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 // <condition_variable>
12 
13 // class condition_variable_any;
14 
15 // template <class Lock, class Rep, class Period, class Predicate>
16 //   bool
17 //   wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time,
18 //            Predicate pred);
19 
20 #include <condition_variable>
21 #include <mutex>
22 #include <thread>
23 #include <chrono>
24 #include <cassert>
25 
26 class Pred
27 {
28     int& i_;
29 public:
30     explicit Pred(int& i) : i_(i) {}
31 
32     bool operator()() {return i_ != 0;}
33 };
34 
35 std::condition_variable_any cv;
36 
37 typedef std::timed_mutex L0;
38 typedef std::unique_lock<L0> L1;
39 
40 L0 m0;
41 
42 int test1 = 0;
43 int test2 = 0;
44 
45 int runs = 0;
46 bool expect_result = false;
47 
48 void f()
49 {
50     typedef std::chrono::system_clock Clock;
51     typedef std::chrono::milliseconds milliseconds;
52     L1 lk(m0);
53     assert(test2 == 0);
54     test1 = 1;
55     cv.notify_one();
56     Clock::time_point t0 = Clock::now();
57     bool result = cv.wait_for(lk, milliseconds(250), Pred(test2));
58     assert(result == expect_result);
59     Clock::time_point t1 = Clock::now();
60     if (runs == 0)
61     {
62         assert(t1 - t0 < milliseconds(250));
63         assert(test2 != 0);
64     }
65     else
66     {
67         assert(t1 - t0 - milliseconds(250) < milliseconds(50));
68         assert(test2 == 0);
69     }
70     ++runs;
71 }
72 
73 int main(int, char**)
74 {
75     {
76         expect_result = true;
77         L1 lk(m0);
78         std::thread t(f);
79         assert(test1 == 0);
80         while (test1 == 0)
81             cv.wait(lk);
82         assert(test1 != 0);
83         test2 = 1;
84         lk.unlock();
85         cv.notify_one();
86         t.join();
87     }
88     test1 = 0;
89     test2 = 0;
90     {
91         expect_result = false;
92         L1 lk(m0);
93         std::thread t(f);
94         assert(test1 == 0);
95         while (test1 == 0)
96             cv.wait(lk);
97         assert(test1 != 0);
98         lk.unlock();
99         t.join();
100     }
101 
102   return 0;
103 }
104