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 12 // <condition_variable> 13 14 // class condition_variable; 15 16 // template <class Rep, class Period, class Predicate> 17 // bool 18 // wait_for(unique_lock<mutex>& lock, 19 // const chrono::duration<Rep, Period>& rel_time, 20 // Predicate pred); 21 22 #include <condition_variable> 23 #include <mutex> 24 #include <thread> 25 #include <chrono> 26 #include <cassert> 27 28 class Pred 29 { 30 int& i_; 31 public: Pred(int & i)32 explicit Pred(int& i) : i_(i) {} 33 operator ()()34 bool operator()() {return i_ != 0;} 35 }; 36 37 std::condition_variable cv; 38 std::mutex mut; 39 40 int test1 = 0; 41 int test2 = 0; 42 43 int runs = 0; 44 f()45void f() 46 { 47 typedef std::chrono::system_clock Clock; 48 typedef std::chrono::milliseconds milliseconds; 49 std::unique_lock<std::mutex> lk(mut); 50 assert(test2 == 0); 51 test1 = 1; 52 cv.notify_one(); 53 Clock::time_point t0 = Clock::now(); 54 bool r = cv.wait_for(lk, milliseconds(250), Pred(test2)); 55 Clock::time_point t1 = Clock::now(); 56 if (runs == 0) 57 { 58 assert(t1 - t0 < milliseconds(250)); 59 assert(test2 != 0); 60 } 61 else 62 { 63 assert(t1 - t0 - milliseconds(250) < milliseconds(50)); 64 assert(test2 == 0); 65 } 66 ++runs; 67 } 68 main()69int main() 70 { 71 { 72 std::unique_lock<std::mutex>lk(mut); 73 std::thread t(f); 74 assert(test1 == 0); 75 while (test1 == 0) 76 cv.wait(lk); 77 assert(test1 != 0); 78 test2 = 1; 79 lk.unlock(); 80 cv.notify_one(); 81 t.join(); 82 } 83 test1 = 0; 84 test2 = 0; 85 { 86 std::unique_lock<std::mutex>lk(mut); 87 std::thread t(f); 88 assert(test1 == 0); 89 while (test1 == 0) 90 cv.wait(lk); 91 assert(test1 != 0); 92 lk.unlock(); 93 t.join(); 94 } 95 } 96