9fans - fans of the OS Plan 9 from Bell Labs
 help / color / mirror / Atom feed
From: smiley@icebubble.org
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
Subject: [9fans] server push in 9P protocol
Date: Wed, 15 Oct 2014 15:56:14 +0000	[thread overview]
Message-ID: <86iojlmin5.fsf@cmarib.ramside> (raw)

Hello,

I'm wondering if there is any way to do server push using the 9P
protocol.  I'm trying to imagine use of 9P for applications such as data
acquisition.  One example might be caputing MIDI messages from digital
musical instruments.

As I understand the protocol, if an instrument served MIDI over 9P,
every MIDI message would have to be explicitly requested with a Tread.
And the instrument would have to wait for a Tread in order to send data.
If the instrument (server) sent more than one Rread with the same tag,
that would be a violation of the protocol.

It might be possible to reverse roles: for the instrument to act as a 9P
client and treat the MIDI host as a 9P server.  In that case, each MIDI
message could take the form of a Twrite to the MIDI host.  But that
would generate a series of Rwrites back from the host to the instrument,
which would be unnecessary and have to be ignored.

Another example might be isochronous data streams, such as video
captured at a fixed framerate from a video capture device.  Having to
send the same Tread or Rread 30x/second seems silly.

So, is there any way use 9P in a server-push mode, where the server
spits out a stream of data to be captured?

Thanks!



             reply	other threads:[~2014-10-15 15:56 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-10-15 15:56 smiley [this message]
2014-10-15 16:53 ` andrey mirtchovski
2014-10-15 16:55 ` Skip Tavakkolian
2014-10-15 17:14   ` Fran. j. Ballesteros 
2014-10-15 17:18   ` David du Colombier
2014-10-15 18:27   ` erik quanstrom
2014-10-15 17:01 ` Bakul Shah
2014-10-15 18:29   ` erik quanstrom
2014-10-15 19:03     ` Bakul Shah
2014-10-15 23:07       ` Enrico Weigelt, metux IT consult

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=86iojlmin5.fsf@cmarib.ramside \
    --to=smiley@icebubble.org \
    --cc=9fans@9fans.net \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).