服务端必须先监听该端口，使用accept阻塞等待，等待客户端用connect请求；
客户端用connect请求服务端，accept收到后就分配给该客户端一个专用的socker建立专用链接；
后续就在该链接(socket)上和该客户端用recv和send进行通信。
总结：也就比Udp多了一个accept和connect环节，这能保证专用稳定的链接。
默认情况下，新建的 Socket 是阻塞模式的。可以调用 ioctlsocket()函数将 Socket 设置为非阻塞模式，函数原型如下：
参考链接：socket编程TCP/IP通信（windows下，C++实现）
先别看那些原理介绍，会看晕的，直接看代码，很容易懂，再返回去看原理介绍。
话不多说，代码如下：
//server.cpp
#include<iostream>
#include<winsock.h> // windows平台的网络库头文件
#pragma comment(lib,"ws2_32.lib") // 库文件
using namespace std;
// 服务端
// socket编程TCP/IP通信（windows下，C++实现）
// https://blog.csdn.net/qq_44184049/article/details/122291617
#define PORT 5050
#define BUFSIZ 512
void initialization() {
//初始化套接字库
// WSA windows socket async windows异步套接字 WSAStartup启动套接字
// parm1:请求的socket版本 2.2 2.1 1.0 parm2:传出参数 参数形式：WORD WSADATA
WORD w_req = MAKEWORD(2, 2);//版本号
WSADATA wsadata;
// 成功：WSAStartup函数返回零
if (WSAStartup(w_req, &wsadata) != 0) {
cout << "init socket lib failed!" << endl;
}
else {
cout << "init socket lib success!" << endl;
}
}
SOCKET createServeSocket(const char* ip)
{
//1.创建空的Socket
//parm1:af 地址协议族 ipv4 ipv6
//parm2:type 传输协议类型 流式套接字(SOCK_STREAM) 数据报
//parm3：protocl 使用具体的某个传输协议
SOCKET s_server = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (s_server == INVALID_SOCKET)
{
cout << "socket create failed!" << endl;
WSACleanup();
}
else {
cout << "socket create sucess!" << endl;
}
//2.给socket绑定ip地址和端口号
struct sockaddr_in server_addr; // sockaddr_in, sockaddr 老版本和新版的区别
server_addr.sin_family = AF_INET; // 和创建socket时必须一样
server_addr.sin_port = htons(PORT); // 端口号 大端（高位）存储(本地)和小端（低位）存储(网络），两个存储顺序是反着的 htons 将本地字节序转为网络字节序
server_addr.sin_addr.S_un.S_addr = inet_addr(ip); //inet_addr将点分十进制的ip地址转为二进制
if (bind(s_server, (SOCKADDR*)&server_addr, sizeof(SOCKADDR)) == SOCKET_ERROR) {
cout << "socket bind failed!" << endl;
WSACleanup();
}
else {
cout << "socket bind success!" << endl;
}
//3.设置套接字为监听状态 SOMAXCONN 监听的端口数 右键转到定义为5
if (listen(s_server, SOMAXCONN) < 0) {
cout << "set listen states failed!" << endl;
WSACleanup();
}
else {
cout << "set listen status succes!" << endl;
}
return s_server;
}
int main_tcp_send() {
//定义发送缓冲区和接受缓冲区长度
char send_buf[BUFSIZ];
char recv_buf[BUFSIZ];
//定义服务端套接字，接受请求套接字
SOCKET s_server;
SOCKET s_accept;
initialization(); // 初始化启动套接字
s_server = createServeSocket("127.0.0.1");
cout << "wait client connect..." << endl;
// 如果有客户端请求连接
printf("waiting for client! zuse!!!!\n");
s_accept = accept(s_server, NULL, NULL); // 阻塞住，等待客户端发消息
printf("client send info to server! zuse end!!!!\n");
if (s_accept == INVALID_SOCKET) {
cout << "link failed!" << endl;
WSACleanup();
return 0;
}
// 可以和客户端进行通信了
while (true) {
// recv从指定的socket接受消息
if (recv(s_accept, recv_buf, BUFSIZ, 0) > 0){
cout << "client info: " << recv_buf << endl;
}
else {
cout << "receive failed!" << endl;
break;
}
cout << "please input replay info:";
cin >> send_buf;
if (send(s_accept, send_buf, BUFSIZ, 0) < 0) {
cout << "sned failed!" << endl;
break;
}
}
//关闭套接字
closesocket(s_server);
closesocket(s_accept);
//释放DLL资源
WSACleanup();
return 0;
}参考链接：socket编程TCP/IP通信（windows下，C++实现）
代码如下：
// client.cpp
#include<iostream>
#include<winsock.h> // windows平台的网络库头文件
#pragma comment(lib,"ws2_32.lib") // 库文件
using namespace std;
// 客户端
// socket编程TCP/IP通信（windows下，C++实现）
// https://blog.csdn.net/qq_44184049/article/details/122291617
#define PORT 5050
#define BUFSIZ 512
void initialization() {
//初始化套接字库
// WSA windows socket async windows异步套接字 WSAStartup启动套接字
// parm1:请求的socket版本 2.2 2.1 1.0 parm2:传出参数 参数形式：WORD WSADATA
WORD w_req = MAKEWORD(2, 2);//版本号
WSADATA wsadata;
// 成功：WSAStartup函数返回零
if (WSAStartup(w_req, &wsadata) != 0) {
cout << "初始化套接字库失败！" << endl;
}
else {
cout << "初始化套接字库成功！" << endl;
}
}
SOCKET createClientSocket(const char* ip)
{
//1.创建空的Socket
//parm1:af 地址协议族 ipv4 ipv6
//parm2:type 传输协议类型 流式套接字(SOCK_STREAM) 数据报
//parm3：protocl 使用具体的某个传输协议
SOCKET c_client = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (c_client == INVALID_SOCKET)
{
cout << "套接字创建失败！" << endl;
WSACleanup();
}
else {
cout << "套接字创建成功！" << endl;
}
//2.连接服务器
struct sockaddr_in addr; // sockaddr_in, sockaddr 老版本和新版的区别
addr.sin_family = AF_INET; // 和创建socket时必须一样
addr.sin_port = htons(PORT); // 端口号 大端（高位）存储(本地)和小端（低位）存储(网络），两个存储顺序是反着的 htons 将本地字节序转为网络字节序
addr.sin_addr.S_un.S_addr = inet_addr(ip); //inet_addr将点分十进制的ip地址转为二进制
if (connect(c_client, (struct sockaddr*)&addr, sizeof(addr)) == INVALID_SOCKET)
{
cout << "服务器连接失败！" << endl;
WSACleanup();
}
else {
cout << "服务器连接成功！" << endl;
}
return c_client;
}
int main() {
//定义发送缓冲区和接受缓冲区长度
char send_buf[BUFSIZ];
char recv_buf[BUFSIZ];
//定义客户端套接字，接受请求套接字
SOCKET s_server;
initialization(); // 初始化启动套接字
s_server = createClientSocket("127.0.0.1");
//发送,接收数据
while (true) {
cout << "请输入发送信息:";
cin >> send_buf;
if (send(s_server, send_buf, BUFSIZ, 0) < 0) {
cout << "发送失败！" << endl;
break;
}
if (recv(s_server, recv_buf, BUFSIZ, 0) < 0) {
cout << "接受失败！" << endl;
break;
}
else {
cout << "服务端信息:" << recv_buf << endl;
}
}
//关闭套接字
closesocket(s_server);
//释放DLL资源
WSACleanup();
return 0;
}#include<iostream>
#include <WinSock2.h>
#include <WS2tcpip.h>
#include<vector>
#include<List>
using namespace std;
#pragma comment(lib,"ws2_32.lib")
#define PORT 65432
#define buff_len 500
int main_tcp_send()
{
//初始化winsock2.DLL
WSADATA wsaData;
WORD wVersionRequested = MAKEWORD(2, 2);
if (WSAStartup(wVersionRequested, &wsaData) != 0)
{
cout << "load winsock.dll failed！" << endl;
return 0;
}
//创建套接字
SOCKET sock_server;
if ((sock_server = socket(AF_INET, SOCK_STREAM, 0)) == SOCKET_ERROR)
{
cout << "create socket failed! error code:" << WSAGetLastError() << endl;
WSACleanup();
return 0;
}
//设置为非阻塞方式
u_long ul = 1;
if (ioctlsocket(sock_server, FIONBIO, &ul) == SOCKET_ERROR)
{
cout << "ioctlsocket failure, error:" << GetLastError() << endl;
WSACleanup();
return 0;
}
//绑定端口和Ip
sockaddr_in addr;
int addr_len = sizeof(struct sockaddr_in);
addr.sin_family = AF_INET;
addr.sin_port = htons(PORT);
inet_pton(AF_INET, "127.0.0.1", &addr.sin_addr);//绑定本机的环回地址
if (SOCKET_ERROR == bind(sock_server, (SOCKADDR*)&addr, sizeof(sockaddr_in)))
{
cout << "addr bind failed! error code:" << WSAGetLastError() << endl;
closesocket(sock_server);
WSACleanup();
return 0;
}
//将套接字设为监听状态
int size=listen(sock_server, 0);
if (size != 0)
{
cout << "listen func use failed!\n";
closesocket(sock_server);
WSACleanup();
return 0;
}
list<SOCKET> liSock;//将连接的套接字存储在list中
char msg[buff_len];//发送数据缓冲区
char msgbuffer[buff_len];//接收数据缓冲区
int n = 0; //标记已经连接的套接字数量
int num = 0;
//实现交互
while (1)
{
num++;
sockaddr_in client_addr;
auto sc = accept(sock_server, (struct sockaddr*)&client_addr, &addr_len);
if (sc == INVALID_SOCKET)
{
if (GetLastError() == WSAEWOULDBLOCK)
{
cout << "this time accept func has no client build link!" << endl;
Sleep(3000);//设置令其间隔一段时间
}
else
{
cout << "accept func use failed! net not normal, program exit" << endl;
closesocket(sock_server);
WSACleanup();
return 0;
}
}
else
{
cout << "server link with: " << sc << "success!" << endl;
liSock.push_back(sc);//将建立连接的套接字压入list
}
auto it = liSock.begin();
auto ccc = liSock.end();
while (it != liSock.end())
{
auto itTemp = it++;
cout << "please input, server send data to client" << *itTemp << "." << endl;
// cin.getline(msg, sizeof(msg));
sprintf(msg,"%d",num);
int size = send(*itTemp, msg, sizeof(msg), 0);
// int size = send(*itTemp, "abc", 4, 0);
if (strcmp(msg, "end\0") == 0)
{
cout << "close link with " << *itTemp << "!" << endl;
liSock.erase(itTemp);//移除已关闭连接的套接字
system("pause");
}
if (size <= 0)
{
if (GetLastError() == WSAEWOULDBLOCK)
{
cout << "Send data failure！\n";
}
else
{
cout << *itTemp << " is closed" << endl;
liSock.erase(itTemp);
system("pause");
}
}
}
it = liSock.begin();
while (it != liSock.end())
{
auto itTemp = it++;
size = recv(*itTemp, msgbuffer, sizeof(msgbuffer), 0);
if (size <= 0)
{
if (GetLastError() == WSAEWOULDBLOCK)
{
cout << "recv data failure！\n";
}
else
{
cout << *itTemp << " is closed" << endl;
liSock.erase(itTemp);
system("pause");
}
}
else
{
cout << *itTemp << " say: " << msgbuffer << endl;
system("pause");
}
}
}
return 0;
}
#include<iostream>
#include <WinSock2.h>
#include <WS2tcpip.h>
#include<vector>
#include<List>
using namespace std;
#pragma comment(lib,"ws2_32.lib")
#define PORT 65432
#define buff_len 500
int main_tcp_send()
{
//初始化winsock2.DLL
WSADATA wsaData;
WORD wVersionRequested = MAKEWORD(2, 2);
if (WSAStartup(wVersionRequested, &wsaData) != 0)
{
cout << "load winsock.dll failed！" << endl;
return 0;
}
//创建套接字
SOCKET sock_server;
if ((sock_server = socket(AF_INET, SOCK_STREAM, 0)) == SOCKET_ERROR)
{
cout << "create socket failed! error code:" << WSAGetLastError() << endl;
WSACleanup();
return 0;
}
//设置为非阻塞方式
u_long ul = 1;
if (ioctlsocket(sock_server, FIONBIO, &ul) == SOCKET_ERROR)
{
cout << "ioctlsocket failure, error:" << GetLastError() << endl;
WSACleanup();
return 0;
}
//绑定端口和Ip
sockaddr_in addr;
int addr_len = sizeof(struct sockaddr_in);
addr.sin_family = AF_INET;
addr.sin_port = htons(PORT);
inet_pton(AF_INET, "127.0.0.1", &addr.sin_addr);//绑定本机的环回地址
if (SOCKET_ERROR == bind(sock_server, (SOCKADDR*)&addr, sizeof(sockaddr_in)))
{
cout << "addr bind failed! error code:" << WSAGetLastError() << endl;
closesocket(sock_server);
WSACleanup();
return 0;
}
//将套接字设为监听状态
int size=listen(sock_server, 0);
if (size != 0)
{
cout << "listen func use failed!\n";
closesocket(sock_server);
WSACleanup();
return 0;
}
list<SOCKET> liSock;//将连接的套接字存储在list中
char msg[buff_len];//发送数据缓冲区
char msgbuffer[buff_len];//接收数据缓冲区
int n = 0; //标记已经连接的套接字数量
int num = 0;
//实现交互
while (1)
{
num++;
sockaddr_in client_addr;
auto sc = accept(sock_server, (struct sockaddr*)&client_addr, &addr_len);
if (sc == INVALID_SOCKET)
{
if (GetLastError() == WSAEWOULDBLOCK)
{
cout << "this time accept func has no client build link!" << endl;
Sleep(3000);//设置令其间隔一段时间
}
else
{
cout << "accept func use failed! net not normal, program exit" << endl;
closesocket(sock_server);
WSACleanup();
return 0;
}
}
else
{
cout << "server link with: " << sc << "success!" << endl;
liSock.push_back(sc);//将建立连接的套接字压入list
}
auto it = liSock.begin();
auto ccc = liSock.end();
while (it != liSock.end())
{
auto itTemp = it++;
cout << "please input, server send data to client" << *itTemp << "." << endl;
// cin.getline(msg, sizeof(msg));
sprintf(msg,"%d",num);
int size = send(*itTemp, msg, sizeof(msg), 0);
// int size = send(*itTemp, "abc", 4, 0);
if (strcmp(msg, "end\0") == 0)
{
cout << "close link with " << *itTemp << "!" << endl;
liSock.erase(itTemp);//移除已关闭连接的套接字
system("pause");
}
if (size <= 0)
{
if (GetLastError() == WSAEWOULDBLOCK)
{
cout << "Send data failure！\n";
}
else
{
cout << *itTemp << " is closed" << endl;
liSock.erase(itTemp);
system("pause");
}
}
}
it = liSock.begin();
while (it != liSock.end())
{
auto itTemp = it++;
size = recv(*itTemp, msgbuffer, sizeof(msgbuffer), 0);
if (size <= 0)
{
if (GetLastError() == WSAEWOULDBLOCK)
{
cout << "recv data failure！\n";
}
else
{
cout << *itTemp << " is closed" << endl;
liSock.erase(itTemp);
system("pause");
}
}
else
{
cout << *itTemp << " say: " << msgbuffer << endl;
system("pause");
}
}
}
return 0;
}参考链接：C++实现TCP服务器端同时和多个客户端通信(多线程)
#include <WinSock2.h>
#include <WS2tcpip.h>
#include <iostream>
using namespace std;
#pragma comment(lib, "ws2_32.lib")
#define PORT 65432
DWORD WINAPI ThreadFun(LPVOID lpThreadParameter);
int main_tcp_send()
{
//初始化winsock2.DLL
WSADATA wsaData;
WORD wVersionRequested = MAKEWORD(2, 2);
if (WSAStartup(wVersionRequested, &wsaData) != 0)
{
cout << "load winsock.dll failed！" << endl;
return 0;
}
//创建套接字
SOCKET sock_server;
if ((sock_server = socket(AF_INET, SOCK_STREAM, 0)) == SOCKET_ERROR)
{
cout << "create socket failed! error code:" << WSAGetLastError() << endl;
WSACleanup();
return 0;
}
//绑定端口和Ip
sockaddr_in addr;
addr.sin_family = AF_INET;
addr.sin_port = htons(PORT);
inet_pton(AF_INET, "127.0.0.1", &addr.sin_addr);//绑定本机的环回地址
if (SOCKET_ERROR == bind(sock_server, (SOCKADDR*)&addr, sizeof(sockaddr_in)))
{
cout << "addr bind failed! error code:" << WSAGetLastError() << endl;
closesocket(sock_server);
WSACleanup();
return 0;
}
//将套接字设为监听状态
listen(sock_server, 0);
int i = 0;
//主线程循环接收客户端的连接
while (1)
{
sockaddr_in addrClient;
int len = sizeof(sockaddr_in);
//接收成功返回与client通讯的socket
SOCKET con = accept(sock_server, (SOCKADDR*)&addrClient, &len);
printf("the %dth time accept!\n", i + 1);
if (con != INVALID_SOCKET)
{
//创建线程 并且传入与client通讯的套接字
HANDLE hThread = CreateThread(NULL, 0, ThreadFun, (LPVOID)con, 0, NULL);
CloseHandle(hThread); //关闭对线程的引用
}
cout << "===" << endl;
if (i >= 1) break;
i++;
}
cout << "end" << endl;
getchar();
closesocket(sock_server);
WSACleanup();
return 0;
}
//线程通讯部分
DWORD WINAPI ThreadFun(LPVOID lpThreadParameter)
{
//与客户端通讯 先发送再接收数据
SOCKET sock = (SOCKET)lpThreadParameter;
cout << "establish link with " << sock << " success!" << endl;
while (1)
{
char msgbuffer[1000];//字符缓冲区
printf("server send data to %d: aaa\n", sock);
//cin.getline(msgbuffer, sizeof(msgbuffer));
//int size = send(sock, msgbuffer, sizeof(msgbuffer), 0);//给客户端发送一段信息
// 为了方便，我把server端的输入，改成了直接发aaa
int size = send(sock, "aaa", 4, 0);//给客户端发送一段信息
if (strcmp(msgbuffer, "end\0") == 0)
{
cout << "close link with " << sock << "!" << endl;
return 0;
}
if (size == SOCKET_ERROR || size == 0)
{
cout << "send info failed! error code:" << WSAGetLastError() << endl;
return 0;
}
else cout << "info send success!" << endl;
//接收客户端数据
msgbuffer[999] = { 0 };
int ret = recv(sock, msgbuffer, sizeof(msgbuffer), 0);
if(ret == SOCKET_ERROR || ret == 0)
{
cout << sock << "link breaked!" << endl;
break;
}
else cout << sock << " say: " << msgbuffer << endl;
}
return 0;
}参考链接：C++实现TCP服务器端同时和多个客户端通信(多线程)
#include <winsock2.h>
#include <WS2tcpip.h>
#include <iostream>
using namespace std;
#pragma comment(lib, "ws2_32.lib")
#define PORT 65432
int main()
{
//初始化winsock2.DLL
WSADATA wsaData;
WORD wVersionRequested = MAKEWORD(2, 2);
if (WSAStartup(wVersionRequested, &wsaData) != 0)
{
cout << "加载winsock.dll失败！" << endl;
return 0;
}
//创建套接字
SOCKET sock_client;
if ((sock_client = socket(AF_INET, SOCK_STREAM, 0)) == SOCKET_ERROR)
{
cout << "创建套接字失败！错误代码：" << WSAGetLastError() << endl;
WSACleanup();
return 0;
}
//连接服务器
sockaddr_in addr;
addr.sin_family = AF_INET;
addr.sin_port = htons(PORT);
inet_pton(AF_INET, "127.0.0.1", &addr.sin_addr);//绑定本机的环回地址
int len = sizeof(sockaddr_in);
if (connect(sock_client, (SOCKADDR*)&addr, len) == SOCKET_ERROR) {
cout << "连接失败！错误代码：" << WSAGetLastError() << endl;
return 0;
}
//实现交互部分，客户端先接收后发送数据
while (1)
{
//接收服务端的消息
char msgbuffer[1000] = { 0 };
int size = recv(sock_client, msgbuffer, sizeof(msgbuffer), 0);
if (strcmp(msgbuffer, "end\0") == 0)
{
cout << "服务器端已经关闭连接！" << endl;
break;
}
if (size < 0)
{
cout << "接收信息失败！错误代码：" << WSAGetLastError() << endl;
break;
}
else if (size == 0)
{
cout << "对方已经关闭连接" << endl;
break;
}
else cout << "The message from Server:" << msgbuffer << endl;
//从键盘输入一行文字发送给服务器
msgbuffer[999] = 0;
cout << "从键盘输入发给服务器的信息：" << endl;
cin.getline(msgbuffer, sizeof(msgbuffer));
if (strcmp(msgbuffer, "end\0") == 0)
{
cout << "关闭连接！" << endl;
break;
}
int ret = send(sock_client, msgbuffer, sizeof(msgbuffer), 0);
if (ret == SOCKET_ERROR || ret == 0)
{
cout << "发送信息失败！错误代码：" << WSAGetLastError() << endl;
break;
}
else cout << "信息发送成功！" << endl;
}
closesocket(sock_client);
WSACleanup();
return 0;
}参考资料：python多线程实现TCP服务端
# 导入模块
import socket
import threading
# 接收消息
def recv(client_socket, ip_port):
while True:
client_socket.send("send test\n".encode())
client_text = client_socket.recv(1024)
# 如果接收的消息长度不为0，则将其解码输出
if client_text:
print("[客户端消息]", ip_port, ":", client_text.decode("gbk"))
# 给客户端响应
client_socket.send("received\n".encode())
# 当客户端断开连接时，会一直发送''空字符串，所以长度为0已下线
else:
print("客户端", ip_port, "已下线")
client_socket.close()
break
# 程序主入口
def main():
# 创建TCP套接字
tcp_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# 设置端口复用
tcp_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, True)
# 绑定端口
tcp_socket.bind(("", 65432))
# 设置为被动监听状态，128表示最大连接数
tcp_socket.listen(128)
while True:
# 等待客户端连接
client_socket, ip_port = tcp_socket.accept()
print("[新客户端]:", ip_port, "已连接")
# 有客户端连接后，创建一个线程将客户端套接字，IP端口传入recv函数，
t1 = threading.Thread(target=recv, args=(client_socket, ip_port))
# 设置线程守护
# Python多线程中的setDaemon: https://www.cnblogs.com/-wenli/p/12907355.html
# 当子线程不设置时(默认)，主进程结束后，子线程会继续执行完后，程序结束。
# 当设置时，主进程不会等待子线程，当主线程结束，子线程就会被强制停止运行并回收。
t1.setDaemon(True)
# 启动线程
t1.start()
if __name__ == '__main__':
main()参考资料：C++实现TCP服务器端非阻塞方式同时和多个客户端通信
#include<iostream>
#include <WinSock2.h>
#include <WS2tcpip.h>
#include<vector>
#include<List>
using namespace std;
#pragma comment(lib,"ws2_32.lib")
#define PORT 65432
#define buff_len 500
int main_tcp_send()
{
//初始化winsock2.DLL
WSADATA wsaData;
WORD wVersionRequested = MAKEWORD(2, 2);
if (WSAStartup(wVersionRequested, &wsaData) != 0)
{
cout << "load winsock.dll failed！" << endl;
return 0;
}
//创建套接字
SOCKET sock_server;
if ((sock_server = socket(AF_INET, SOCK_STREAM, 0)) == SOCKET_ERROR)
{
cout << "create socket failed! error code:" << WSAGetLastError() << endl;
WSACleanup();
return 0;
}
//设置为非阻塞方式
u_long ul = 1;
if (ioctlsocket(sock_server, FIONBIO, &ul) == SOCKET_ERROR)
{
cout << "ioctlsocket failure, error:" << GetLastError() << endl;
WSACleanup();
return 0;
}
//绑定端口和Ip
sockaddr_in addr;
int addr_len = sizeof(struct sockaddr_in);
addr.sin_family = AF_INET;
addr.sin_port = htons(PORT);
inet_pton(AF_INET, "127.0.0.1", &addr.sin_addr);//绑定本机的环回地址
if (SOCKET_ERROR == bind(sock_server, (SOCKADDR*)&addr, sizeof(sockaddr_in)))
{
cout << "addr bind failed! error code:" << WSAGetLastError() << endl;
closesocket(sock_server);
WSACleanup();
return 0;
}
//将套接字设为监听状态
int size=listen(sock_server, 0);
if (size != 0)
{
cout << "listen func use failed!\n";
closesocket(sock_server);
WSACleanup();
return 0;
}
list<SOCKET> liSock;//将连接的套接字存储在list中
char msg[buff_len];//发送数据缓冲区
char msgbuffer[buff_len];//接收数据缓冲区
int n = 0; //标记已经连接的套接字数量
int num = 0;
//实现交互
while (1)
{
num++;
sockaddr_in client_addr;
auto sc = accept(sock_server, (struct sockaddr*)&client_addr, &addr_len);
if (sc == INVALID_SOCKET)
{
if (GetLastError() == WSAEWOULDBLOCK)
{
cout << "this time accept func has no client build link!" << endl;
Sleep(3000);//设置令其间隔一段时间
}
else
{
cout << "accept func use failed! net not normal, program exit" << endl;
closesocket(sock_server);
WSACleanup();
return 0;
}
}
else
{
cout << "server link with: " << sc << "success!" << endl;
liSock.push_back(sc);//将建立连接的套接字压入list
}
auto it = liSock.begin();
auto ccc = liSock.end();
while (it != liSock.end())
{
auto itTemp = it++;
cout << "please input, server send data to client" << *itTemp << "." << endl;
// cin.getline(msg, sizeof(msg));
sprintf(msg,"%d",num);
int size = send(*itTemp, msg, sizeof(msg), 0);
// int size = send(*itTemp, "abc", 4, 0);
if (strcmp(msg, "end\0") == 0)
{
cout << "close link with " << *itTemp << "!" << endl;
liSock.erase(itTemp);//移除已关闭连接的套接字
system("pause");
}
if (size <= 0)
{
if (GetLastError() == WSAEWOULDBLOCK)
{
cout << "Send data failure！\n";
}
else
{
cout << *itTemp << " is closed" << endl;
liSock.erase(itTemp);
system("pause");
}
}
}
it = liSock.begin();
while (it != liSock.end())
{
auto itTemp = it++;
size = recv(*itTemp, msgbuffer, sizeof(msgbuffer), 0);
if (size <= 0)
{
if (GetLastError() == WSAEWOULDBLOCK)
{
cout << "recv data failure！\n";
}
else
{
cout << *itTemp << " is closed" << endl;
liSock.erase(itTemp);
system("pause");
}
}
else
{
cout << *itTemp << " say: " << msgbuffer << endl;
system("pause");
}
}
}
return 0;
}// TcpClient.cpp : 定义控制台应用程序的入口点。
//
#include <winsock2.h>
#include <string>
#include <iostream>
#pragma comment(lib,"ws2_32.lib")
#define BUF_SIZE 64
int main(int argc, char* argv[])
{
WSADATA wsd;
SOCKET sHost;
SOCKADDR_IN servAddr;
char buf[BUF_SIZE];
int retVal;
//初始化Socket
if (WSAStartup(MAKEWORD(2, 2), &wsd) != 0)
{
printf("WSAStartup failed!\n");
return -1;
}
//创建Socket
sHost = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (INVALID_SOCKET == sHost)
{
printf("socket failed!\n");
WSACleanup();
return -1;
}
//设置Socket为非阻塞模式
int iMode = 1;
retVal = ioctlsocket(sHost, FIONBIO, (u_long FAR*) & iMode);
if (retVal == SOCKET_ERROR)
{
printf("ioctlsocket failed!\n");
WSACleanup();
return -1;
}
//设置服务器Socket地址
servAddr.sin_family = AF_INET;
servAddr.sin_port = htons(65432);
servAddr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");//htonl(INADDR_ANY);
int sServerAddlen = sizeof(servAddr);
//连接到服务器
while (true)
{
retVal = connect(sHost, (LPSOCKADDR)&servAddr, sizeof(servAddr));
if (SOCKET_ERROR == retVal)
{
int err = WSAGetLastError();
if (err == WSAEWOULDBLOCK || err == WSAEINVAL)
{
Sleep(1000);
printf("try next connect!\n");
continue;
}
else if (err == WSAEISCONN)
{
break;
}
else
{
printf("connection failed!\n");
closesocket(sHost);
WSACleanup();
return -1;
}
}
}
//收发数据
while (true)
{
printf("Please input a string to send:");
std::string str;
std::getline(std::cin, str);
ZeroMemory(buf, BUF_SIZE);
strcpy_s(buf, str.c_str());
while (true)
{
retVal = send(sHost, buf, strlen(buf), 0);
if (SOCKET_ERROR == retVal)
{
int err = WSAGetLastError();
if (err == WSAEWOULDBLOCK)
{
Sleep(500);
continue;
}
else
{
printf("send failed!\n");
closesocket(sHost);
WSACleanup();
return -1;
}
}
break;
}
while (true)
{
ZeroMemory(buf, BUF_SIZE);
retVal = recv(sHost, buf, sizeof(buf) + 1, 0);
if (SOCKET_ERROR == retVal)
{
int err = WSAGetLastError();
if (err == WSAEWOULDBLOCK)
{
Sleep(100);
printf("waiting back msg!\n");
continue;
}
else if (err == WSAETIMEDOUT || err == WSAENETDOWN)
{
printf("recv failed!\n");
closesocket(sHost);
WSACleanup();
return -1;
}
break;
}
break;
}
printf("Recv From Server:%s\n", buf);
if (strcmp(buf, "quit") == 0)
{
printf("quit!\n");
break;
}
}
closesocket(sHost);
WSACleanup();
system("pause");
return 0;
}参考资料：[python实现单线程多任务非阻塞TCP服务端](https://www.cnblogs.com/vathe/p/7001127.html)
# coding:utf-8
from socket import *
# 1.创建服务器socket
sock = socket(AF_INET, SOCK_STREAM)
# 2.绑定主机和端口
addr = ('', 65432) #
sock.bind(addr)
# 3. 设置最大监听数目，并发
sock.listen(10)
# 4. 设置成非阻塞
sock.setblocking(False)
# 保存客户端socket
clientAddrList = []
# print(sock.)
while 1:
try:
clientSocket, clientAddr = sock.accept()
print("accepp!")
except:
pass
# print("accept failed!")
else:
print("一个新客户端到来：%s" % str(clientAddr))
clientSocket.setblocking(False)
clientAddrList.append((clientSocket, clientAddr))
for clientSocket, clientAddr in clientAddrList:
# try:
# # 给客户端响应
# clientSocket.send("received\n".encode())
# except:
# pass
# else:
# pass
try:
recvData = clientSocket.recv(1024)
except:
pass
else:
if len(recvData) > 0:
print("%s:%s" % (str(clientAddr), recvData))
else:
clientSocket.close()
clientAddrList.remove((clientSocket, clientAddr))
print("%s 已经下线" % str(clientAddr))===
这个介绍原理比较详细，比如非阻塞式，多线程机制，三次握手等。