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From: forsyth@plan9.cs.york.ac.uk forsyth@plan9.cs.york.ac.uk
Subject: remote device access
Date: Thu, 27 Apr 1995 04:29:06 -0400	[thread overview]
Message-ID: <19950427082906.AJWj51cGIJbfUyNCKsnC3lZ10OZJCYr-gQEtVDnM5SQ@z> (raw)

>>escape/special case, more uniformity, etc. :-) You could even
>>conceivably bind /cpu/dri/xxx to /dev/xxx to access cpu server's drivers?

you can already do that (several ways).  for example,
when the cpu command connects a terminal to a cpu server,
it exports the devices in that window to the
cpu process on the cpu server, which imports them into its name space
and rebinds them on /dev/bitblt, etc., where the graphics programs find them.
X11-style network graphics thus requires no code at all that's specific
to network graphics: it simply reuses the existing code supporting import/export
of any file system.

i frequently use my terminal's floppy on the CPU server to take work home.
on plan 9, i don't need GNU-style remote-tape hacks to every conceivable
program.  furthermore, i can export at various levels: i can export
the floppy device (allowing me to tar to it, or perhaps run dossrv remotely),
or i can export dossrv's view of it (making the DOS files available
remotely), or even do both at the same time.  similarly, i can export
a CDROM device, or 9660srv's view of it. 

of course, import/export/bind works the other way round,
so that a terminal can get the cpu server's files, including devices.
for example, plan 9 machines here can import the /dev/rtctime file on one of our cpu servers
that is updated by the Rugby time service, replacing its own /dev/rtctime
or /dev/time if desired.  another cpu server acts as the Usenet news server,
using a local disc containing /n/kfs/news.  any client (cpu server or terminal)
that wants to read news simply imports that.

improvements can perhaps be made in the way a name space
is built, but the functionality you suggest
is already available with little fuss (and no code bloat).






             reply	other threads:[~1995-04-27  8:29 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
1995-04-27  8:29 forsyth [this message]
1995-04-28  0:18 serge
1995-04-28  6:52 Boyd
1995-04-28  8:26 forsyth
1995-04-28 16:04 rob
1995-04-28 21:39 serge
1995-04-29  6:09 serge
1995-04-29  6:51 David
1995-04-29  6:54 David

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