[HECnet] Others DECnets

[Johnny Billquist]

Paul Koning wrote:
-----Original Message-----
From: owner-hecnet at Update.UU.SE [mailto:owner-hecnet at Update.UU.SE] On
Behalf Of Johnny Billquist
Sent: Friday, December 04, 2009 10:17 AM
To: hecnet at Update.UU.SE
Subject: Re: [HECnet] Others DECnets

Hmm, which wouldn't neccesarily result in the same thing...
Named objects use object #0, and then you specify the object name,
which
for instance in RSX means the task name.
Now, I don't even think numbered objects and named ones are handled
the
same way in RSX, since numbered objects are usually in the form
NNN$$$,
where $$$ is replaced by a number, for the service to be able to run
several instances in parallel. I don't think this $$$ replaced by a
number ever is done for named objects.
Also, the name of the task used for a service is not standardized. So,
the mail service task name can be anything. All you know is that it is
#27.
So, trying to talk with an named object called MAIL might cause to you
to talk with just about anything.

In RSX, the known objects of my system looks like this:
.ncp sho kno obj

Known objects summary as of 4-DEC-09 16:07:24

Object   Name       Copies   User         Verification

0                             Single   Default   Off
15           TCL...   Single   Default   On
16           LSN$$$   5             Default   Off
17           FAL$$$   8             Login       On
18           HLD...   Single   Default   Off
19           NIC$$$   5             Default   Inspect
23           RMHACP   Single   Default   Off
25           MIR$$$   5             Default   Off
26           EVR$$$   5             Default   Off
27           MAL$$$   8             Default   Off
29           PHO$$$   5             Default   Off
42           RTH         Single   Default   Off
63           DTR...   Single   Default   Off

So, trying to talk to MAIL would simply just fail, unless there is a
MAIL task installed, in which case that will be started. What program
that might be, and what it might do is beyond guess, but most likely
not
what a programmer of a remote system might have expected, if he tried
to
talk to an object called MAIL, thinking that was the right way to talk
with a MAIL-11 server accepting mails.
Good point.   The name flavor of object reference is OS specific, because
the conventions for what names appear aren't the same everywhere.   So
the numbers provide the portable way.   If you use the name form you have
to know what you're dealing with.   The example I gave (connect to
"MAIL") would work for DECnet/E.

Yes, it will be OS specific.
But even more so, I don't think it will work out right for you even if you try to talk to MAL$$$ on an RSX system, because RSX will see that MAL$$$ is a prototype task, and is not allowed to run, and will just fail on you.
When you invoke object 27, as I mentioned, DECnet will actually create a copy from the prototype task, and replace $$$ with a number, making an actual task appear, which is started, and which is not a prototype.

Now, I haven't actually tried this, so I could be wrong, and that DECnet-RSX will actually handle the $$$ substitution for named tasks as well, but I don't think it do. I think that is also tied into the "Copies" parameter, which for named tasks is "Single".

	Johnny