xref: /llvm-project/libcxx/test/std/thread/thread.semaphore/try_acquire.pass.cpp (revision fa1c077b41ae1335332d65399802f2c68e82ca7b)
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++03, c++11
11 
12 // This test requires the dylib support introduced in D68480, which shipped in macOS 11.0.
13 // XFAIL: use_system_cxx_lib && target={{.+}}-apple-macosx10.{{9|10|11|12|13|14|15}}
14 
15 // <semaphore>
16 
17 #include <cassert>
18 #include <semaphore>
19 #include <thread>
20 
21 #include "make_test_thread.h"
22 #include "test_macros.h"
23 
24 int main(int, char**)
25 {
26   std::counting_semaphore<> s(1);
27 
28   assert(s.try_acquire());
29   assert(!s.try_acquire());
30   s.release();
31   assert(s.try_acquire());
32   assert(!s.try_acquire());
33   s.release(2);
34   std::thread t = support::make_test_thread([&](){
35     assert(s.try_acquire());
36   });
37   t.join();
38   assert(s.try_acquire());
39   assert(!s.try_acquire());
40 
41   return 0;
42 }
43