Date:         Tue, 3 Feb 1998 18:24:51 -0600
Reply-To:     CICS List <CICS-L@UGA.CC.UGA.EDU>
Sender:       CICS List <CICS-L@UGA.CC.UGA.EDU>
From:         Joe Larson <joel@COREDCS.COM>
Subject:      Re: CICS storage violation
Content-Type: text/plain; charset="iso-8859-1"

-----Original Message-----
From: Abraham, Robert <Robert.Abraham@AETNA.COM>
To: CICS-L@UGA.CC.UGA.EDU <CICS-L@UGA.CC.UGA.EDU>
Date: Tuesday, February 03, 1998 3:12 PM
Subject: CICS storage violation
 
 
>We've got an interesting storage violation, and I'm looking for any
>dump is incredibly similar, including the fact that the overlay is to a
>leading crumple zone, with the contents from the most recent prior task.
>The questions:
>Has anyone seen a similar scenario?  If so, what caused it, and how was
>it fixed?
>What other areas would you look at?  Program reentrancy, syncpoint
>management, OSV products?
 
Some kind of reentrancy problem, definitely, given that it only happens when
you have multiple "copies" of the same transaction running.
 
If it were me looking, I'd go deeply into exactly what changed -- you did
say they made a small change just before this started happening.  I would
look at all the storage areas used in the program(s), and make the
assumption that one of those areas was not being getmained properly.  You
did mention that the overlay was to the equivalent storage area each time,
and in a storage area for one task that was used for the same purpose by a
preceding task.  Are you passing addresses or other information between
these multiple tasks?  If so, how?  Is there any possibility of reentrance
problems in your method of passing information?
 
Running the trace/trap program ought to help you pin things down very well.
I haven't run it for a while, but the trap I remember (CSFE DEBUG) I think
would chase all storage chains after every trace entry.  Using that, when
you got a storage violation, you could know for certain that everything was
fine up to that last trace entry, and that last trace entry was when the
problem started.  An excellent debugging tool, although it does take a great
amount of CPU to run all those checks every time.
 
Just some thoughts to get you started.  Hope this helps.
 
Joe Larson <joel8@bigfoot.com>
N9JW Stevens Point, Wisconsin USA