[HECnet] Others DECnets

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