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 // ALLOW_RETRIES: 2
12 
13 // <condition_variable>
14 
15 // class condition_variable;
16 
17 // template <class Clock, class Duration, class Predicate>
18 //     bool
19 //     wait_until(unique_lock<mutex>& lock,
20 //                const chrono::time_point<Clock, Duration>& abs_time,
21 //                Predicate pred);
22 
23 #include <condition_variable>
24 #include <mutex>
25 #include <thread>
26 #include <chrono>
27 #include <cassert>
28 
29 #include "make_test_thread.h"
30 #include "test_macros.h"
31 
32 struct Clock
33 {
34     typedef std::chrono::milliseconds duration;
35     typedef duration::rep             rep;
36     typedef duration::period          period;
37     typedef std::chrono::time_point<Clock> time_point;
38     static const bool is_steady =  true;
39 
40     static time_point now()
41     {
42         using namespace std::chrono;
43         return time_point(duration_cast<duration>(
44                 steady_clock::now().time_since_epoch()
45                                                  ));
46     }
47 };
48 
49 class Pred
50 {
51     int& i_;
52 public:
53     explicit Pred(int& i) : i_(i) {}
54 
55     bool operator()() {return i_ != 0;}
56 };
57 
58 std::condition_variable cv;
59 std::mutex mut;
60 
61 int test1 = 0;
62 int test2 = 0;
63 
64 int runs = 0;
65 
66 void f()
67 {
68     std::unique_lock<std::mutex> lk(mut);
69     assert(test2 == 0);
70     test1 = 1;
71     cv.notify_one();
72     Clock::time_point t0 = Clock::now();
73     Clock::time_point t = t0 + Clock::duration(250);
74     bool r = cv.wait_until(lk, t, Pred(test2));
75     Clock::time_point t1 = Clock::now();
76     if (runs == 0)
77     {
78         assert(t1 - t0 < Clock::duration(250));
79         assert(test2 != 0);
80         assert(r);
81     }
82     else
83     {
84         assert(t1 - t0 - Clock::duration(250) < Clock::duration(50));
85         assert(test2 == 0);
86         assert(!r);
87     }
88     ++runs;
89 }
90 
91 int main(int, char**)
92 {
93     {
94         std::unique_lock<std::mutex> lk(mut);
95         std::thread t = support::make_test_thread(f);
96         assert(test1 == 0);
97         while (test1 == 0)
98             cv.wait(lk);
99         assert(test1 != 0);
100         test2 = 1;
101         lk.unlock();
102         cv.notify_one();
103         t.join();
104     }
105     test1 = 0;
106     test2 = 0;
107     {
108         std::unique_lock<std::mutex> lk(mut);
109         std::thread t = support::make_test_thread(f);
110         assert(test1 == 0);
111         while (test1 == 0)
112             cv.wait(lk);
113         assert(test1 != 0);
114         lk.unlock();
115         t.join();
116     }
117 
118   return 0;
119 }
120