stop.cc

#include <chrono>
#include <condition_variable>
#include <cstdint>
#include <iostream>
#include <mutex>
#include <stop_token>
#include <thread>

auto main() -> int32_t {
	std::mutex mut;
	std::condition_variable cond;
	std::stop_source source;

	std::thread th([&mut, &cond, &source]() {
		std::cout << "child start" << std::endl;
		auto token = source.get_token();
		{
			std::cout << "child try lock" << std::endl;
			std::unique_lock<std::mutex> lock(mut);
			std::cout << "child locked" << std::endl;
			cond.wait(lock, [&token]() {
				bool requested = token.stop_requested();
				std::cout << "child check request: " << requested << std::endl;
				std::this_thread::sleep_for(std::chrono::seconds(3));
				std::cout << "child sleep" << std::endl;
				return requested;
				});
			std::cout << "child wakeup" << std::endl;
		}
		});

	std::this_thread::sleep_for(std::chrono::seconds(2));

	{
		std::cout << "parent try lock" << std::endl;
		// std::lock_guard<std::mutex> lock(mut);
		std::cout << "parent locked" << std::endl;
		source.request_stop();
		std::cout << "parent send stop" << std::endl;
	}
	cond.notify_all();
	std::cout << "parent send notify" << std::endl;

	th.join();

	std::cout << "parent join success" << std::endl;

	return 0;
}