xref: /llvm-project/libcxx/test/std/thread/thread.condition/thread.condition.condvar/wait.pass.cpp (revision a7f9895cc18995549c7facb96e72718da282a864)
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: no-threads
10 
11 // <condition_variable>
12 
13 // class condition_variable;
14 
15 // void wait(unique_lock<mutex>& lock);
16 
17 #include <condition_variable>
18 #include <mutex>
19 #include <thread>
20 #include <cassert>
21 
22 #include "make_test_thread.h"
23 #include "test_macros.h"
24 
25 std::condition_variable cv;
26 std::mutex mut;
27 
28 int test1 = 0;
29 int test2 = 0;
30 
f()31 void f()
32 {
33     std::unique_lock<std::mutex> lk(mut);
34     assert(test2 == 0);
35     test1 = 1;
36     cv.notify_one();
37     while (test2 == 0)
38         cv.wait(lk);
39     assert(test2 != 0);
40 }
41 
main(int,char **)42 int main(int, char**)
43 {
44     std::unique_lock<std::mutex> lk(mut);
45     std::thread t = support::make_test_thread(f);
46     assert(test1 == 0);
47     while (test1 == 0)
48         cv.wait(lk);
49     assert(test1 != 0);
50     test2 = 1;
51     lk.unlock();
52     cv.notify_one();
53     t.join();
54 
55   return 0;
56 }
57