C++ TCP网络编程--服务器端多线程处理会话连接

客户端程序： 

#include <winsock.h> 
#include<iostream>
#pragma comment(lib,"ws2_32.lib") 

#include <Windows.h>
#include<string>

int main()
{
	//初始化Windows Socket Application
	WORD sockVersion = MAKEWORD(2, 2);
	WSADATA wsaData;

	//WinSock的注册函数，初始化底层的Windows Sockets DLL
	if (WSAStartup(sockVersion, &wsaData) != 0)
		return 0;

	//创建一个socket并返回socket的标识符
	SOCKET sclient = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	if (sclient == INVALID_SOCKET)
	{
		std::cout << "invalid socket!" << std::endl;
		return 0;
	}
	sockaddr_in serAddr;
	serAddr.sin_family = AF_INET;
	serAddr.sin_port = htons(8888);
	serAddr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
	if (connect(sclient, (sockaddr *)&serAddr, sizeof(serAddr)) == SOCKET_ERROR)
	{  			//连接失败 	
		std::cout << "connect error !" << std::endl;
		closesocket(sclient);
		return 0;
	}

	std::string data="abcdef_";

	int n = 0;
	while (1)
	{
		data = "abcdef_"+std::to_string(n);
		//std::cin >> data;
		const char * sendData;
		sendData = data.c_str();
		//string转const char* 		
		/*		send()用来将数据由指定的socket传给对方主机
		int send(int s, const void * msg, int len, unsigned int flags)
		s为已建立好连接的socket，msg指向数据内容，len则为数据长度，参数flags一般设0
		成功则返回实际传送出去的字符数，失败返回-1，错误原因存于error		*/
		send(sclient, sendData, strlen(sendData), 0);

		//接收返回的数据
		char recData[255];
		int ret = recv(sclient, recData, 255, 0);//阻塞在此处等待接收
		if (ret > 0)
		{
			recData[ret] = 0x00;
			std::cout <<"第"<<n<<"回:"<< recData << std::endl;
		}

		if (n++>20)
		{
			break;
		}

		Sleep(1000);
	}

	//关闭
	closesocket(sclient);

	WSACleanup();
	system("pause");
	return 0;
}

服务器端程序： 

#include <winsock.h> 
#include<iostream>
#pragma comment(lib,"ws2_32.lib") 
#include <Windows.h>
#include <string>


DWORD WINAPI ThreadTCP(LPVOID pParam);

int main()
{
	//初始化Windows Socket Application
	WORD sockVersion = MAKEWORD(2, 2);
	WSADATA wsaData;

	//WinSock的注册函数，初始化底层的Windows Sockets DLL
	if (WSAStartup(sockVersion, &wsaData) != 0)
		return 0;

	//创建套接字 
	SOCKET slisten = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	if (slisten == INVALID_SOCKET)
	{
		std::cout << "create socket error!" << std::endl;
		return 0;
	}

	//绑定IP和端口  	
	sockaddr_in sin;
	sin.sin_family = AF_INET;
	//
	sin.sin_port = htons(8888);//指定端口，将端口号转换为网络字节顺序
	sin.sin_addr.S_un.S_addr = INADDR_ANY;

	//bind()把socket绑定到特定的网络地址上
	if (bind(slisten, (LPSOCKADDR)&sin, sizeof(sin)) == SOCKET_ERROR)
	{
		std::cout << "bind error!" << std::endl;
		return 0;
	}

	//开始监听
//启动指定的socket，监听到来的连接请求  
5指定了监听socket的等待连接缓冲区队列的最大长度，一般设为5	
	if (listen(slisten, 5) == SOCKET_ERROR)
	{
		std::cout << "listen error !" << std::endl;
		return 0;
	}

	//循环接收数据 
	SOCKET sClient;
	sockaddr_in remoteAddr;
	int nAddrlen = sizeof(remoteAddr);
	

	while (true)
	{
		std::cout << "阻塞。。。。等待连接。。。" << std::endl;
		//接收一个连接请求，并新建一个socket，原来的socket返回监听状态
		sClient = accept(slisten, (SOCKADDR *)&remoteAddr, &nAddrlen);
		if (sClient == INVALID_SOCKET)
		{
			std::cout << "accept error !" << std::endl;
			continue;
		}

		//inet_addr()把一个标准的点分十进制的IP地址转换成长整型的地址数据
		//inet_ntoa()把长整型的IP地址数据转换成点分十进制的ASCII字符串	
		std::cout << "接受一个连接：" << inet_ntoa(remoteAddr.sin_addr)<<":"<<remoteAddr.sin_port << std::endl;


		//创建一个线程与客户端进行会话
		CreateThread(NULL, 0, ThreadTCP, (LPVOID)sClient, 0, NULL);

	}

	closesocket(slisten);

	//winsock的注销函数，从底层的Windows Sockets DLL 中撤销注册
	WSACleanup();
	system("pause");
	return 0;
}

DWORD WINAPI ThreadTCP(LPVOID pParam)
{
	SOCKET sClient = (SOCKET)pParam;

	char revData[255];
	std::string data = "hello_";
	int n = 0;
	while (1)
	{
		data = "hello_"+std::to_string(n);
		//接收数据  
		//从一个已经与对方建立连接的socket接收数据	
		int ret = recv(sClient, revData, 255, 0);//阻塞于此进行接收
		if (ret > 0)
		{
			revData[ret] = 0x00;
			std::cout << "第" << n++ << "回:" << revData << std::endl;
			//printf(revData);
		}

		//发送数据  	
		const char * sendData = data.c_str();

		向一个已经与对方建立连接的socket发送数据	
		int nb=send(sClient, sendData, strlen(sendData), 0);
		if (nb != strlen(sendData))
		{
			break;
		}
		//Sleep(5000);
	}


	//断开连接
	std::cout << "断开连接" << std::endl;
	//关闭socket，释放相应的资源
	closesocket(sClient);
	return 0;
}

 服务器端每接收一个连接，则添加一个线程对连接会话进行处理。

一个服务器端--->两个客户端口同时连接 

一个客户端结束会话时的通信包：

 另一个客户端会话结束的通信包