win socket select的一个疑问
本帖最后由 keke_zkt 于 2013-02-27 10:48:43 编辑 网上找了一段程序 有几个地方不明白 请帮我解释一下
bool bReuseAddr=true;
iResult=setsockopt(sockServer,SOL_SOCKET,SO_REUSEADDR,(char *)&bReuseAddr,sizeof(bReuseAddr)); // 是允许套接口和一个已经允许使用的地址捆绑的意思吧 这里概念有点模糊 允许捆绑 是什么时候捆绑？
if(SOCKET_ERROR == iResult)
{
printf("Failed to set resueaddr socket!/r/n");
WSACleanup();
return;
}
iResult = bind(sockServer,(sockaddr *)&addrServer,sizeof(addrServer));// 是指的这里的捆绑吗？
if (SOCKET_ERROR == iResult)
{
printf("Failed to bind address!/r/n");
WSACleanup();
return;
}
if (0 != listen(sockServer,5))
{
printf("Failed to listen client!/r/n");
WSACleanup();
return;
}
UINT i = 0;
SOCKET sockAccept;
sockaddr_in addrAccept;
int iAcceptLen = sizeof(addrAccept);
char szDataBuff[INT_DATABUFFER_SIZE];
int iRecvSize;
sockaddr_in addrTemp;
int iTempLen;
fd_set fd;
FD_ZERO(&fd);
FD_SET(sockServer,&fd);
printf("Start server...\r\n");
while(1)
{
fd_set fdOld = fd;
iResult = select(0,&fdOld,NULL,NULL,/*&tm*/NULL);
if (0 <= iResult)
{
for(i = 0;i < fd.fd_count; i++)
{
if (FD_ISSET(fd.fd_array[i],&fdOld))
{
//如果socket是服务器，则接收连接 主要是这里不明白
if (fd.fd_array[i] == sockServer)// 这里不明白了 “如果socket是服务器，则接收连接”为什么？
{
memset(&addrAccept,0,sizeof(addrTemp));
sockAccept = accept(sockServer,(sockaddr *)&addrAccept,&iAcceptLen);
if (INVALID_SOCKET != sockAccept)
{
FD_SET(sockAccept,&fd);
printf("%s:%d has connected server!\r\n",inet_ntoa(addrAccept.sin_addr),
ntohs(addrAccept.sin_port));
}
}
else //非服务器,接收数据(因为fd是读数据集)
{
memset(szDataBuff,0,INT_DATABUFFER_SIZE);
iRecvSize = recv(fd.fd_array[i],szDataBuff,INT_DATABUFFER_SIZE,0);
memset(&addrTemp,0,sizeof(addrTemp));
iTempLen = sizeof(addrTemp);
getpeername(fd.fd_array[i],(sockaddr *)&addrTemp,&iTempLen);
if (SOCKET_ERROR == iRecvSize)
{
closesocket(fd.fd_array[i]);
FD_CLR(fd.fd_array[i],&fd);
i--;
printf("Failed to recv data ,%s:%d errorcode:%d.\r\n",
inet_ntoa(addrTemp.sin_addr),ntohs(addrTemp.sin_port),WSAGetLastError());
continue;
}
if (0 == iRecvSize)
{
//客户socket关闭
printf("%s:%d has closed!\r\n",inet_ntoa(addrTemp.sin_addr),
ntohs(addrTemp.sin_port));
closesocket(fd.fd_array[i]);
FD_CLR(fd.fd_array[i],&fd);
i--;
}
if (0 < iRecvSize)
{
//打印接收的数据
printf("recv %s:%d data:%s\r\n",inet_ntoa(addrTemp.sin_addr),
ntohs(addrTemp.sin_port),szDataBuff);
}
}
}
}
}
else if (SOCKET_ERROR == iResult)
{
//WSACleanup();
Sleep(100);
}
