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 
13 // <mutex>
14 
15 // template <class Mutex> class unique_lock;
16 
17 // void lock();
18 
19 #include <mutex>
20 #include <thread>
21 #include <cstdlib>
22 #include <cassert>
23 
24 std::mutex m;
25 
26 typedef std::chrono::system_clock Clock;
27 typedef Clock::time_point time_point;
28 typedef Clock::duration duration;
29 typedef std::chrono::milliseconds ms;
30 typedef std::chrono::nanoseconds ns;
31 
32 void f()
33 {
34     std::unique_lock<std::mutex> lk(m, std::defer_lock);
35     time_point t0 = Clock::now();
36     lk.lock();
37     time_point t1 = Clock::now();
38     assert(lk.owns_lock() == true);
39     ns d = t1 - t0 - ms(250);
40     assert(d < ms(25));  // within 25ms
41     try
42     {
43         lk.lock();
44         assert(false);
45     }
46     catch (std::system_error& e)
47     {
48         assert(e.code().value() == EDEADLK);
49     }
50     lk.unlock();
51     lk.release();
52     try
53     {
54         lk.lock();
55         assert(false);
56     }
57     catch (std::system_error& e)
58     {
59         assert(e.code().value() == EPERM);
60     }
61 }
62 
63 int main()
64 {
65     m.lock();
66     std::thread t(f);
67     std::this_thread::sleep_for(ms(250));
68     m.unlock();
69     t.join();
70 }
71