xref: /llvm-project/libcxx/test/std/thread/thread.semaphore/try_acquire.pass.cpp (revision bf1666fb0bc19ffa18072e2727e4611c293a9aee)
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 // UNSUPPORTED: c++03, c++11, c++14, c++17
11 
12 // XFAIL: availability-synchronization_library-missing
13 
14 // <semaphore>
15 
16 #include <cassert>
17 #include <semaphore>
18 #include <thread>
19 
20 #include "make_test_thread.h"
21 #include "test_macros.h"
22 
23 int main(int, char**)
24 {
25   std::counting_semaphore<> s(1);
26 
27   assert(s.try_acquire());
28   assert(!s.try_acquire());
29   s.release();
30   assert(s.try_acquire());
31   assert(!s.try_acquire());
32   s.release(2);
33   std::thread t = support::make_test_thread([&](){
34     assert(s.try_acquire());
35   });
36   t.join();
37   assert(s.try_acquire());
38   assert(!s.try_acquire());
39 
40   return 0;
41 }
42