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 // FLAKY_TEST 13 14 // <mutex> 15 16 // template <class Mutex> class lock_guard; 17 18 // lock_guard(mutex_type& m, adopt_lock_t); 19 20 #include <mutex> 21 #include <thread> 22 #include <cstdlib> 23 #include <cassert> 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 33 void f() 34 { 35 time_point t0 = Clock::now(); 36 time_point t1; 37 { 38 m.lock(); 39 std::lock_guard<std::mutex> lg(m, std::adopt_lock); 40 t1 = Clock::now(); 41 } 42 ns d = t1 - t0 - ms(250); 43 assert(d < ms(50)); // within 50ms 44 } 45 46 int main() 47 { 48 m.lock(); 49 std::thread t(f); 50 std::this_thread::sleep_for(ms(250)); 51 m.unlock(); 52 t.join(); 53 } 54
