Pointer usage in CICS

akodakka · New User Joined: 20 May 2010 Posts: 75 Location: India

Hi All

Could you please help to understand what value will be in progA after the call to Progb

Bill Woodger · Posted: Fri Feb 24, 2012 4:04 am

You have to show the CALL and PROCEDURE DIVISION USING from the compile output listing, as progB at least hase been compiled as a CICS program.

dbzTHEdinosauer · Posted: Fri Feb 24, 2012 5:05 am

since proga will not compile and even if progb compiles, it will have a run time error.

what the TS should do is spend some time reading
the COBOL Programmers' guide
and the reference,
both of which do an excellent job of explaining pointers.

then he TS should spend some time programming and testing,
THEN return to the forum with his questions.
we are not tutors, we answer specific questions.

the garbage presented as an example indicate that the TS
requires basic knowledge.

dbzTHEdinosauer · Posted: Fri Feb 24, 2012 5:26 am

as a final note.

cobol pointers (used to contain addresses) are no different in CICS than in a batch environment,
other than the exception that the areas to which they point should not exceed 4K for earlier releases of CICS.

Mickeydusaor · Posted: Fri Feb 24, 2012 10:12 pm

as these are supposed to CICS program the TS should be using LINK and not CALL

Bill O'Boyle · Posted: Fri Feb 24, 2012 10:25 pm

Adding to Mickey's post, CALL's can only be issued as Local (confined to the local region).

However, issuing a LINK-API, passing a pointer in a commarea (not recommended by IBM), could backfire if suddenly, the target program is no longer Local and is now defined as Remote in the PPT entry (parameter REMOTESYSTEM is non-space) or some bonehead has added the SYSID keyword to the API.

Attempting to establish addressability to storage in a Remote region via a pointer in the commarea won't work and could cause many problems.

Mr. Bill

Mickeydusaor · Posted: Fri Feb 24, 2012 10:28 pm

Good point Bill, as I assumed the TS is trying to attempt this in the same CICS region... Shame on me

Bill Woodger · Posted: Fri Feb 24, 2012 10:58 pm

I was thinking TS is taking it from a "working" system and wanting to understand what value ends up where, having foolishly typed out a shortened version of what they feel is relevant, rather than pasting from the screen.

Bill O'Boyle · Posted: Fri Feb 24, 2012 11:20 pm

Perhaps he fails to understand that a CALL passes the address of the storage of a given parameter (won't go into Assembler geekiness breakdown).

I see no purpose in passing a pointer in this CALL example.

Mr. Bill

Mickeydusaor · Posted: Fri Feb 24, 2012 11:27 pm

also what is the pointer suppose to be point to.???? and why are you using a pointer for this purpose..????

dbzTHEdinosauer · Posted: Sat Feb 25, 2012 2:35 am

in cics, as well as in batch,
(thus requiring the methodology to be used only in local CICS regions and never with remote)
passing a GROUP (defined with copybook) which contains a list of pointers
allows one to pass many structures, yet having only one parameter in the CALL USING list,
thus allowing for a common CALL in all modules.

example:

you have a CALL chain of potentially 10 modules.
the high level initiator of the CALL chain can pass, say, 15 structures,
yet have only one parm in the CALL USING list.
each of the 10 modules in the chain can then address any of the 15 structures.
if a new module is added to the CALL chain,
and it requires yet a new structure,
only the

copybook changed to add the new pointer
high level module changed to add
- the new structure in WORKING-STORAGE
- SET the new pointer to address of new structure
the module initiating the new CALL changed by adding the new CALL

and all 10 modules recompiled, without having the need to change the parameter list in the common CALL USING list

this methodology is often employed with COBOL modules that are used by both batch and CICS
and obviously not using the outdated DFH parms and forcing a CICS precompile for modules that invoke no CICS API's.

dbzTHEdinosauer · Posted: Sat Feb 25, 2012 3:02 am

actually, you do not have to recompile the modules that do not address the added (at the end of the group structure) element of the group structure (new pointer).

you only have to
recompile the

high level module
module making new CALL

and compile the newly CALLed module

using pointers has the
advantage over extended CALL USING lists in that intervening modules must not be recompiled
but has the disadvantage of requiring all your programmers to understand pointers.

akodakka · New User Joined: 20 May 2010 Posts: 75 Location: India

hi dbzTHEdinosauer

Yes this is what exactly am doing.

Thanks'