1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // UNSUPPORTED: libcpp-has-no-threads
10 // UNSUPPORTED: c++98, c++03
11 
12 // <future>
13 
14 // class shared_future<R>
15 
16 // template <class Rep, class Period>
17 //   future_status
18 //   wait_for(const chrono::duration<Rep, Period>& rel_time) const;
19 
20 #include <future>
21 #include <cassert>
22 
23 typedef std::chrono::milliseconds ms;
24 
25 void func1(std::promise<int> p)
26 {
27     std::this_thread::sleep_for(ms(500));
28     p.set_value(3);
29 }
30 
31 int j = 0;
32 
33 void func3(std::promise<int&> p)
34 {
35     std::this_thread::sleep_for(ms(500));
36     j = 5;
37     p.set_value(j);
38 }
39 
40 void func5(std::promise<void> p)
41 {
42     std::this_thread::sleep_for(ms(500));
43     p.set_value();
44 }
45 
46 int main(int, char**)
47 {
48     typedef std::chrono::high_resolution_clock Clock;
49     {
50         typedef int T;
51         std::promise<T> p;
52         std::shared_future<T> f = p.get_future();
53         std::thread(func1, std::move(p)).detach();
54         assert(f.valid());
55         assert(f.wait_for(ms(300)) == std::future_status::timeout);
56         assert(f.valid());
57         assert(f.wait_for(ms(300)) == std::future_status::ready);
58         assert(f.valid());
59         Clock::time_point t0 = Clock::now();
60         f.wait();
61         Clock::time_point t1 = Clock::now();
62         assert(f.valid());
63         assert(t1-t0 < ms(5));
64     }
65     {
66         typedef int& T;
67         std::promise<T> p;
68         std::shared_future<T> f = p.get_future();
69         std::thread(func3, std::move(p)).detach();
70         assert(f.valid());
71         assert(f.wait_for(ms(300)) == std::future_status::timeout);
72         assert(f.valid());
73         assert(f.wait_for(ms(300)) == std::future_status::ready);
74         assert(f.valid());
75         Clock::time_point t0 = Clock::now();
76         f.wait();
77         Clock::time_point t1 = Clock::now();
78         assert(f.valid());
79         assert(t1-t0 < ms(5));
80     }
81     {
82         typedef void T;
83         std::promise<T> p;
84         std::shared_future<T> f = p.get_future();
85         std::thread(func5, std::move(p)).detach();
86         assert(f.valid());
87         assert(f.wait_for(ms(300)) == std::future_status::timeout);
88         assert(f.valid());
89         assert(f.wait_for(ms(300)) == std::future_status::ready);
90         assert(f.valid());
91         Clock::time_point t0 = Clock::now();
92         f.wait();
93         Clock::time_point t1 = Clock::now();
94         assert(f.valid());
95         assert(t1-t0 < ms(5));
96     }
97 
98   return 0;
99 }
100