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 // <future> 11 12 // class future<R> 13 14 // void wait() const; 15 16 #include <future> 17 #include <cassert> 18 19 void func1(std::promise<int> p) 20 { 21 std::this_thread::sleep_for(std::chrono::milliseconds(500)); 22 p.set_value(3); 23 } 24 25 int j = 0; 26 27 void func3(std::promise<int&> p) 28 { 29 std::this_thread::sleep_for(std::chrono::milliseconds(500)); 30 j = 5; 31 p.set_value(j); 32 } 33 34 void func5(std::promise<void> p) 35 { 36 std::this_thread::sleep_for(std::chrono::milliseconds(500)); 37 p.set_value(); 38 } 39 40 int main() 41 { 42 typedef std::chrono::high_resolution_clock Clock; 43 typedef std::chrono::duration<double, std::milli> ms; 44 { 45 typedef int T; 46 std::promise<T> p; 47 std::future<T> f = p.get_future(); 48 std::thread(func1, std::move(p)).detach(); 49 assert(f.valid()); 50 f.wait(); 51 assert(f.valid()); 52 Clock::time_point t0 = Clock::now(); 53 f.wait(); 54 Clock::time_point t1 = Clock::now(); 55 assert(f.valid()); 56 assert(t1-t0 < ms(5)); 57 } 58 { 59 typedef int& T; 60 std::promise<T> p; 61 std::future<T> f = p.get_future(); 62 std::thread(func3, std::move(p)).detach(); 63 assert(f.valid()); 64 f.wait(); 65 assert(f.valid()); 66 Clock::time_point t0 = Clock::now(); 67 f.wait(); 68 Clock::time_point t1 = Clock::now(); 69 assert(f.valid()); 70 assert(t1-t0 < ms(5)); 71 } 72 { 73 typedef void T; 74 std::promise<T> p; 75 std::future<T> f = p.get_future(); 76 std::thread(func5, std::move(p)).detach(); 77 assert(f.valid()); 78 f.wait(); 79 assert(f.valid()); 80 Clock::time_point t0 = Clock::now(); 81 f.wait(); 82 Clock::time_point t1 = Clock::now(); 83 assert(f.valid()); 84 assert(t1-t0 < ms(5)); 85 } 86 } 87
