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 // UNSUPPORTED: c++98, c++03, c++11 12 13 // FLAKY_TEST. 14 15 // <shared_mutex> 16 17 // class shared_timed_mutex; 18 19 // template <class Clock, class Duration> 20 // bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time); 21 22 #include <shared_mutex> 23 #include <thread> 24 #include <cstdlib> 25 #include <cassert> 26 27 #include "test_macros.h" 28 29 std::shared_timed_mutex m; 30 31 typedef std::chrono::steady_clock Clock; 32 typedef Clock::time_point time_point; 33 typedef Clock::duration duration; 34 typedef std::chrono::milliseconds ms; 35 typedef std::chrono::nanoseconds ns; 36 37 38 ms WaitTime = ms(250); 39 40 // Thread sanitizer causes more overhead and will sometimes cause this test 41 // to fail. To prevent this we give Thread sanitizer more time to complete the 42 // test. 43 #if !defined(TEST_HAS_SANITIZERS) 44 ms Tolerance = ms(50); 45 #else 46 ms Tolerance = ms(50 * 5); 47 #endif 48 49 void f1() 50 { 51 time_point t0 = Clock::now(); 52 assert(m.try_lock_until(Clock::now() + WaitTime + Tolerance) == true); 53 time_point t1 = Clock::now(); 54 m.unlock(); 55 ns d = t1 - t0 - WaitTime; 56 assert(d < Tolerance); // within tolerance 57 } 58 59 void f2() 60 { 61 time_point t0 = Clock::now(); 62 assert(m.try_lock_until(Clock::now() + WaitTime) == false); 63 time_point t1 = Clock::now(); 64 ns d = t1 - t0 - WaitTime; 65 assert(d < Tolerance); // within tolerance 66 } 67 68 int main() 69 { 70 { 71 m.lock(); 72 std::thread t(f1); 73 std::this_thread::sleep_for(WaitTime); 74 m.unlock(); 75 t.join(); 76 } 77 { 78 m.lock(); 79 std::thread t(f2); 80 std::this_thread::sleep_for(WaitTime + Tolerance); 81 m.unlock(); 82 t.join(); 83 } 84 } 85
