单例模式的线程池c++

以下是一个使用单例模式实现的线程池的C++示例：

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

class ThreadPool {
public:
    static ThreadPool& getInstance() {
        static ThreadPool instance;
        return instance;
    }

    void addTask(std::function<void()> task) {
        std::unique_lock<std::mutex> lock(mutex_);
        tasks_.push(task);
        condition_.notify_one();
    }

private:
    ThreadPool() {
        int numThreads = std::thread::hardware_concurrency();
        for (int i = 0; i < numThreads; ++i) {
            threads_.emplace_back([this]() {
                while (true) {
                    std::function<void()> task;
                    {
                        std::unique_lock<std::mutex> lock(mutex_);
                        condition_.wait(lock, [this]() {
                            return !tasks_.empty();
                        });
                        task = tasks_.front();
                        tasks_.pop();
                    }
                    task();
                }
            });
        }
    }

    ~ThreadPool() {
        {
            std::unique_lock<std::mutex> lock(mutex_);
            stop_ = true;
        }
        condition_.notify_all();
        for (std::thread& thread : threads_) {
            thread.join();
        }
    }

    ThreadPool(const ThreadPool&) = delete;
    ThreadPool& operator=(const ThreadPool&) = delete;

private:
    std::vector<std::thread> threads_;
    std::queue<std::function<void()>> tasks_;
    std::mutex mutex_;
    std::condition_variable condition_;
    bool stop_ = false;
};

// 使用示例
void task1() {
    std::cout << "Task 1 executed" << std::endl;
}

void task2() {
    std::cout << "Task 2 executed" << std::endl;
}

int main() {
    ThreadPool& threadPool = ThreadPool::getInstance();

    threadPool.addTask(task1);
    threadPool.addTask(task2);

    // 等待任务执行完成
    std::this_thread::sleep_for(std::chrono::seconds(1));

    return 0;
}