Re: How to deal with full-duplex communication?

From:
"Scott McPhillips [MVP]" <org-dot-mvps-at-scottmcp>
Newsgroups:
microsoft.public.vc.mfc
Date:
Fri, 26 May 2006 11:16:46 -0400
Message-ID:
<ubg4EeNgGHA.5092@TK2MSFTNGP04.phx.gbl>
fadics wrote:

Thank you.

The return receipt I use is the size of all received data. So I can know
which message has been received. But the problem is still there. When both
side send and receive data at same time, the return receipts can not be
sent. Because they don't know whether the last message has been received.


That sounds like a design problem with your code or protocol. It seems
to be based on incorrect assumptions about the order of events.

If I send the return receipt immediately regardless of the receiving of other
side, the return receipt may be lost. By the way, I use TCP with
CAsyncSocket. But the lost is still on. I add watch to the OnReceive
function. The return receipt was not received.


This can be caused by code that fails to check the return value of Send.
  Send can fail and your code must remember this and try again later,
when OnSend is called. TCP with CAsyncSocket does not lose data when
properly used.

--
Scott McPhillips [VC++ MVP]

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