Re: [Winsock]Multiple OnReceive function exist?

From:

"Scott McPhillips [MVP]" <org-dot-mvps-at-scottmcp>

Newsgroups:

microsoft.public.vc.mfc

Date:

Mon, 12 Mar 2007 09:29:32 -0400

Message-ID:

<ebrwwqKZHHA.1008@TK2MSFTNGP03.phx.gbl>

mmlab_js wrote:

I use VSocket derived from CSocket class to create a server-client
application.At client side, I receives data sent from server to client in the
OnReceive notification funcion:
---
void VSocket::OnReceive(int nErrorCode)
{
      unsigned int port,retvalue;
      retvalue = ReceiveFrom(s_szData, s_nLength, address, port);
      if(retvalue==SOCKET_ERROR)
         return;
      m_pDlg
      (CClientDlg *)m_pDlg)->ProcessData(s_szData,retvalue);
}
---
I know that when there is data in the buffer that can be retrieved, the
winsock framework calls OnReceive function to notify this socket. I call
ReceiveFrom function to receive data and call the PorcessData function to
process it. If the ProcessData function has not finished (I think:so the
OnReceive function hasn't finished), at same time, there is data in the
buffer that can be retrieved. Does the winsock framework still call OnReceive
function, again???

The OnReceive function is a message handler, using the same queue and
message loop that gives you such messages as mouse clicks and keys. So
if your "ProcessData" code permits the message loop to run then yes,
OnReceive could be called while it is already running. For example,
displaying a MessageBox pumps messages and could let reentry happen. If
you do not let the message loop run during OnReceive processing there
will be no reentry.

--
Scott McPhillips [VC++ MVP]