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 future<R>
15
16 // template <class Clock, class Duration>
17 // future_status
18 // wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
19
20 #include <atomic>
21 #include <cassert>
22 #include <chrono>
23 #include <future>
24
25 #include "make_test_thread.h"
26 #include "test_macros.h"
27
28 enum class WorkerThreadState { Uninitialized, AllowedToRun, Exiting };
29 typedef std::chrono::milliseconds ms;
30
31 std::atomic<WorkerThreadState> thread_state(WorkerThreadState::Uninitialized);
32
set_worker_thread_state(WorkerThreadState state)33 void set_worker_thread_state(WorkerThreadState state)
34 {
35 thread_state.store(state, std::memory_order_relaxed);
36 }
37
wait_for_worker_thread_state(WorkerThreadState state)38 void wait_for_worker_thread_state(WorkerThreadState state)
39 {
40 while (thread_state.load(std::memory_order_relaxed) != state)
41 std::this_thread::yield();
42 }
43
func1(std::promise<int> p)44 void func1(std::promise<int> p)
45 {
46 wait_for_worker_thread_state(WorkerThreadState::AllowedToRun);
47 p.set_value(3);
48 set_worker_thread_state(WorkerThreadState::Exiting);
49 }
50
51 int j = 0;
52
func3(std::promise<int &> p)53 void func3(std::promise<int&> p)
54 {
55 wait_for_worker_thread_state(WorkerThreadState::AllowedToRun);
56 j = 5;
57 p.set_value(j);
58 set_worker_thread_state(WorkerThreadState::Exiting);
59 }
60
func5(std::promise<void> p)61 void func5(std::promise<void> p)
62 {
63 wait_for_worker_thread_state(WorkerThreadState::AllowedToRun);
64 p.set_value();
65 set_worker_thread_state(WorkerThreadState::Exiting);
66 }
67
main(int,char **)68 int main(int, char**)
69 {
70 typedef std::chrono::high_resolution_clock Clock;
71 {
72 typedef int T;
73 std::promise<T> p;
74 std::future<T> f = p.get_future();
75 support::make_test_thread(func1, std::move(p)).detach();
76 assert(f.valid());
77 assert(f.wait_until(Clock::now() + ms(10)) == std::future_status::timeout);
78 assert(f.valid());
79
80 // allow the worker thread to produce the result and wait until the worker is done
81 set_worker_thread_state(WorkerThreadState::AllowedToRun);
82 wait_for_worker_thread_state(WorkerThreadState::Exiting);
83
84 assert(f.wait_until(Clock::now() + ms(10)) == std::future_status::ready);
85 assert(f.valid());
86 f.wait();
87 assert(f.valid());
88 }
89 {
90 typedef int& T;
91 std::promise<T> p;
92 std::future<T> f = p.get_future();
93 support::make_test_thread(func3, std::move(p)).detach();
94 assert(f.valid());
95 assert(f.wait_until(Clock::now() + ms(10)) == std::future_status::timeout);
96 assert(f.valid());
97
98 // allow the worker thread to produce the result and wait until the worker is done
99 set_worker_thread_state(WorkerThreadState::AllowedToRun);
100 wait_for_worker_thread_state(WorkerThreadState::Exiting);
101
102 assert(f.wait_until(Clock::now() + ms(10)) == std::future_status::ready);
103 assert(f.valid());
104 f.wait();
105 assert(f.valid());
106 }
107 {
108 typedef void T;
109 std::promise<T> p;
110 std::future<T> f = p.get_future();
111 support::make_test_thread(func5, std::move(p)).detach();
112 assert(f.valid());
113 assert(f.wait_until(Clock::now() + ms(10)) == std::future_status::timeout);
114 assert(f.valid());
115
116 // allow the worker thread to produce the result and wait until the worker is done
117 set_worker_thread_state(WorkerThreadState::AllowedToRun);
118 wait_for_worker_thread_state(WorkerThreadState::Exiting);
119
120 assert(f.wait_until(Clock::now() + ms(10)) == std::future_status::ready);
121 assert(f.valid());
122 f.wait();
123 assert(f.valid());
124 }
125
126 return 0;
127 }
128