//===----------------------------------------------------------------------===// // // The LLVM Compiler Infrastructure // // This file is dual licensed under the MIT and the University of Illinois Open // Source Licenses. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // template class lock_guard; // explicit lock_guard(mutex_type& m); #include #include #include #include std::mutex m; typedef std::chrono::system_clock Clock; typedef Clock::time_point time_point; typedef Clock::duration duration; typedef std::chrono::milliseconds ms; typedef std::chrono::nanoseconds ns; void f() { time_point t0 = Clock::now(); time_point t1; { std::lock_guard lg = m; t1 = Clock::now(); } ns d = t1 - t0 - ms(250); assert(d < ns(2500000)); // within 2.5ms } int main() { m.lock(); std::thread t(f); std::this_thread::sleep_for(ms(250)); m.unlock(); t.join(); }