1 // <condition_variable> -*- C++ -*-
3 // Copyright (C) 2008-2014 Free Software Foundation, Inc.
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
25 /** @file include/condition_variable
26 * This is a Standard C++ Library header.
29 #ifndef _GLIBCXX_CONDITION_VARIABLE
30 #define _GLIBCXX_CONDITION_VARIABLE 1
32 #pragma GCC system_header
34 #if __cplusplus < 201103L
35 # include <bits/c++0x_warning.h>
40 #include <ext/concurrence.h>
41 #include <bits/alloc_traits.h>
42 #include <bits/allocator.h>
43 #include <bits/unique_ptr.h>
44 #include <bits/shared_ptr.h>
46 #if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
48 namespace std _GLIBCXX_VISIBILITY(default)
50 _GLIBCXX_BEGIN_NAMESPACE_VERSION
53 * @defgroup condition_variables Condition Variables
54 * @ingroup concurrency
56 * Classes for condition_variable support.
61 enum class cv_status { no_timeout, timeout };
63 /// condition_variable
64 class condition_variable
66 typedef chrono::system_clock __clock_t;
67 typedef __gthread_cond_t __native_type;
69 #ifdef __GTHREAD_COND_INIT
70 __native_type _M_cond = __GTHREAD_COND_INIT;
72 __native_type _M_cond;
76 typedef __native_type* native_handle_type;
78 condition_variable() noexcept;
79 ~condition_variable() noexcept;
81 condition_variable(const condition_variable&) = delete;
82 condition_variable& operator=(const condition_variable&) = delete;
85 notify_one() noexcept;
88 notify_all() noexcept;
91 wait(unique_lock<mutex>& __lock);
93 template<typename _Predicate>
95 wait(unique_lock<mutex>& __lock, _Predicate __p)
101 template<typename _Duration>
103 wait_until(unique_lock<mutex>& __lock,
104 const chrono::time_point<__clock_t, _Duration>& __atime)
105 { return __wait_until_impl(__lock, __atime); }
107 template<typename _Clock, typename _Duration>
109 wait_until(unique_lock<mutex>& __lock,
110 const chrono::time_point<_Clock, _Duration>& __atime)
112 // DR 887 - Sync unknown clock to known clock.
113 const typename _Clock::time_point __c_entry = _Clock::now();
114 const __clock_t::time_point __s_entry = __clock_t::now();
115 const auto __delta = __atime - __c_entry;
116 const auto __s_atime = __s_entry + __delta;
118 return __wait_until_impl(__lock, __s_atime);
121 template<typename _Clock, typename _Duration, typename _Predicate>
123 wait_until(unique_lock<mutex>& __lock,
124 const chrono::time_point<_Clock, _Duration>& __atime,
128 if (wait_until(__lock, __atime) == cv_status::timeout)
133 template<typename _Rep, typename _Period>
135 wait_for(unique_lock<mutex>& __lock,
136 const chrono::duration<_Rep, _Period>& __rtime)
137 { return wait_until(__lock, __clock_t::now() + __rtime); }
139 template<typename _Rep, typename _Period, typename _Predicate>
141 wait_for(unique_lock<mutex>& __lock,
142 const chrono::duration<_Rep, _Period>& __rtime,
144 { return wait_until(__lock, __clock_t::now() + __rtime, std::move(__p)); }
151 template<typename _Dur>
153 __wait_until_impl(unique_lock<mutex>& __lock,
154 const chrono::time_point<__clock_t, _Dur>& __atime)
156 auto __s = chrono::time_point_cast<chrono::seconds>(__atime);
157 auto __ns = chrono::duration_cast<chrono::nanoseconds>(__atime - __s);
159 __gthread_time_t __ts =
161 static_cast<std::time_t>(__s.time_since_epoch().count()),
162 static_cast<long>(__ns.count())
165 __gthread_cond_timedwait(&_M_cond, __lock.mutex()->native_handle(),
168 return (__clock_t::now() < __atime
169 ? cv_status::no_timeout : cv_status::timeout);
173 inline namespace _V2 {
175 /// condition_variable_any
176 // Like above, but mutex is not required to have try_lock.
177 class condition_variable_any
179 typedef chrono::system_clock __clock_t;
180 condition_variable _M_cond;
181 shared_ptr<mutex> _M_mutex;
183 // scoped unlock - unlocks in ctor, re-locks in dtor
184 template<typename _Lock>
187 explicit _Unlock(_Lock& __lk) : _M_lock(__lk) { __lk.unlock(); }
189 ~_Unlock() noexcept(false)
191 if (uncaught_exception())
192 __try { _M_lock.lock(); } __catch(...) { }
197 _Unlock(const _Unlock&) = delete;
198 _Unlock& operator=(const _Unlock&) = delete;
204 condition_variable_any() : _M_mutex(std::make_shared<mutex>()) { }
205 ~condition_variable_any() = default;
207 condition_variable_any(const condition_variable_any&) = delete;
208 condition_variable_any& operator=(const condition_variable_any&) = delete;
211 notify_one() noexcept
213 lock_guard<mutex> __lock(*_M_mutex);
214 _M_cond.notify_one();
218 notify_all() noexcept
220 lock_guard<mutex> __lock(*_M_mutex);
221 _M_cond.notify_all();
224 template<typename _Lock>
228 shared_ptr<mutex> __mutex = _M_mutex;
229 unique_lock<mutex> __my_lock(*__mutex);
230 _Unlock<_Lock> __unlock(__lock);
231 // *__mutex must be unlocked before re-locking __lock so move
232 // ownership of *__mutex lock to an object with shorter lifetime.
233 unique_lock<mutex> __my_lock2(std::move(__my_lock));
234 _M_cond.wait(__my_lock2);
238 template<typename _Lock, typename _Predicate>
240 wait(_Lock& __lock, _Predicate __p)
246 template<typename _Lock, typename _Clock, typename _Duration>
248 wait_until(_Lock& __lock,
249 const chrono::time_point<_Clock, _Duration>& __atime)
251 shared_ptr<mutex> __mutex = _M_mutex;
252 unique_lock<mutex> __my_lock(*__mutex);
253 _Unlock<_Lock> __unlock(__lock);
254 // *__mutex must be unlocked before re-locking __lock so move
255 // ownership of *__mutex lock to an object with shorter lifetime.
256 unique_lock<mutex> __my_lock2(std::move(__my_lock));
257 return _M_cond.wait_until(__my_lock2, __atime);
260 template<typename _Lock, typename _Clock,
261 typename _Duration, typename _Predicate>
263 wait_until(_Lock& __lock,
264 const chrono::time_point<_Clock, _Duration>& __atime,
268 if (wait_until(__lock, __atime) == cv_status::timeout)
273 template<typename _Lock, typename _Rep, typename _Period>
275 wait_for(_Lock& __lock, const chrono::duration<_Rep, _Period>& __rtime)
276 { return wait_until(__lock, __clock_t::now() + __rtime); }
278 template<typename _Lock, typename _Rep,
279 typename _Period, typename _Predicate>
281 wait_for(_Lock& __lock,
282 const chrono::duration<_Rep, _Period>& __rtime, _Predicate __p)
283 { return wait_until(__lock, __clock_t::now() + __rtime, std::move(__p)); }
286 } // end inline namespace
288 // @} group condition_variables
289 _GLIBCXX_END_NAMESPACE_VERSION
292 #endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1
296 #endif // _GLIBCXX_CONDITION_VARIABLE