include/mutex - llvm-project/libcxx - Git at Google

 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
 // 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 { explicit defer_lock_t() = default; };
 struct try_to_lock_t { explicit try_to_lock_t() = default; };
 struct adopt_lock_t { explicit adopt_lock_t() = default; };

 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;  // Only if sizeof...(MutexTypes) == 1

     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 <__chrono/steady_clock.h>
 #include <__chrono/time_point.h>
 #include <__condition_variable/condition_variable.h>
 #include <__config>
 #include <__memory/shared_ptr.h>
 #include <__mutex/lock_guard.h>
 #include <__mutex/mutex.h>
 #include <__mutex/once_flag.h>
 #include <__mutex/tag_types.h>
 #include <__mutex/unique_lock.h>
 #include <__thread/id.h>
 #include <__thread/support.h>
 #include <__utility/forward.h>
 #include <cstddef>
 #include <limits>
 #ifndef _LIBCPP_CXX03_LANG
 #  include <tuple>
 #endif
 #include <version>

 #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_EXPORTED_FROM_ABI recursive_mutex {
   __libcpp_recursive_mutex_t __m_;

 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() _NOEXCEPT;

   typedef __libcpp_recursive_mutex_t* native_handle_type;

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

 class _LIBCPP_EXPORTED_FROM_ABI timed_mutex {
   mutex __m_;
   condition_variable __cv_;
   bool __locked_;

 public:
   timed_mutex();
   ~timed_mutex();

   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_HIDE_FROM_ABI 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_EXPORTED_FROM_ABI recursive_timed_mutex {
   mutex __m_;
   condition_variable __cv_;
   size_t __count_;
   __thread_id __id_;

 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>
   _LIBCPP_HIDE_FROM_ABI 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;
   __thread_id __id = this_thread::get_id();
   unique_lock<mutex> __lk(__m_);
   if (__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>
 _LIBCPP_HIDE_FROM_ABI int try_lock(_L0& __l0, _L1& __l1) {
   unique_lock<_L0> __u0(__l0, try_to_lock_t());
   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>
 _LIBCPP_HIDE_FROM_ABI 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 = std::try_lock(__l1, __l2, __l3...);
     if (__r == -1)
       __u0.release();
     else
       ++__r;
   }
   return __r;
 }

 #  endif // _LIBCPP_CXX03_LANG

 template <class _L0, class _L1>
 _LIBCPP_HIDE_FROM_ABI 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 = std::try_lock(__l1, __l2, __l3...);
       if (__i == -1) {
         __u0.release();
         return;
       }
     }
       ++__i;
       __libcpp_thread_yield();
       break;
     case 1: {
       unique_lock<_L1> __u1(__l1);
       __i = std::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:
       std::__lock_first(__i - 2, __l2, __l3..., __l0, __l1);
       return;
     }
   }
 }

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

 #  endif // _LIBCPP_CXX03_LANG

 #  if _LIBCPP_STD_VER >= 17
 template <class... _Mutexes>
 class _LIBCPP_TEMPLATE_VIS scoped_lock;

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

   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI 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:
   [[nodiscard]]
   _LIBCPP_HIDE_FROM_ABI 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(); }

   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI 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:
   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI explicit scoped_lock(_MArgs&... __margs) : __t_(__margs...) {
     std::lock(__margs...);
   }

   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI scoped_lock(adopt_lock_t, _MArgs&... __margs) : __t_(__margs...) {}

   _LIBCPP_HIDE_FROM_ABI ~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_HIDE_FROM_ABI static void __unlock_unpack(__tuple_indices<_Indx...>, _MutexTuple& __mt) {
     (std::get<_Indx>(__mt).unlock(), ...);
   }

   _MutexTuple __t_;
 };
 _LIBCPP_CTAD_SUPPORTED_FOR_TYPE(scoped_lock);

 #  endif // _LIBCPP_STD_VER >= 17
 #endif   // !_LIBCPP_HAS_NO_THREADS

 _LIBCPP_END_NAMESPACE_STD

 _LIBCPP_POP_MACROS

 #if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
 #  include <atomic>
 #  include <concepts>
 #  include <cstdlib>
 #  include <cstring>
 #  include <ctime>
 #  include <initializer_list>
 #  include <iosfwd>
 #  include <new>
 #  include <stdexcept>
 #  include <system_error>
 #  include <type_traits>
 #  include <typeinfo>
 #endif

 #endif // _LIBCPP_MUTEX
	// -- C++ --
	//===----------------------------------------------------------------------===//
	//
	// 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 { explicit defer_lock_t() = default; };
	struct try_to_lock_t { explicit try_to_lock_t() = default; };
	struct adopt_lock_t { explicit adopt_lock_t() = default; };

	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; // Only if sizeof...(MutexTypes) == 1

	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 <__chrono/steady_clock.h>
	#include <__chrono/time_point.h>
	#include <__condition_variable/condition_variable.h>
	#include <__config>
	#include <__memory/shared_ptr.h>
	#include <__mutex/lock_guard.h>
	#include <__mutex/mutex.h>
	#include <__mutex/once_flag.h>
	#include <__mutex/tag_types.h>
	#include <__mutex/unique_lock.h>
	#include <__thread/id.h>
	#include <__thread/support.h>
	#include <__utility/forward.h>
	#include <cstddef>
	#include <limits>
	#ifndef _LIBCPP_CXX03_LANG
	# include <tuple>
	#endif
	#include <version>

	#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_EXPORTED_FROM_ABI recursive_mutex {
	__libcpp_recursive_mutex_t __m_;

	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() _NOEXCEPT;

	typedef __libcpp_recursive_mutex_t* native_handle_type;

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

	class _LIBCPP_EXPORTED_FROM_ABI timed_mutex {
	mutex __m_;
	condition_variable __cv_;
	bool __locked_;

	public:
	timed_mutex();
	~timed_mutex();

	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_HIDE_FROM_ABI 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_EXPORTED_FROM_ABI recursive_timed_mutex {
	mutex __m_;
	condition_variable __cv_;
	size_t __count_;
	__thread_id __id_;

	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>
	_LIBCPP_HIDE_FROM_ABI 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;
	__thread_id __id = this_thread::get_id();
	unique_lock<mutex> __lk(__m_);
	if (__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>
	_LIBCPP_HIDE_FROM_ABI int try_lock(_L0& __l0, _L1& __l1) {
	unique_lock<_L0> __u0(__l0, try_to_lock_t());
	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>
	_LIBCPP_HIDE_FROM_ABI 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 = std::try_lock(__l1, __l2, __l3...);
	if (__r == -1)
	__u0.release();
	else
	++__r;
	}
	return __r;
	}

	# endif // _LIBCPP_CXX03_LANG

	template <class _L0, class _L1>
	_LIBCPP_HIDE_FROM_ABI 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 = std::try_lock(__l1, __l2, __l3...);
	if (__i == -1) {
	__u0.release();
	return;
	}
	}
	++__i;
	__libcpp_thread_yield();
	break;
	case 1: {
	unique_lock<_L1> __u1(__l1);
	__i = std::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:
	std::__lock_first(__i - 2, __l2, __l3..., __l0, __l1);
	return;
	}
	}
	}

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

	# endif // _LIBCPP_CXX03_LANG

	# if _LIBCPP_STD_VER >= 17
	template <class... _Mutexes>
	class _LIBCPP_TEMPLATE_VIS scoped_lock;

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

	[[nodiscard]] _LIBCPP_HIDE_FROM_ABI 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:
	[[nodiscard]]
	_LIBCPP_HIDE_FROM_ABI 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(); }

	[[nodiscard]] _LIBCPP_HIDE_FROM_ABI 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:
	[[nodiscard]] _LIBCPP_HIDE_FROM_ABI explicit scoped_lock(_MArgs&... __margs) : __t_(__margs...) {
	std::lock(__margs...);
	}

	[[nodiscard]] _LIBCPP_HIDE_FROM_ABI scoped_lock(adopt_lock_t, _MArgs&... __margs) : __t_(__margs...) {}

	_LIBCPP_HIDE_FROM_ABI ~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_HIDE_FROM_ABI static void __unlock_unpack(__tuple_indices<_Indx...>, _MutexTuple& __mt) {
	(std::get<_Indx>(__mt).unlock(), ...);
	}

	_MutexTuple __t_;
	};
	_LIBCPP_CTAD_SUPPORTED_FOR_TYPE(scoped_lock);

	# endif // _LIBCPP_STD_VER >= 17
	#endif // !_LIBCPP_HAS_NO_THREADS

	_LIBCPP_END_NAMESPACE_STD

	_LIBCPP_POP_MACROS

	#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
	# include <atomic>
	# include <concepts>
	# include <cstdlib>
	# include <cstring>
	# include <ctime>
	# include <initializer_list>
	# include <iosfwd>
	# include <new>
	# include <stdexcept>
	# include <system_error>
	# include <type_traits>
	# include <typeinfo>
	#endif

	#endif // _LIBCPP_MUTEX