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 // TODO(ldionne): This test fails on Ubuntu Focal on our CI nodes (and only there), in 32 bit mode.
13 // UNSUPPORTED: linux && 32bits-on-64bits
14 
15 // <condition_variable>
16 
17 // class condition_variable;
18 
19 // template <class Clock, class Duration, class Predicate>
20 //     bool
21 //     wait_until(unique_lock<mutex>& lock,
22 //                const chrono::time_point<Clock, Duration>& abs_time,
23 //                Predicate pred);
24 
25 #include <condition_variable>
26 #include <mutex>
27 #include <thread>
28 #include <chrono>
29 #include <cassert>
30 
31 #include "make_test_thread.h"
32 #include "test_macros.h"
33 
34 struct Clock
35 {
36     typedef std::chrono::milliseconds duration;
37     typedef duration::rep             rep;
38     typedef duration::period          period;
39     typedef std::chrono::time_point<Clock> time_point;
40     static const bool is_steady =  true;
41 
42     static time_point now()
43     {
44         using namespace std::chrono;
45         return time_point(duration_cast<duration>(
46                 steady_clock::now().time_since_epoch()
47                                                  ));
48     }
49 };
50 
51 class Pred
52 {
53     int& i_;
54 public:
55     explicit Pred(int& i) : i_(i) {}
56 
57     bool operator()() {return i_ != 0;}
58 };
59 
60 std::condition_variable cv;
61 std::mutex mut;
62 
63 int test1 = 0;
64 int test2 = 0;
65 
66 int runs = 0;
67 
68 void f()
69 {
70     std::unique_lock<std::mutex> lk(mut);
71     assert(test2 == 0);
72     test1 = 1;
73     cv.notify_one();
74     Clock::time_point t0 = Clock::now();
75     Clock::time_point t = t0 + Clock::duration(250);
76     bool r = cv.wait_until(lk, t, Pred(test2));
77     Clock::time_point t1 = Clock::now();
78     if (runs == 0)
79     {
80         assert(t1 - t0 < Clock::duration(250));
81         assert(test2 != 0);
82         assert(r);
83     }
84     else
85     {
86         assert(t1 - t0 - Clock::duration(250) < Clock::duration(50));
87         assert(test2 == 0);
88         assert(!r);
89     }
90     ++runs;
91 }
92 
93 int main(int, char**)
94 {
95     {
96         std::unique_lock<std::mutex> lk(mut);
97         std::thread t = support::make_test_thread(f);
98         assert(test1 == 0);
99         while (test1 == 0)
100             cv.wait(lk);
101         assert(test1 != 0);
102         test2 = 1;
103         lk.unlock();
104         cv.notify_one();
105         t.join();
106     }
107     test1 = 0;
108     test2 = 0;
109     {
110         std::unique_lock<std::mutex> lk(mut);
111         std::thread t = support::make_test_thread(f);
112         assert(test1 == 0);
113         while (test1 == 0)
114             cv.wait(lk);
115         assert(test1 != 0);
116         lk.unlock();
117         t.join();
118     }
119 
120   return 0;
121 }
122