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      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 // <shared_mutex>
     11 
     12 // template <class Mutex> class shared_lock;
     13 
     14 // void lock();
     15 
     16 #include <shared_mutex>
     17 #include <thread>
     18 #include <vector>
     19 #include <cstdlib>
     20 #include <cassert>
     21 
     22 #if _LIBCPP_STD_VER > 11
     23 
     24 std::shared_timed_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::shared_lock<std::shared_timed_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 #endif  // _LIBCPP_STD_VER > 11
     64 
     65 int main()
     66 {
     67 #if _LIBCPP_STD_VER > 11
     68     m.lock();
     69     std::vector<std::thread> v;
     70     for (int i = 0; i < 5; ++i)
     71         v.push_back(std::thread(f));
     72     std::this_thread::sleep_for(ms(250));
     73     m.unlock();
     74     for (auto& t : v)
     75         t.join();
     76 #endif  // _LIBCPP_STD_VER > 11
     77 }
     78