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 // UNSUPPORTED: libcpp-has-no-threads
11 // UNSUPPORTED: c++98, c++03, c++11
12 
13 // <shared_mutex>
14 
15 // template <class Mutex> class shared_lock;
16 
17 // void lock();
18 
19 #include <shared_mutex>
20 #include <thread>
21 #include <vector>
22 #include <cstdlib>
23 #include <cassert>
24 
25 #include "test_macros.h"
26 
27 std::shared_timed_mutex m;
28 
29 typedef std::chrono::system_clock Clock;
30 typedef Clock::time_point time_point;
31 typedef Clock::duration duration;
32 typedef std::chrono::milliseconds ms;
33 typedef std::chrono::nanoseconds ns;
34 
35 ms WaitTime = ms(250);
36 
37 // Thread sanitizer causes more overhead and will sometimes cause this test
38 // to fail. To prevent this we give Thread sanitizer more time to complete the
39 // test.
40 #if !defined(TEST_HAS_SANITIZERS)
41 ms Tolerance = ms(25);
42 #else
43 ms Tolerance = ms(25 * 5);
44 #endif
45 
46 
f()47 void f()
48 {
49     std::shared_lock<std::shared_timed_mutex> lk(m, std::defer_lock);
50     time_point t0 = Clock::now();
51     lk.lock();
52     time_point t1 = Clock::now();
53     assert(lk.owns_lock() == true);
54     ns d = t1 - t0 - WaitTime;
55     assert(d < Tolerance);  // within tolerance
56 #ifndef TEST_HAS_NO_EXCEPTIONS
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 #endif
67     lk.unlock();
68     lk.release();
69 #ifndef TEST_HAS_NO_EXCEPTIONS
70     try
71     {
72         lk.lock();
73         assert(false);
74     }
75     catch (std::system_error& e)
76     {
77         assert(e.code().value() == EPERM);
78     }
79 #endif
80 }
81 
main()82 int main()
83 {
84     m.lock();
85     std::vector<std::thread> v;
86     for (int i = 0; i < 5; ++i)
87         v.push_back(std::thread(f));
88     std::this_thread::sleep_for(WaitTime);
89     m.unlock();
90     for (auto& t : v)
91         t.join();
92 }
93