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 // UNSUPPORTED: c++98, c++03, c++11
11 
12 // <semaphore>
13 
14 #include <semaphore>
15 #include <thread>
16 #include <chrono>
17 
18 #include "test_macros.h"
19 
20 int main(int, char**)
21 {
22   auto const start = std::chrono::steady_clock::now();
23 
24   std::counting_semaphore<> s(0);
25 
26   assert(!s.try_acquire_until(start + std::chrono::milliseconds(250)));
27   assert(!s.try_acquire_for(std::chrono::milliseconds(250)));
28 
29   std::thread t([&](){
30     std::this_thread::sleep_for(std::chrono::milliseconds(250));
31     s.release();
32     std::this_thread::sleep_for(std::chrono::milliseconds(250));
33     s.release();
34   });
35 
36   assert(s.try_acquire_until(start + std::chrono::seconds(2)));
37   assert(s.try_acquire_for(std::chrono::seconds(2)));
38   t.join();
39 
40   auto const end = std::chrono::steady_clock::now();
41   assert(end - start < std::chrono::seconds(10));
42 
43   return 0;
44 }
45