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 // template <class Clock, class Duration> 20 // bool try_lock_shared_until(const chrono::time_point<Clock, Duration>& abs_time); 21 22 #include <shared_mutex> 23 #include <thread> 24 #include <vector> 25 #include <cstdlib> 26 #include <cassert> 27 28 #include "test_macros.h" 29 30 std::shared_timed_mutex m; 31 32 typedef std::chrono::steady_clock Clock; 33 typedef Clock::time_point time_point; 34 typedef Clock::duration duration; 35 typedef std::chrono::milliseconds ms; 36 typedef std::chrono::nanoseconds ns; 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_shared_until(Clock::now() + WaitTime + Tolerance) == true); 53 time_point t1 = Clock::now(); 54 m.unlock_shared(); 55 ns d = t1 - t0 - WaitTime; 56 assert(d < Tolerance); // within 50ms 57 } 58 59 void f2() 60 { 61 time_point t0 = Clock::now(); 62 assert(m.try_lock_shared_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::vector<std::thread> v; 73 for (int i = 0; i < 5; ++i) 74 v.push_back(std::thread(f1)); 75 std::this_thread::sleep_for(WaitTime); 76 m.unlock(); 77 for (auto& t : v) 78 t.join(); 79 } 80 { 81 m.lock(); 82 std::vector<std::thread> v; 83 for (int i = 0; i < 5; ++i) 84 v.push_back(std::thread(f2)); 85 std::this_thread::sleep_for(WaitTime + Tolerance); 86 m.unlock(); 87 for (auto& t : v) 88 t.join(); 89 } 90 } 91
