c++ thread 线程池代码

以下是一个简单的 C++ 线程池实现代码，使用了 C++11 中的 `<thread>` 和 `<queue>` 库：

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

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

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

                    task();
                }
            });
        }
    }

    template <typename Function>
    void enqueue(Function&& f) {
        {
            std::unique_lock<std::mutex> lock(queue_mutex);

            tasks.emplace(std::forward<Function>(f));
        }
        condition.notify_one();
    }

    ~ThreadPool() {
        {
            std::unique_lock<std::mutex> lock(queue_mutex);
            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 queue_mutex;
    std::condition_variable condition;
    bool stop = false;
};

使用方式：

ThreadPool pool(4); // 创建一个具有 4 个线程的线程池

pool.enqueue([] {
    // 执行任务 1
});

pool.enqueue([] {
    // 执行任务 2
});

// 等待所有任务完成