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 // 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 // template <class Clock, class Duration>
22 //     bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
23 
24 #include <shared_mutex>
25 #include <thread>
26 #include <cstdlib>
27 #include <cassert>
28 
29 #include "make_test_thread.h"
30 #include "test_macros.h"
31 
32 std::shared_timed_mutex m;
33 
34 typedef std::chrono::steady_clock Clock;
35 typedef Clock::time_point time_point;
36 typedef Clock::duration duration;
37 typedef std::chrono::milliseconds ms;
38 typedef std::chrono::nanoseconds ns;
39 
40 
41 ms WaitTime = ms(250);
42 
43 // Thread sanitizer causes more overhead and will sometimes cause this test
44 // to fail. To prevent this we give Thread sanitizer more time to complete the
45 // test.
46 #if !defined(TEST_HAS_SANITIZERS)
47 ms Tolerance = ms(50);
48 #else
49 ms Tolerance = ms(50 * 5);
50 #endif
51 
f1()52 void f1()
53 {
54     time_point t0 = Clock::now();
55     assert(m.try_lock_until(Clock::now() + WaitTime + Tolerance) == true);
56     time_point t1 = Clock::now();
57     m.unlock();
58     ns d = t1 - t0 - WaitTime;
59     assert(d < Tolerance);  // within tolerance
60 }
61 
f2()62 void f2()
63 {
64     time_point t0 = Clock::now();
65     assert(m.try_lock_until(Clock::now() + WaitTime) == false);
66     time_point t1 = Clock::now();
67     ns d = t1 - t0 - WaitTime;
68     assert(d < Tolerance);  // within tolerance
69 }
70 
main(int,char **)71 int main(int, char**)
72 {
73     {
74         m.lock();
75         std::thread t = support::make_test_thread(f1);
76         std::this_thread::sleep_for(WaitTime);
77         m.unlock();
78         t.join();
79     }
80     {
81         m.lock();
82         std::thread t = support::make_test_thread(f2);
83         std::this_thread::sleep_for(WaitTime + Tolerance);
84         m.unlock();
85         t.join();
86     }
87 
88   return 0;
89 }
90