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, c++11, c++14, c++17
11// XFAIL: availability-synchronization_library-missing
12
13// ~jthread();
14
15#include <atomic>
16#include <cassert>
17#include <optional>
18#include <stop_token>
19#include <thread>
20#include <type_traits>
21#include <vector>
22
23#include "make_test_thread.h"
24#include "test_macros.h"
25
26int main(int, char**) {
27 // !joinable()
28 {
29 std::jthread jt;
30 assert(!jt.joinable());
31 }
32
33 // If joinable() is true, calls request_stop() and then join().
34 // request_stop is called
35 {
36 std::optional<std::jthread> jt = support::make_test_jthread([] {});
37 bool called = false;
38 std::stop_callback cb(jt->get_stop_token(), [&called] { called = true; });
39 jt.reset();
40 assert(called);
41 }
42
43 // If joinable() is true, calls request_stop() and then join().
44 // join is called
45 {
46 std::atomic_int calledTimes = 0;
47 std::vector<std::jthread> jts;
48
49 constexpr auto numberOfThreads = 10u;
50 jts.reserve(numberOfThreads);
51 for (auto i = 0u; i < numberOfThreads; ++i) {
52 jts.emplace_back(support::make_test_jthread([&calledTimes] {
53 std::this_thread::sleep_for(std::chrono::milliseconds{2});
54 calledTimes.fetch_add(1, std::memory_order_relaxed);
55 }));
56 }
57 jts.clear();
58
59 // If join was called as expected, calledTimes must equal to numberOfThreads
60 // If join was not called, there is a chance that the check below happened
61 // before test threads incrementing the counter, thus calledTimed would
62 // be less than numberOfThreads.
63 // This is not going to catch issues 100%. Creating more threads would increase
64 // the probability of catching the issue
65 assert(calledTimes.load(std::memory_order_relaxed) == numberOfThreads);
66 }
67
68 return 0;
69}
70

source code of libcxx/test/std/thread/thread.jthread/dtor.pass.cpp