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 
12 // FLAKY_TEST
13 
14 // <mutex>
15 
16 // template <class Mutex> class unique_lock;
17 
18 // void lock();
19 
20 #include <mutex>
21 #include <thread>
22 #include <cstdlib>
23 #include <cassert>
24 
25 #include "test_macros.h"
26 
27 std::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 
f()35 void f()
36 {
37     std::unique_lock<std::mutex> lk(m, std::defer_lock);
38     time_point t0 = Clock::now();
39     lk.lock();
40     time_point t1 = Clock::now();
41     assert(lk.owns_lock() == true);
42     ns d = t1 - t0 - ms(250);
43     assert(d < ms(25));  // within 25ms
44 #ifndef TEST_HAS_NO_EXCEPTIONS
45     try
46     {
47         lk.lock();
48         assert(false);
49     }
50     catch (std::system_error& e)
51     {
52         assert(e.code().value() == EDEADLK);
53     }
54 #endif
55     lk.unlock();
56     lk.release();
57 #ifndef TEST_HAS_NO_EXCEPTIONS
58     try
59     {
60         lk.lock();
61         assert(false);
62     }
63     catch (std::system_error& e)
64     {
65         assert(e.code().value() == EPERM);
66     }
67 #endif
68 }
69 
main()70 int main()
71 {
72     m.lock();
73     std::thread t(f);
74     std::this_thread::sleep_for(ms(250));
75     m.unlock();
76     t.join();
77 }
78