xref: /freebsd-src/contrib/llvm-project/libcxx/include/condition_variable (revision 5f757f3ff9144b609b3c433dfd370cc6bdc191ad) 
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    // [thread.condvarany.intwait], interruptible waits
105    template <class Lock, class Predicate>
106      bool wait(Lock& lock, stop_token stoken, Predicate pred);                               // since C++20
107
108    template <class Lock, class Clock, class Duration, class Predicate>
109      bool wait_until(Lock& lock, stop_token stoken,
110                      const chrono::time_point<Clock, Duration>& abs_time, Predicate pred);   // since C++20
111
112    template <class Lock, class Rep, class Period, class Predicate>
113      bool wait_for(Lock& lock, stop_token stoken,
114                    const chrono::duration<Rep, Period>& rel_time, Predicate pred);           // since C++20
115};
116
117}  // std
118
119*/
120
121#include <__assert> // all public C++ headers provide the assertion handler
122#include <__availability>
123#include <__chrono/duration.h>
124#include <__chrono/steady_clock.h>
125#include <__chrono/time_point.h>
126#include <__condition_variable/condition_variable.h>
127#include <__config>
128#include <__memory/shared_ptr.h>
129#include <__memory/unique_ptr.h>
130#include <__mutex/lock_guard.h>
131#include <__mutex/mutex.h>
132#include <__mutex/tag_types.h>
133#include <__mutex/unique_lock.h>
134#include <__stop_token/stop_token.h>
135#include <__utility/move.h>
136#include <version>
137
138#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
139#  pragma GCC system_header
140#endif
141
142#ifndef _LIBCPP_HAS_NO_THREADS
143
144_LIBCPP_BEGIN_NAMESPACE_STD
145
146class _LIBCPP_EXPORTED_FROM_ABI condition_variable_any
147{
148    condition_variable __cv_;
149    shared_ptr<mutex>  __mut_;
150public:
151    _LIBCPP_HIDE_FROM_ABI
152    condition_variable_any();
153
154    _LIBCPP_HIDE_FROM_ABI
155    void notify_one() _NOEXCEPT;
156    _LIBCPP_HIDE_FROM_ABI
157    void notify_all() _NOEXCEPT;
158
159    template <class _Lock>
160        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
161        void wait(_Lock& __lock);
162    template <class _Lock, class _Predicate>
163        _LIBCPP_HIDE_FROM_ABI
164        void wait(_Lock& __lock, _Predicate __pred);
165
166    template <class _Lock, class _Clock, class _Duration>
167        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
168        cv_status
169        wait_until(_Lock& __lock,
170                   const chrono::time_point<_Clock, _Duration>& __t);
171
172    template <class _Lock, class _Clock, class _Duration, class _Predicate>
173        bool
174        _LIBCPP_HIDE_FROM_ABI
175        wait_until(_Lock& __lock,
176                   const chrono::time_point<_Clock, _Duration>& __t,
177                   _Predicate __pred);
178
179    template <class _Lock, class _Rep, class _Period>
180        cv_status
181        _LIBCPP_HIDE_FROM_ABI
182        wait_for(_Lock& __lock,
183                 const chrono::duration<_Rep, _Period>& __d);
184
185    template <class _Lock, class _Rep, class _Period, class _Predicate>
186        bool
187        _LIBCPP_HIDE_FROM_ABI
188        wait_for(_Lock& __lock,
189                 const chrono::duration<_Rep, _Period>& __d,
190                 _Predicate __pred);
191
192#if _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN)
193
194    template <class _Lock, class _Predicate>
195    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_HIDE_FROM_ABI bool wait(_Lock& __lock, stop_token __stoken, _Predicate __pred);
196
197    template <class _Lock, class _Clock, class _Duration, class _Predicate>
198    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_HIDE_FROM_ABI bool wait_until(_Lock& __lock, stop_token __stoken,
199                const chrono::time_point<_Clock, _Duration>& __abs_time, _Predicate __pred);
200
201    template <class _Lock, class _Rep, class _Period, class _Predicate>
202    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_HIDE_FROM_ABI bool wait_for(_Lock& __lock, stop_token __stoken,
203                const chrono::duration<_Rep, _Period>& __rel_time, _Predicate __pred);
204
205#endif // _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN)
206};
207
208inline
209condition_variable_any::condition_variable_any()
210    : __mut_(make_shared<mutex>()) {}
211
212inline
213void
214condition_variable_any::notify_one() _NOEXCEPT
215{
216    {lock_guard<mutex> __lx(*__mut_);}
217    __cv_.notify_one();
218}
219
220inline
221void
222condition_variable_any::notify_all() _NOEXCEPT
223{
224    {lock_guard<mutex> __lx(*__mut_);}
225    __cv_.notify_all();
226}
227
228struct __lock_external
229{
230    template <class _Lock>
231    _LIBCPP_HIDE_FROM_ABI void operator()(_Lock* __m) {__m->lock();}
232};
233
234template <class _Lock>
235void
236condition_variable_any::wait(_Lock& __lock)
237{
238    shared_ptr<mutex> __mut = __mut_;
239    unique_lock<mutex> __lk(*__mut);
240    __lock.unlock();
241    unique_ptr<_Lock, __lock_external> __lxx(&__lock);
242    lock_guard<unique_lock<mutex> > __lx(__lk, adopt_lock_t());
243    __cv_.wait(__lk);
244}  // __mut_.unlock(), __lock.lock()
245
246template <class _Lock, class _Predicate>
247inline
248void
249condition_variable_any::wait(_Lock& __lock, _Predicate __pred)
250{
251    while (!__pred())
252        wait(__lock);
253}
254
255template <class _Lock, class _Clock, class _Duration>
256cv_status
257condition_variable_any::wait_until(_Lock& __lock,
258                                   const chrono::time_point<_Clock, _Duration>& __t)
259{
260    shared_ptr<mutex> __mut = __mut_;
261    unique_lock<mutex> __lk(*__mut);
262    __lock.unlock();
263    unique_ptr<_Lock, __lock_external> __lxx(&__lock);
264    lock_guard<unique_lock<mutex> > __lx(__lk, adopt_lock_t());
265    return __cv_.wait_until(__lk, __t);
266}  // __mut_.unlock(), __lock.lock()
267
268template <class _Lock, class _Clock, class _Duration, class _Predicate>
269inline
270bool
271condition_variable_any::wait_until(_Lock& __lock,
272                                   const chrono::time_point<_Clock, _Duration>& __t,
273                                   _Predicate __pred)
274{
275    while (!__pred())
276        if (wait_until(__lock, __t) == cv_status::timeout)
277            return __pred();
278    return true;
279}
280
281template <class _Lock, class _Rep, class _Period>
282inline
283cv_status
284condition_variable_any::wait_for(_Lock& __lock,
285                                 const chrono::duration<_Rep, _Period>& __d)
286{
287    return wait_until(__lock, chrono::steady_clock::now() + __d);
288}
289
290template <class _Lock, class _Rep, class _Period, class _Predicate>
291inline
292bool
293condition_variable_any::wait_for(_Lock& __lock,
294                                 const chrono::duration<_Rep, _Period>& __d,
295                                 _Predicate __pred)
296{
297    return wait_until(__lock, chrono::steady_clock::now() + __d,
298                      std::move(__pred));
299}
300
301#if _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN)
302
303template <class _Lock, class _Predicate>
304bool condition_variable_any::wait(_Lock& __lock, stop_token __stoken, _Predicate __pred) {
305    while (!__stoken.stop_requested()) {
306        if (__pred())
307            return true;
308        wait(__lock);
309    }
310    return __pred();
311}
312
313template <class _Lock, class _Clock, class _Duration, class _Predicate>
314bool condition_variable_any::wait_until(
315    _Lock& __lock, stop_token __stoken, const chrono::time_point<_Clock, _Duration>& __abs_time, _Predicate __pred) {
316    while (!__stoken.stop_requested()) {
317        if (__pred())
318            return true;
319        if (wait_until(__lock, __abs_time) == cv_status::timeout)
320            return __pred();
321    }
322    return __pred();
323}
324
325template <class _Lock, class _Rep, class _Period, class _Predicate>
326bool condition_variable_any::wait_for(
327    _Lock& __lock, stop_token __stoken, const chrono::duration<_Rep, _Period>& __rel_time, _Predicate __pred) {
328    return wait_until(__lock, std::move(__stoken), chrono::steady_clock::now() + __rel_time, std::move(__pred));
329}
330
331#endif // _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN)
332
333_LIBCPP_EXPORTED_FROM_ABI void notify_all_at_thread_exit(condition_variable&, unique_lock<mutex>);
334
335_LIBCPP_END_NAMESPACE_STD
336
337#endif // !_LIBCPP_HAS_NO_THREADS
338
339#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
340#  include <atomic>
341#  include <concepts>
342#  include <cstdint>
343#  include <cstdlib>
344#  include <cstring>
345#  include <initializer_list>
346#  include <iosfwd>
347#  include <new>
348#  include <stdexcept>
349#  include <system_error>
350#  include <type_traits>
351#  include <typeinfo>
352#endif
353
354#endif // _LIBCPP_CONDITION_VARIABLE
355