1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // UNSUPPORTED: libcpp-has-no-threads
10 // ALLOW_RETRIES: 2
11 
12 // <condition_variable>
13 
14 // class condition_variable;
15 
16 // template <class Clock, class Duration>
17 //   cv_status
18 //   wait_until(unique_lock<mutex>& lock,
19 //              const chrono::time_point<Clock, Duration>& abs_time);
20 
21 #include <condition_variable>
22 #include <mutex>
23 #include <thread>
24 #include <chrono>
25 #include <cassert>
26 
27 #include "make_test_thread.h"
28 #include "test_macros.h"
29 
30 struct TestClock
31 {
32     typedef std::chrono::milliseconds duration;
33     typedef duration::rep             rep;
34     typedef duration::period          period;
35     typedef std::chrono::time_point<TestClock> time_point;
36     static const bool is_steady =  true;
37 
38     static time_point now()
39     {
40         using namespace std::chrono;
41         return time_point(duration_cast<duration>(
42                 steady_clock::now().time_since_epoch()
43                                                  ));
44     }
45 };
46 
47 std::condition_variable cv;
48 std::mutex mut;
49 
50 int test1 = 0;
51 int test2 = 0;
52 
53 int runs = 0;
54 
55 template <typename Clock>
56 void f()
57 {
58     std::unique_lock<std::mutex> lk(mut);
59     assert(test2 == 0);
60     test1 = 1;
61     cv.notify_one();
62     typename Clock::time_point t0 = Clock::now();
63     typename Clock::time_point t = t0 + std::chrono::milliseconds(250);
64     while (test2 == 0 && cv.wait_until(lk, t) == std::cv_status::no_timeout)
65         ;
66     typename Clock::time_point t1 = Clock::now();
67     if (runs == 0)
68     {
69         assert(t1 - t0 < std::chrono::milliseconds(250));
70         assert(test2 != 0);
71     }
72     else
73     {
74         assert(t1 - t0 - std::chrono::milliseconds(250) < std::chrono::milliseconds(50));
75         assert(test2 == 0);
76     }
77     ++runs;
78 }
79 
80 template <typename Clock>
81 void run_test()
82 {
83     runs = 0;
84     test1 = 0;
85     test2 = 0;
86     {
87         std::unique_lock<std::mutex>lk(mut);
88         std::thread t = support::make_test_thread(f<Clock>);
89         assert(test1 == 0);
90         while (test1 == 0)
91             cv.wait(lk);
92         assert(test1 != 0);
93         test2 = 1;
94         lk.unlock();
95         cv.notify_one();
96         t.join();
97     }
98     test1 = 0;
99     test2 = 0;
100     {
101         std::unique_lock<std::mutex>lk(mut);
102         std::thread t = support::make_test_thread(f<Clock>);
103         assert(test1 == 0);
104         while (test1 == 0)
105             cv.wait(lk);
106         assert(test1 != 0);
107         lk.unlock();
108         t.join();
109     }
110 }
111 
112 int main(int, char**)
113 {
114     run_test<TestClock>();
115     run_test<std::chrono::steady_clock>();
116     run_test<std::chrono::system_clock>();
117     return 0;
118 }
119