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 // <mutex> 13 14 // class mutex; 15 16 // void lock(); 17 18 #include <mutex> 19 #include <thread> 20 #include <cstdlib> 21 #include <cassert> 22 23 #include <iostream> 24 25 std::mutex m; 26 27 typedef std::chrono::system_clock Clock; 28 typedef Clock::time_point time_point; 29 typedef Clock::duration duration; 30 typedef std::chrono::milliseconds ms; 31 typedef std::chrono::nanoseconds ns; 32 f()33void f() 34 { 35 time_point t0 = Clock::now(); 36 m.lock(); 37 time_point t1 = Clock::now(); 38 m.unlock(); 39 ns d = t1 - t0 - ms(250); 40 assert(d < ms(50)); // within 50ms 41 } 42 main()43int main() 44 { 45 m.lock(); 46 std::thread t(f); 47 std::this_thread::sleep_for(ms(250)); 48 m.unlock(); 49 t.join(); 50 } 51