1 //===----------------------------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // UNSUPPORTED: libcpp-has-no-threads
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 struct Clock
28 {
29     typedef std::chrono::milliseconds duration;
30     typedef duration::rep             rep;
31     typedef duration::period          period;
32     typedef std::chrono::time_point<Clock> time_point;
33     static const bool is_steady =  true;
34 
nowClock35     static time_point now()
36     {
37         using namespace std::chrono;
38         return time_point(duration_cast<duration>(
39                 steady_clock::now().time_since_epoch()
40                                                  ));
41     }
42 };
43 
44 std::condition_variable cv;
45 std::mutex mut;
46 
47 int test1 = 0;
48 int test2 = 0;
49 
50 int runs = 0;
51 
f()52 void f()
53 {
54     std::unique_lock<std::mutex> lk(mut);
55     assert(test2 == 0);
56     test1 = 1;
57     cv.notify_one();
58     Clock::time_point t0 = Clock::now();
59     Clock::time_point t = t0 + Clock::duration(250);
60     while (test2 == 0 && cv.wait_until(lk, t) == std::cv_status::no_timeout)
61         ;
62     Clock::time_point t1 = Clock::now();
63     if (runs == 0)
64     {
65         assert(t1 - t0 < Clock::duration(250));
66         assert(test2 != 0);
67     }
68     else
69     {
70         assert(t1 - t0 - Clock::duration(250) < Clock::duration(50));
71         assert(test2 == 0);
72     }
73     ++runs;
74 }
75 
main()76 int main()
77 {
78     {
79         std::unique_lock<std::mutex>lk(mut);
80         std::thread t(f);
81         assert(test1 == 0);
82         while (test1 == 0)
83             cv.wait(lk);
84         assert(test1 != 0);
85         test2 = 1;
86         lk.unlock();
87         cv.notify_one();
88         t.join();
89     }
90     test1 = 0;
91     test2 = 0;
92     {
93         std::unique_lock<std::mutex>lk(mut);
94         std::thread t(f);
95         assert(test1 == 0);
96         while (test1 == 0)
97             cv.wait(lk);
98         assert(test1 != 0);
99         lk.unlock();
100         t.join();
101     }
102 }
103