xref: /freebsd/contrib/llvm-project/libcxx/include/condition_variable (revision 7ef62cebc2f965b0f640263e179276928885e33d) 
1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
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 <__assert> // all public C++ headers provide the assertion handler
110#include <__config>
111#include <__memory/shared_ptr.h>
112#include <__memory/unique_ptr.h>
113#include <__mutex_base>
114#include <version>
115
116#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
117#  pragma GCC system_header
118#endif
119
120#ifndef _LIBCPP_HAS_NO_THREADS
121
122_LIBCPP_BEGIN_NAMESPACE_STD
123
124class _LIBCPP_TYPE_VIS condition_variable_any
125{
126    condition_variable __cv_;
127    shared_ptr<mutex>  __mut_;
128public:
129    _LIBCPP_INLINE_VISIBILITY
130    condition_variable_any();
131
132    _LIBCPP_INLINE_VISIBILITY
133    void notify_one() _NOEXCEPT;
134    _LIBCPP_INLINE_VISIBILITY
135    void notify_all() _NOEXCEPT;
136
137    template <class _Lock>
138        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
139        void wait(_Lock& __lock);
140    template <class _Lock, class _Predicate>
141        _LIBCPP_INLINE_VISIBILITY
142        void wait(_Lock& __lock, _Predicate __pred);
143
144    template <class _Lock, class _Clock, class _Duration>
145        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
146        cv_status
147        wait_until(_Lock& __lock,
148                   const chrono::time_point<_Clock, _Duration>& __t);
149
150    template <class _Lock, class _Clock, class _Duration, class _Predicate>
151        bool
152        _LIBCPP_INLINE_VISIBILITY
153        wait_until(_Lock& __lock,
154                   const chrono::time_point<_Clock, _Duration>& __t,
155                   _Predicate __pred);
156
157    template <class _Lock, class _Rep, class _Period>
158        cv_status
159        _LIBCPP_INLINE_VISIBILITY
160        wait_for(_Lock& __lock,
161                 const chrono::duration<_Rep, _Period>& __d);
162
163    template <class _Lock, class _Rep, class _Period, class _Predicate>
164        bool
165        _LIBCPP_INLINE_VISIBILITY
166        wait_for(_Lock& __lock,
167                 const chrono::duration<_Rep, _Period>& __d,
168                 _Predicate __pred);
169};
170
171inline
172condition_variable_any::condition_variable_any()
173    : __mut_(make_shared<mutex>()) {}
174
175inline
176void
177condition_variable_any::notify_one() _NOEXCEPT
178{
179    {lock_guard<mutex> __lx(*__mut_);}
180    __cv_.notify_one();
181}
182
183inline
184void
185condition_variable_any::notify_all() _NOEXCEPT
186{
187    {lock_guard<mutex> __lx(*__mut_);}
188    __cv_.notify_all();
189}
190
191struct __lock_external
192{
193    template <class _Lock>
194    void operator()(_Lock* __m) {__m->lock();}
195};
196
197template <class _Lock>
198void
199condition_variable_any::wait(_Lock& __lock)
200{
201    shared_ptr<mutex> __mut = __mut_;
202    unique_lock<mutex> __lk(*__mut);
203    __lock.unlock();
204    unique_ptr<_Lock, __lock_external> __lxx(&__lock);
205    lock_guard<unique_lock<mutex> > __lx(__lk, adopt_lock);
206    __cv_.wait(__lk);
207}  // __mut_.unlock(), __lock.lock()
208
209template <class _Lock, class _Predicate>
210inline
211void
212condition_variable_any::wait(_Lock& __lock, _Predicate __pred)
213{
214    while (!__pred())
215        wait(__lock);
216}
217
218template <class _Lock, class _Clock, class _Duration>
219cv_status
220condition_variable_any::wait_until(_Lock& __lock,
221                                   const chrono::time_point<_Clock, _Duration>& __t)
222{
223    shared_ptr<mutex> __mut = __mut_;
224    unique_lock<mutex> __lk(*__mut);
225    __lock.unlock();
226    unique_ptr<_Lock, __lock_external> __lxx(&__lock);
227    lock_guard<unique_lock<mutex> > __lx(__lk, adopt_lock);
228    return __cv_.wait_until(__lk, __t);
229}  // __mut_.unlock(), __lock.lock()
230
231template <class _Lock, class _Clock, class _Duration, class _Predicate>
232inline
233bool
234condition_variable_any::wait_until(_Lock& __lock,
235                                   const chrono::time_point<_Clock, _Duration>& __t,
236                                   _Predicate __pred)
237{
238    while (!__pred())
239        if (wait_until(__lock, __t) == cv_status::timeout)
240            return __pred();
241    return true;
242}
243
244template <class _Lock, class _Rep, class _Period>
245inline
246cv_status
247condition_variable_any::wait_for(_Lock& __lock,
248                                 const chrono::duration<_Rep, _Period>& __d)
249{
250    return wait_until(__lock, chrono::steady_clock::now() + __d);
251}
252
253template <class _Lock, class _Rep, class _Period, class _Predicate>
254inline
255bool
256condition_variable_any::wait_for(_Lock& __lock,
257                                 const chrono::duration<_Rep, _Period>& __d,
258                                 _Predicate __pred)
259{
260    return wait_until(__lock, chrono::steady_clock::now() + __d,
261                      _VSTD::move(__pred));
262}
263
264_LIBCPP_FUNC_VIS
265void notify_all_at_thread_exit(condition_variable&, unique_lock<mutex>);
266
267_LIBCPP_END_NAMESPACE_STD
268
269#endif // !_LIBCPP_HAS_NO_THREADS
270
271#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
272#  include <concepts>
273#  include <type_traits>
274#endif
275
276#endif // _LIBCPP_CONDITION_VARIABLE
277