From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Mike Voytovich <mike@zermattsystems.com>
Cc: linux-kernel@vger.kernel.org
Subject: RE: termios VMIN and VTIME behavior
Date: Wed, 23 Nov 2005 11:15:27 +0000 [thread overview]
Message-ID: <1132744527.7268.5.camel@localhost.localdomain> (raw)
In-Reply-To: <64F9B87B6B770947A9F8391472E0321603A075B1@ehost011-8.exch011.intermedia.net>
On Maw, 2005-11-22 at 20:32 -0800, Mike Voytovich wrote:
> Please disregard - the user app was reading less than VMIN in the read()
> call, so I suppose the current behavior in that case would be correct
> (returning immediately with the number of bytes passed into read()
> rather than waiting for VMIN or VTIME to be met before returning).
>
> It doesn't appear that the behavior in this case is explicitly defined
> by POSIX, but it seems like a reasonable thing to do.
Its pretty well defined. It was designed to optimise block serial
operations (uucp and the like)
VMIN - number of bytes you expect this packet
VTIME - when to give up waiting
The form 0, VTIME also being used to do polling on old SYSV that lacked
select/poll
next prev parent reply other threads:[~2005-11-23 10:42 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-11-23 4:32 termios VMIN and VTIME behavior Mike Voytovich
2005-11-23 11:15 ` Alan Cox [this message]
-- strict thread matches above, loose matches on Subject: below --
2005-11-23 2:18 Mike Voytovich
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=1132744527.7268.5.camel@localhost.localdomain \
--to=alan@lxorguk.ukuu.org.uk \
--cc=linux-kernel@vger.kernel.org \
--cc=mike@zermattsystems.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.