| // <condition_variable> -*- C++ -*- |
| |
| // Copyright (C) 2008-2020 Free Software Foundation, Inc. |
| // |
| // This file is part of the GNU ISO C++ Library. This library is free |
| // software; you can redistribute it and/or modify it under the |
| // terms of the GNU General Public License as published by the |
| // Free Software Foundation; either version 3, or (at your option) |
| // any later version. |
| |
| // This library is distributed in the hope that it will be useful, |
| // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| // GNU General Public License for more details. |
| |
| // Under Section 7 of GPL version 3, you are granted additional |
| // permissions described in the GCC Runtime Library Exception, version |
| // 3.1, as published by the Free Software Foundation. |
| |
| // You should have received a copy of the GNU General Public License and |
| // a copy of the GCC Runtime Library Exception along with this program; |
| // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| // <http://www.gnu.org/licenses/>. |
| |
| /** @file include/condition_variable |
| * This is a Standard C++ Library header. |
| */ |
| |
| #ifndef _GLIBCXX_CONDITION_VARIABLE |
| #define _GLIBCXX_CONDITION_VARIABLE 1 |
| |
| #pragma GCC system_header |
| |
| #if __cplusplus < 201103L |
| # include <bits/c++0x_warning.h> |
| #else |
| |
| #include <chrono> |
| |
| #include <bits/std_mutex.h> |
| #include <bits/unique_lock.h> |
| #include <ext/concurrence.h> |
| #include <bits/alloc_traits.h> |
| #include <bits/allocator.h> |
| #include <bits/unique_ptr.h> |
| #include <bits/shared_ptr.h> |
| #include <bits/cxxabi_forced.h> |
| |
| #if __cplusplus > 201703L |
| # include <stop_token> |
| #endif |
| |
| #if defined(_GLIBCXX_HAS_GTHREADS) |
| |
| namespace std _GLIBCXX_VISIBILITY(default) |
| { |
| _GLIBCXX_BEGIN_NAMESPACE_VERSION |
| |
| /** |
| * @defgroup condition_variables Condition Variables |
| * @ingroup concurrency |
| * |
| * Classes for condition_variable support. |
| * @{ |
| */ |
| |
| /// cv_status |
| enum class cv_status { no_timeout, timeout }; |
| |
| /// condition_variable |
| class condition_variable |
| { |
| using steady_clock = chrono::steady_clock; |
| using system_clock = chrono::system_clock; |
| #ifdef _GLIBCXX_USE_PTHREAD_COND_CLOCKWAIT |
| using __clock_t = steady_clock; |
| #else |
| using __clock_t = system_clock; |
| #endif |
| typedef __gthread_cond_t __native_type; |
| |
| #ifdef __GTHREAD_COND_INIT |
| __native_type _M_cond = __GTHREAD_COND_INIT; |
| #else |
| __native_type _M_cond; |
| #endif |
| |
| public: |
| typedef __native_type* native_handle_type; |
| |
| condition_variable() noexcept; |
| ~condition_variable() noexcept; |
| |
| 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>& __lock) noexcept; |
| |
| template<typename _Predicate> |
| void |
| wait(unique_lock<mutex>& __lock, _Predicate __p) |
| { |
| while (!__p()) |
| wait(__lock); |
| } |
| |
| #ifdef _GLIBCXX_USE_PTHREAD_COND_CLOCKWAIT |
| template<typename _Duration> |
| cv_status |
| wait_until(unique_lock<mutex>& __lock, |
| const chrono::time_point<steady_clock, _Duration>& __atime) |
| { return __wait_until_impl(__lock, __atime); } |
| #endif |
| |
| template<typename _Duration> |
| cv_status |
| wait_until(unique_lock<mutex>& __lock, |
| const chrono::time_point<system_clock, _Duration>& __atime) |
| { return __wait_until_impl(__lock, __atime); } |
| |
| template<typename _Clock, typename _Duration> |
| cv_status |
| wait_until(unique_lock<mutex>& __lock, |
| const chrono::time_point<_Clock, _Duration>& __atime) |
| { |
| #if __cplusplus > 201703L |
| static_assert(chrono::is_clock_v<_Clock>); |
| #endif |
| const typename _Clock::time_point __c_entry = _Clock::now(); |
| const __clock_t::time_point __s_entry = __clock_t::now(); |
| const auto __delta = __atime - __c_entry; |
| const auto __s_atime = __s_entry + __delta; |
| |
| if (__wait_until_impl(__lock, __s_atime) == cv_status::no_timeout) |
| return cv_status::no_timeout; |
| // We got a timeout when measured against __clock_t but |
| // we need to check against the caller-supplied clock |
| // to tell whether we should return a timeout. |
| if (_Clock::now() < __atime) |
| return cv_status::no_timeout; |
| return cv_status::timeout; |
| } |
| |
| template<typename _Clock, typename _Duration, typename _Predicate> |
| bool |
| wait_until(unique_lock<mutex>& __lock, |
| const chrono::time_point<_Clock, _Duration>& __atime, |
| _Predicate __p) |
| { |
| while (!__p()) |
| if (wait_until(__lock, __atime) == cv_status::timeout) |
| return __p(); |
| return true; |
| } |
| |
| template<typename _Rep, typename _Period> |
| cv_status |
| wait_for(unique_lock<mutex>& __lock, |
| const chrono::duration<_Rep, _Period>& __rtime) |
| { |
| using __dur = typename steady_clock::duration; |
| auto __reltime = chrono::duration_cast<__dur>(__rtime); |
| if (__reltime < __rtime) |
| ++__reltime; |
| return wait_until(__lock, steady_clock::now() + __reltime); |
| } |
| |
| template<typename _Rep, typename _Period, typename _Predicate> |
| bool |
| wait_for(unique_lock<mutex>& __lock, |
| const chrono::duration<_Rep, _Period>& __rtime, |
| _Predicate __p) |
| { |
| using __dur = typename steady_clock::duration; |
| auto __reltime = chrono::duration_cast<__dur>(__rtime); |
| if (__reltime < __rtime) |
| ++__reltime; |
| return wait_until(__lock, steady_clock::now() + __reltime, |
| std::move(__p)); |
| } |
| |
| native_handle_type |
| native_handle() |
| { return &_M_cond; } |
| |
| private: |
| #ifdef _GLIBCXX_USE_PTHREAD_COND_CLOCKWAIT |
| template<typename _Dur> |
| cv_status |
| __wait_until_impl(unique_lock<mutex>& __lock, |
| const chrono::time_point<steady_clock, _Dur>& __atime) |
| { |
| auto __s = chrono::time_point_cast<chrono::seconds>(__atime); |
| auto __ns = chrono::duration_cast<chrono::nanoseconds>(__atime - __s); |
| |
| __gthread_time_t __ts = |
| { |
| static_cast<std::time_t>(__s.time_since_epoch().count()), |
| static_cast<long>(__ns.count()) |
| }; |
| |
| pthread_cond_clockwait(&_M_cond, __lock.mutex()->native_handle(), |
| CLOCK_MONOTONIC, |
| &__ts); |
| |
| return (steady_clock::now() < __atime |
| ? cv_status::no_timeout : cv_status::timeout); |
| } |
| #endif |
| |
| template<typename _Dur> |
| cv_status |
| __wait_until_impl(unique_lock<mutex>& __lock, |
| const chrono::time_point<system_clock, _Dur>& __atime) |
| { |
| auto __s = chrono::time_point_cast<chrono::seconds>(__atime); |
| auto __ns = chrono::duration_cast<chrono::nanoseconds>(__atime - __s); |
| |
| __gthread_time_t __ts = |
| { |
| static_cast<std::time_t>(__s.time_since_epoch().count()), |
| static_cast<long>(__ns.count()) |
| }; |
| |
| __gthread_cond_timedwait(&_M_cond, __lock.mutex()->native_handle(), |
| &__ts); |
| |
| return (system_clock::now() < __atime |
| ? cv_status::no_timeout : cv_status::timeout); |
| } |
| }; |
| |
| void |
| notify_all_at_thread_exit(condition_variable&, unique_lock<mutex>); |
| |
| struct __at_thread_exit_elt |
| { |
| __at_thread_exit_elt* _M_next; |
| void (*_M_cb)(void*); |
| }; |
| |
| inline namespace _V2 { |
| |
| /// condition_variable_any |
| // Like above, but mutex is not required to have try_lock. |
| class condition_variable_any |
| { |
| #ifdef _GLIBCXX_USE_PTHREAD_COND_CLOCKWAIT |
| using __clock_t = chrono::steady_clock; |
| #else |
| using __clock_t = chrono::system_clock; |
| #endif |
| condition_variable _M_cond; |
| shared_ptr<mutex> _M_mutex; |
| |
| // scoped unlock - unlocks in ctor, re-locks in dtor |
| template<typename _Lock> |
| struct _Unlock |
| { |
| explicit _Unlock(_Lock& __lk) : _M_lock(__lk) { __lk.unlock(); } |
| |
| #pragma GCC diagnostic push |
| #pragma GCC diagnostic ignored "-Wdeprecated-declarations" |
| ~_Unlock() noexcept(false) |
| { |
| if (uncaught_exception()) |
| { |
| __try |
| { _M_lock.lock(); } |
| __catch(const __cxxabiv1::__forced_unwind&) |
| { __throw_exception_again; } |
| __catch(...) |
| { } |
| } |
| else |
| _M_lock.lock(); |
| } |
| #pragma GCC diagnostic pop |
| |
| _Unlock(const _Unlock&) = delete; |
| _Unlock& operator=(const _Unlock&) = delete; |
| |
| _Lock& _M_lock; |
| }; |
| |
| public: |
| condition_variable_any() : _M_mutex(std::make_shared<mutex>()) { } |
| ~condition_variable_any() = default; |
| |
| condition_variable_any(const condition_variable_any&) = delete; |
| condition_variable_any& operator=(const condition_variable_any&) = delete; |
| |
| void |
| notify_one() noexcept |
| { |
| lock_guard<mutex> __lock(*_M_mutex); |
| _M_cond.notify_one(); |
| } |
| |
| void |
| notify_all() noexcept |
| { |
| lock_guard<mutex> __lock(*_M_mutex); |
| _M_cond.notify_all(); |
| } |
| |
| template<typename _Lock> |
| void |
| wait(_Lock& __lock) |
| { |
| shared_ptr<mutex> __mutex = _M_mutex; |
| unique_lock<mutex> __my_lock(*__mutex); |
| _Unlock<_Lock> __unlock(__lock); |
| // *__mutex must be unlocked before re-locking __lock so move |
| // ownership of *__mutex lock to an object with shorter lifetime. |
| unique_lock<mutex> __my_lock2(std::move(__my_lock)); |
| _M_cond.wait(__my_lock2); |
| } |
| |
| |
| template<typename _Lock, typename _Predicate> |
| void |
| wait(_Lock& __lock, _Predicate __p) |
| { |
| while (!__p()) |
| wait(__lock); |
| } |
| |
| template<typename _Lock, typename _Clock, typename _Duration> |
| cv_status |
| wait_until(_Lock& __lock, |
| const chrono::time_point<_Clock, _Duration>& __atime) |
| { |
| shared_ptr<mutex> __mutex = _M_mutex; |
| unique_lock<mutex> __my_lock(*__mutex); |
| _Unlock<_Lock> __unlock(__lock); |
| // *__mutex must be unlocked before re-locking __lock so move |
| // ownership of *__mutex lock to an object with shorter lifetime. |
| unique_lock<mutex> __my_lock2(std::move(__my_lock)); |
| return _M_cond.wait_until(__my_lock2, __atime); |
| } |
| |
| template<typename _Lock, typename _Clock, |
| typename _Duration, typename _Predicate> |
| bool |
| wait_until(_Lock& __lock, |
| const chrono::time_point<_Clock, _Duration>& __atime, |
| _Predicate __p) |
| { |
| while (!__p()) |
| if (wait_until(__lock, __atime) == cv_status::timeout) |
| return __p(); |
| return true; |
| } |
| |
| template<typename _Lock, typename _Rep, typename _Period> |
| cv_status |
| wait_for(_Lock& __lock, const chrono::duration<_Rep, _Period>& __rtime) |
| { return wait_until(__lock, __clock_t::now() + __rtime); } |
| |
| template<typename _Lock, typename _Rep, |
| typename _Period, typename _Predicate> |
| bool |
| wait_for(_Lock& __lock, |
| const chrono::duration<_Rep, _Period>& __rtime, _Predicate __p) |
| { return wait_until(__lock, __clock_t::now() + __rtime, std::move(__p)); } |
| |
| #ifdef __cpp_lib_jthread |
| template <class _Lock, class _Predicate> |
| bool wait(_Lock& __lock, |
| stop_token __stoken, |
| _Predicate __p) |
| { |
| if (__stoken.stop_requested()) |
| { |
| return __p(); |
| } |
| |
| std::stop_callback __cb(__stoken, [this] { notify_all(); }); |
| shared_ptr<mutex> __mutex = _M_mutex; |
| while (!__p()) |
| { |
| unique_lock<mutex> __my_lock(*__mutex); |
| if (__stoken.stop_requested()) |
| { |
| return false; |
| } |
| // *__mutex must be unlocked before re-locking __lock so move |
| // ownership of *__mutex lock to an object with shorter lifetime. |
| _Unlock<_Lock> __unlock(__lock); |
| unique_lock<mutex> __my_lock2(std::move(__my_lock)); |
| _M_cond.wait(__my_lock2); |
| } |
| return true; |
| } |
| |
| template <class _Lock, class _Clock, class _Duration, class _Predicate> |
| bool wait_until(_Lock& __lock, |
| stop_token __stoken, |
| const chrono::time_point<_Clock, _Duration>& __abs_time, |
| _Predicate __p) |
| { |
| if (__stoken.stop_requested()) |
| { |
| return __p(); |
| } |
| |
| std::stop_callback __cb(__stoken, [this] { notify_all(); }); |
| shared_ptr<mutex> __mutex = _M_mutex; |
| while (!__p()) |
| { |
| bool __stop; |
| { |
| unique_lock<mutex> __my_lock(*__mutex); |
| if (__stoken.stop_requested()) |
| { |
| return false; |
| } |
| _Unlock<_Lock> __u(__lock); |
| unique_lock<mutex> __my_lock2(std::move(__my_lock)); |
| const auto __status = _M_cond.wait_until(__my_lock2, __abs_time); |
| __stop = (__status == std::cv_status::timeout) || __stoken.stop_requested(); |
| } |
| if (__stop) |
| { |
| return __p(); |
| } |
| } |
| return true; |
| } |
| |
| template <class _Lock, class _Rep, class _Period, class _Predicate> |
| bool wait_for(_Lock& __lock, |
| stop_token __stoken, |
| const chrono::duration<_Rep, _Period>& __rel_time, |
| _Predicate __p) |
| { |
| auto __abst = std::chrono::steady_clock::now() + __rel_time; |
| return wait_until(__lock, |
| std::move(__stoken), |
| __abst, |
| std::move(__p)); |
| } |
| #endif |
| }; |
| |
| } // end inline namespace |
| |
| /// @} group condition_variables |
| _GLIBCXX_END_NAMESPACE_VERSION |
| } // namespace |
| |
| #endif // _GLIBCXX_HAS_GTHREADS |
| #endif // C++11 |
| #endif // _GLIBCXX_CONDITION_VARIABLE |