive_mutex *mutex)
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|     {
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| #if __GTHREADS
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|       {
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| 	  if (__gthread_cond_wait_recursive(&_M_cond,
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| 					    mutex->gthread_recursive_mutex())
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| 	      != 0)
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| 	    __throw_concurrence_wait_error();
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|       }
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| #endif
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|     }
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|   };
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| #endif
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| 
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| _GLIBCXX_END_NAMESPACE_VERSION
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| } // namespace
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| 
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| #endif
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