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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// UNSUPPORTED: no-threads
// UNSUPPORTED: libcpp-has-no-experimental-stop_token
// UNSUPPORTED: c++03, c++11, c++14, c++17
// XFAIL: availability-synchronization_library-missing
// void join();
#include <atomic>
#include <cassert>
#include <chrono>
#include <concepts>
#include <functional>
#include <system_error>
#include <thread>
#include <type_traits>
#include <vector>
#include "make_test_thread.h"
#include "test_macros.h"
int main(int, char**) {
// Effects: Blocks until the thread represented by *this has completed.
{
std::atomic_int calledTimes = 0;
std::vector<std::jthread> jts;
constexpr auto numberOfThreads = 10u;
jts.reserve(numberOfThreads);
for (auto i = 0u; i < numberOfThreads; ++i) {
jts.emplace_back(support::make_test_jthread([&] {
std::this_thread::sleep_for(std::chrono::milliseconds(2));
calledTimes.fetch_add(1, std::memory_order_relaxed);
}));
}
for (auto i = 0u; i < numberOfThreads; ++i) {
jts[i].join();
}
// If join did block, calledTimes must equal to numberOfThreads
// If join did not block, there is a chance that the check below happened
// before test threads incrementing the counter, thus calledTimed would
// be less than numberOfThreads.
// This is not going to catch issues 100%. Creating more threads to increase
// the probability of catching the issue
assert(calledTimes.load(std::memory_order_relaxed) == numberOfThreads);
}
// Synchronization: The completion of the thread represented by *this synchronizes with
// ([intro.multithread]) the corresponding successful join() return.
{
bool flag = false;
std::jthread jt = support::make_test_jthread([&] { flag = true; });
jt.join();
assert(flag); // non atomic write is visible to the current thread
}
// Postconditions: The thread represented by *this has completed. get_id() == id().
{
std::jthread jt = support::make_test_jthread([] {});
assert(jt.get_id() != std::jthread::id());
jt.join();
assert(jt.get_id() == std::jthread::id());
}
#if !defined(TEST_HAS_NO_EXCEPTIONS)
// Throws: system_error when an exception is required ([thread.req.exception]).
// invalid_argument - if the thread is not joinable.
{
std::jthread jt;
try {
jt.join();
assert(false);
} catch (const std::system_error& err) {
assert(err.code() == std::errc::invalid_argument);
}
}
#endif
return 0;
}
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