C++非阻塞模式Socket编程

iocServer.cpp：
#include<WINSOCK2.H>
#include<iostream>
using namespace std;
#include<stdlib.h>
#define BUF_SIZE 64
#pragma comment(lib,"WS2_32.lib")
int main()
{
WSADATA wsd;
SOCKET sServer;
SOCKET sClient;
int retVal;//调用Socket函数的返回值
char buf[BUF_SIZE];


//初始化Socket环境
if(WSAStartup(MAKEWORD(2,2),&wsd)!=0)
{
printf("WSAStartup failed! ");
return 1;
}
//创建监听的Socket
sServer=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
if(INVALID_SOCKET==sServer)
{
printf("socket failed! ");
WSACleanup();
return -1;
}
//设置服务器Socket地址
SOCKADDR_IN addrServ;
addrServ.sin_family=AF_INET;
addrServ.sin_port=htons(9990);
addrServ.sin_addr.S_un.S_addr=htonl(INADDR_ANY);
//绑定Sockets Server
retVal=bind(sServer,(const struct sockaddr*)&addrServ,sizeof(SOCKADDR_IN));
if(SOCKET_ERROR==retVal)
{
printf("bind failed! ");
closesocket(sServer);
WSACleanup();
return -1;
}
//在Sockets Server上进行监听
retVal=listen(sServer,1);
if(SOCKET_ERROR==retVal)
{
printf("listen failed! ");
closesocket(sServer);
WSACleanup();
return -1;
}
//设置Socket为非阻塞模式
int iMode = 1;
retVal = ioctlsocket(sServer,FIONBIO,(u_long FAR*) &iMode);
if(retVal == SOCKET_ERROR)
{
printf("ioctlsocket failed! ");
WSACleanup();
return -1;
}
//接受来自客户端的请求
printf("TCPServer start... ");
sockaddr_in addrClient;
int addrClientlen=sizeof(addrClient);
while(true)
{
sClient=accept(sServer,(sockaddr FAR*)&addrClient,&addrClientlen);
if(INVALID_SOCKET == sClient)
{
int err = WSAGetLastError();
if(err == WSAEWOULDBLOCK)
{
Sleep(5);
continue;
}
else
{
printf("accept failed! ");
closesocket(sServer);
WSACleanup();
return -1;
}
}
break;
}
while(true)
{
ZeroMemory(buf,BUF_SIZE);
retVal = recv(sClient,buf,BUF_SIZE,0);
if(SOCKET_ERROR == retVal)
{
int err = WSAGetLastError();
if(err == WSAEWOULDBLOCK)
{
Sleep(5);
continue;
}
else if(err == WSAETIMEDOUT || err == WSAENETDOWN)
{
printf("recv failed! ");
closesocket(sServer);
closesocket(sClient);
WSACleanup();
return -1;
}
}
SYSTEMTIME st;
GetLocalTime(&st);
char sDateTime[30];
sprintf(sDateTime,"%4d-%2d-%2d-%2d:%2d:%2d:%2d",st.wYear,st.wMonth,st.wDay,st.wHour,st.wMinute,st.wSecond);
//打印输出的信息
printf("%s,Recv From Client [%s:%d]:%s ",sDateTime,inet_ntoa(addrClient.sin_addr),addrClient.sin_port,buf);
//如果客户端发送quit字符串，则服务器退出
if(strcmp(buf,"quit")==1)//////////////////////////////////////////
{
retVal=send(sClient,"quit",strlen("quit"),0);
break;
}
//否则向客户端发送回显字符串
else
{
char msg[BUF_SIZE];
sprintf(msg,"Message received - %s ",buf);
while(true)
{
retVal = send(sClient,msg,strlen(msg),0);
if(SOCKET_ERROR == retVal)
{
int err = WSAGetLastError();
if(err == WSAEWOULDBLOCK)
{
Sleep(5);
continue;
}
else
{
printf("send failed! ");
closesocket(sServer);
closesocket(sClient);
WSACleanup();
return -1;
}
}
}
break;
}
}
}
iocClient.cpp：
#include<WINSOCK2.H>
#include<iostream>
#include<string>
using namespace std;
#include<stdlib.h>
#define BUF_SIZE 64
#pragma comment(lib,"WS2_32.lib")
int main()
{
WSADATA wsd;
SOCKET sHost;
SOCKADDR_IN servAddr;//服务器地址
int retVal;//调用Socket函数的返回值
char buf[BUF_SIZE];
int iMode=1;
//初始化Socket环境
if(WSAStartup(MAKEWORD(2,2),&wsd)!=0)
{
printf("WSAStartup failed! ");
return -1;
}
sHost=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
//设置服务器Socket地址
servAddr.sin_family=AF_INET;
servAddr.sin_addr.S_un.S_addr=inet_addr("127.0.0.1");
//在实际应用中，建议将服务器的IP地址和端口号保存在配置文件中
servAddr.sin_port=htons(9990);
//计算地址的长度
int sServerAddlen=sizeof(servAddr);
//调用ioctlsocket（）将其设置为非阻塞模式
retVal=ioctlsocket(sHost,FIONBIO,(u_long FAR*)&iMode);
if(retVal==SOCKET_ERROR)
{
printf("ioctlsocket failed!");
WSACleanup();
return -1;
}


//循环等待
while(true)
{
//连接到服务器
retVal=connect(sHost,(LPSOCKADDR)&servAddr,sizeof(servAddr));
if(SOCKET_ERROR==retVal)
{
int err=WSAGetLastError();
//无法立即完成非阻塞Socket上的操作
if(err==WSAEWOULDBLOCK||err==WSAEINVAL)
{
Sleep(5);
continue;
}
else if(err==WSAEISCONN)//已建立连接
{
break;
}
else
{
printf("connection failed! ");
closesocket(sHost);
WSACleanup();
return -1;
}
}
}
while(true)
{
//向服务器发送字符串，并显示反馈信息
printf("input a string to send: ");
std::string str;
//接收输入的数据
std::getline(std::cin,str);
//将用户输入的数据复制到buf中
ZeroMemory(buf,BUF_SIZE);
strcpy(buf,str.c_str());
while(true)
{
retVal=send(sHost,buf,strlen(buf),0);
if(SOCKET_ERROR==retVal)
{
int err=WSAGetLastError();
if(err==WSAEWOULDBLOCK)
{
//无法立即完成非阻塞Socket上的操作
Sleep(5);
continue;
}

else
{
printf("send failed! ");
closesocket(sHost);
WSACleanup();
return -1;
}
}
break;
}
while(true)
{
ZeroMemory(buf,BUF_SIZE);//清空接收数据的缓冲区
retVal=recv(sHost,buf,sizeof(buf)+1,0);
if(SOCKET_ERROR==retVal)
{
int err=WSAGetLastError();
//无法立即完成非阻塞Socket上的操作
if(err==WSAEWOULDBLOCK)
{
Sleep(5000);
printf("waiting back msg! ");
continue;
}
else if(err==WSAETIMEDOUT||err==WSAENETDOWN)//已建立连接
{
printf("recv failed!");
closesocket(sHost);
WSACleanup();
return -1;
}
break;
}
break;
}
ZeroMemory(buf,BUF_SIZE);
retVal=recv(sHost,buf,sizeof(buf)+1,0);
printf("Recv from Server:%s ",buf);
//如果接收到quit，则退出
if(strcmp(buf,"quit")==0)
{
printf("quit! ");
break;
}
}
return 0;
}