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