C++中如何使用结构化并发_任务调度方案

#include <iostream>
#include <thread>
#include <vector>
#include <future>
#include <queue>
#include <mutex>
#include <condition_variable>

class ThreadPool {
public:
    ThreadPool(size_t numThreads) : stop(false) {
        for (size_t i = 0; i < numThreads; ++i) {
            workers.emplace_back([this] {
                while (true) {
                    std::function<void()> task;

                    {
                        std::unique_lock<std::mutex> lock(queueMutex);
                        condition.wait(lock, [this] { return stop || !tasks.empty(); });
                        if (stop && tasks.empty())
                            return;
                        task = std::move(tasks.front());
                        tasks.pop();
                    }

                    task();
                }
            });
        }
    }

    template<class F, class... Args>
    auto enqueue(F&& f, Args&&... args) -> std::future<typename std::result_of<F(Args...)>::type> {
        using return_type = typename std::result_of<F(Args...)>::type;
        auto task = std::make_shared<std::packaged_task<return_type()>>(
            std::bind(std::forward<F>(f), std::forward<Args>(args)...)
        );

        std::future<return_type> res = task->get_future();
        {
            std::unique_lock<std::mutex> lock(queueMutex);
            if (stop)
                throw std::runtime_error("enqueue on stopped ThreadPool");

            tasks.emplace([task]() { (*task)(); });
        }
        condition.notify_one();
        return res;
    }

    ~ThreadPool() {
        {
            std::unique_lock<std::mutex> lock(queueMutex);
            stop = true;
        }
        condition.notify_all();
        for (std::thread& worker : workers)
            worker.join();
    }

private:
    std::vector<std::thread> workers;
    std::queue<std::function<void()>> tasks;
    std::mutex queueMutex;
    std::condition_variable condition;
    bool stop;
};

int main() {
    ThreadPool pool(4);

    std::vector<std::future<int>> results;
    for (int i = 0; i < 8; ++i) {
        results.emplace_back(
            pool.enqueue([i]() {
                std::cout << "Task " << i << " executed by thread " << std::this_thread::get_id() << std::endl;
                std::this_thread::sleep_for(std::chrono::seconds(1));
                return i * 2;
            })
        );
    }

    for (auto& result : results) {
        std::cout << "Result: " << result.get() << std::endl;
    }

    return 0;
}

#include <iostream>
#include <thread>
#include <stop_token>

void task(std::stop_token stopToken) {
    while (!stopToken.stop_requested()) {
        std::cout << "Task running..." << std::endl;
        std::this_thread::sleep_for(std::chrono::milliseconds(500));
    }
    std::cout << "Task stopped." << std::endl;
}

int main() {
    std::jthread t(task);
    std::this_thread::sleep_for(std::chrono::seconds(3));
    t.request_stop(); // 请求线程停止
    return 0;
}