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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: c++03, c++11, c++14, c++17
// ADDITIONAL_COMPILE_FLAGS(gcc-style-warnings): -Wno-self-move
// jthread& operator=(jthread&&) noexcept;
#include <atomic>
#include <cassert>
#include <concepts>
#include <stop_token>
#include <thread>
#include <type_traits>
#include <utility>
#include <vector>
#include "make_test_thread.h"
#include "test_macros.h"
static_assert(std::is_nothrow_move_assignable_v<std::jthread>);
int main(int, char**) {
// If &x == this is true, there are no effects.
{
std::jthread j = support::make_test_jthread([] {});
auto id = j.get_id();
auto ssource = j.get_stop_source();
j = std::move(j);
assert(j.get_id() == id);
assert(j.get_stop_source() == ssource);
}
// if joinable() is true, calls request_stop() and then join()
// request_stop is called
{
std::jthread j1 = support::make_test_jthread([] {});
bool called = false;
std::stop_callback cb(j1.get_stop_token(), [&called] { called = true; });
std::jthread j2 = support::make_test_jthread([] {});
j1 = std::move(j2);
assert(called);
}
// if joinable() is true, calls request_stop() and then join()
// join is called
{
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] = std::jthread{};
}
// If join was called as expected, calledTimes must equal to numberOfThreads
// If join was not called, 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);
}
// then assigns the state of x to *this
{
std::jthread j1 = support::make_test_jthread([] {});
std::jthread j2 = support::make_test_jthread([] {});
auto id2 = j2.get_id();
auto ssource2 = j2.get_stop_source();
j1 = std::move(j2);
assert(j1.get_id() == id2);
assert(j1.get_stop_source() == ssource2);
}
// sets x to a default constructed state
{
std::jthread j1 = support::make_test_jthread([] {});
std::jthread j2 = support::make_test_jthread([] {});
j1 = std::move(j2);
assert(j2.get_id() == std::jthread::id());
assert(!j2.get_stop_source().stop_possible());
}
// joinable is false
{
std::jthread j1;
std::jthread j2 = support::make_test_jthread([] {});
auto j2Id = j2.get_id();
j1 = std::move(j2);
assert(j1.get_id() == j2Id);
}
// LWG3788: self-assignment
{
std::jthread j = support::make_test_jthread([] {});
auto oldId = j.get_id();
j = std::move(j);
assert(j.get_id() == oldId);
}
return 0;
}
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