include/mutex - third_party/libcxx - Git at Google

 // -*- C++ -*-
 //===--------------------------- mutex ------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//

 #ifndef _LIBCPP_MUTEX
 #define _LIBCPP_MUTEX

 /*
     mutex synopsis

 namespace std
 {

 class mutex
 {
 public:
      constexpr mutex() noexcept;
      ~mutex();

     mutex(const mutex&) = delete;
     mutex& operator=(const mutex&) = delete;

     void lock();
     bool try_lock();
     void unlock();

     typedef pthread_mutex_t* native_handle_type;
     native_handle_type native_handle();
 };

 class recursive_mutex
 {
 public:
      recursive_mutex();
      ~recursive_mutex();

     recursive_mutex(const recursive_mutex&) = delete;
     recursive_mutex& operator=(const recursive_mutex&) = delete;

     void lock();
     bool try_lock() noexcept;
     void unlock();

     typedef pthread_mutex_t* native_handle_type;
     native_handle_type native_handle();
 };

 class timed_mutex
 {
 public:
      timed_mutex();
      ~timed_mutex();

     timed_mutex(const timed_mutex&) = delete;
     timed_mutex& operator=(const timed_mutex&) = delete;

     void lock();
     bool try_lock();
     template <class Rep, class Period>
         bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
     template <class Clock, class Duration>
         bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
     void unlock();
 };

 class recursive_timed_mutex
 {
 public:
      recursive_timed_mutex();
      ~recursive_timed_mutex();

     recursive_timed_mutex(const recursive_timed_mutex&) = delete;
     recursive_timed_mutex& operator=(const recursive_timed_mutex&) = delete;

     void lock();
     bool try_lock() noexcept;
     template <class Rep, class Period>
         bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
     template <class Clock, class Duration>
         bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
     void unlock();
 };

 struct defer_lock_t {};
 struct try_to_lock_t {};
 struct adopt_lock_t {};

 inline constexpr defer_lock_t  defer_lock{};
 inline constexpr try_to_lock_t try_to_lock{};
 inline constexpr adopt_lock_t  adopt_lock{};

 template <class Mutex>
 class lock_guard
 {
 public:
     typedef Mutex mutex_type;

     explicit lock_guard(mutex_type& m);
     lock_guard(mutex_type& m, adopt_lock_t);
     ~lock_guard();

     lock_guard(lock_guard const&) = delete;
     lock_guard& operator=(lock_guard const&) = delete;
 };

 template <class... MutexTypes>
 class scoped_lock // C++17
 {
 public:
     using mutex_type = Mutex;  // If MutexTypes... consists of the single type Mutex

     explicit scoped_lock(MutexTypes&... m);
     scoped_lock(adopt_lock_t, MutexTypes&... m);
     ~scoped_lock();
     scoped_lock(scoped_lock const&) = delete;
     scoped_lock& operator=(scoped_lock const&) = delete;
 private:
     tuple<MutexTypes&...> pm; // exposition only
 };

 template <class Mutex>
 class unique_lock
 {
 public:
     typedef Mutex mutex_type;
     unique_lock() noexcept;
     explicit unique_lock(mutex_type& m);
     unique_lock(mutex_type& m, defer_lock_t) noexcept;
     unique_lock(mutex_type& m, try_to_lock_t);
     unique_lock(mutex_type& m, adopt_lock_t);
     template <class Clock, class Duration>
         unique_lock(mutex_type& m, const chrono::time_point<Clock, Duration>& abs_time);
     template <class Rep, class Period>
         unique_lock(mutex_type& m, const chrono::duration<Rep, Period>& rel_time);
     ~unique_lock();

     unique_lock(unique_lock const&) = delete;
     unique_lock& operator=(unique_lock const&) = delete;

     unique_lock(unique_lock&& u) noexcept;
     unique_lock& operator=(unique_lock&& u) noexcept;

     void lock();
     bool try_lock();

     template <class Rep, class Period>
         bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
     template <class Clock, class Duration>
         bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);

     void unlock();

     void swap(unique_lock& u) noexcept;
     mutex_type* release() noexcept;

     bool owns_lock() const noexcept;
     explicit operator bool () const noexcept;
     mutex_type* mutex() const noexcept;
 };

 template <class Mutex>
   void swap(unique_lock<Mutex>& x, unique_lock<Mutex>& y) noexcept;

 template <class L1, class L2, class... L3>
   int try_lock(L1&, L2&, L3&...);
 template <class L1, class L2, class... L3>
   void lock(L1&, L2&, L3&...);

 struct once_flag
 {
     constexpr once_flag() noexcept;

     once_flag(const once_flag&) = delete;
     once_flag& operator=(const once_flag&) = delete;
 };

 template<class Callable, class ...Args>
   void call_once(once_flag& flag, Callable&& func, Args&&... args);

 }  // std

 */

 #include <__config>
 #include <__mutex_base>
 #include <cstdint>
 #include <functional>
 #include <memory>
 #ifndef _LIBCPP_CXX03_LANG
 #include <tuple>
 #endif
 #include <version>
 #include <__threading_support>

 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
 #endif

 _LIBCPP_PUSH_MACROS
 #include <__undef_macros>


 _LIBCPP_BEGIN_NAMESPACE_STD

 #ifndef _LIBCPP_HAS_NO_THREADS

 class _LIBCPP_TYPE_VIS recursive_mutex
 {
     __libcpp_recursive_mutex_t __m_;

 public:
      recursive_mutex();
      ~recursive_mutex();

 private:
     recursive_mutex(const recursive_mutex&); // = delete;
     recursive_mutex& operator=(const recursive_mutex&); // = delete;

 public:
     void lock();
     bool try_lock() _NOEXCEPT;
     void unlock()  _NOEXCEPT;

     typedef __libcpp_recursive_mutex_t* native_handle_type;

     _LIBCPP_INLINE_VISIBILITY
     native_handle_type native_handle() {return &__m_;}
 };

 class _LIBCPP_TYPE_VIS timed_mutex
 {
     mutex              __m_;
     condition_variable __cv_;
     bool               __locked_;
 public:
      timed_mutex();
      ~timed_mutex();

 private:
     timed_mutex(const timed_mutex&); // = delete;
     timed_mutex& operator=(const timed_mutex&); // = delete;

 public:
     void lock();
     bool try_lock() _NOEXCEPT;
     template <class _Rep, class _Period>
         _LIBCPP_INLINE_VISIBILITY
         bool try_lock_for(const chrono::duration<_Rep, _Period>& __d)
             {return try_lock_until(chrono::steady_clock::now() + __d);}
     template <class _Clock, class _Duration>
         _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
         bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
     void unlock() _NOEXCEPT;
 };

 template <class _Clock, class _Duration>
 bool
 timed_mutex::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
 {
     using namespace chrono;
     unique_lock<mutex> __lk(__m_);
     bool no_timeout = _Clock::now() < __t;
     while (no_timeout && __locked_)
         no_timeout = __cv_.wait_until(__lk, __t) == cv_status::no_timeout;
     if (!__locked_)
     {
         __locked_ = true;
         return true;
     }
     return false;
 }

 class _LIBCPP_TYPE_VIS recursive_timed_mutex
 {
     mutex              __m_;
     condition_variable __cv_;
     size_t             __count_;
     __libcpp_thread_id __id_;
 public:
      recursive_timed_mutex();
      ~recursive_timed_mutex();

 private:
     recursive_timed_mutex(const recursive_timed_mutex&); // = delete;
     recursive_timed_mutex& operator=(const recursive_timed_mutex&); // = delete;

 public:
     void lock();
     bool try_lock() _NOEXCEPT;
     template <class _Rep, class _Period>
         _LIBCPP_INLINE_VISIBILITY
         bool try_lock_for(const chrono::duration<_Rep, _Period>& __d)
             {return try_lock_until(chrono::steady_clock::now() + __d);}
     template <class _Clock, class _Duration>
         _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
         bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
     void unlock() _NOEXCEPT;
 };

 template <class _Clock, class _Duration>
 bool
 recursive_timed_mutex::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
 {
     using namespace chrono;
     __libcpp_thread_id __id = __libcpp_thread_get_current_id();
     unique_lock<mutex> lk(__m_);
     if (__libcpp_thread_id_equal(__id, __id_))
     {
         if (__count_ == numeric_limits<size_t>::max())
             return false;
         ++__count_;
         return true;
     }
     bool no_timeout = _Clock::now() < __t;
     while (no_timeout && __count_ != 0)
         no_timeout = __cv_.wait_until(lk, __t) == cv_status::no_timeout;
     if (__count_ == 0)
     {
         __count_ = 1;
         __id_ = __id;
         return true;
     }
     return false;
 }

 template <class _L0, class _L1>
 int
 try_lock(_L0& __l0, _L1& __l1)
 {
     unique_lock<_L0> __u0(__l0, try_to_lock);
     if (__u0.owns_lock())
     {
         if (__l1.try_lock())
         {
             __u0.release();
             return -1;
         }
         else
             return 1;
     }
     return 0;
 }

 #ifndef _LIBCPP_CXX03_LANG

 template <class _L0, class _L1, class _L2, class... _L3>
 int
 try_lock(_L0& __l0, _L1& __l1, _L2& __l2, _L3&... __l3)
 {
     int __r = 0;
     unique_lock<_L0> __u0(__l0, try_to_lock);
     if (__u0.owns_lock())
     {
         __r = try_lock(__l1, __l2, __l3...);
         if (__r == -1)
             __u0.release();
         else
             ++__r;
     }
     return __r;
 }

 #endif  // _LIBCPP_CXX03_LANG

 template <class _L0, class _L1>
 void
 lock(_L0& __l0, _L1& __l1)
 {
     while (true)
     {
         {
             unique_lock<_L0> __u0(__l0);
             if (__l1.try_lock())
             {
                 __u0.release();
                 break;
             }
         }
         __libcpp_thread_yield();
         {
             unique_lock<_L1> __u1(__l1);
             if (__l0.try_lock())
             {
                 __u1.release();
                 break;
             }
         }
         __libcpp_thread_yield();
     }
 }

 #ifndef _LIBCPP_CXX03_LANG

 template <class _L0, class _L1, class _L2, class ..._L3>
 void
 __lock_first(int __i, _L0& __l0, _L1& __l1, _L2& __l2, _L3& ...__l3)
 {
     while (true)
     {
         switch (__i)
         {
         case 0:
             {
                 unique_lock<_L0> __u0(__l0);
                 __i = try_lock(__l1, __l2, __l3...);
                 if (__i == -1)
                 {
                     __u0.release();
                     return;
                 }
             }
             ++__i;
             __libcpp_thread_yield();
             break;
         case 1:
             {
                 unique_lock<_L1> __u1(__l1);
                 __i = try_lock(__l2, __l3..., __l0);
                 if (__i == -1)
                 {
                     __u1.release();
                     return;
                 }
             }
             if (__i == sizeof...(_L3) + 1)
                 __i = 0;
             else
                 __i += 2;
             __libcpp_thread_yield();
             break;
         default:
             __lock_first(__i - 2, __l2, __l3..., __l0, __l1);
             return;
         }
     }
 }

 template <class _L0, class _L1, class _L2, class ..._L3>
 inline _LIBCPP_INLINE_VISIBILITY
 void
 lock(_L0& __l0, _L1& __l1, _L2& __l2, _L3& ...__l3)
 {
     __lock_first(0, __l0, __l1, __l2, __l3...);
 }

 template <class _L0>
 inline _LIBCPP_INLINE_VISIBILITY
 void __unlock(_L0& __l0) {
     __l0.unlock();
 }

 template <class _L0, class _L1>
 inline _LIBCPP_INLINE_VISIBILITY
 void __unlock(_L0& __l0, _L1& __l1) {
     __l0.unlock();
     __l1.unlock();
 }

 template <class _L0, class _L1, class _L2, class ..._L3>
 inline _LIBCPP_INLINE_VISIBILITY
 void __unlock(_L0& __l0, _L1& __l1, _L2& __l2, _L3&... __l3) {
     __l0.unlock();
     __l1.unlock();
     _VSTD::__unlock(__l2, __l3...);
 }

 #endif  // _LIBCPP_CXX03_LANG

 #if _LIBCPP_STD_VER > 14
 template <class ..._Mutexes>
 class _LIBCPP_TEMPLATE_VIS scoped_lock;

 template <>
 class _LIBCPP_TEMPLATE_VIS scoped_lock<> {
 public:
     explicit scoped_lock() {}
     ~scoped_lock() = default;

     _LIBCPP_INLINE_VISIBILITY
     explicit scoped_lock(adopt_lock_t) {}

     scoped_lock(scoped_lock const&) = delete;
     scoped_lock& operator=(scoped_lock const&) = delete;
 };

 template <class _Mutex>
 class _LIBCPP_TEMPLATE_VIS _LIBCPP_THREAD_SAFETY_ANNOTATION(scoped_lockable) scoped_lock<_Mutex> {
 public:
     typedef _Mutex  mutex_type;
 private:
     mutex_type& __m_;
 public:
     explicit scoped_lock(mutex_type & __m) _LIBCPP_THREAD_SAFETY_ANNOTATION(acquire_capability(__m))
         : __m_(__m) {__m_.lock();}

     ~scoped_lock() _LIBCPP_THREAD_SAFETY_ANNOTATION(release_capability()) {__m_.unlock();}

     _LIBCPP_INLINE_VISIBILITY
     explicit scoped_lock(adopt_lock_t, mutex_type& __m) _LIBCPP_THREAD_SAFETY_ANNOTATION(requires_capability(__m))
         : __m_(__m) {}

     scoped_lock(scoped_lock const&) = delete;
     scoped_lock& operator=(scoped_lock const&) = delete;
 };

 template <class ..._MArgs>
 class _LIBCPP_TEMPLATE_VIS scoped_lock
 {
     static_assert(sizeof...(_MArgs) > 1, "At least 2 lock types required");
     typedef tuple<_MArgs&...> _MutexTuple;

 public:
     _LIBCPP_INLINE_VISIBILITY
     explicit scoped_lock(_MArgs&... __margs)
       : __t_(__margs...)
     {
         _VSTD::lock(__margs...);
     }

     _LIBCPP_INLINE_VISIBILITY
     scoped_lock(adopt_lock_t, _MArgs&... __margs)
         : __t_(__margs...)
     {
     }

     _LIBCPP_INLINE_VISIBILITY
     ~scoped_lock() {
         typedef typename __make_tuple_indices<sizeof...(_MArgs)>::type _Indices;
         __unlock_unpack(_Indices{}, __t_);
     }

     scoped_lock(scoped_lock const&) = delete;
     scoped_lock& operator=(scoped_lock const&) = delete;

 private:
     template <size_t ..._Indx>
     _LIBCPP_INLINE_VISIBILITY
     static void __unlock_unpack(__tuple_indices<_Indx...>, _MutexTuple& __mt) {
         _VSTD::__unlock(_VSTD::get<_Indx>(__mt)...);
     }

     _MutexTuple __t_;
 };

 #endif // _LIBCPP_STD_VER > 14
 #endif // !_LIBCPP_HAS_NO_THREADS

 struct _LIBCPP_TEMPLATE_VIS once_flag;

 #ifndef _LIBCPP_CXX03_LANG

 template<class _Callable, class... _Args>
 _LIBCPP_INLINE_VISIBILITY
 void call_once(once_flag&, _Callable&&, _Args&&...);

 #else  // _LIBCPP_CXX03_LANG

 template<class _Callable>
 _LIBCPP_INLINE_VISIBILITY
 void call_once(once_flag&, _Callable&);

 template<class _Callable>
 _LIBCPP_INLINE_VISIBILITY
 void call_once(once_flag&, const _Callable&);

 #endif  // _LIBCPP_CXX03_LANG

 struct _LIBCPP_TEMPLATE_VIS once_flag
 {
     _LIBCPP_INLINE_VISIBILITY
     _LIBCPP_CONSTEXPR
         once_flag() _NOEXCEPT : __state_(0) {}

 #if defined(_LIBCPP_ABI_MICROSOFT)
    typedef uintptr_t _State_type;
 #else
    typedef unsigned long _State_type;
 #endif


 private:
     once_flag(const once_flag&); // = delete;
     once_flag& operator=(const once_flag&); // = delete;

     _State_type __state_;

 #ifndef _LIBCPP_CXX03_LANG
     template<class _Callable, class... _Args>
     friend
     void call_once(once_flag&, _Callable&&, _Args&&...);
 #else  // _LIBCPP_CXX03_LANG
     template<class _Callable>
     friend
     void call_once(once_flag&, _Callable&);

     template<class _Callable>
     friend
     void call_once(once_flag&, const _Callable&);
 #endif  // _LIBCPP_CXX03_LANG
 };

 #ifndef _LIBCPP_CXX03_LANG

 template <class _Fp>
 class __call_once_param
 {
     _Fp& __f_;
 public:
     _LIBCPP_INLINE_VISIBILITY
     explicit __call_once_param(_Fp& __f) : __f_(__f) {}

     _LIBCPP_INLINE_VISIBILITY
     void operator()()
     {
         typedef typename __make_tuple_indices<tuple_size<_Fp>::value, 1>::type _Index;
         __execute(_Index());
     }

 private:
     template <size_t ..._Indices>
     _LIBCPP_INLINE_VISIBILITY
     void __execute(__tuple_indices<_Indices...>)
     {
         __invoke(_VSTD::get<0>(_VSTD::move(__f_)), _VSTD::get<_Indices>(_VSTD::move(__f_))...);
     }
 };

 #else

 template <class _Fp>
 class __call_once_param
 {
     _Fp& __f_;
 public:
     _LIBCPP_INLINE_VISIBILITY
     explicit __call_once_param(_Fp& __f) : __f_(__f) {}

     _LIBCPP_INLINE_VISIBILITY
     void operator()()
     {
         __f_();
     }
 };

 #endif

 template <class _Fp>
 void
 __call_once_proxy(void* __vp)
 {
     __call_once_param<_Fp>* __p = static_cast<__call_once_param<_Fp>*>(__vp);
     (*__p)();
 }

 _LIBCPP_FUNC_VIS void __call_once(volatile once_flag::_State_type&, void*,
                                   void (*)(void*));

 #ifndef _LIBCPP_CXX03_LANG

 template<class _Callable, class... _Args>
 inline _LIBCPP_INLINE_VISIBILITY
 void
 call_once(once_flag& __flag, _Callable&& __func, _Args&&... __args)
 {
     if (__libcpp_acquire_load(&__flag.__state_) != ~once_flag::_State_type(0))
     {
         typedef tuple<_Callable&&, _Args&&...> _Gp;
         _Gp __f(_VSTD::forward<_Callable>(__func), _VSTD::forward<_Args>(__args)...);
         __call_once_param<_Gp> __p(__f);
         __call_once(__flag.__state_, &__p, &__call_once_proxy<_Gp>);
     }
 }

 #else  // _LIBCPP_CXX03_LANG

 template<class _Callable>
 inline _LIBCPP_INLINE_VISIBILITY
 void
 call_once(once_flag& __flag, _Callable& __func)
 {
     if (__libcpp_acquire_load(&__flag.__state_) != ~once_flag::_State_type(0))
     {
         __call_once_param<_Callable> __p(__func);
         __call_once(__flag.__state_, &__p, &__call_once_proxy<_Callable>);
     }
 }

 template<class _Callable>
 inline _LIBCPP_INLINE_VISIBILITY
 void
 call_once(once_flag& __flag, const _Callable& __func)
 {
     if (__libcpp_acquire_load(&__flag.__state_) != ~once_flag::_State_type(0))
     {
         __call_once_param<const _Callable> __p(__func);
         __call_once(__flag.__state_, &__p, &__call_once_proxy<const _Callable>);
     }
 }

 #endif  // _LIBCPP_CXX03_LANG

 _LIBCPP_END_NAMESPACE_STD

 _LIBCPP_POP_MACROS

 #endif  // _LIBCPP_MUTEX
	// -- C++ --
	//===--------------------------- mutex ------------------------------------===//
	//
	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
	// See https://llvm.org/LICENSE.txt for license information.
	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
	//
	//===----------------------------------------------------------------------===//

	#ifndef _LIBCPP_MUTEX
	#define _LIBCPP_MUTEX

	/*
	mutex synopsis

	namespace std
	{

	class mutex
	{
	public:
	constexpr mutex() noexcept;
	~mutex();

	mutex(const mutex&) = delete;
	mutex& operator=(const mutex&) = delete;

	void lock();
	bool try_lock();
	void unlock();

	typedef pthread_mutex_t* native_handle_type;
	native_handle_type native_handle();
	};

	class recursive_mutex
	{
	public:
	recursive_mutex();
	~recursive_mutex();

	recursive_mutex(const recursive_mutex&) = delete;
	recursive_mutex& operator=(const recursive_mutex&) = delete;

	void lock();
	bool try_lock() noexcept;
	void unlock();

	typedef pthread_mutex_t* native_handle_type;
	native_handle_type native_handle();
	};

	class timed_mutex
	{
	public:
	timed_mutex();
	~timed_mutex();

	timed_mutex(const timed_mutex&) = delete;
	timed_mutex& operator=(const timed_mutex&) = delete;

	void lock();
	bool try_lock();
	template <class Rep, class Period>
	bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
	template <class Clock, class Duration>
	bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
	void unlock();
	};

	class recursive_timed_mutex
	{
	public:
	recursive_timed_mutex();
	~recursive_timed_mutex();

	recursive_timed_mutex(const recursive_timed_mutex&) = delete;
	recursive_timed_mutex& operator=(const recursive_timed_mutex&) = delete;

	void lock();
	bool try_lock() noexcept;
	template <class Rep, class Period>
	bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
	template <class Clock, class Duration>
	bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
	void unlock();
	};

	struct defer_lock_t {};
	struct try_to_lock_t {};
	struct adopt_lock_t {};

	inline constexpr defer_lock_t defer_lock{};
	inline constexpr try_to_lock_t try_to_lock{};
	inline constexpr adopt_lock_t adopt_lock{};

	template <class Mutex>
	class lock_guard
	{
	public:
	typedef Mutex mutex_type;

	explicit lock_guard(mutex_type& m);
	lock_guard(mutex_type& m, adopt_lock_t);
	~lock_guard();

	lock_guard(lock_guard const&) = delete;
	lock_guard& operator=(lock_guard const&) = delete;
	};

	template <class... MutexTypes>
	class scoped_lock // C++17
	{
	public:
	using mutex_type = Mutex; // If MutexTypes... consists of the single type Mutex

	explicit scoped_lock(MutexTypes&... m);
	scoped_lock(adopt_lock_t, MutexTypes&... m);
	~scoped_lock();
	scoped_lock(scoped_lock const&) = delete;
	scoped_lock& operator=(scoped_lock const&) = delete;
	private:
	tuple<MutexTypes&...> pm; // exposition only
	};

	template <class Mutex>
	class unique_lock
	{
	public:
	typedef Mutex mutex_type;
	unique_lock() noexcept;
	explicit unique_lock(mutex_type& m);
	unique_lock(mutex_type& m, defer_lock_t) noexcept;
	unique_lock(mutex_type& m, try_to_lock_t);
	unique_lock(mutex_type& m, adopt_lock_t);
	template <class Clock, class Duration>
	unique_lock(mutex_type& m, const chrono::time_point<Clock, Duration>& abs_time);
	template <class Rep, class Period>
	unique_lock(mutex_type& m, const chrono::duration<Rep, Period>& rel_time);
	~unique_lock();

	unique_lock(unique_lock const&) = delete;
	unique_lock& operator=(unique_lock const&) = delete;

	unique_lock(unique_lock&& u) noexcept;
	unique_lock& operator=(unique_lock&& u) noexcept;

	void lock();
	bool try_lock();

	template <class Rep, class Period>
	bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
	template <class Clock, class Duration>
	bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);

	void unlock();

	void swap(unique_lock& u) noexcept;
	mutex_type* release() noexcept;

	bool owns_lock() const noexcept;
	explicit operator bool () const noexcept;
	mutex_type* mutex() const noexcept;
	};

	template <class Mutex>
	void swap(unique_lock<Mutex>& x, unique_lock<Mutex>& y) noexcept;

	template <class L1, class L2, class... L3>
	int try_lock(L1&, L2&, L3&...);
	template <class L1, class L2, class... L3>
	void lock(L1&, L2&, L3&...);

	struct once_flag
	{
	constexpr once_flag() noexcept;

	once_flag(const once_flag&) = delete;
	once_flag& operator=(const once_flag&) = delete;
	};

	template<class Callable, class ...Args>
	void call_once(once_flag& flag, Callable&& func, Args&&... args);

	} // std

	*/

	#include <__config>
	#include <__mutex_base>
	#include <cstdint>
	#include <functional>
	#include <memory>
	#ifndef _LIBCPP_CXX03_LANG
	#include <tuple>
	#endif
	#include <version>
	#include <__threading_support>

	#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
	#pragma GCC system_header
	#endif

	_LIBCPP_PUSH_MACROS
	#include <__undef_macros>


	_LIBCPP_BEGIN_NAMESPACE_STD

	#ifndef _LIBCPP_HAS_NO_THREADS

	class _LIBCPP_TYPE_VIS recursive_mutex
	{
	__libcpp_recursive_mutex_t __m_;

	public:
	recursive_mutex();
	~recursive_mutex();

	private:
	recursive_mutex(const recursive_mutex&); // = delete;
	recursive_mutex& operator=(const recursive_mutex&); // = delete;

	public:
	void lock();
	bool try_lock() _NOEXCEPT;
	void unlock() _NOEXCEPT;

	typedef __libcpp_recursive_mutex_t* native_handle_type;

	_LIBCPP_INLINE_VISIBILITY
	native_handle_type native_handle() {return &__m_;}
	};

	class _LIBCPP_TYPE_VIS timed_mutex
	{
	mutex __m_;
	condition_variable __cv_;
	bool __locked_;
	public:
	timed_mutex();
	~timed_mutex();

	private:
	timed_mutex(const timed_mutex&); // = delete;
	timed_mutex& operator=(const timed_mutex&); // = delete;

	public:
	void lock();
	bool try_lock() _NOEXCEPT;
	template <class _Rep, class _Period>
	_LIBCPP_INLINE_VISIBILITY
	bool try_lock_for(const chrono::duration<_Rep, _Period>& __d)
	{return try_lock_until(chrono::steady_clock::now() + __d);}
	template <class _Clock, class _Duration>
	_LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
	bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
	void unlock() _NOEXCEPT;
	};

	template <class _Clock, class _Duration>
	bool
	timed_mutex::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
	{
	using namespace chrono;
	unique_lock<mutex> __lk(__m_);
	bool no_timeout = _Clock::now() < __t;
	while (no_timeout && __locked_)
	no_timeout = __cv_.wait_until(__lk, __t) == cv_status::no_timeout;
	if (!__locked_)
	{
	__locked_ = true;
	return true;
	}
	return false;
	}

	class _LIBCPP_TYPE_VIS recursive_timed_mutex
	{
	mutex __m_;
	condition_variable __cv_;
	size_t __count_;
	__libcpp_thread_id __id_;
	public:
	recursive_timed_mutex();
	~recursive_timed_mutex();

	private:
	recursive_timed_mutex(const recursive_timed_mutex&); // = delete;
	recursive_timed_mutex& operator=(const recursive_timed_mutex&); // = delete;

	public:
	void lock();
	bool try_lock() _NOEXCEPT;
	template <class _Rep, class _Period>
	_LIBCPP_INLINE_VISIBILITY
	bool try_lock_for(const chrono::duration<_Rep, _Period>& __d)
	{return try_lock_until(chrono::steady_clock::now() + __d);}
	template <class _Clock, class _Duration>
	_LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
	bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
	void unlock() _NOEXCEPT;
	};

	template <class _Clock, class _Duration>
	bool
	recursive_timed_mutex::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
	{
	using namespace chrono;
	__libcpp_thread_id __id = __libcpp_thread_get_current_id();
	unique_lock<mutex> lk(__m_);
	if (__libcpp_thread_id_equal(__id, __id_))
	{
	if (__count_ == numeric_limits<size_t>::max())
	return false;
	++__count_;
	return true;
	}
	bool no_timeout = _Clock::now() < __t;
	while (no_timeout && __count_ != 0)
	no_timeout = __cv_.wait_until(lk, __t) == cv_status::no_timeout;
	if (__count_ == 0)
	{
	__count_ = 1;
	__id_ = __id;
	return true;
	}
	return false;
	}

	template <class _L0, class _L1>
	int
	try_lock(_L0& __l0, _L1& __l1)
	{
	unique_lock<_L0> __u0(__l0, try_to_lock);
	if (__u0.owns_lock())
	{
	if (__l1.try_lock())
	{
	__u0.release();
	return -1;
	}
	else
	return 1;
	}
	return 0;
	}

	#ifndef _LIBCPP_CXX03_LANG

	template <class _L0, class _L1, class _L2, class... _L3>
	int
	try_lock(_L0& __l0, _L1& __l1, _L2& __l2, _L3&... __l3)
	{
	int __r = 0;
	unique_lock<_L0> __u0(__l0, try_to_lock);
	if (__u0.owns_lock())
	{
	__r = try_lock(__l1, __l2, __l3...);
	if (__r == -1)
	__u0.release();
	else
	++__r;
	}
	return __r;
	}

	#endif // _LIBCPP_CXX03_LANG

	template <class _L0, class _L1>
	void
	lock(_L0& __l0, _L1& __l1)
	{
	while (true)
	{
	{
	unique_lock<_L0> __u0(__l0);
	if (__l1.try_lock())
	{
	__u0.release();
	break;
	}
	}
	__libcpp_thread_yield();
	{
	unique_lock<_L1> __u1(__l1);
	if (__l0.try_lock())
	{
	__u1.release();
	break;
	}
	}
	__libcpp_thread_yield();
	}
	}

	#ifndef _LIBCPP_CXX03_LANG

	template <class _L0, class _L1, class _L2, class ..._L3>
	void
	__lock_first(int __i, _L0& __l0, _L1& __l1, _L2& __l2, _L3& ...__l3)
	{
	while (true)
	{
	switch (__i)
	{
	case 0:
	{
	unique_lock<_L0> __u0(__l0);
	__i = try_lock(__l1, __l2, __l3...);
	if (__i == -1)
	{
	__u0.release();
	return;
	}
	}
	++__i;
	__libcpp_thread_yield();
	break;
	case 1:
	{
	unique_lock<_L1> __u1(__l1);
	__i = try_lock(__l2, __l3..., __l0);
	if (__i == -1)
	{
	__u1.release();
	return;
	}
	}
	if (__i == sizeof...(_L3) + 1)
	__i = 0;
	else
	__i += 2;
	__libcpp_thread_yield();
	break;
	default:
	__lock_first(__i - 2, __l2, __l3..., __l0, __l1);
	return;
	}
	}
	}

	template <class _L0, class _L1, class _L2, class ..._L3>
	inline _LIBCPP_INLINE_VISIBILITY
	void
	lock(_L0& __l0, _L1& __l1, _L2& __l2, _L3& ...__l3)
	{
	__lock_first(0, __l0, __l1, __l2, __l3...);
	}

	template <class _L0>
	inline _LIBCPP_INLINE_VISIBILITY
	void __unlock(_L0& __l0) {
	__l0.unlock();
	}

	template <class _L0, class _L1>
	inline _LIBCPP_INLINE_VISIBILITY
	void __unlock(_L0& __l0, _L1& __l1) {
	__l0.unlock();
	__l1.unlock();
	}

	template <class _L0, class _L1, class _L2, class ..._L3>
	inline _LIBCPP_INLINE_VISIBILITY
	void __unlock(_L0& __l0, _L1& __l1, _L2& __l2, _L3&... __l3) {
	__l0.unlock();
	__l1.unlock();
	_VSTD::__unlock(__l2, __l3...);
	}

	#endif // _LIBCPP_CXX03_LANG

	#if _LIBCPP_STD_VER > 14
	template <class ..._Mutexes>
	class _LIBCPP_TEMPLATE_VIS scoped_lock;

	template <>
	class _LIBCPP_TEMPLATE_VIS scoped_lock<> {
	public:
	explicit scoped_lock() {}
	~scoped_lock() = default;

	_LIBCPP_INLINE_VISIBILITY
	explicit scoped_lock(adopt_lock_t) {}

	scoped_lock(scoped_lock const&) = delete;
	scoped_lock& operator=(scoped_lock const&) = delete;
	};

	template <class _Mutex>
	class _LIBCPP_TEMPLATE_VIS _LIBCPP_THREAD_SAFETY_ANNOTATION(scoped_lockable) scoped_lock<_Mutex> {
	public:
	typedef _Mutex mutex_type;
	private:
	mutex_type& __m_;
	public:
	explicit scoped_lock(mutex_type & __m) _LIBCPP_THREAD_SAFETY_ANNOTATION(acquire_capability(__m))
	: __m_(__m) {__m_.lock();}

	~scoped_lock() _LIBCPP_THREAD_SAFETY_ANNOTATION(release_capability()) {__m_.unlock();}

	_LIBCPP_INLINE_VISIBILITY
	explicit scoped_lock(adopt_lock_t, mutex_type& __m) _LIBCPP_THREAD_SAFETY_ANNOTATION(requires_capability(__m))
	: __m_(__m) {}

	scoped_lock(scoped_lock const&) = delete;
	scoped_lock& operator=(scoped_lock const&) = delete;
	};

	template <class ..._MArgs>
	class _LIBCPP_TEMPLATE_VIS scoped_lock
	{
	static_assert(sizeof...(_MArgs) > 1, "At least 2 lock types required");
	typedef tuple<_MArgs&...> _MutexTuple;

	public:
	_LIBCPP_INLINE_VISIBILITY
	explicit scoped_lock(_MArgs&... __margs)
	: __t_(__margs...)
	{
	_VSTD::lock(__margs...);
	}

	_LIBCPP_INLINE_VISIBILITY
	scoped_lock(adopt_lock_t, _MArgs&... __margs)
	: __t_(__margs...)
	{
	}

	_LIBCPP_INLINE_VISIBILITY
	~scoped_lock() {
	typedef typename __make_tuple_indices<sizeof...(_MArgs)>::type _Indices;
	__unlock_unpack(_Indices{}, __t_);
	}

	scoped_lock(scoped_lock const&) = delete;
	scoped_lock& operator=(scoped_lock const&) = delete;

	private:
	template <size_t ..._Indx>
	_LIBCPP_INLINE_VISIBILITY
	static void __unlock_unpack(__tuple_indices<_Indx...>, _MutexTuple& __mt) {
	_VSTD::__unlock(_VSTD::get<_Indx>(__mt)...);
	}

	_MutexTuple __t_;
	};

	#endif // _LIBCPP_STD_VER > 14
	#endif // !_LIBCPP_HAS_NO_THREADS

	struct _LIBCPP_TEMPLATE_VIS once_flag;

	#ifndef _LIBCPP_CXX03_LANG

	template<class _Callable, class... _Args>
	_LIBCPP_INLINE_VISIBILITY
	void call_once(once_flag&, _Callable&&, _Args&&...);

	#else // _LIBCPP_CXX03_LANG

	template<class _Callable>
	_LIBCPP_INLINE_VISIBILITY
	void call_once(once_flag&, _Callable&);

	template<class _Callable>
	_LIBCPP_INLINE_VISIBILITY
	void call_once(once_flag&, const _Callable&);

	#endif // _LIBCPP_CXX03_LANG

	struct _LIBCPP_TEMPLATE_VIS once_flag
	{
	_LIBCPP_INLINE_VISIBILITY
	_LIBCPP_CONSTEXPR
	once_flag() _NOEXCEPT : __state_(0) {}

	#if defined(_LIBCPP_ABI_MICROSOFT)
	typedef uintptr_t _State_type;
	#else
	typedef unsigned long _State_type;
	#endif


	private:
	once_flag(const once_flag&); // = delete;
	once_flag& operator=(const once_flag&); // = delete;

	_State_type __state_;

	#ifndef _LIBCPP_CXX03_LANG
	template<class _Callable, class... _Args>
	friend
	void call_once(once_flag&, _Callable&&, _Args&&...);
	#else // _LIBCPP_CXX03_LANG
	template<class _Callable>
	friend
	void call_once(once_flag&, _Callable&);

	template<class _Callable>
	friend
	void call_once(once_flag&, const _Callable&);
	#endif // _LIBCPP_CXX03_LANG
	};

	#ifndef _LIBCPP_CXX03_LANG

	template <class _Fp>
	class __call_once_param
	{
	_Fp& __f_;
	public:
	_LIBCPP_INLINE_VISIBILITY
	explicit __call_once_param(_Fp& __f) : __f_(__f) {}

	_LIBCPP_INLINE_VISIBILITY
	void operator()()
	{
	typedef typename __make_tuple_indices<tuple_size<_Fp>::value, 1>::type _Index;
	__execute(_Index());
	}

	private:
	template <size_t ..._Indices>
	_LIBCPP_INLINE_VISIBILITY
	void __execute(__tuple_indices<_Indices...>)
	{
	__invoke(_VSTD::get<0>(_VSTD::move(__f_)), _VSTD::get<_Indices>(_VSTD::move(__f_))...);
	}
	};

	#else

	template <class _Fp>
	class __call_once_param
	{
	_Fp& __f_;
	public:
	_LIBCPP_INLINE_VISIBILITY
	explicit __call_once_param(_Fp& __f) : __f_(__f) {}

	_LIBCPP_INLINE_VISIBILITY
	void operator()()
	{
	__f_();
	}
	};

	#endif

	template <class _Fp>
	void
	__call_once_proxy(void* __vp)
	{
	__call_once_param<_Fp>* __p = static_cast<__call_once_param<_Fp>*>(__vp);
	(*__p)();
	}

	_LIBCPP_FUNC_VIS void __call_once(volatile once_flag::_State_type&, void*,
	void ()(void));

	#ifndef _LIBCPP_CXX03_LANG

	template<class _Callable, class... _Args>
	inline _LIBCPP_INLINE_VISIBILITY
	void
	call_once(once_flag& __flag, _Callable&& __func, _Args&&... __args)
	{
	if (__libcpp_acquire_load(&__flag.__state_) != ~once_flag::_State_type(0))
	{
	typedef tuple<_Callable&&, _Args&&...> _Gp;
	_Gp __f(_VSTD::forward<_Callable>(__func), _VSTD::forward<_Args>(__args)...);
	__call_once_param<_Gp> __p(__f);
	__call_once(__flag.__state_, &__p, &__call_once_proxy<_Gp>);
	}
	}

	#else // _LIBCPP_CXX03_LANG

	template<class _Callable>
	inline _LIBCPP_INLINE_VISIBILITY
	void
	call_once(once_flag& __flag, _Callable& __func)
	{
	if (__libcpp_acquire_load(&__flag.__state_) != ~once_flag::_State_type(0))
	{
	__call_once_param<_Callable> __p(__func);
	__call_once(__flag.__state_, &__p, &__call_once_proxy<_Callable>);
	}
	}

	template<class _Callable>
	inline _LIBCPP_INLINE_VISIBILITY
	void
	call_once(once_flag& __flag, const _Callable& __func)
	{
	if (__libcpp_acquire_load(&__flag.__state_) != ~once_flag::_State_type(0))
	{
	__call_once_param<const _Callable> __p(__func);
	__call_once(__flag.__state_, &__p, &__call_once_proxy<const _Callable>);
	}
	}

	#endif // _LIBCPP_CXX03_LANG

	_LIBCPP_END_NAMESPACE_STD

	_LIBCPP_POP_MACROS

	#endif // _LIBCPP_MUTEX