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南部县人民医院招聘信息关键词优化哪家强

wzjs 2025/8/11 14:33:08

南部县人民医院招聘信息,关键词优化哪家强,做博客网站最好用什么系统,关于室内设计的网站有哪些客户端会面临服务器崩溃的情况，我们可以试着写一个客户端重连的代码，模拟并理解一些客户端行为，比如游戏客户端等 TcpClient.cc 采用状态机，实现一个简单的tcp client可以实现重连效果 #include <iostream> #include <…

客户端会面临服务器崩溃的情况，我们可以试着写一个客户端重连的代码，模拟并理解一些客户端行为，比如游戏客户端等

TcpClient.cc

采用状态机，实现一个简单的tcp client可以实现重连效果

#include <iostream>
#include <string>
#include <cstring>
#include <cstdlib>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>using namespace std;void Usage(const std::string &process)
{std::cout << "Usage: " << process << " server_ip server_port" << std::endl;
}enum class Status // C++11 强类型枚举
{NEW,        // 新建状态，就是单纯的连接CONNECTING, // 正在连接，仅仅方便查询conn状态CONNECTED,  // 连接或者重连成功DISCONNECTED, // 重连失败CLOSED        // 连接失败，经历重连，无法连接
};class ClientConnection
{
public:ClientConnection(uint16_t serverport, const std::string &serverip): _sockfd(-1),_serverport(serverport),_serverip(serverip),_retry_interval(1),_max_retries(5),_status(Status::NEW){}void Connect(){// 1. 创建socket_sockfd = socket(AF_INET, SOCK_STREAM, 0);if (_sockfd < 0){cerr << "socket error" << endl;exit(1);}// 2. 要不要bind？必须要有Ip和Port, 需要bind，但是不需要用户显示的bind，client系统随机端口// 发起连接的时候，client会被OS自动进行本地绑定// 2. connectstruct sockaddr_in server;memset(&server, 0, sizeof(server));server.sin_family = AF_INET;server.sin_port = htons(_serverport);// p:process(进程), n(网络) -- 不太准确，但是好记忆inet_pton(AF_INET, _serverip.c_str(), &server.sin_addr); // 1. 字符串ip->4字节IP 2. 网络序列int n = connect(_sockfd, (struct sockaddr *)&server, sizeof(server)); // 自动进行bind哦！if (n < 0){Disconnect();                   // 恢复_sockfd的默认值，是连接没有成功，不代表sockfd创建没有成功_status = Status::DISCONNECTED; // 没有连接成功return;}_status = Status::CONNECTED; // 连接成功}int SocketFd(){return _sockfd;}void Reconnect(){_status = Status::CONNECTING; // 正在重连int count = 0;while (count < _max_retries){Connect(); // 重连if (_status == Status::CONNECTED){return;}sleep(_retry_interval);count++;std::cout << "重连次数: " << count << ", 最大上限: " << _max_retries << std::endl;}_status = Status::CLOSED; // 重连失败，可以关闭了}void Disconnect(){if (_sockfd != -1){close(_sockfd);_status = Status::CLOSED;_sockfd = -1;}}Status GetStatus(){return _status;}void Process(){// 简单的IO即可while (true){string inbuffer;cout << "Please Enter# ";getline(cin, inbuffer);if(inbuffer.empty()) continue;ssize_t n = write(_sockfd, inbuffer.c_str(), inbuffer.size());if (n > 0){char buffer[1024];ssize_t m = read(_sockfd, buffer, sizeof(buffer) - 1);if (m > 0){buffer[m] = 0;cout << "echo messsge -> " << buffer << endl;}else if (m == 0) // 这里证明server端掉线了{_status = Status::DISCONNECTED;break;}else{std::cout << "read m : " << m << "errno: " << errno << "errno string: " << strerror(errno) << std::endl;_status = Status::CLOSED;break;}}else{std::cout << "write n : " << n << "errno: " << errno << "errno string: " << strerror(errno) << std::endl;_status = Status::CLOSED;break;}}}~ClientConnection(){Disconnect();}private:int _sockfd;uint16_t _serverport;  // server port 端口号std::string _serverip; // server ip地址int _retry_interval;   // 重试时间间隔int _max_retries;      // 重试次数Status _status;        // 连接状态
};class TcpClient
{
public:TcpClient(uint16_t serverport, const std::string &serverip) : _conn(serverport, serverip){}void Execute(){while (true){switch (_conn.GetStatus()){case Status::NEW:_conn.Connect();break;case Status::CONNECTED:std::cout << "连接成功, 开始进行通信." << std::endl;_conn.Process();break;case Status::DISCONNECTED:std::cout << "连接失败或者对方掉线，开始重连." << std::endl;_conn.Reconnect();break;case Status::CLOSED:_conn.Disconnect();std::cout << "重连失败, 退出." << std::endl;return; // 退出default:break;}}}~TcpClient(){}private:ClientConnection _conn; // 简单组合起来即可
};
// class Tcp// ./tcp_client serverip serverport
int main(int argc, char *argv[])
{if (argc != 3){Usage(argv[0]);return 1;}std::string serverip = argv[1];uint16_t serverport = stoi(argv[2]);TcpClient client(serverport, serverip);client.Execute();return 0;
}

TcpServer.cc

#include <iostream>
#include <string>
#include <cerrno>
#include <cstring>
#include <cstdlib>
#include <memory>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/wait.h>
#include <unistd.h>const static int default_backlog = 6;enum
{Usage_Err = 1,Socket_Err,Bind_Err,Listen_Err
};#define CONV(addr_ptr) ((struct sockaddr *)addr_ptr)class TcpServer
{
public:TcpServer(uint16_t port) : _port(port), _isrunning(false){}// 都是固定套路void Init(){// 1. 创建socket, file fd, 本质是文件_listensock = socket(AF_INET, SOCK_STREAM, 0);if (_listensock < 0){exit(0);}int opt = 1;setsockopt(_listensock, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt));// 2. 填充本地网络信息并bindstruct sockaddr_in local;memset(&local, 0, sizeof(local));local.sin_family = AF_INET;local.sin_port = htons(_port);local.sin_addr.s_addr = htonl(INADDR_ANY);// 2.1 bindif (bind(_listensock, CONV(&local), sizeof(local)) != 0){exit(Bind_Err);}// 3. 设置socket为监听状态，tcp特有的if (listen(_listensock, default_backlog) != 0){exit(Listen_Err);}}void ProcessConnection(int sockfd, struct sockaddr_in &peer){uint16_t clientport = ntohs(peer.sin_port);std::string clientip = inet_ntoa(peer.sin_addr);std::string prefix = clientip + ":" + std::to_string(clientport);std::cout << "get a new connection, info is : " << prefix << std::endl;while (true){char inbuffer[1024];ssize_t s = ::read(sockfd, inbuffer, sizeof(inbuffer)-1);if(s > 0){inbuffer[s] = 0;std::cout << prefix << "# " << inbuffer << std::endl;std::string echo = inbuffer;echo += "[tcp server echo message]";write(sockfd, echo.c_str(), echo.size());}else{std::cout << prefix << " client quit" << std::endl;break;}}}void Start(){_isrunning = true;while (_isrunning){// 4. 获取连接struct sockaddr_in peer;socklen_t len = sizeof(peer);int sockfd = accept(_listensock, CONV(&peer), &len);if (sockfd < 0){continue;}ProcessConnection(sockfd, peer);}}~TcpServer(){}private:uint16_t _port;int _listensock; // TODObool _isrunning;
};using namespace std;void Usage(std::string proc)
{std::cout << "Usage : \n\t" << proc << " local_port\n"<< std::endl;
}
// ./tcp_server 8888
int main(int argc, char *argv[])
{if (argc != 2){Usage(argv[0]);return Usage_Err;}uint16_t port = stoi(argv[1]);std::unique_ptr<TcpServer> tsvr = make_unique<TcpServer>(port);tsvr->Init();tsvr->Start();return 0;
}

测试1：不启动服务端，直接客户端连接