I would think it's up to CICS to initialize CICS acquired memory on your
behalf.
And if your applications (vendor or otherwise) run under LE, then LE
controls whether it will initialize the storage based on options you set.
But you have a valid concern about vendors' assembler code. We should
be asked whether we know about this. Note that it says that the
behaviour is not changed, which means this exposure has existed before
z/OS 1.10. The availability of the CHECKZERO option means that users of
GETMAIN/STORAGE may not always have to zero the storage they obtained to
ensure that it is initialized to zeroes.
Regards, Gary
PS: try to avoid copying the entire digest when replying to the list.
Gary Weinhold
Senior Application Architect
DATAKINETICS | Data Performance & Optimization
Phone +1.613.523.5500 x216
Email: [email protected]
Visit us online at www.DKL.com
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On 2015-11-19 09:52, Leonard.John.J wrote:
Virtual Storage Manager in z/OS 1.10 HBB7750 which results in different
behavior when storage is Getmained
We are trying to understand the ramifications of this change to the GETMAIN and
I was wondering if anyone else has dealt with this. I have this document that
says
“References to GETMAIN also apply to STORAGE OBTAIN.
The description and behavior of the GETMAIN macro as documented
in the z/OS MVS Assembler Services Reference remain unchanged
by this APAR. With respect to whether or not the system zeroes
the newly getmained storage, the guidelines remain as follows:
When you obtain storage, the system clears the requested storage
to zeros if you obtain either:
o 8192 bytes or more from a pageable, private storage subpool.
o 4096 bytes or more from a pageable, private storage subpool,
with BNDRY=PAGE specified
In all other cases you must NOT assume that the storage is
cleared to zeros, unless indicated by the return code when
CHECKZERO=YES is specified.”
The way I read this is getmained storage may not be initialized in all cases.
What if I do a CICS GETMAIN and specify INITIMG(BLANK)
Even if I figure out what to do with every GETMAIN what do I do about vendor
code I don’t have the source so I can’t tell if the code assumes the storage is
initialized or not
John J. Leonard
Application Developer III SOA Team
Westfield Group
One Park Circle P.O. Box 5001
Westfield Center Ohio 44251-5001
Office (330) 887-8249
Toll Free 1-(800) 243-0210 ext 4308249
Email [email protected]
Extension 430-8249
