1 //===----------------------------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // UNSUPPORTED: libcpp-has-no-threads
11 
12 // <condition_variable>
13 
14 // class condition_variable;
15 
16 // void notify_one();
17 
18 #include <condition_variable>
19 #include <atomic>
20 #include <mutex>
21 #include <thread>
22 #include <cassert>
23 
24 
25 std::condition_variable cv;
26 std::mutex mut;
27 
28 std::atomic_int test1(0);
29 std::atomic_int test2(0);
30 
f1()31 void f1()
32 {
33     std::unique_lock<std::mutex> lk(mut);
34     assert(test1 == 0);
35     while (test1 == 0)
36         cv.wait(lk);
37     assert(test1 == 1);
38     test1 = 2;
39 }
40 
f2()41 void f2()
42 {
43     std::unique_lock<std::mutex> lk(mut);
44     assert(test2 == 0);
45     while (test2 == 0)
46         cv.wait(lk);
47     assert(test2 == 1);
48     test2 = 2;
49 }
50 
main()51 int main()
52 {
53     std::thread t1(f1);
54     std::thread t2(f2);
55     std::this_thread::sleep_for(std::chrono::milliseconds(100));
56     {
57         std::unique_lock<std::mutex>lk(mut);
58         test1 = 1;
59         test2 = 1;
60     }
61     cv.notify_one();
62     {
63         std::this_thread::sleep_for(std::chrono::milliseconds(100));
64         std::unique_lock<std::mutex>lk(mut);
65     }
66     if (test1 == 2)
67     {
68         assert(test2 == 1);
69         t1.join();
70         test1 = 0;
71     }
72     else if (test2 == 2)
73     {
74         assert(test1 == 1);
75         t2.join();
76         test2 = 0;
77     }
78     else
79         assert(false);
80     cv.notify_one();
81     {
82         std::this_thread::sleep_for(std::chrono::milliseconds(100));
83         std::unique_lock<std::mutex>lk(mut);
84     }
85     if (test1 == 2)
86     {
87         assert(test2 == 0);
88         t1.join();
89         test1 = 0;
90     }
91     else if (test2 == 2)
92     {
93         assert(test1 == 0);
94         t2.join();
95         test2 = 0;
96     }
97     else
98         assert(false);
99 }
100