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