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 // <condition_variable> 11 12 // class condition_variable; 13 14 // template <class Clock, class Duration> 15 // cv_status 16 // wait_until(unique_lock<mutex>& lock, 17 // const chrono::time_point<Clock, Duration>& abs_time); 18 19 #include <condition_variable> 20 #include <mutex> 21 #include <thread> 22 #include <chrono> 23 #include <cassert> 24 25 struct Clock 26 { 27 typedef std::chrono::milliseconds duration; 28 typedef duration::rep rep; 29 typedef duration::period period; 30 typedef std::chrono::time_point<Clock> time_point; 31 static const bool is_steady = true; 32 nowClock33 static time_point now() 34 { 35 using namespace std::chrono; 36 return time_point(duration_cast<duration>( 37 steady_clock::now().time_since_epoch() 38 )); 39 } 40 }; 41 42 std::condition_variable cv; 43 std::mutex mut; 44 45 int test1 = 0; 46 int test2 = 0; 47 48 int runs = 0; 49 f()50void f() 51 { 52 std::unique_lock<std::mutex> lk(mut); 53 assert(test2 == 0); 54 test1 = 1; 55 cv.notify_one(); 56 Clock::time_point t0 = Clock::now(); 57 Clock::time_point t = t0 + Clock::duration(250); 58 while (test2 == 0 && cv.wait_until(lk, t) == std::cv_status::no_timeout) 59 ; 60 Clock::time_point t1 = Clock::now(); 61 if (runs == 0) 62 { 63 assert(t1 - t0 < Clock::duration(250)); 64 assert(test2 != 0); 65 } 66 else 67 { 68 assert(t1 - t0 - Clock::duration(250) < Clock::duration(50)); 69 assert(test2 == 0); 70 } 71 ++runs; 72 } 73 main()74int main() 75 { 76 { 77 std::unique_lock<std::mutex>lk(mut); 78 std::thread t(f); 79 assert(test1 == 0); 80 while (test1 == 0) 81 cv.wait(lk); 82 assert(test1 != 0); 83 test2 = 1; 84 lk.unlock(); 85 cv.notify_one(); 86 t.join(); 87 } 88 test1 = 0; 89 test2 = 0; 90 { 91 std::unique_lock<std::mutex>lk(mut); 92 std::thread t(f); 93 assert(test1 == 0); 94 while (test1 == 0) 95 cv.wait(lk); 96 assert(test1 != 0); 97 lk.unlock(); 98 t.join(); 99 } 100 } 101