From: Bill Fink <billfink@mindspring•com>
To: Rick Jones <rick.jones2@hp•com>
Cc: Herbert Xu <herbert@gondor•apana.org.au>,
ilpo.jarvinen@helsinki•fi, zbr@ioremap•net,
bert.hubert@netherlabs•nl, h.willstrand@gmail•com,
netdev@vger•kernel.org
Subject: Re: sendfile()? Re: SO_LINGER dead: I get an immediate RST on 2.6.24?
Date: Wed, 14 Jan 2009 03:32:43 -0500 [thread overview]
Message-ID: <20090114033243.49c54c19.billfink@mindspring.com> (raw)
In-Reply-To: <496D9D8A.8080804@hp.com>
On Wed, 14 Jan 2009, Rick Jones wrote:
> >>How likely is it that the "additional small delay" above would be much
> >>less than waiting for a read return of zero after a shutdown(SHUT_WR) call?
> >
> >
> > I'm not sure I understand what you're getting at. I did consider doing
> > something like what you suggested, but in the end decided it was simpler
> > to deal with a fully ESTABLISHED connection, than worrying about possible
> > races with a socket being (partially or fully) closed.
>
> Ostensibly, using a shutdown(SHUT_WR) and then a wait for a recv return
> of zero would take about the same length of time as polling local
> connection stats to see that there were no ostensibly unacked data -
> both will take one RTT right? and shutdown/read has the added property
> that it will deal with zero windows automagically.
With the shutdown(SHUT_WR)/read() approach, I would have had to set
a timeout on the read, to handle the case where the peer just went
away, whereas currently I just check elapsed time (I strive to make
nuttcp robust in such cases to allow it to be used reliably within
scripts run for example from cron).
Also, I was (perhaps unncessarily) worried that after the zero read(),
the socket would effectively be closed, and I wasn't sure then about
the reliability of using tcp_info to get the tcpi_total_retrans at that
point.
As with most things, there's more than one way to skin a cat.
-Bill
next prev parent reply other threads:[~2009-01-14 8:32 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-01-13 6:32 sendfile()? Re: SO_LINGER dead: I get an immediate RST on 2.6.24? Herbert Xu
2009-01-13 6:56 ` Bill Fink
2009-01-13 7:01 ` Herbert Xu
2009-01-14 7:43 ` Bill Fink
2009-01-14 8:29 ` Herbert Xu
2009-01-14 9:05 ` Bill Fink
2009-01-14 11:30 ` Herbert Xu
2009-01-15 6:33 ` Bill Fink
2009-01-13 7:06 ` Rick Jones
2009-01-14 8:05 ` Bill Fink
2009-01-14 8:08 ` Rick Jones
2009-01-14 8:32 ` Bill Fink [this message]
-- strict thread matches above, loose matches on Subject: below --
2009-01-11 21:23 bert hubert
2009-01-11 22:08 ` H. Willstrand
2009-01-11 22:45 ` sendfile()? " bert hubert
2009-01-11 22:54 ` Evgeniy Polyakov
2009-01-11 23:08 ` bert hubert
2009-01-11 23:18 ` Evgeniy Polyakov
2009-01-12 4:50 ` Bill Fink
2009-01-12 9:18 ` Ilpo Järvinen
2009-01-13 5:31 ` Bill Fink
2009-02-13 17:02 ` Jeremy Jackson
2009-02-20 18:10 ` Bill Fink
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20090114033243.49c54c19.billfink@mindspring.com \
--to=billfink@mindspring$(echo .)com \
--cc=bert.hubert@netherlabs$(echo .)nl \
--cc=h.willstrand@gmail$(echo .)com \
--cc=herbert@gondor$(echo .)apana.org.au \
--cc=ilpo.jarvinen@helsinki$(echo .)fi \
--cc=netdev@vger$(echo .)kernel.org \
--cc=rick.jones2@hp$(echo .)com \
--cc=zbr@ioremap$(echo .)net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox