Re: Programming Performance

[PaulMmn <PaulMmn@xxxxxxxxxxxxx>]

James wrote:
>
>Erick wrote:
>
>> Recently, I read an article that suggested that using a return in an RPG
>> program would improve system performance simply by staying resident in
>> memory during the job stream.
>>
>> If this is the case, would all the data areas and work variables have to
>> be reinitialized?
>
>Short answer .... yes.
>
>Longer answer ..... it depends.
>
>It depends upon how the program is structured upon initiation/exit.  Is
>there an
>indicator or variable that gets set upon initiation which controls a "first
>call"?  This may need to be cleared upon doing a return instead of LR.
>
>Basically, upon return, the variables start out at the value of last exit.
>Unless the sweeper has come in to mop up afterwards or you send them it
>first ...
>you pick.
>
>My personal preference has been to write code assuming that the slate
>needs to be
>cleaned before the program goes to work.  (takes into account slobs that
>may have
>been there before me <g>) Some like to clean up before they leave, some
>like to
>clean up before they start to work.  Sort of like a DOx preference ....
>what ever
>floats your boat .... just be consistent.


Another thing to consider is a 'shutdown' parameter in the parm list.  If
the value of SHUTDOWN = 'NO', the program will do a return with LR -off-.
The program stays resident, files are open, and the next call will be
quicker.

If  SHUTDOWN = 'YES', the proram will turn on LR and quit.

This will let the progrma stay open when needed, and shutdown gracefully
when you're finished with it.


James' comment about cleaning up before or after you execute reminds me of
a somewhat on-topic philosophical note:

There was a girl's school dormitory that had a bathtub.  There was a
problem with a ring around the tub from time to time.

Finally a sign appeared over the tub:

        "An optimist cleans the tub -after- she uses it.
        A pessimist cleans the tub -before- she uses it.
        A -Lady- cleans the tube before -and- after she uses it."

--Paul E Musselman
PaulMmn@ix.netcom.com


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