https://github.com/rti7743/rtilabs/blob/master/files/asobiba/gomi/taskqueue.cpp

taskqueue.cpp

#include <iostream>
#include <thread>
#include <future>
#include <chrono>
#include <functional>
#include <deque>

struct task_queue {
	task_queue() = default;
	task_queue(const task_queue &) = delete;
	task_queue &operator =(const task_queue &) = delete;
	void operator ()() {
		std::function<void()> f([]{});
		do {
			f();
			std::unique_lock<std::mutex> lk(mut);
			cond.wait(lk, [this]() { return !queue.empty(); });
			f = std::move(queue.front());
			queue.pop_front();
		} while (f) ;
		std::cout <<  "タスクスレッド終了\n";
	}
	template <typename Fn>
	void append_task(const Fn &f) {
		std::unique_lock<std::mutex> lk(mut);
		queue.push_back(f);
		cond.notify_one();
	}
	template <typename Fn>
	auto do_sync_task(const Fn &f) -> decltype(f()) {
		typedef decltype(f()) RetT;
		std::packaged_task<RetT()> pt(f);
		std::future<RetT> uf(pt.get_future());
		{
			std::unique_lock<std::mutex> lk(mut);
			queue.push_front(ref(pt));
			cond.notify_one();
		}
		return uf.get();
	}
	void kill() {
		std::unique_lock<std::mutex> lk(mut);
		queue.push_front({});
		cond.notify_one();
	}
	std::mutex mut;
	std::condition_variable cond;
	std::deque<std::function<void()>> queue;
};

int main() {
	task_queue obj;
	std::thread th(std::ref(obj));

	int task_number = 0;
	std::mutex mut;
	std::condition_variable waiter;

	const auto numbered_task = [&mut, &waiter](int num) -> int {
		std::cout << "Task スタート! Number:" << num << std::endl;
		std::unique_lock<std::mutex> lk(mut);
		if (waiter.wait_until(lk, std::chrono::system_clock::now() + std::chrono::milliseconds(2000)) == std::cv_status::no_timeout) {
			std::cout << "Task 中断 Number:" << num << std::endl;
		} else {
			std::cout << "Task 終了! Number:" << num << std::endl;
		}
		return num * num;
	};

	while(1)
	{
		std::cout << "コマンドを入れて エンターキーおしてください。(q:終了 / a:非同期タスクの追加 / s:同期タスクの実行) " << std::endl;
		std::string str;
		getline( std::cin, str );
		if (str == "q")
		{
			break;
		}
		if (str == "a")
		{
			obj.append_task(std::bind(numbered_task, task_number));
			std::cout << "task " << task_number << " を登録しました。" << std::endl;
			task_number++;
		}
		if (str == "s")
		{
			std::cout << "task " << task_number << " を同期実行します。" << std::endl;
			const auto r = obj.do_sync_task(std::bind(numbered_task, task_number));
			std::cout << "task " << task_number << " の結果: " << r << std::endl;
			task_number++;
		}

	}
	std::cout << " ( ﾟдﾟ)ﾎﾟｶｰﾝ" << std::endl;
	std::cout << "notify_all 停止命令送信" << std::endl;
	waiter.notify_all();
	obj.kill();
	std::cout << "join 停止待ち" << std::endl;
	th.join();
	std::cout << "プログラムを終了します" << std::endl;
	return 0;
}