如何在C++中实现线程池_线程池设计与实现详解

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

class ThreadPool {
public:
    ThreadPool(size_t numThreads) : stop(false) {
        threads.resize(numThreads);
        for (size_t i = 0; i < numThreads; ++i) {
            threads[i] = std::thread([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 = tasks.front();
                        tasks.pop();
                    }
                    task();
                }
            });
        }
    }

    template<typename F, typename... Args>
    void enqueue(F&& f, Args&&... args) {
        std::function<void()> task = std::bind(std::forward<F>(f), std::forward<Args>(args)...);
        {
            std::unique_lock<std::mutex> lock(queueMutex);
            tasks.push(task);
        }
        condition.notify_one();
    }

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

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

int main() {
    ThreadPool pool(4); // 创建一个包含4个线程的线程池

    for (int i = 0; i < 8; ++i) {
        pool.enqueue([i]() {
            std::cout << "Task " << i << " executed by thread " << std::this_thread::get_id() << std::endl;
            std::this_thread::sleep_for(std::chrono::milliseconds(100)); // 模拟耗时操作
        });
    }

    std::this_thread::sleep_for(std::chrono::seconds(1)); // 等待任务完成

    return 0;
}

threads[i] = std::thread([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 = tasks.front();
            tasks.pop();
        }
        try {
            task();
        } catch (const std::exception& e) {
            std::cerr << "Exception caught in thread: " << e.what() << std::endl;
            // 可以选择将异常信息记录到日志中，或者进行其他错误处理
        } catch (...) {
            std::cerr << "Unknown exception caught in thread" << std::endl;
        }
    }
});