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 // shared_lock(mutex_type& m, 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 std::shared_lock<std::shared_timed_mutex> lk(m, Clock::now() + WaitTime + Tolerance); 53 assert(lk.owns_lock() == true); 54 time_point t1 = Clock::now(); 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 std::shared_lock<std::shared_timed_mutex> lk(m, Clock::now() + WaitTime); 63 assert(lk.owns_lock() == false); 64 time_point t1 = Clock::now(); 65 ns d = t1 - t0 - WaitTime; 66 assert(d < Tolerance); // within 50ms 67 } 68 69 int main() 70 { 71 { 72 m.lock(); 73 std::vector<std::thread> v; 74 for (int i = 0; i < 5; ++i) 75 v.push_back(std::thread(f1)); 76 std::this_thread::sleep_for(WaitTime); 77 m.unlock(); 78 for (auto& t : v) 79 t.join(); 80 } 81 { 82 m.lock(); 83 std::vector<std::thread> v; 84 for (int i = 0; i < 5; ++i) 85 v.push_back(std::thread(f2)); 86 std::this_thread::sleep_for(WaitTime + Tolerance); 87 m.unlock(); 88 for (auto& t : v) 89 t.join(); 90 } 91 } 92
