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 // ALLOW_RETRIES: 2
13 
14 // shared_timed_mutex was introduced in macosx10.12
15 // UNSUPPORTED: use_system_cxx_lib && target={{.+}}-apple-macosx10.{{9|10|11}}
16 
17 // <shared_mutex>
18 
19 // class shared_timed_mutex;
20 
21 // bool try_lock();
22 
23 #include <shared_mutex>
24 #include <thread>
25 #include <cstdlib>
26 #include <cassert>
27 
28 #include "make_test_thread.h"
29 #include "test_macros.h"
30 
31 std::shared_timed_mutex m;
32 
33 typedef std::chrono::system_clock Clock;
34 typedef Clock::time_point time_point;
35 typedef Clock::duration duration;
36 typedef std::chrono::milliseconds ms;
37 typedef std::chrono::nanoseconds ns;
38 
39 void f()
40 {
41     time_point t0 = Clock::now();
42     assert(!m.try_lock());
43     assert(!m.try_lock());
44     assert(!m.try_lock());
45     while(!m.try_lock())
46         ;
47     time_point t1 = Clock::now();
48     m.unlock();
49     ns d = t1 - t0 - ms(250);
50     assert(d < ms(200));  // within 200ms
51 }
52 
53 int main(int, char**)
54 {
55     m.lock();
56     std::thread t = support::make_test_thread(f);
57     std::this_thread::sleep_for(ms(250));
58     m.unlock();
59     t.join();
60 
61   return 0;
62 }
63