Below is the WSAAsyncSelect processing code, but always feel uncomfortable,
1. If there is a boring man connect up and don't send data doesn't close the connection there will never be FD_CLOSE lead to store the information of lp_client_read_info will always be kept in the list,
2. Use the list for group packet buffer, this way or not appropriate, how to save a general WSAAsyncSelect model SOCKET set of packet buffer?

 void DSocketServer: : OnMessage (SOCKET sock, LPARAM LPARAM, HWND HWND) 
{
If (WSAGETSELECTERROR (lParam)) {
Closesocket (sock); 
return; 
} 
The switch (WSAGETSELECTEVENT (lParam)) 
{
Case FD_ACCEPT: 
{
Sockaddr_in clientAddr; 
Int addr_size=sizeof (sockaddr); 
The SOCKET clientSock=accept (m_socket_server, (sockaddr *) & amp; ClientAddr, & amp; Addr_size); 
If (INVALID_SOCKET==clientSock) 
{
GlobalUserLog. Error (TEXT (" the client sets according to the word is invalid! Error code: % ld "), WSAGetLastError ()); 
return; 
} 
Char * clientIp=inet_ntoa (clientAddr sin_addr); 

//read the data structure, for the first time in first need further information, describe the size of the packet information 
Lp_client_read_info lpReadInfo=new client_read_info {0}. 
//save the client's IP 
_tcscpy_s (lpReadInfo - & gt; Client_ip, 88, clientIp); 
LpReadInfo - & gt; Client_sock=clientSock; 
//should receive data length, h_info header structure 
LpReadInfo - & gt; Data_len=sizeof (h_info); 
//receiving data buffer 
LpReadInfo - & gt; Data=https://bbs.csdn.net/topics/new TCHAR [lpReadInfo -> data_len] {0}. 
//to save structure to a list, it is a class attribute 
Push_client_info (lpReadInfo); 
//bind the READ and CLOSE message 
WSAAsyncSelect (clientSock, hWnd WM_ASYNC_SOCKET, FD_READ | FD_CLOSE); 
break; 
} 
Case FD_READ: 
{
WSAAsyncSelect (sock, hWnd, 0, 0); 
//based on SOCKET out corresponding lp_client_read_info structure 
Lp_client_read_info lpReadInfo=get_client_info (sock); 
If (the sock!=lpReadInfo - & gt; Client_sock) 
{
return; 
} 

//calculate the rest need to read the data 
UINT readBufLen=lpReadInfo - & gt; Data_len lpReadInfo - & gt; Readed_len; 
//up to a read MAX_READ_BUF bytes 
If (readBufLen & gt; MAX_READ_BUF) 
{
ReadBufLen=MAX_READ_BUF; 
} 

TCHAR tmpBuf [MAX_READ_BUF]={0}; 
Int recvLen=recv (sock, tmpBuf readBufLen, 0). 
If (SOCKET_ERROR==recvLen) 
{
Int wsaErrorNo=WSAGetLastError (); 
If (wsaErrorNo!=WSAEWOULDBLOCK & amp; & WsaErrorNo!=WSAEINTR) 
{
The switch (wsaErrorNo) 
{
Case WSAETIMEDOUT: 
{
GlobalUserLog. Error (TEXT (" read data timeout, IP: % s "), lpReadInfo - & gt; Client_ip); 
} 
break; 
Case WSAECONNRESET: 
{
GlobalUserLog. Error (TEXT (" remote host mandatory disconnected, IP: % s "), lpReadInfo - & gt; Client_ip); 
} 
break; 
Default: 
{
GlobalUserLog. Error (TEXT (" unknown network Error condition occurred while reading data, Error code: % d, IP: % s "), wsaErrorNo, lpReadInfo - & gt; Client_ip); 
} 
break; 
} 
WSAAsyncSelect (sock, hWnd WM_ASYNC_SOCKET, FD_CLOSE); 
} 
The else 
{
WSAAsyncSelect (sock, hWnd WM_ASYNC_SOCKET, FD_READ); 
} 
} 
Else if (recvLen & gt; 0 & & RecvLen + lpReadInfo - & gt; Readed_len & gt; LpReadInfo - & gt; Data_len) 
{
GlobalUserLog. Error (TEXT (" data may have been tampered with, IP: % s "), lpReadInfo - & gt; Client_ip); 
WSAAsyncSelect (sock, hWnd WM_ASYNC_SOCKET, FD_CLOSE); 
} 
The else 
{
//read data saved to the buffer after 
If (recvLen & gt; 0) 
{
Memcpy_s (lpReadInfo - & gt; The data + lpReadInfo - & gt; Readed_len lpReadInfo - & gt; Data_len lpReadInfo - & gt; Readed_len tmpBuf, recvLen); 
LpReadInfo - & gt; Readed_len +=recvLen; 
} 
//if the data is read complete start processing data 
If (lpReadInfo - & gt; Data_len==lpReadInfo - & gt; Readed_len) 
{

//judge set package whether the data packet, if is the first packet, continue to read the actual data to be used 
if (! LpReadInfo - & gt; Readed_header) 
{
H_info header_info={0}; 
Memcpy_s (& amp; Header_info, sizeof (h_info), lpReadInfo - & gt; The data, sizeof (h_info)); 
The delete [] lpReadInfo - & gt; The data; 
LpReadInfo - & gt; Data=https://bbs.csdn.net/topics/nullptr; 

//logo for the first packet has finished reading 
LpReadInfo - & gt; Readed_header=TRUE; 
LpReadInfo - & gt; Data_len=ntohl (header_info. Data_len); 
LpReadInfo - & gt; Origin_data_len=ntohl (header_info. Origin_data_len); 
LpReadInfo - & gt; Readed_len=0; 
Try 
{
LpReadInfo - & gt; Data=https://bbs.csdn.net/topics/new TCHAR [lpReadInfo -> data_len] {0}. 
If (NULL==lpReadInfo - & gt; Data) 
{
WSAAsyncSelect (sock, hWnd WM_ASYNC_SOCKET, FD_CLOSE); 
GlobalUserLog. Error (TEXT (" distribution of memory allocation failure, size: % ld "), lpReadInfo - & gt; Data_len); 
} 
The else 
{
WSAAsyncSelect (sock, hWnd WM_ASYNC_SOCKET, FD_READ); 
} 
} 
The catch (const STD: : bad_alloc & amp; MemEx) 
{
WSAAsyncSelect (sock, hWnd WM_ASYNC_SOCKET, FD_CLOSE); 
GlobalUserLog. Error (TEXT (" the extraordinary memory allocation, the allocation size: % ld "), lpReadInfo - & gt; Data_len); 
} 
} 
The else 
{
//the last processing data 
The EnterCriticalSection (& amp; M_cs); 
UINT ret=m_dataHandler. Handler (lpReadInfo - & gt; The data, lpReadInfo - & gt; Data_len lpReadInfo - & gt; Origin_data_len); 
LeaveCriticalSection (& amp; M_cs); 
Ret=htonl (ret); 
Int sendRet=send (the sock, (const char *) & amp; Ret, sizeof (UINT), 0); 
If (SOCKET_ERROR==sendRet) 
{
GlobalUserLog. Error (TEXT (" there was an unknown network Error, Error code: % d, IP: % s "), WSAGetLastError (), lpReadInfo - & gt; Client_ip); 
} 
WSAAsyncSelect (sock, hWnd WM_ASYNC_SOCKET, FD_CLOSE); 
} 
} 
The else 
nullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnull