xref: /freebsd/contrib/llvm-project/libcxx/include/condition_variable (revision cfd6422a5217410fbd66f7a7a8a64d9d85e61229) 
1// -*- C++ -*-
2//===---------------------- condition_variable ----------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_CONDITION_VARIABLE
11#define _LIBCPP_CONDITION_VARIABLE
12
13/*
14    condition_variable synopsis
15
16namespace std
17{
18
19enum class cv_status { no_timeout, timeout };
20
21class condition_variable
22{
23public:
24    condition_variable();
25    ~condition_variable();
26
27    condition_variable(const condition_variable&) = delete;
28    condition_variable& operator=(const condition_variable&) = delete;
29
30    void notify_one() noexcept;
31    void notify_all() noexcept;
32
33    void wait(unique_lock<mutex>& lock);
34    template <class Predicate>
35        void wait(unique_lock<mutex>& lock, Predicate pred);
36
37    template <class Clock, class Duration>
38        cv_status
39        wait_until(unique_lock<mutex>& lock,
40                   const chrono::time_point<Clock, Duration>& abs_time);
41
42    template <class Clock, class Duration, class Predicate>
43        bool
44        wait_until(unique_lock<mutex>& lock,
45                   const chrono::time_point<Clock, Duration>& abs_time,
46                   Predicate pred);
47
48    template <class Rep, class Period>
49        cv_status
50        wait_for(unique_lock<mutex>& lock,
51                 const chrono::duration<Rep, Period>& rel_time);
52
53    template <class Rep, class Period, class Predicate>
54        bool
55        wait_for(unique_lock<mutex>& lock,
56                 const chrono::duration<Rep, Period>& rel_time,
57                 Predicate pred);
58
59    typedef pthread_cond_t* native_handle_type;
60    native_handle_type native_handle();
61};
62
63void notify_all_at_thread_exit(condition_variable& cond, unique_lock<mutex> lk);
64
65class condition_variable_any
66{
67public:
68    condition_variable_any();
69    ~condition_variable_any();
70
71    condition_variable_any(const condition_variable_any&) = delete;
72    condition_variable_any& operator=(const condition_variable_any&) = delete;
73
74    void notify_one() noexcept;
75    void notify_all() noexcept;
76
77    template <class Lock>
78        void wait(Lock& lock);
79    template <class Lock, class Predicate>
80        void wait(Lock& lock, Predicate pred);
81
82    template <class Lock, class Clock, class Duration>
83        cv_status
84        wait_until(Lock& lock,
85                   const chrono::time_point<Clock, Duration>& abs_time);
86
87    template <class Lock, class Clock, class Duration, class Predicate>
88        bool
89        wait_until(Lock& lock,
90                   const chrono::time_point<Clock, Duration>& abs_time,
91                   Predicate pred);
92
93    template <class Lock, class Rep, class Period>
94        cv_status
95        wait_for(Lock& lock,
96                 const chrono::duration<Rep, Period>& rel_time);
97
98    template <class Lock, class Rep, class Period, class Predicate>
99        bool
100        wait_for(Lock& lock,
101                 const chrono::duration<Rep, Period>& rel_time,
102                 Predicate pred);
103};
104
105}  // std
106
107*/
108
109#include <__config>
110#include <__mutex_base>
111#include <memory>
112
113#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
114#pragma GCC system_header
115#endif
116
117#ifndef _LIBCPP_HAS_NO_THREADS
118
119_LIBCPP_BEGIN_NAMESPACE_STD
120
121class _LIBCPP_TYPE_VIS condition_variable_any
122{
123    condition_variable __cv_;
124    shared_ptr<mutex>  __mut_;
125public:
126    _LIBCPP_INLINE_VISIBILITY
127    condition_variable_any();
128
129    _LIBCPP_INLINE_VISIBILITY
130    void notify_one() _NOEXCEPT;
131    _LIBCPP_INLINE_VISIBILITY
132    void notify_all() _NOEXCEPT;
133
134    template <class _Lock>
135        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
136        void wait(_Lock& __lock);
137    template <class _Lock, class _Predicate>
138        _LIBCPP_INLINE_VISIBILITY
139        void wait(_Lock& __lock, _Predicate __pred);
140
141    template <class _Lock, class _Clock, class _Duration>
142        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
143        cv_status
144        wait_until(_Lock& __lock,
145                   const chrono::time_point<_Clock, _Duration>& __t);
146
147    template <class _Lock, class _Clock, class _Duration, class _Predicate>
148        bool
149        _LIBCPP_INLINE_VISIBILITY
150        wait_until(_Lock& __lock,
151                   const chrono::time_point<_Clock, _Duration>& __t,
152                   _Predicate __pred);
153
154    template <class _Lock, class _Rep, class _Period>
155        cv_status
156        _LIBCPP_INLINE_VISIBILITY
157        wait_for(_Lock& __lock,
158                 const chrono::duration<_Rep, _Period>& __d);
159
160    template <class _Lock, class _Rep, class _Period, class _Predicate>
161        bool
162        _LIBCPP_INLINE_VISIBILITY
163        wait_for(_Lock& __lock,
164                 const chrono::duration<_Rep, _Period>& __d,
165                 _Predicate __pred);
166};
167
168inline
169condition_variable_any::condition_variable_any()
170    : __mut_(make_shared<mutex>()) {}
171
172inline
173void
174condition_variable_any::notify_one() _NOEXCEPT
175{
176    {lock_guard<mutex> __lx(*__mut_);}
177    __cv_.notify_one();
178}
179
180inline
181void
182condition_variable_any::notify_all() _NOEXCEPT
183{
184    {lock_guard<mutex> __lx(*__mut_);}
185    __cv_.notify_all();
186}
187
188struct __lock_external
189{
190    template <class _Lock>
191    void operator()(_Lock* __m) {__m->lock();}
192};
193
194template <class _Lock>
195void
196condition_variable_any::wait(_Lock& __lock)
197{
198    shared_ptr<mutex> __mut = __mut_;
199    unique_lock<mutex> __lk(*__mut);
200    __lock.unlock();
201    unique_ptr<_Lock, __lock_external> __lxx(&__lock);
202    lock_guard<unique_lock<mutex> > __lx(__lk, adopt_lock);
203    __cv_.wait(__lk);
204}  // __mut_.unlock(), __lock.lock()
205
206template <class _Lock, class _Predicate>
207inline
208void
209condition_variable_any::wait(_Lock& __lock, _Predicate __pred)
210{
211    while (!__pred())
212        wait(__lock);
213}
214
215template <class _Lock, class _Clock, class _Duration>
216cv_status
217condition_variable_any::wait_until(_Lock& __lock,
218                                   const chrono::time_point<_Clock, _Duration>& __t)
219{
220    shared_ptr<mutex> __mut = __mut_;
221    unique_lock<mutex> __lk(*__mut);
222    __lock.unlock();
223    unique_ptr<_Lock, __lock_external> __lxx(&__lock);
224    lock_guard<unique_lock<mutex> > __lx(__lk, adopt_lock);
225    return __cv_.wait_until(__lk, __t);
226}  // __mut_.unlock(), __lock.lock()
227
228template <class _Lock, class _Clock, class _Duration, class _Predicate>
229inline
230bool
231condition_variable_any::wait_until(_Lock& __lock,
232                                   const chrono::time_point<_Clock, _Duration>& __t,
233                                   _Predicate __pred)
234{
235    while (!__pred())
236        if (wait_until(__lock, __t) == cv_status::timeout)
237            return __pred();
238    return true;
239}
240
241template <class _Lock, class _Rep, class _Period>
242inline
243cv_status
244condition_variable_any::wait_for(_Lock& __lock,
245                                 const chrono::duration<_Rep, _Period>& __d)
246{
247    return wait_until(__lock, chrono::steady_clock::now() + __d);
248}
249
250template <class _Lock, class _Rep, class _Period, class _Predicate>
251inline
252bool
253condition_variable_any::wait_for(_Lock& __lock,
254                                 const chrono::duration<_Rep, _Period>& __d,
255                                 _Predicate __pred)
256{
257    return wait_until(__lock, chrono::steady_clock::now() + __d,
258                      _VSTD::move(__pred));
259}
260
261_LIBCPP_FUNC_VIS
262void notify_all_at_thread_exit(condition_variable& cond, unique_lock<mutex> lk);
263
264_LIBCPP_END_NAMESPACE_STD
265
266#endif // !_LIBCPP_HAS_NO_THREADS
267
268#endif  // _LIBCPP_CONDITION_VARIABLE
269