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 
11 // FLAKY_TEST.
12 
13 // <condition_variable>
14 
15 // class condition_variable_any;
16 
17 // template <class Lock, class Rep, class Period>
18 //   cv_status
19 //   wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time);
20 
21 #include <condition_variable>
22 #include <mutex>
23 #include <thread>
24 #include <chrono>
25 #include <cassert>
26 
27 std::condition_variable_any cv;
28 
29 typedef std::timed_mutex L0;
30 typedef std::unique_lock<L0> L1;
31 
32 L0 m0;
33 
34 int test1 = 0;
35 int test2 = 0;
36 
37 int runs = 0;
38 
39 void f()
40 {
41     typedef std::chrono::system_clock Clock;
42     typedef std::chrono::milliseconds milliseconds;
43     L1 lk(m0);
44     assert(test2 == 0);
45     test1 = 1;
46     cv.notify_one();
47     Clock::time_point t0 = Clock::now();
48     while (test2 == 0 &&
49            cv.wait_for(lk, milliseconds(250)) == std::cv_status::no_timeout)
50         ;
51     Clock::time_point t1 = Clock::now();
52     if (runs == 0)
53     {
54         assert(t1 - t0 < milliseconds(250));
55         assert(test2 != 0);
56     }
57     else
58     {
59         assert(t1 - t0 - milliseconds(250) < milliseconds(50));
60         assert(test2 == 0);
61     }
62     ++runs;
63 }
64 
65 int main(int, char**)
66 {
67     {
68         L1 lk(m0);
69         std::thread t(f);
70         assert(test1 == 0);
71         while (test1 == 0)
72             cv.wait(lk);
73         assert(test1 != 0);
74         test2 = 1;
75         lk.unlock();
76         cv.notify_one();
77         t.join();
78     }
79     test1 = 0;
80     test2 = 0;
81     {
82         L1 lk(m0);
83         std::thread t(f);
84         assert(test1 == 0);
85         while (test1 == 0)
86             cv.wait(lk);
87         assert(test1 != 0);
88         lk.unlock();
89         t.join();
90     }
91 
92   return 0;
93 }
94