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++03, c++98, c++11 12 13 // FLAKY_TEST. 14 15 // <shared_mutex> 16 17 // class shared_timed_mutex; 18 19 // void lock(); 20 21 #include <shared_mutex> 22 #include <thread> 23 #include <cstdlib> 24 #include <cassert> 25 26 #include "test_macros.h" 27 28 std::shared_timed_mutex m; 29 30 typedef std::chrono::system_clock Clock; 31 typedef Clock::time_point time_point; 32 typedef Clock::duration duration; 33 typedef std::chrono::milliseconds ms; 34 typedef std::chrono::nanoseconds ns; 35 36 37 ms WaitTime = ms(250); 38 39 // Thread sanitizer causes more overhead and will sometimes cause this test 40 // to fail. To prevent this we give Thread sanitizer more time to complete the 41 // test. 42 #if !TEST_HAS_FEATURE(thread_sanitizer) 43 ms Tolerance = ms(50); 44 #else 45 ms Tolerance = ms(100); 46 #endif 47 48 f()49void f() 50 { 51 time_point t0 = Clock::now(); 52 m.lock(); 53 time_point t1 = Clock::now(); 54 m.unlock(); 55 ns d = t1 - t0 - ms(250); 56 assert(d < ms(50)); // within 50ms 57 } 58 main()59int main() 60 { 61 m.lock(); 62 std::thread t(f); 63 std::this_thread::sleep_for(ms(250)); 64 m.unlock(); 65 t.join(); 66 } 67