libcxx/include/__condition_variable/condition_variable.h - toolchain/llvm-project - Git at Google

 //===----------------------------------------------------------------------===//
 //
 // 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___CONDITION_VARIABLE_CONDITION_VARIABLE_H
 #define _LIBCPP___CONDITION_VARIABLE_CONDITION_VARIABLE_H

 #include <__chrono/duration.h>
 #include <__chrono/steady_clock.h>
 #include <__chrono/system_clock.h>
 #include <__chrono/time_point.h>
 #include <__config>
 #include <__mutex/mutex.h>
 #include <__mutex/unique_lock.h>
 #include <__system_error/system_error.h>
 #include <__thread/support.h>
 #include <__type_traits/enable_if.h>
 #include <__type_traits/is_floating_point.h>
 #include <__utility/move.h>
 #include <limits>
 #include <ratio>

 #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

 // enum class cv_status
 _LIBCPP_DECLARE_STRONG_ENUM(cv_status){no_timeout, timeout};
 _LIBCPP_DECLARE_STRONG_ENUM_EPILOG(cv_status)

 class _LIBCPP_EXPORTED_FROM_ABI condition_variable {
   __libcpp_condvar_t __cv_ = _LIBCPP_CONDVAR_INITIALIZER;

 public:
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR condition_variable() _NOEXCEPT = default;

 #  ifdef _LIBCPP_HAS_TRIVIAL_CONDVAR_DESTRUCTION
   ~condition_variable() = default;
 #  else
   ~condition_variable();
 #  endif

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

   void notify_one() _NOEXCEPT;
   void notify_all() _NOEXCEPT;

   void wait(unique_lock<mutex>& __lk) _NOEXCEPT;
   template <class _Predicate>
   _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS void wait(unique_lock<mutex>& __lk, _Predicate __pred);

   template <class _Clock, class _Duration>
   _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS cv_status
   wait_until(unique_lock<mutex>& __lk, const chrono::time_point<_Clock, _Duration>& __t);

   template <class _Clock, class _Duration, class _Predicate>
   _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS bool
   wait_until(unique_lock<mutex>& __lk, const chrono::time_point<_Clock, _Duration>& __t, _Predicate __pred);

   template <class _Rep, class _Period>
   _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS cv_status
   wait_for(unique_lock<mutex>& __lk, const chrono::duration<_Rep, _Period>& __d);

   template <class _Rep, class _Period, class _Predicate>
   bool _LIBCPP_HIDE_FROM_ABI
   wait_for(unique_lock<mutex>& __lk, const chrono::duration<_Rep, _Period>& __d, _Predicate __pred);

   typedef __libcpp_condvar_t* native_handle_type;
   _LIBCPP_HIDE_FROM_ABI native_handle_type native_handle() { return &__cv_; }

 private:
   void
   __do_timed_wait(unique_lock<mutex>& __lk, chrono::time_point<chrono::system_clock, chrono::nanoseconds>) _NOEXCEPT;
 #  if defined(_LIBCPP_HAS_COND_CLOCKWAIT)
   _LIBCPP_HIDE_FROM_ABI void
   __do_timed_wait(unique_lock<mutex>& __lk, chrono::time_point<chrono::steady_clock, chrono::nanoseconds>) _NOEXCEPT;
 #  endif
   template <class _Clock>
   _LIBCPP_HIDE_FROM_ABI void
   __do_timed_wait(unique_lock<mutex>& __lk, chrono::time_point<_Clock, chrono::nanoseconds>) _NOEXCEPT;
 };
 #endif // !_LIBCPP_HAS_NO_THREADS

 template <class _Rep, class _Period, __enable_if_t<is_floating_point<_Rep>::value, int> = 0>
 inline _LIBCPP_HIDE_FROM_ABI chrono::nanoseconds __safe_nanosecond_cast(chrono::duration<_Rep, _Period> __d) {
   using namespace chrono;
   using __ratio       = ratio_divide<_Period, nano>;
   using __ns_rep      = nanoseconds::rep;
   _Rep __result_float = __d.count() * __ratio::num / __ratio::den;

   _Rep __result_max = numeric_limits<__ns_rep>::max();
   if (__result_float >= __result_max) {
     return nanoseconds::max();
   }

   _Rep __result_min = numeric_limits<__ns_rep>::min();
   if (__result_float <= __result_min) {
     return nanoseconds::min();
   }

   return nanoseconds(static_cast<__ns_rep>(__result_float));
 }

 template <class _Rep, class _Period, __enable_if_t<!is_floating_point<_Rep>::value, int> = 0>
 inline _LIBCPP_HIDE_FROM_ABI chrono::nanoseconds __safe_nanosecond_cast(chrono::duration<_Rep, _Period> __d) {
   using namespace chrono;
   if (__d.count() == 0) {
     return nanoseconds(0);
   }

   using __ratio         = ratio_divide<_Period, nano>;
   using __ns_rep        = nanoseconds::rep;
   __ns_rep __result_max = numeric_limits<__ns_rep>::max();
   if (__d.count() > 0 && __d.count() > __result_max / __ratio::num) {
     return nanoseconds::max();
   }

   __ns_rep __result_min = numeric_limits<__ns_rep>::min();
   if (__d.count() < 0 && __d.count() < __result_min / __ratio::num) {
     return nanoseconds::min();
   }

   __ns_rep __result = __d.count() * __ratio::num / __ratio::den;
   if (__result == 0) {
     return nanoseconds(1);
   }

   return nanoseconds(__result);
 }

 #ifndef _LIBCPP_HAS_NO_THREADS
 template <class _Predicate>
 void condition_variable::wait(unique_lock<mutex>& __lk, _Predicate __pred) {
   while (!__pred())
     wait(__lk);
 }

 template <class _Clock, class _Duration>
 cv_status condition_variable::wait_until(unique_lock<mutex>& __lk, const chrono::time_point<_Clock, _Duration>& __t) {
   using namespace chrono;
   using __clock_tp_ns = time_point<_Clock, nanoseconds>;

   typename _Clock::time_point __now = _Clock::now();
   if (__t <= __now)
     return cv_status::timeout;

   __clock_tp_ns __t_ns = __clock_tp_ns(std::__safe_nanosecond_cast(__t.time_since_epoch()));

   __do_timed_wait(__lk, __t_ns);
   return _Clock::now() < __t ? cv_status::no_timeout : cv_status::timeout;
 }

 template <class _Clock, class _Duration, class _Predicate>
 bool condition_variable::wait_until(
     unique_lock<mutex>& __lk, const chrono::time_point<_Clock, _Duration>& __t, _Predicate __pred) {
   while (!__pred()) {
     if (wait_until(__lk, __t) == cv_status::timeout)
       return __pred();
   }
   return true;
 }

 template <class _Rep, class _Period>
 cv_status condition_variable::wait_for(unique_lock<mutex>& __lk, const chrono::duration<_Rep, _Period>& __d) {
   using namespace chrono;
   if (__d <= __d.zero())
     return cv_status::timeout;
   using __ns_rep                   = nanoseconds::rep;
   steady_clock::time_point __c_now = steady_clock::now();

 #  if defined(_LIBCPP_HAS_COND_CLOCKWAIT)
   using __clock_tp_ns     = time_point<steady_clock, nanoseconds>;
   __ns_rep __now_count_ns = std::__safe_nanosecond_cast(__c_now.time_since_epoch()).count();
 #  else
   using __clock_tp_ns     = time_point<system_clock, nanoseconds>;
   __ns_rep __now_count_ns = std::__safe_nanosecond_cast(system_clock::now().time_since_epoch()).count();
 #  endif

   __ns_rep __d_ns_count = std::__safe_nanosecond_cast(__d).count();

   if (__now_count_ns > numeric_limits<__ns_rep>::max() - __d_ns_count) {
     __do_timed_wait(__lk, __clock_tp_ns::max());
   } else {
     __do_timed_wait(__lk, __clock_tp_ns(nanoseconds(__now_count_ns + __d_ns_count)));
   }

   return steady_clock::now() - __c_now < __d ? cv_status::no_timeout : cv_status::timeout;
 }

 template <class _Rep, class _Period, class _Predicate>
 inline bool
 condition_variable::wait_for(unique_lock<mutex>& __lk, const chrono::duration<_Rep, _Period>& __d, _Predicate __pred) {
   return wait_until(__lk, chrono::steady_clock::now() + __d, std::move(__pred));
 }

 #  if defined(_LIBCPP_HAS_COND_CLOCKWAIT)
 inline void condition_variable::__do_timed_wait(
     unique_lock<mutex>& __lk, chrono::time_point<chrono::steady_clock, chrono::nanoseconds> __tp) _NOEXCEPT {
   using namespace chrono;
   if (!__lk.owns_lock())
     __throw_system_error(EPERM, "condition_variable::timed wait: mutex not locked");
   nanoseconds __d = __tp.time_since_epoch();
   timespec __ts;
   seconds __s                 = duration_cast<seconds>(__d);
   using __ts_sec              = decltype(__ts.tv_sec);
   const __ts_sec __ts_sec_max = numeric_limits<__ts_sec>::max();
   if (__s.count() < __ts_sec_max) {
     __ts.tv_sec  = static_cast<__ts_sec>(__s.count());
     __ts.tv_nsec = (__d - __s).count();
   } else {
     __ts.tv_sec  = __ts_sec_max;
     __ts.tv_nsec = giga::num - 1;
   }
   int __ec = pthread_cond_clockwait(&__cv_, __lk.mutex()->native_handle(), CLOCK_MONOTONIC, &__ts);
   if (__ec != 0 && __ec != ETIMEDOUT)
     __throw_system_error(__ec, "condition_variable timed_wait failed");
 }
 #  endif // _LIBCPP_HAS_COND_CLOCKWAIT

 template <class _Clock>
 inline void condition_variable::__do_timed_wait(unique_lock<mutex>& __lk,
                                                 chrono::time_point<_Clock, chrono::nanoseconds> __tp) _NOEXCEPT {
   wait_for(__lk, __tp - _Clock::now());
 }

 #endif // _LIBCPP_HAS_NO_THREADS

 _LIBCPP_END_NAMESPACE_STD

 _LIBCPP_POP_MACROS

 #endif // _LIBCPP___CONDITION_VARIABLE_CONDITION_VARIABLE_H
	//===----------------------------------------------------------------------===//
	//
	// 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___CONDITION_VARIABLE_CONDITION_VARIABLE_H
	#define _LIBCPP___CONDITION_VARIABLE_CONDITION_VARIABLE_H

	#include <__chrono/duration.h>
	#include <__chrono/steady_clock.h>
	#include <__chrono/system_clock.h>
	#include <__chrono/time_point.h>
	#include <__config>
	#include <__mutex/mutex.h>
	#include <__mutex/unique_lock.h>
	#include <__system_error/system_error.h>
	#include <__thread/support.h>
	#include <__type_traits/enable_if.h>
	#include <__type_traits/is_floating_point.h>
	#include <__utility/move.h>
	#include <limits>
	#include <ratio>

	#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

	// enum class cv_status
	_LIBCPP_DECLARE_STRONG_ENUM(cv_status){no_timeout, timeout};
	_LIBCPP_DECLARE_STRONG_ENUM_EPILOG(cv_status)

	class _LIBCPP_EXPORTED_FROM_ABI condition_variable {
	__libcpp_condvar_t __cv_ = _LIBCPP_CONDVAR_INITIALIZER;

	public:
	_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR condition_variable() _NOEXCEPT = default;

	# ifdef _LIBCPP_HAS_TRIVIAL_CONDVAR_DESTRUCTION
	~condition_variable() = default;
	# else
	~condition_variable();
	# endif

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

	void notify_one() _NOEXCEPT;
	void notify_all() _NOEXCEPT;

	void wait(unique_lock<mutex>& __lk) _NOEXCEPT;
	template <class _Predicate>
	_LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS void wait(unique_lock<mutex>& __lk, _Predicate __pred);

	template <class _Clock, class _Duration>
	_LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS cv_status
	wait_until(unique_lock<mutex>& __lk, const chrono::time_point<_Clock, _Duration>& __t);

	template <class _Clock, class _Duration, class _Predicate>
	_LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS bool
	wait_until(unique_lock<mutex>& __lk, const chrono::time_point<_Clock, _Duration>& __t, _Predicate __pred);

	template <class _Rep, class _Period>
	_LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS cv_status
	wait_for(unique_lock<mutex>& __lk, const chrono::duration<_Rep, _Period>& __d);

	template <class _Rep, class _Period, class _Predicate>
	bool _LIBCPP_HIDE_FROM_ABI
	wait_for(unique_lock<mutex>& __lk, const chrono::duration<_Rep, _Period>& __d, _Predicate __pred);

	typedef __libcpp_condvar_t* native_handle_type;
	_LIBCPP_HIDE_FROM_ABI native_handle_type native_handle() { return &__cv_; }

	private:
	void
	__do_timed_wait(unique_lock<mutex>& __lk, chrono::time_point<chrono::system_clock, chrono::nanoseconds>) _NOEXCEPT;
	# if defined(_LIBCPP_HAS_COND_CLOCKWAIT)
	_LIBCPP_HIDE_FROM_ABI void
	__do_timed_wait(unique_lock<mutex>& __lk, chrono::time_point<chrono::steady_clock, chrono::nanoseconds>) _NOEXCEPT;
	# endif
	template <class _Clock>
	_LIBCPP_HIDE_FROM_ABI void
	__do_timed_wait(unique_lock<mutex>& __lk, chrono::time_point<_Clock, chrono::nanoseconds>) _NOEXCEPT;
	};
	#endif // !_LIBCPP_HAS_NO_THREADS

	template <class _Rep, class _Period, __enable_if_t<is_floating_point<_Rep>::value, int> = 0>
	inline _LIBCPP_HIDE_FROM_ABI chrono::nanoseconds __safe_nanosecond_cast(chrono::duration<_Rep, _Period> __d) {
	using namespace chrono;
	using __ratio = ratio_divide<_Period, nano>;
	using __ns_rep = nanoseconds::rep;
	_Rep __result_float = __d.count() * __ratio::num / __ratio::den;

	_Rep __result_max = numeric_limits<__ns_rep>::max();
	if (__result_float >= __result_max) {
	return nanoseconds::max();
	}

	_Rep __result_min = numeric_limits<__ns_rep>::min();
	if (__result_float <= __result_min) {
	return nanoseconds::min();
	}

	return nanoseconds(static_cast<__ns_rep>(__result_float));
	}

	template <class _Rep, class _Period, __enable_if_t<!is_floating_point<_Rep>::value, int> = 0>
	inline _LIBCPP_HIDE_FROM_ABI chrono::nanoseconds __safe_nanosecond_cast(chrono::duration<_Rep, _Period> __d) {
	using namespace chrono;
	if (__d.count() == 0) {
	return nanoseconds(0);
	}

	using __ratio = ratio_divide<_Period, nano>;
	using __ns_rep = nanoseconds::rep;
	__ns_rep __result_max = numeric_limits<__ns_rep>::max();
	if (__d.count() > 0 && __d.count() > __result_max / __ratio::num) {
	return nanoseconds::max();
	}

	__ns_rep __result_min = numeric_limits<__ns_rep>::min();
	if (__d.count() < 0 && __d.count() < __result_min / __ratio::num) {
	return nanoseconds::min();
	}

	__ns_rep __result = __d.count() * __ratio::num / __ratio::den;
	if (__result == 0) {
	return nanoseconds(1);
	}

	return nanoseconds(__result);
	}

	#ifndef _LIBCPP_HAS_NO_THREADS
	template <class _Predicate>
	void condition_variable::wait(unique_lock<mutex>& __lk, _Predicate __pred) {
	while (!__pred())
	wait(__lk);
	}

	template <class _Clock, class _Duration>
	cv_status condition_variable::wait_until(unique_lock<mutex>& __lk, const chrono::time_point<_Clock, _Duration>& __t) {
	using namespace chrono;
	using __clock_tp_ns = time_point<_Clock, nanoseconds>;

	typename _Clock::time_point __now = _Clock::now();
	if (__t <= __now)
	return cv_status::timeout;

	__clock_tp_ns __t_ns = __clock_tp_ns(std::__safe_nanosecond_cast(__t.time_since_epoch()));

	__do_timed_wait(__lk, __t_ns);
	return _Clock::now() < __t ? cv_status::no_timeout : cv_status::timeout;
	}

	template <class _Clock, class _Duration, class _Predicate>
	bool condition_variable::wait_until(
	unique_lock<mutex>& __lk, const chrono::time_point<_Clock, _Duration>& __t, _Predicate __pred) {
	while (!__pred()) {
	if (wait_until(__lk, __t) == cv_status::timeout)
	return __pred();
	}
	return true;
	}

	template <class _Rep, class _Period>
	cv_status condition_variable::wait_for(unique_lock<mutex>& __lk, const chrono::duration<_Rep, _Period>& __d) {
	using namespace chrono;
	if (__d <= __d.zero())
	return cv_status::timeout;
	using __ns_rep = nanoseconds::rep;
	steady_clock::time_point __c_now = steady_clock::now();

	# if defined(_LIBCPP_HAS_COND_CLOCKWAIT)
	using __clock_tp_ns = time_point<steady_clock, nanoseconds>;
	__ns_rep __now_count_ns = std::__safe_nanosecond_cast(__c_now.time_since_epoch()).count();
	# else
	using __clock_tp_ns = time_point<system_clock, nanoseconds>;
	__ns_rep __now_count_ns = std::__safe_nanosecond_cast(system_clock::now().time_since_epoch()).count();
	# endif

	__ns_rep __d_ns_count = std::__safe_nanosecond_cast(__d).count();

	if (__now_count_ns > numeric_limits<__ns_rep>::max() - __d_ns_count) {
	__do_timed_wait(__lk, __clock_tp_ns::max());
	} else {
	__do_timed_wait(__lk, __clock_tp_ns(nanoseconds(__now_count_ns + __d_ns_count)));
	}

	return steady_clock::now() - __c_now < __d ? cv_status::no_timeout : cv_status::timeout;
	}

	template <class _Rep, class _Period, class _Predicate>
	inline bool
	condition_variable::wait_for(unique_lock<mutex>& __lk, const chrono::duration<_Rep, _Period>& __d, _Predicate __pred) {
	return wait_until(__lk, chrono::steady_clock::now() + __d, std::move(__pred));
	}

	# if defined(_LIBCPP_HAS_COND_CLOCKWAIT)
	inline void condition_variable::__do_timed_wait(
	unique_lock<mutex>& __lk, chrono::time_point<chrono::steady_clock, chrono::nanoseconds> __tp) _NOEXCEPT {
	using namespace chrono;
	if (!__lk.owns_lock())
	__throw_system_error(EPERM, "condition_variable::timed wait: mutex not locked");
	nanoseconds __d = __tp.time_since_epoch();
	timespec __ts;
	seconds __s = duration_cast<seconds>(__d);
	using __ts_sec = decltype(__ts.tv_sec);
	const __ts_sec __ts_sec_max = numeric_limits<__ts_sec>::max();
	if (__s.count() < __ts_sec_max) {
	__ts.tv_sec = static_cast<__ts_sec>(__s.count());
	__ts.tv_nsec = (__d - __s).count();
	} else {
	__ts.tv_sec = __ts_sec_max;
	__ts.tv_nsec = giga::num - 1;
	}
	int __ec = pthread_cond_clockwait(&__cv_, __lk.mutex()->native_handle(), CLOCK_MONOTONIC, &__ts);
	if (__ec != 0 && __ec != ETIMEDOUT)
	__throw_system_error(__ec, "condition_variable timed_wait failed");
	}
	# endif // _LIBCPP_HAS_COND_CLOCKWAIT

	template <class _Clock>
	inline void condition_variable::__do_timed_wait(unique_lock<mutex>& __lk,
	chrono::time_point<_Clock, chrono::nanoseconds> __tp) _NOEXCEPT {
	wait_for(__lk, __tp - _Clock::now());
	}

	#endif // _LIBCPP_HAS_NO_THREADS

	_LIBCPP_END_NAMESPACE_STD

	_LIBCPP_POP_MACROS

	#endif // _LIBCPP___CONDITION_VARIABLE_CONDITION_VARIABLE_H