Peter Relson wrote:
Ed Jaffe wrote
And, if IBM, ISV, and customer in-house developers would use
IgvInitGetmain and IgvInitFreemain on their test/development systems--as
we do--nobody would have experienced this issue to begin with. Of
course, it's hard to fault someone for not using an undocumented
feature. These TRAPs have been around since OS/390 V2R6. They work.
Perhaps it's time they were documented, too!
IBM does use these traps. Many ISVs do. ISVs have been made aware of the
trap options a long time ago, and also were made aware of the z/OS 1.10
algorithm change.
IBM is a large company, with many development and testing
organizations--some large, some small. Some of them use these traps.
Others don't.
Jim will attest that I, more than probably any other ISV or customer,
have been sacrificing the stability of my systems *for years* in an
effort to help IBM fix issues uncovered by IgvInitGetmain and other
similar TRAPs. Why? So we can run with them 24x7, of course!
I have suffered through damaged HSM control data sets and other
corrupted files, PSF abends, TCP/IP and VTAM issues, RMF problems, JES
problems, systems that won't IPL or crash shortly after IPL, and dozens
of subtle and bizarre behaviors that eventually led to a discovery of
IBM-written programs making assumptions about "things" being zero:
storage, access registers, high halves, you name it. IBM did not
discover these things because they did not run with the TRAPs enabled.
I make an effort to report things I know are related to DIAG traps
through Jim. But, many of the issues looked like "ordinary" bugs until
research proved otherwise. These were reported via ETR. I can tell you
that, in almost every case, Level 2 and change team had never heard of
these TRAPs!
I know that Marna Walle has been a great help in getting more IBM
testing organizations to use various TRAPs. The last time we exchanged
notes about what she was recommending, IgvInitGetmain was definitely
*not* on her list!
I realize this is an evolving space. And, it's always possible that
things have changed enough, since I last asked, that your blanket
statement "IBM does use these traps" is now accurate. But, knowing IBM
as I do, I have my doubts. Case in point: If IBM was religiously using
IgvInitGetmain on their test and development systems, the issue with the
CICS DFHPD640 dump formatter Jim mentioned yesterday would almost
certainly have been discovered by someone at IBM and not by an ISV.
If there was a problem with an ISV application (as I believe was Jon V's
case, but I could be mistaken), you should consider targeting the "finger
pointing" towards that ISV. It is precisely to allow ISVs to test and
verify and fix their code in advance of a release (and thus protect the
customer from running into the problems) that we make these disclosures.
Agreed.
Customer applications are the innocent victims here as there is no
mechanism for alerting the customers ahead of time. Customer concern over
the testability of their own applications is the impetus for providing the
APAR.
But, if IgvInitGetmain and similar traps were documented and the system
reliably worked with them enabled, at last some customers would use them
to help ensure that their in-house applications also had no dependency
on storage being cleared by the operating system. All developers will,
from time to time, accidentally depend on undocumented behaviors. Any
tool that helps you detect such exposures is a good thing.
GETMAIN has documented for a long time exactly under what circumstances a
program may assume that the storage it obtains is zero. As Jim Mulder
wrote, none of this behavior has changed. Perhaps the posters think they
know just when it is with z/OS 1.10 that storage might not be 0 where it
might have been 0 on earlier releases. I'd guess that unless they have
thought long and hard about it, their thought is wrong.
Agreed.
--
Edward E Jaffe
Phoenix Software International, Inc
5200 W Century Blvd, Suite 800
Los Angeles, CA 90045
310-338-0400 x318
[EMAIL PROTECTED]
http://www.phoenixsoftware.com/
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