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 Rep, class Period, class Predicate>
20 //     bool
21 //     wait_for(unique_lock<mutex>& lock,
22 //              const chrono::duration<Rep, Period>& rel_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 class Pred
35 {
36     int& i_;
37 public:
38     explicit Pred(int& i) : i_(i) {}
39 
40     bool operator()() {return i_ != 0;}
41 };
42 
43 std::condition_variable cv;
44 std::mutex mut;
45 
46 int test1 = 0;
47 int test2 = 0;
48 
49 int runs = 0;
50 
51 void f()
52 {
53     typedef std::chrono::system_clock Clock;
54     typedef std::chrono::milliseconds milliseconds;
55     std::unique_lock<std::mutex> lk(mut);
56     assert(test2 == 0);
57     test1 = 1;
58     cv.notify_one();
59     Clock::time_point t0 = Clock::now();
60     bool r = cv.wait_for(lk, milliseconds(250), Pred(test2));
61     ((void)r); // Prevent unused warning
62     Clock::time_point t1 = Clock::now();
63     if (runs == 0)
64     {
65         assert(t1 - t0 < milliseconds(250));
66         assert(test2 != 0);
67     }
68     else
69     {
70         assert(t1 - t0 - milliseconds(250) < milliseconds(50));
71         assert(test2 == 0);
72     }
73     ++runs;
74 }
75 
76 int main(int, char**)
77 {
78     {
79         std::unique_lock<std::mutex>lk(mut);
80         std::thread t = support::make_test_thread(f);
81         assert(test1 == 0);
82         while (test1 == 0)
83             cv.wait(lk);
84         assert(test1 != 0);
85         test2 = 1;
86         lk.unlock();
87         cv.notify_one();
88         t.join();
89     }
90     test1 = 0;
91     test2 = 0;
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         lk.unlock();
100         t.join();
101     }
102 
103   return 0;
104 }
105