xref: /llvm-project/libcxx/test/std/thread/futures/futures.shared_future/wait.pass.cpp (revision e655d8a54880cf550567dda0e9a1a33f6ee98df5)
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: no-threads
10 // UNSUPPORTED: c++03
11 
12 // <future>
13 
14 // class shared_future<R>
15 
16 // void wait() const;
17 
18 #include <cassert>
19 #include <chrono>
20 #include <future>
21 #include <ratio>
22 
23 #include "make_test_thread.h"
24 #include "test_macros.h"
25 
func1(std::promise<int> p)26 void func1(std::promise<int> p)
27 {
28     std::this_thread::sleep_for(std::chrono::milliseconds(500));
29     p.set_value(3);
30 }
31 
32 int j = 0;
33 
func3(std::promise<int &> p)34 void func3(std::promise<int&> p)
35 {
36     std::this_thread::sleep_for(std::chrono::milliseconds(500));
37     j = 5;
38     p.set_value(j);
39 }
40 
func5(std::promise<void> p)41 void func5(std::promise<void> p)
42 {
43     std::this_thread::sleep_for(std::chrono::milliseconds(500));
44     p.set_value();
45 }
46 
main(int,char **)47 int main(int, char**)
48 {
49     typedef std::chrono::high_resolution_clock Clock;
50     typedef std::chrono::duration<double, std::milli> ms;
51     {
52         typedef int T;
53         std::promise<T> p;
54         std::shared_future<T> f = p.get_future();
55         support::make_test_thread(func1, std::move(p)).detach();
56         assert(f.valid());
57         f.wait();
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         support::make_test_thread(func3, std::move(p)).detach();
70         assert(f.valid());
71         f.wait();
72         assert(f.valid());
73         Clock::time_point t0 = Clock::now();
74         f.wait();
75         Clock::time_point t1 = Clock::now();
76         assert(f.valid());
77         assert(t1-t0 < ms(5));
78     }
79     {
80         typedef void T;
81         std::promise<T> p;
82         std::shared_future<T> f = p.get_future();
83         support::make_test_thread(func5, std::move(p)).detach();
84         assert(f.valid());
85         f.wait();
86         assert(f.valid());
87         Clock::time_point t0 = Clock::now();
88         f.wait();
89         Clock::time_point t1 = Clock::now();
90         assert(f.valid());
91         assert(t1-t0 < ms(5));
92     }
93 
94   return 0;
95 }
96