xref: /freebsd/contrib/llvm-project/libcxx/include/condition_variable (revision 1db9f3b21e39176dd5b67cf8ac378633b172463e) 
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  condition_variable __cv_;
148  shared_ptr<mutex> __mut_;
149
150public:
151  _LIBCPP_HIDE_FROM_ABI condition_variable_any();
152
153  _LIBCPP_HIDE_FROM_ABI void notify_one() _NOEXCEPT;
154  _LIBCPP_HIDE_FROM_ABI void notify_all() _NOEXCEPT;
155
156  template <class _Lock>
157  _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS void wait(_Lock& __lock);
158  template <class _Lock, class _Predicate>
159  _LIBCPP_HIDE_FROM_ABI void wait(_Lock& __lock, _Predicate __pred);
160
161  template <class _Lock, class _Clock, class _Duration>
162  _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS cv_status
163  wait_until(_Lock& __lock, const chrono::time_point<_Clock, _Duration>& __t);
164
165  template <class _Lock, class _Clock, class _Duration, class _Predicate>
166  bool _LIBCPP_HIDE_FROM_ABI
167  wait_until(_Lock& __lock, const chrono::time_point<_Clock, _Duration>& __t, _Predicate __pred);
168
169  template <class _Lock, class _Rep, class _Period>
170  cv_status _LIBCPP_HIDE_FROM_ABI wait_for(_Lock& __lock, const chrono::duration<_Rep, _Period>& __d);
171
172  template <class _Lock, class _Rep, class _Period, class _Predicate>
173  bool _LIBCPP_HIDE_FROM_ABI wait_for(_Lock& __lock, const chrono::duration<_Rep, _Period>& __d, _Predicate __pred);
174
175#  if _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN)
176
177  template <class _Lock, class _Predicate>
178  _LIBCPP_AVAILABILITY_SYNC _LIBCPP_HIDE_FROM_ABI bool wait(_Lock& __lock, stop_token __stoken, _Predicate __pred);
179
180  template <class _Lock, class _Clock, class _Duration, class _Predicate>
181  _LIBCPP_AVAILABILITY_SYNC _LIBCPP_HIDE_FROM_ABI bool wait_until(
182      _Lock& __lock, stop_token __stoken, const chrono::time_point<_Clock, _Duration>& __abs_time, _Predicate __pred);
183
184  template <class _Lock, class _Rep, class _Period, class _Predicate>
185  _LIBCPP_AVAILABILITY_SYNC _LIBCPP_HIDE_FROM_ABI bool
186  wait_for(_Lock& __lock, stop_token __stoken, const chrono::duration<_Rep, _Period>& __rel_time, _Predicate __pred);
187
188#  endif // _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN)
189};
190
191inline condition_variable_any::condition_variable_any() : __mut_(make_shared<mutex>()) {}
192
193inline void condition_variable_any::notify_one() _NOEXCEPT {
194  { lock_guard<mutex> __lx(*__mut_); }
195  __cv_.notify_one();
196}
197
198inline void condition_variable_any::notify_all() _NOEXCEPT {
199  { lock_guard<mutex> __lx(*__mut_); }
200  __cv_.notify_all();
201}
202
203struct __lock_external {
204  template <class _Lock>
205  _LIBCPP_HIDE_FROM_ABI void operator()(_Lock* __m) {
206    __m->lock();
207  }
208};
209
210template <class _Lock>
211void condition_variable_any::wait(_Lock& __lock) {
212  shared_ptr<mutex> __mut = __mut_;
213  unique_lock<mutex> __lk(*__mut);
214  __lock.unlock();
215  unique_ptr<_Lock, __lock_external> __lxx(&__lock);
216  lock_guard<unique_lock<mutex> > __lx(__lk, adopt_lock_t());
217  __cv_.wait(__lk);
218} // __mut_.unlock(), __lock.lock()
219
220template <class _Lock, class _Predicate>
221inline void condition_variable_any::wait(_Lock& __lock, _Predicate __pred) {
222  while (!__pred())
223    wait(__lock);
224}
225
226template <class _Lock, class _Clock, class _Duration>
227cv_status condition_variable_any::wait_until(_Lock& __lock, const chrono::time_point<_Clock, _Duration>& __t) {
228  shared_ptr<mutex> __mut = __mut_;
229  unique_lock<mutex> __lk(*__mut);
230  __lock.unlock();
231  unique_ptr<_Lock, __lock_external> __lxx(&__lock);
232  lock_guard<unique_lock<mutex> > __lx(__lk, adopt_lock_t());
233  return __cv_.wait_until(__lk, __t);
234} // __mut_.unlock(), __lock.lock()
235
236template <class _Lock, class _Clock, class _Duration, class _Predicate>
237inline bool
238condition_variable_any::wait_until(_Lock& __lock, const chrono::time_point<_Clock, _Duration>& __t, _Predicate __pred) {
239  while (!__pred())
240    if (wait_until(__lock, __t) == cv_status::timeout)
241      return __pred();
242  return true;
243}
244
245template <class _Lock, class _Rep, class _Period>
246inline cv_status condition_variable_any::wait_for(_Lock& __lock, const chrono::duration<_Rep, _Period>& __d) {
247  return wait_until(__lock, chrono::steady_clock::now() + __d);
248}
249
250template <class _Lock, class _Rep, class _Period, class _Predicate>
251inline bool
252condition_variable_any::wait_for(_Lock& __lock, const chrono::duration<_Rep, _Period>& __d, _Predicate __pred) {
253  return wait_until(__lock, chrono::steady_clock::now() + __d, std::move(__pred));
254}
255
256#  if _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN)
257
258template <class _Lock, class _Predicate>
259bool condition_variable_any::wait(_Lock& __lock, stop_token __stoken, _Predicate __pred) {
260  while (!__stoken.stop_requested()) {
261    if (__pred())
262      return true;
263    wait(__lock);
264  }
265  return __pred();
266}
267
268template <class _Lock, class _Clock, class _Duration, class _Predicate>
269bool condition_variable_any::wait_until(
270    _Lock& __lock, stop_token __stoken, const chrono::time_point<_Clock, _Duration>& __abs_time, _Predicate __pred) {
271  while (!__stoken.stop_requested()) {
272    if (__pred())
273      return true;
274    if (wait_until(__lock, __abs_time) == cv_status::timeout)
275      return __pred();
276  }
277  return __pred();
278}
279
280template <class _Lock, class _Rep, class _Period, class _Predicate>
281bool condition_variable_any::wait_for(
282    _Lock& __lock, stop_token __stoken, const chrono::duration<_Rep, _Period>& __rel_time, _Predicate __pred) {
283  return wait_until(__lock, std::move(__stoken), chrono::steady_clock::now() + __rel_time, std::move(__pred));
284}
285
286#  endif // _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN)
287
288_LIBCPP_EXPORTED_FROM_ABI void notify_all_at_thread_exit(condition_variable&, unique_lock<mutex>);
289
290_LIBCPP_END_NAMESPACE_STD
291
292#endif // !_LIBCPP_HAS_NO_THREADS
293
294#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
295#  include <atomic>
296#  include <concepts>
297#  include <cstdint>
298#  include <cstdlib>
299#  include <cstring>
300#  include <initializer_list>
301#  include <iosfwd>
302#  include <new>
303#  include <stdexcept>
304#  include <system_error>
305#  include <type_traits>
306#  include <typeinfo>
307#endif
308
309#endif // _LIBCPP_CONDITION_VARIABLE
310