On Tue, 10 May 2005, Sam Michaels wrote:
> Perhaps an EXPERIMENTAL_ option to send null packets at an interval
> after a specified time period? If the connection doesn't exist, won't
> the null packets fail?
I don't know how to send a null packet - and in any case, Exim operates
at an application level, where it is dealing with streams and file
descriptors, not packets.
In any case, I don't think it would fail. I did try testing in the
poll() call for POLLOUT (fd available for output), and that came back as
OK. I'm not surprised, because it seems to me that the connection stays
in the "up" state from the server's point of view until it actually
tries to read from it. Also, since this is deep TCP/IP stack magic, it
is no doubt different in different stacks.
--
Philip Hazel University of Cambridge Computing Service,
ph10@??? Cambridge, England. Phone: +44 1223 334714.
Get the Exim 4 book: http://www.uit.co.uk/exim-book
