[Info-vax] [OpenVMS Alpha V8.3] SET TERM hang

[Michael Moroney]

peter at langstoeger.at (Peter 'EPLAN' LANGSTOeGER) writes:

>A shutdown today which didn't complete, reminded me of a behaviour I
>observed, but didn't know if this is bad and something to become fixed
>or is a simple fact (now) and I have to live with it (now).

>$ SET TERMINAL/PERM/BROAD OPA0:

>sets the OPA0: device to /Broadcast.

>But if someone is logged into OPA0:, then this command needs the SHARE
>privilege (which all mgrs have) and I/O on OPA0: terminal. That means,
>if the user on OPA0: is only logged in, but does nothing, then above
>SET TERMINAL (in my SYSHUTDWN.COM) never completes (until someone simply
>presses return on OPA0:).

>Is this something to be expected (or will it get fixed)?
>(I don't remember having seen this problem in 80/90 at all)

>I can workaround (like logging out the user on OPA0 or removing the
>SET TERM or organizational things) but like to have a permanent solution.

>Any comments?

QIO stands for Queued Input/Output.  Many I/Os have to wait until other
ones complete.  I believe that any SETMODE (SET TERM) on a terminal (any
terminal, not jist OPA0:) has to wait for any READs to complete.  There is
a READ at the DCL prompt where DCL is waiting for a commend.  I bet the
SET TERM request completes immediately if someone walks up to OPA0: and
presses RETURN.