c++如何实现一个简单的Actor模型_c++并发编程新思路

#include 
#include 
#include 
#include 
#include 

// 消息基类
struct Message {
    virtual ~Message() = default;
};

// Actor可接收的消息处理器
using MessageHandler = std::function)>;

class Actor {
private:
    std::queue> mailbox_;
    std::mutex mtx_;
    bool running_ = false;
    MessageHandler handler_;

public:
    // 设置消息处理函数
    void setHandler(MessageHandler handler) {
        handler_ = std::move(handler);
    }

    // 发送消息到该Actor
    void send(std::shared_ptr msg) {
        {
            std::lock_guard lock(mtx_);
            mailbox_.push(msg);
        }
    }

    // 启动Actor事件循环
    void start() {
        if (running_ || !handler_) return;
        running_ = true;

        std::thread([this]() {
            while (running_) {
                std::shared_ptr msg = nullptr;
                {
                    std::lock_guard lock(mtx_);
                    if (!mailbox_.empty()) {
                        msg = mailbox_.front();
                        mailbox_.pop();
                    }
                }

                if (msg && handler_) {
                    handler_(msg);
                } else {
                    std::this_thread::yield(); // 没有消息时让出CPU
                }
            }
        }).detach(); // 分离线程，由系统自动回收
    }

    virtual ~Actor() = default;
};

struct Increment : Message {};
struct Decrement : Message {};
struct Print : Message {};

#include 

int main() {
    Actor counter;

    int value = 0;

    counter.setHandler([&value](std::shared_ptr msg) {
        if (dynamic_cast(msg.get())) {
            ++value;
        } else if (dynamic_cast(msg.get())) {
            --value;
        } else if (dynamic_cast(msg.get())) {
            std::cout << "Current value: " << value << std::endl;
        }
    });

    counter.start();

    // 发送一些消息
    counter.send(std::make_shared());
    counter.send(std::make_shared());
    counter.send(std::make_shared());
    counter.send(std::make_shared());

    std::this_thread::sleep_for(std::chrono::milliseconds(100)); // 等待输出

    return 0;
}