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++03
11 
12 // <future>
13 
14 // class future<R>
15 
16 // void wait() const;
17 
18 #include <future>
19 #include <cassert>
20 
21 #include "make_test_thread.h"
22 #include "test_macros.h"
23 
24 void func1(std::promise<int> p)
25 {
26     std::this_thread::sleep_for(std::chrono::milliseconds(500));
27     p.set_value(3);
28 }
29 
30 int j = 0;
31 
32 void func3(std::promise<int&> p)
33 {
34     std::this_thread::sleep_for(std::chrono::milliseconds(500));
35     j = 5;
36     p.set_value(j);
37 }
38 
39 void func5(std::promise<void> p)
40 {
41     std::this_thread::sleep_for(std::chrono::milliseconds(500));
42     p.set_value();
43 }
44 
45 template <typename T, typename F>
46 void test(F func) {
47     typedef std::chrono::high_resolution_clock Clock;
48     typedef std::chrono::duration<double, std::milli> ms;
49 
50     std::promise<T> p;
51     std::future<T> f = p.get_future();
52     support::make_test_thread(func, std::move(p)).detach();
53     assert(f.valid());
54     f.wait();
55     assert(f.valid());
56     Clock::time_point t0 = Clock::now();
57     f.wait();
58     Clock::time_point t1 = Clock::now();
59     assert(f.valid());
60     assert(t1-t0 < ms(5));
61 }
62 
63 int main(int, char**)
64 {
65     test<int>(func1);
66     test<int&>(func3);
67     test<void>(func5);
68     return 0;
69 }
70