From: gwtmp01@...
Date: 2007-01-23T01:55:56+09:00
Subject: Re: Socket issue


On Jan 22, 2007, at 10:53 AM, Marc Soda wrote:
> Any suggestions?  I'm running on Linux, BTW.

What you are seeing is in the nature of TCP.

After the connection succeeds your server shuts down *its* end of
the TCP session (i.e. it tells the client that it won't send any
more data).  Since TCP is full duplex, the client-> server part of
the connection is still up and running as far as the client is
concerned.

Your first write stuffs the data in a buffer and returns (with no
error).  Shortly thereafter the kernel decides to actually transmit
the data.  The server responds with a RESET indicating that it will
no longer accept data on that TCP session.  The error is noted by
the kernel and is reported to your client code on the *next* attempt
to write to the socket (which is now in an error state).

There is no one-to-one mapping of a write call on the socket to
data transmission on the wire for TCP due to buffering. This is
why the first write doesn't cause the transmit/detect/report of
the error.

Gary Wright