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 // class shared_mutex; 13 14 // template <class Rep, class Period> 15 // bool try_lock_for(const chrono::duration<Rep, Period>& rel_time); 16 17 #include <shared_mutex> 18 #include <thread> 19 #include <cstdlib> 20 #include <cassert> 21 22 #if _LIBCPP_STD_VER > 11 23 24 std::shared_mutex m; 25 26 typedef std::chrono::steady_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 f1()32void f1() 33 { 34 time_point t0 = Clock::now(); 35 assert(m.try_lock_for(ms(300)) == true); 36 time_point t1 = Clock::now(); 37 m.unlock(); 38 ns d = t1 - t0 - ms(250); 39 assert(d < ms(50)); // within 50ms 40 } 41 f2()42void f2() 43 { 44 time_point t0 = Clock::now(); 45 assert(m.try_lock_for(ms(250)) == false); 46 time_point t1 = Clock::now(); 47 ns d = t1 - t0 - ms(250); 48 assert(d < ms(50)); // within 50ms 49 } 50 51 #endif // _LIBCPP_STD_VER > 11 52 main()53int main() 54 { 55 #if _LIBCPP_STD_VER > 11 56 { 57 m.lock(); 58 std::thread t(f1); 59 std::this_thread::sleep_for(ms(250)); 60 m.unlock(); 61 t.join(); 62 } 63 { 64 m.lock(); 65 std::thread t(f2); 66 std::this_thread::sleep_for(ms(300)); 67 m.unlock(); 68 t.join(); 69 } 70 #endif // _LIBCPP_STD_VER > 11 71 } 72