c++写一个发送、接收、处理心跳包的例子

在C++中，你可以使用`std::chrono`和`std::condition_variable`来实现一个简单的心跳检测机制。这里我们假设有一个基础的TCP套接字通信框架。首先，我们需要发送和接收心跳包，然后在接收端处理这些心跳以确认连接是否仍然活跃。

**发送心跳包（客户端）：**

#include <boost/asio.hpp>
#include <chrono>
#include <thread>
#include <condition_variable>

class HeartbeatSender {
public:
    void start(std::shared_ptr<tcp::socket>& client_socket) {
        heartbeat_thread_ = std::thread([this, client_socket]() {
            while (!stop_) {
                send_heartbeat(client_socket);
                std::this_thread::sleep_for(std::chrono::seconds(5)); // 每隔5秒发送一次心跳
            }
        });
    }

private:
    void send_heartbeat(std::shared_ptr<tcp::socket>& socket) {
        std::string message = "Heartbeat";
        boost::system::error_code ignored_error;
        boost::asio::write(*socket, boost::asio::buffer(message), ignored_error);
    }

    bool stop_{false};
    std::thread heartbeat_thread_;
};

**接收心跳包（服务器）：**

class HeartbeatReceiver {
public:
    void start(std::shared_ptr<tcp::socket>& server_socket, std::function<void()> on_received) {
        receiver_thread_ = std::thread([this, server_socket, on_received]() {
            while (!stop_) {
                on_received(); // 当收到心跳时调用回调
                std::this_thread::sleep_for(std::chrono::seconds(1)); // 防止频繁读取
            }
        });

        read_loop(server_socket);
    }

private:
    void read_loop(std::shared_ptr<tcp::socket>& socket) {
        boost::array<char, 64> buffer; // 假设心跳消息最大长度为64字节
        while (!stop_) {
            boost::system::error_code error;
            size_t bytes_transferred = boost::asio::read(*socket, boost::asio::buffer(buffer), error);

            if (!error && bytes_transferred > 0) {
                // 处理心跳包
                if (std::string_view message(buffer.data(), bytes_transferred) == "Heartbeat") {
                    on_received(); // 执行回调
                } else {
                    std::cerr << "Invalid heartbeat received!" << std::endl;
                }
            } else if (error) {
                // 关闭连接
                break;
            }
        }
    }

    std::thread receiver_thread_;
    bool stop_{false};
};

在客户端启动`HeartbeatSender`，服务器启动`HeartbeatReceiver`，当接收到心跳包时，服务器会执行传递的回调函数。