While coding an other program I was getting strange errors so I have wrote below code to see how my COMMAREA variable is changing. The intent of this program is to display var1 content and see if the value is the same:
IDENTIFICATION DIVISION.
PROGRAM-ID. MAPBROW2.
DATA DIVISION.
WORKING-STORAGE SECTION.
COPY MAPBROW.
COPY DFHAID.
01 WS-COMMAREA.
05 VAR1 PIC X(15).
01 RESPCODE PIC S9(8) COMP.
01 EXIT-MSG PIC X(10) VALUE 'NORMAL END'.
PROCEDURE DIVISION.
MAIN.
IF EIBCALEN = 0 THEN
MOVE LOW-VALUES TO MAP1O
MOVE 'ABCD1234' TO VAR1
MOVE VAR1 TO MSGO
PERFORM SEND-THE-MAP
ELSE
EVALUATE EIBAID
WHEN DFHENTER
PERFORM SEND-VAR1
WHEN DFHPF1
PERFORM CLEAR-THE-MAP
WHEN DFHPF3
EXEC CICS
SEND TEXT FROM(EXIT-MSG)
ERASE
END-EXEC
EXEC CICS RETURN END-EXEC
WHEN OTHER
MOVE 'INVALID KEY' TO MSGO
PERFORM SEND-THE-MAP
END-EVALUATE
END-IF
EXEC CICS
RETURN TRANSID('TRN3') COMMAREA(WS-COMMAREA)
END-EXEC.
SEND-THE-MAP.
EXEC CICS
SEND MAP('MAP1') MAPSET('MAPBROW')
ERASE
NOHANDLE
END-EXEC
EXIT.
SEND-VAR1.
MOVE LOW-VALUES TO MAP1O
MOVE VAR1 TO MSGO
PERFORM SEND-THE-MAP
EXIT.
CLEAR-THE-MAP.
MOVE LOW-VALUES TO MAP1O
PERFORM SEND-THE-MAP
EXIT.
The output if EIBCALEN = 0 is as should be 'ABCD1234' but later after pressing enter 'NDONIEC@ RMALN'
I am still learning and i wasn't able to find the solution myself, I am feeling like I missing something. What is wrong in that program?
Thanks in advance.
This is a pseudo-conversational CICS program, so...
your transaction begins for the first time
the initial program is invoked with a pointer to DFHEIBLK, a structure for which is automatically inserted into your Linkage Section by the CICS pre-compiler or the CICS co-processor
memory for Working-Storage is allocated
the program code begins executing, including code inserted by the compiler to make all your Working-Storage VALUE clauses true
since this is the first time in, EIBCALEN = 0 and 'ABCD1234' is moved into VAR1, VAR1 is moved into MSGO, the map is sent, and there is a RETURN to CICS with WS-COMMAREA and your tranID
the memory for Working-storage is freed
CICS remembers the contents of your commarea for you
DFHENTER is pressed
your transaction begins but CICS knows it is not for the first time
the initial program is invoked with a pointer to DFHEIBLK and a pointer to your commarea
memory for Working-Storage is allocated
the program code begins executing, including code inserted by the compiler to make all your Working-Storage VALUE clauses true
since this is not the first time in, EIBCALEN = 15 (the length of WS-COMMAREA), EIBAID is EVALUATEd to be DFHENTER so paragraph SEND-VAR1 is PERFORMED, the contents of VAR1 (which at this point is uninitialized storage) is moved to MSGO, the map is sent, and there is a RETURN to CICS with WS-COMMAREA and your tranID
the memory for Working-storage is freed
CICS remembers the contents of your commarea for you
...I think what you want is to code...
[...same as you have coded...]
Linkage Section.
01 DFHCOMMAREA.
05 CA-VAR1 PIC X(15).
Procedure Division Using DFHCOMMAREA.
MAIN.
IF EIBCALEN = 0 THEN
MOVE LOW-VALUES TO MAP1O
MOVE 'ABCD1234' TO VAR1
MOVE VAR1 TO MSGO
PERFORM SEND-THE-MAP
EXEC CICS
RETURN
TRANSID(EIBTRNID)
COMMAREA(WS-COMMAREA)
END-EXEC
ELSE
MOVE DFHCOMMAREA to WS-COMMAREA
[...same as you have coded...]
END-IF
MOVE WS-COMMAREA TO DFHCOMMAREA
EXEC CICS
RETURN
TRANSID(EIBTRNID)
COMMAREA(DFHCOMMAREA)
END-EXEC.
[...same as you have coded...]
...which, on second and subsequent invocations, will restore your WS-COMMAREA from the commarea CICS remembered for you because when CICS starts your program it does so with two pointers, one to DFHEIBLK (the Execute Interface Block) and one to your commarea.
First time in there is no commarea, so DFHCOMMAREA doesn't have any memory allocated for it. On subsequent invocations of your program there is a commarea because when you RETURN to CICS the first time you do so with a commarea and CICS remembers that for you in memory it allocates.
Second and subsequent times you RETURN to CICS you do so with a commarea pointing to memory in your Linkage Section, but that was initially allocated for you by CICS on your first invocation.
One important thing to remember here is that items in the Linkage Section must have memory allocated for them. In the case of DFHEIBLK, CICS does that for you. In the case of DFHCOMMAREA, that happens because you did your first RETURN to CICS with a commarea and that was copied into memory which was allocated for you by CICS.