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 // ALLOW_RETRIES: 2
12 
13 // shared_timed_mutex was introduced in macosx10.12
14 // UNSUPPORTED: use_system_cxx_lib && target={{.+}}-apple-macosx10.{{9|10|11}}
15 
16 // <shared_mutex>
17 
18 // class shared_timed_mutex;
19 
20 // template <class Rep, class Period>
21 //     bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
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::steady_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 
40 ms WaitTime = ms(250);
41 
42 // Thread sanitizer causes more overhead and will sometimes cause this test
43 // to fail. To prevent this we give Thread sanitizer more time to complete the
44 // test.
45 #if !defined(TEST_HAS_SANITIZERS)
46 ms Tolerance = ms(50);
47 #else
48 ms Tolerance = ms(50 * 5);
49 #endif
50 
f1()51 void f1()
52 {
53     time_point t0 = Clock::now();
54     assert(m.try_lock_for(WaitTime + Tolerance) == true);
55     time_point t1 = Clock::now();
56     m.unlock();
57     ns d = t1 - t0 - WaitTime;
58     assert(d < Tolerance);  // within tolerance
59 }
60 
f2()61 void f2()
62 {
63     time_point t0 = Clock::now();
64     assert(m.try_lock_for(WaitTime) == false);
65     time_point t1 = Clock::now();
66     ns d = t1 - t0 - WaitTime;
67     assert(d < Tolerance);  // within tolerance
68 }
69 
main(int,char **)70 int main(int, char**)
71 {
72     {
73         m.lock();
74         std::thread t = support::make_test_thread(f1);
75         std::this_thread::sleep_for(WaitTime);
76         m.unlock();
77         t.join();
78     }
79     {
80         m.lock();
81         std::thread t = support::make_test_thread(f2);
82         std::this_thread::sleep_for(WaitTime + Tolerance);
83         m.unlock();
84         t.join();
85     }
86 
87   return 0;
88 }
89