C++中如何实现进程池

在C++中可以使用多线程库来实现进程池，以下是一个简单的进程池实现示例：

#include <iostream>#include <vector>#include <thread>#include <mutex>#include <condition_variable>#include <queue>#include <functional>class ThreadPool {public:    ThreadPool(int numThreads) : stop(false) {        for (int 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 = tasks.front();                        tasks.pop();                    }                    task();                }            });        }    }    template<class F>    void enqueue(F&& f) {        {            std::unique_lock<std::mutex> lock(queueMutex);            tasks.emplace(std::forward<F>(f));        }        condition.notify_one();    }    ~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);    for (int i = 0; i < 8; ++i) {        pool.enqueue([i] {            std::this_thread::sleep_for(std::chrono::seconds(1));            std::cout << "Task " << i << " completed" << std::endl;        });    }    return 0;}

在上面的示例中，通过创建一个ThreadPool类来实现进程池，其中包含了一个线程池的构造函数、任务入队函数enqueue和析构函数。可以通过调用enqueue函数向进程池中添加任务，进程池会自动分配线程来执行这些任务。