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// <condition_variable> -*- C++ -*- |
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|
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// Copyright (C) 2008-2021 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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|
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#include <bits/std_mutex.h> |
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#include <bits/unique_lock.h> |
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#include <bits/alloc_traits.h> |
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#include <bits/shared_ptr.h> |
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#include <bits/cxxabi_forced.h> |
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|
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#if __cplusplus > 201703L |
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# include <stop_token> |
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#endif |
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|
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#if defined(_GLIBCXX_HAS_GTHREADS) |
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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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using steady_clock = chrono::steady_clock; |
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using system_clock = chrono::system_clock; |
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#ifdef _GLIBCXX_USE_PTHREAD_COND_CLOCKWAIT |
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using __clock_t = steady_clock; |
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#else |
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using __clock_t = system_clock; |
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#endif |
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|
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__condvar _M_cond; |
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|
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public: |
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typedef __gthread_cond_t* 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) noexcept; |
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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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#ifdef _GLIBCXX_USE_PTHREAD_COND_CLOCKWAIT |
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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<steady_clock, _Duration>& __atime) |
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{ return __wait_until_impl(__lock, __atime); } |
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#endif |
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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<system_clock, _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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#if __cplusplus > 201703L |
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static_assert(chrono::is_clock_v<_Clock>); |
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#endif |
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using __s_dur = typename __clock_t::duration; |
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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 + |
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chrono::__detail::ceil<__s_dur>(__delta); |
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|
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if (__wait_until_impl(__lock, __s_atime) == cv_status::no_timeout) |
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return cv_status::no_timeout; |
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// We got a timeout when measured against __clock_t but |
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// we need to check against the caller-supplied clock |
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// to tell whether we should return a timeout. |
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if (_Clock::now() < __atime) |
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return cv_status::no_timeout; |
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return cv_status::timeout; |
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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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{ |
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using __dur = typename steady_clock::duration; |
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return wait_until(__lock, |
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steady_clock::now() + |
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chrono::__detail::ceil<__dur>(__rtime)); |
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} |
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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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{ |
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using __dur = typename steady_clock::duration; |
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return wait_until(__lock, |
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steady_clock::now() + |
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chrono::__detail::ceil<__dur>(__rtime), |
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std::move(__p)); |
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} |
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|
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native_handle_type |
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native_handle() |
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{ return _M_cond.native_handle(); } |
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|
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private: |
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#ifdef _GLIBCXX_USE_PTHREAD_COND_CLOCKWAIT |
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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<steady_clock, _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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_M_cond.wait_until(*__lock.mutex(), CLOCK_MONOTONIC, __ts); |
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|
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return (steady_clock::now() < __atime |
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? cv_status::no_timeout : cv_status::timeout); |
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} |
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#endif |
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|
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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<system_clock, _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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_M_cond.wait_until(*__lock.mutex(), __ts); |
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|
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return (system_clock::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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#ifdef _GLIBCXX_USE_PTHREAD_COND_CLOCKWAIT |
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using __clock_t = chrono::steady_clock; |
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#else |
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using __clock_t = chrono::system_clock; |
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#endif |
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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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#pragma GCC diagnostic push |
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#pragma GCC diagnostic ignored "-Wdeprecated-declarations" |
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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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#pragma GCC diagnostic pop |
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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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#ifdef __cpp_lib_jthread |
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template <class _Lock, class _Predicate> |
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bool wait(_Lock& __lock, |
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stop_token __stoken, |
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_Predicate __p) |
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{ |
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if (__stoken.stop_requested()) |
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{ |
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return __p(); |
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} |
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|
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std::stop_callback __cb(__stoken, [this] { notify_all(); }); |
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shared_ptr<mutex> __mutex = _M_mutex; |
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while (!__p()) |
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{ |
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unique_lock<mutex> __my_lock(*__mutex); |
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if (__stoken.stop_requested()) |
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{ |
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return false; |
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} |
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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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_Unlock<_Lock> __unlock(__lock); |
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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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return true; |
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} |
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|
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template <class _Lock, class _Clock, class _Duration, class _Predicate> |
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bool wait_until(_Lock& __lock, |
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stop_token __stoken, |
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const chrono::time_point<_Clock, _Duration>& __abs_time, |
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_Predicate __p) |
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{ |
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if (__stoken.stop_requested()) |
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{ |
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return __p(); |
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} |
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|
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std::stop_callback __cb(__stoken, [this] { notify_all(); }); |
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shared_ptr<mutex> __mutex = _M_mutex; |
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while (!__p()) |
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{ |
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bool __stop; |
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{ |
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unique_lock<mutex> __my_lock(*__mutex); |
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if (__stoken.stop_requested()) |
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{ |
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return false; |
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} |
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_Unlock<_Lock> __u(__lock); |
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unique_lock<mutex> __my_lock2(std::move(__my_lock)); |
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const auto __status = _M_cond.wait_until(__my_lock2, __abs_time); |
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__stop = (__status == std::cv_status::timeout) || __stoken.stop_requested(); |
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} |
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if (__stop) |
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{ |
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return __p(); |
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} |
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} |
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return true; |
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} |
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|
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template <class _Lock, class _Rep, class _Period, class _Predicate> |
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bool wait_for(_Lock& __lock, |
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stop_token __stoken, |
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const chrono::duration<_Rep, _Period>& __rel_time, |
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_Predicate __p) |
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{ |
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auto __abst = std::chrono::steady_clock::now() + __rel_time; |
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return wait_until(__lock, |
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std::move(__stoken), |
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__abst, |
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std::move(__p)); |
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} |
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#endif |
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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 |
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#endif // C++11 |
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#endif // _GLIBCXX_CONDITION_VARIABLE |
