I just do not see a way in which this could be accomplished; in order to
retain control, you have to use conditional locks and that never gets you in
the queue.  If you use unconditional locking, you're toast.

I would hunt down the offending programs and fix them.

Denys...

-----Original Message-----
From: Walter J. Murray [mailto:[log in to unmask]] 
Sent: Tuesday, May 27, 2008 10:43 PM
To: 'Denys Beauchemin'; [log in to unmask]
Subject: RE: [HP3000-L] TurboIMAGE: Timed lock request

The problem is that some of the programs don't "play by the rules," as
Denys puts it.  They lock around terminal reads.  If I do a regular
unconditional lock, which I would like to do, I run the risk of hanging
until the other user gets back from lunch.

Yes, this is a real-world problem for me.  I would like to issue an
unconditional lock request (get queued up waiting for the request to be
satisfied), but be able to bail out if it's not satisfied within 15
seconds, and tell the user to try again later.

No, I am definitely not looking for HP to implement this as an
enhancement--just wondering if it has ever come up.

Yes, I meant to say I could issue a CONDITIONAL lock every second for 15
seconds, but that wouldn't meet my needs.

Walter  

-----Original Message-----
From: Denys Beauchemin [mailto:[log in to unmask]] 
Sent: Monday, May 26, 2008 6:28 PM
To: 'Walter J. Murray'; [log in to unmask]
Subject: RE: [HP3000-L] TurboIMAGE: Timed lock request

It looks like you're asking for something like a second conditional in
English.  I'm not sure if it would be easy to implement in the first
place
and I can see where it may cause more harm than good.  A long time ago,
I
wrote an order entry application that started using conditional locks.
I
quickly changed that to unconditional locks because users complained
about
having to issue a "yes" to retry the locks on many orders.  Granted, it
was
a silly idea but this was about 30 years ago.  I find that as long as
your
programs play by the rules (no MR or strictly controlled MR and no locks
around terminal reads,) the application flows much faster using pure
unconditional locks.  

Did you have a specific application in mind for this?  Perhaps there may
be
another way to implement such a mechanism; I seriously doubt HP will
enhance
IMAGE to add this request.

Also, I think you mean your process would issue a conditional lock one a
second for 15 seconds and no, that will not do the trick, that was the
problem I had 30 years ago.  (Has it really been 30 years? I guess so.
Sigh.)

Denys...
-----Original Message-----
From: HP-3000 Systems Discussion [mailto:[log in to unmask]] On
Behalf
Of Walter J. Murray
Sent: Monday, May 26, 2008 8:04 PM
To: [log in to unmask]
Subject: [HP3000-L] TurboIMAGE: Timed lock request

Greetings,

Time for another TurboIMAGE question.

I'm pretty sure there is no way to do this directly in TurboIMAGE.  I am
curious whether it has ever been an enhancement request, or whether
someone has a suggestion of how to accomplish something equivalent.

I want something that's like a cross between an unconditional and a
conditional lock request.  I'd like to issue a lock request using this
new mode, and specifying a time interval, e.g., 15 seconds.  

If the lock can be granted immediately, fine.  

If not, the request is queued and my process is blocked, just as for an
unconditional lock request.  

If the lock can be granted within the specified interval, control
returns to my process, just as when an unconditional lock request is
granted.

If the lock is still pending when the specified time has elapsed, my
request is deleted from the queue, and I get a status return indicating
that my request was unsuccessful because of a timeout.  

It would be like a timed read against a terminal or a message file.  It
seems like something that would be very useful, but I don't remember
ever having heard it suggested.

Without this feature, the best I know of to do is to issue an
unconditional lock request every second for 15 seconds, and then give
up.  This is not a very good substitute for what I want, because my
request never gets queued up.

Walter  

Walter J. Murray

* To join/leave the list, search archives, change list settings, *
* etc., please visit http://raven.utc.edu/archives/hp3000-l.html *

* To join/leave the list, search archives, change list settings, *
* etc., please visit http://raven.utc.edu/archives/hp3000-l.html *