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From: augustss@cs.chalmers.se (Lennart Augustsson)
Newsgroups: comp.sys.sequent
Subject: How do you distribute file descriptors?
Message-ID: <1990Nov6.015433.10642@mathrt0.math.chalmers.se>
Date: 6 Nov 90 01:54:33 GMT
Sender: news@mathrt0.math.chalmers.se (Evald Nyhetsson)
Organization: Chalmers University of Technology
Lines: 27

In a language implementation that I am doing I've got the following
problem: I'm using multiple processes (processors) to run a program,
during the execution of the program it may be necessary to open files
(and sockets).  After a file has been opened it would be desirable
if all processes (and not just the one doing the open) could read from
that file (the reason for this is to keep all processes "equal").
I can see no clean solution to this problem.  The descriptor that the
opening process gets back needs to be distributed to the others
somehow, but as far as I know there is now mechanism for that.  Or is
there?
4.3 BSD Unix contains a way to distribute file descriptors through the
sendmsg and recvmsg system calls, but as usual Sequent are years
behind when it comes to the operating system (sendmsg&recvmsg can send
file descriptors in the UNIX domain on vanilla 4.3 BSD, Ultrix, and
SunOS).
Has anyone else had this problem?  Have you got any solutions?
Hello Sequent, are you listening?  Are you ever going to catch up with
your competitors?  (I could mention other stuff that are still ridden with
4.2 bugs, but enough Sequent-bashing for one posting.)

(I have another solution using signals in mind, but I don't like it.)

	-- Lennart Augustsson


	-- Lennart Augustsson
Email:	augustss@cs.chalmers.se