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
11
12// Until we drop support for the synchronization library in C++11/14/17
13// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
14
15// XFAIL: availability-synchronization_library-missing
16
17// <semaphore>
18
19#include <cassert>
20#include <semaphore>
21#include <thread>
22
23#include "make_test_thread.h"
24#include "test_macros.h"
25
26int main(int, char**)
27{
28 std::counting_semaphore<> s(1);
29
30 assert(s.try_acquire());
31 assert(!s.try_acquire());
32 s.release();
33 assert(s.try_acquire());
34 assert(!s.try_acquire());
35 s.release(2);
36 std::thread t = support::make_test_thread([&](){
37 assert(s.try_acquire());
38 });
39 t.join();
40 assert(s.try_acquire());
41 assert(!s.try_acquire());
42
43 return 0;
44}
45

source code of libcxx/test/std/thread/thread.semaphore/try_acquire.pass.cpp