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			313 lines
		
	
	
		
			8.4 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			313 lines
		
	
	
		
			8.4 KiB
		
	
	
	
		
			C++
		
	
	
	
| // <condition_variable> -*- C++ -*-
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| 
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| // Copyright (C) 2008-2014 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 include/condition_variable
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|  *  This is a Standard C++ Library header.
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|  */
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| 
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| #ifndef _GLIBCXX_CONDITION_VARIABLE
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| #define _GLIBCXX_CONDITION_VARIABLE 1
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| 
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| #pragma GCC system_header
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| 
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| #if __cplusplus < 201103L
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| # include <bits/c++0x_warning.h>
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| #else
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| 
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| #include <chrono>
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| #include <mutex>
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| #include <ext/concurrence.h>
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| #include <bits/alloc_traits.h>
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| #include <bits/allocator.h>
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| #include <bits/unique_ptr.h>
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| #include <bits/shared_ptr.h>
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| 
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| #if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
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| 
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| namespace std _GLIBCXX_VISIBILITY(default)
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| {
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| _GLIBCXX_BEGIN_NAMESPACE_VERSION
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| 
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|   /**
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|    * @defgroup condition_variables Condition Variables
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|    * @ingroup concurrency
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|    *
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|    * Classes for condition_variable support.
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|    * @{
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|    */
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| 
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|   /// cv_status
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|   enum class cv_status { no_timeout, timeout };
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|   
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|   /// condition_variable
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|   class condition_variable
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|   {
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|     typedef chrono::system_clock	__clock_t;
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|     typedef __gthread_cond_t		__native_type;
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| 
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| #ifdef __GTHREAD_COND_INIT
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|     __native_type			_M_cond = __GTHREAD_COND_INIT;
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| #else
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|     __native_type			_M_cond;
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| #endif
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| 
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|   public:
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|     typedef __native_type* 		native_handle_type;
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| 
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|     condition_variable() noexcept;
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|     ~condition_variable() noexcept;
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| 
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|     condition_variable(const condition_variable&) = delete;
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|     condition_variable& operator=(const condition_variable&) = delete;
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| 
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|     void
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|     notify_one() noexcept;
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| 
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|     void
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|     notify_all() noexcept;
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| 
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|     void
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|     wait(unique_lock<mutex>& __lock);
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| 
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|     template<typename _Predicate>
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|       void
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|       wait(unique_lock<mutex>& __lock, _Predicate __p)
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|       {
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| 	while (!__p())
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| 	  wait(__lock);
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|       }
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| 
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|     template<typename _Duration>
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|       cv_status
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|       wait_until(unique_lock<mutex>& __lock,
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| 		 const chrono::time_point<__clock_t, _Duration>& __atime)
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|       { return __wait_until_impl(__lock, __atime); }
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| 
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|     template<typename _Clock, typename _Duration>
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|       cv_status
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|       wait_until(unique_lock<mutex>& __lock,
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| 		 const chrono::time_point<_Clock, _Duration>& __atime)
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|       {
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| 	// DR 887 - Sync unknown clock to known clock.
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| 	const typename _Clock::time_point __c_entry = _Clock::now();
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| 	const __clock_t::time_point __s_entry = __clock_t::now();
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| 	const auto __delta = __atime - __c_entry;
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| 	const auto __s_atime = __s_entry + __delta;
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| 
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| 	return __wait_until_impl(__lock, __s_atime);
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|       }
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| 
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|     template<typename _Clock, typename _Duration, typename _Predicate>
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|       bool
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|       wait_until(unique_lock<mutex>& __lock,
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| 		 const chrono::time_point<_Clock, _Duration>& __atime,
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| 		 _Predicate __p)
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|       {
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| 	while (!__p())
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| 	  if (wait_until(__lock, __atime) == cv_status::timeout)
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| 	    return __p();
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| 	return true;
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|       }
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| 
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|     template<typename _Rep, typename _Period>
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|       cv_status
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|       wait_for(unique_lock<mutex>& __lock,
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| 	       const chrono::duration<_Rep, _Period>& __rtime)
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|       { return wait_until(__lock, __clock_t::now() + __rtime); }
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| 
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|     template<typename _Rep, typename _Period, typename _Predicate>
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|       bool
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|       wait_for(unique_lock<mutex>& __lock,
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| 	       const chrono::duration<_Rep, _Period>& __rtime,
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| 	       _Predicate __p)
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|       { return wait_until(__lock, __clock_t::now() + __rtime, std::move(__p)); }
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| 
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|     native_handle_type
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|     native_handle()
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|     { return &_M_cond; }
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| 
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|   private:
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|     template<typename _Dur>
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|       cv_status
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|       __wait_until_impl(unique_lock<mutex>& __lock,
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| 			const chrono::time_point<__clock_t, _Dur>& __atime)
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|       {
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| 	auto __s = chrono::time_point_cast<chrono::seconds>(__atime);
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| 	auto __ns = chrono::duration_cast<chrono::nanoseconds>(__atime - __s);
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| 
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| 	__gthread_time_t __ts =
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| 	  {
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| 	    static_cast<std::time_t>(__s.time_since_epoch().count()),
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| 	    static_cast<long>(__ns.count())
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| 	  };
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| 
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| 	__gthread_cond_timedwait(&_M_cond, __lock.mutex()->native_handle(),
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| 				 &__ts);
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| 
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| 	return (__clock_t::now() < __atime
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| 		? cv_status::no_timeout : cv_status::timeout);
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|       }
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|   };
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| 
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|   void
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|   notify_all_at_thread_exit(condition_variable&, unique_lock<mutex>);
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| 
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|   struct __at_thread_exit_elt
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|   {
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|     __at_thread_exit_elt* _M_next;
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|     void (*_M_cb)(void*);
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|   };
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| 
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|   inline namespace _V2 {
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| 
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|   /// condition_variable_any
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|   // Like above, but mutex is not required to have try_lock.
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|   class condition_variable_any
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|   {
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|     typedef chrono::system_clock	__clock_t;
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|     condition_variable			_M_cond;
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|     shared_ptr<mutex>			_M_mutex;
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| 
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|     // scoped unlock - unlocks in ctor, re-locks in dtor
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|     template<typename _Lock>
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|       struct _Unlock
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|       {
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| 	explicit _Unlock(_Lock& __lk) : _M_lock(__lk) { __lk.unlock(); }
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| 
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| 	~_Unlock() noexcept(false)
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| 	{
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| 	  if (uncaught_exception())
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| 	    {
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| 	      __try
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| 	      { _M_lock.lock(); }
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| 	      __catch(const __cxxabiv1::__forced_unwind&)
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| 	      { __throw_exception_again; }
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| 	      __catch(...)
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| 	      { }
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| 	    }
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| 	  else
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| 	    _M_lock.lock();
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| 	}
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| 
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| 	_Unlock(const _Unlock&) = delete;
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| 	_Unlock& operator=(const _Unlock&) = delete;
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| 
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| 	_Lock& _M_lock;
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|       };
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| 
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|   public:
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|     condition_variable_any() : _M_mutex(std::make_shared<mutex>()) { }
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|     ~condition_variable_any() = default;
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| 
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|     condition_variable_any(const condition_variable_any&) = delete;
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|     condition_variable_any& operator=(const condition_variable_any&) = delete;
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| 
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|     void
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|     notify_one() noexcept
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|     {
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|       lock_guard<mutex> __lock(*_M_mutex);
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|       _M_cond.notify_one();
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|     }
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| 
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|     void
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|     notify_all() noexcept
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|     {
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|       lock_guard<mutex> __lock(*_M_mutex);
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|       _M_cond.notify_all();
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|     }
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| 
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|     template<typename _Lock>
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|       void
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|       wait(_Lock& __lock)
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|       {
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| 	shared_ptr<mutex> __mutex = _M_mutex;
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| 	unique_lock<mutex> __my_lock(*__mutex);
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| 	_Unlock<_Lock> __unlock(__lock);
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| 	// *__mutex must be unlocked before re-locking __lock so move
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| 	// ownership of *__mutex lock to an object with shorter lifetime.
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| 	unique_lock<mutex> __my_lock2(std::move(__my_lock));
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| 	_M_cond.wait(__my_lock2);
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|       }
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|       
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| 
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|     template<typename _Lock, typename _Predicate>
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|       void
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|       wait(_Lock& __lock, _Predicate __p)
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|       {
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| 	while (!__p())
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| 	  wait(__lock);
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|       }
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| 
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|     template<typename _Lock, typename _Clock, typename _Duration>
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|       cv_status
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|       wait_until(_Lock& __lock,
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| 		 const chrono::time_point<_Clock, _Duration>& __atime)
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|       {
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| 	shared_ptr<mutex> __mutex = _M_mutex;
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| 	unique_lock<mutex> __my_lock(*__mutex);
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| 	_Unlock<_Lock> __unlock(__lock);
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| 	// *__mutex must be unlocked before re-locking __lock so move
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| 	// ownership of *__mutex lock to an object with shorter lifetime.
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| 	unique_lock<mutex> __my_lock2(std::move(__my_lock));
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| 	return _M_cond.wait_until(__my_lock2, __atime);
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|       }
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| 
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|     template<typename _Lock, typename _Clock,
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| 	     typename _Duration, typename _Predicate>
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|       bool
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|       wait_until(_Lock& __lock,
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| 		 const chrono::time_point<_Clock, _Duration>& __atime,
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| 		 _Predicate __p)
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|       {
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| 	while (!__p())
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| 	  if (wait_until(__lock, __atime) == cv_status::timeout)
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| 	    return __p();
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| 	return true;
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|       }
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| 
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|     template<typename _Lock, typename _Rep, typename _Period>
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|       cv_status
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|       wait_for(_Lock& __lock, const chrono::duration<_Rep, _Period>& __rtime)
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|       { return wait_until(__lock, __clock_t::now() + __rtime); }
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| 
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|     template<typename _Lock, typename _Rep,
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| 	     typename _Period, typename _Predicate>
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|       bool
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|       wait_for(_Lock& __lock,
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| 	       const chrono::duration<_Rep, _Period>& __rtime, _Predicate __p)
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|       { return wait_until(__lock, __clock_t::now() + __rtime, std::move(__p)); }
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|   };
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| 
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|   } // end inline namespace
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| 
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|   // @} group condition_variables
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| _GLIBCXX_END_NAMESPACE_VERSION
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| } // namespace
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| 
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| #endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1
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| 
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| #endif // C++11
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| 
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| #endif // _GLIBCXX_CONDITION_VARIABLE
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