RE: Event-based actions

A physical file trigger would invoke a process based on data changing in
a file with the secondary process not needing to 'wait' or 'poll' for a
change in status.

A Data Queue can also work well. Waiting on a Data Queue will take no
processing time but then the waiting application will instantly 'wake
up' when data is placed on the queue and be able to take action.

That's two pretty standard approaches.


James P. Wiant
Test Systems Administrator

Foodstuffs (Auckland) Limited

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-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Booth Martin
Sent: Monday, 3 September 2012 12:38
To: Midrange Systems Technical Discussion
Subject: Event-based actions

This seems simple enough yet I am stumbling all over the school yard
with it.

This has to do with event-based actions versus waiting for the Enter key

to be pressed or for a timer to run out..

This is a fairly simplistic case, but it should serve to demonstrate the

problem I am trying to solve.

Lets say a desktop gadget displays the local temperature. When the
temperature changes, the gadget changes the display. As I understand
it, this is accomplished by a "listener" that "listens" for a
temperature change event from the mother ship. It is not a timer that
periodically checks to see what the temperature is. When the listener
hears that the temperature has changed, it alerts the desktop gadget and

my desktop display shows the new temperature. As I said, this is a
simplistic case.

So, in midrange world, how do I mimic the behavior of a listener and of
events?

This may not be well presented. For that I apologize. Of course, if I
understood the issue better I probably would also know the answer,
right? ;) If you have questions, please ask. That may help me
explain my issue better.