Path: utzoo!mnetor!uunet!husc6!bbn!rochester!cornell!batcomputer!itsgw!imagine!pawl14.pawl.rpi.edu!jesup
From: jesup@pawl14.pawl.rpi.edu (Randell E. Jesup)
Newsgroups: comp.sys.amiga
Subject: Re: IPC (1): Ports & Messages
Message-ID: <517@imagine.PAWL.RPI.EDU>
Date: 12 Mar 88 06:42:37 GMT
References: <7412@agate.BERKELEY.EDU> <752@nuchat.UUCP> <1948@dino.ulowell.edu> <7590@agate.BERKELEY.EDU>
Sender: news@imagine.PAWL.RPI.EDU
Reply-To: beowulf!lunge!jesup@steinmetz.UUCP
Organization: RPI Public Access Workstation Lab - Troy, NY
Lines: 40
Keywords: InterProgram Communication, tools

In article <7590@agate.BERKELEY.EDU> pete@violet.berkeley.edu.UUCP (Pete Goodeve) writes:
>Is there a pointer to the STRING "REXX" in the ln_name field, or is this
>just those four characters inserted into the longword?  For some reason, in
>all our discussions, we've forgotten about this field (though I've just
>been suggesting it's use to mark ports).  This location could probably
>perfectly well be used for our proposed four-character message-type ID,
>rather than a pointer to a string.  If you happen to do it that way, we'd
...
>[Does anyone see any problem with using this field in this way? I've never
>seen anyone want to name a message, actually, though I think a pointer to
>sundry special data has sometimes been put there.]

	PLEASE don't put random data in a standard pointer position!  It can
really cause some annoying problems/misunderstandings down the road.
	Rexx uses that to say where it came from, not what it's sending.
Use the command field.

>I still feel strongly that the RexxMsg format is inappropriate for a lot --
>if not most -- of the message passing that interacting processes that
>didn't use Rexx would want to do.   We want something initially as
>unstructured as possible, yet formalized enough so that a program can know
>what action to take.

	Actually, if you don't want lots of incompatible extensions, I'd
advise a fairly structured definition as early as possible.  Perhaps Bill Hawes
could come up with a subset REXX message that would please you, but allow
stuff with rexx ports to work with this stuff (ex: TeX).
	Just what don't you like about the Rexx messages?

>I have one question here too: is Rexx single threaded, or is there some way
>that several processes can have scripts active at once?

	I think it's multitasking (it's a library).

     //	Randell Jesup			      Lunge Software Development
    //	Dedicated Amiga Programmer            13 Frear Ave, Troy, NY 12180
 \\//	beowulf!lunge!jesup@steinmetz.UUCP    (518) 272-2942
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