1 //===----------------------------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // XFAIL: libcpp-no-exceptions
11 // UNSUPPORTED: libcpp-has-no-threads
12 // UNSUPPORTED: c++98, c++03, c++11
13 
14 // <shared_mutex>
15 
16 // template <class Mutex> class shared_lock;
17 
18 // void lock();
19 
20 #include <shared_mutex>
21 #include <thread>
22 #include <vector>
23 #include <cstdlib>
24 #include <cassert>
25 
26 #include "test_macros.h"
27 
28 std::shared_timed_mutex m;
29 
30 typedef std::chrono::system_clock Clock;
31 typedef Clock::time_point time_point;
32 typedef Clock::duration duration;
33 typedef std::chrono::milliseconds ms;
34 typedef std::chrono::nanoseconds ns;
35 
36 ms WaitTime = ms(250);
37 
38 // Thread sanitizer causes more overhead and will sometimes cause this test
39 // to fail. To prevent this we give Thread sanitizer more time to complete the
40 // test.
41 #if !defined(TEST_HAS_SANITIZERS)
42 ms Tolerance = ms(25);
43 #else
44 ms Tolerance = ms(25 * 5);
45 #endif
46 
47 
48 void f()
49 {
50     std::shared_lock<std::shared_timed_mutex> lk(m, std::defer_lock);
51     time_point t0 = Clock::now();
52     lk.lock();
53     time_point t1 = Clock::now();
54     assert(lk.owns_lock() == true);
55     ns d = t1 - t0 - WaitTime;
56     assert(d < Tolerance);  // within tolerance
57     try
58     {
59         lk.lock();
60         assert(false);
61     }
62     catch (std::system_error& e)
63     {
64         assert(e.code().value() == EDEADLK);
65     }
66     lk.unlock();
67     lk.release();
68     try
69     {
70         lk.lock();
71         assert(false);
72     }
73     catch (std::system_error& e)
74     {
75         assert(e.code().value() == EPERM);
76     }
77 }
78 
79 int main()
80 {
81     m.lock();
82     std::vector<std::thread> v;
83     for (int i = 0; i < 5; ++i)
84         v.push_back(std::thread(f));
85     std::this_thread::sleep_for(WaitTime);
86     m.unlock();
87     for (auto& t : v)
88         t.join();
89 }
90