Communicating with the exit program

 

After it has been invoked, the exit program is passed a parameter list in the CICS communication area pointed to by a field called DFHEICAP. The CICS Exec Interface Block field EIBCALEN shows the length of this area. The structure of this communication area is defined in the CMQXPA assembler-language macro that is supplied with WebSphere MQ for z/OS :

*
MQXP_COPYPLIST       DSECT
                     DS  0D         Force doubleword alignment
MQXP_PXPB            DS   AL4       Pointer to exit parameter block
MQXP_PCOPYPARM       DS 11AL4       Copy of original plist
*
                        ORG  MQXP_PCOPYPARM
MQXP_PCOPYPARM1      DS   AL4       Copy of 1st parameter
MQXP_PCOPYPARM2      DS   AL4       Copy of 2nd parameter
MQXP_PCOPYPARM3      DS   AL4       Copy of 3rd parameter
MQXP_PCOPYPARM4      DS   AL4       Copy of 4th parameter
MQXP_PCOPYPARM5      DS   AL4       Copy of 5th parameter
MQXP_PCOPYPARM6      DS   AL4       Copy of 6th parameter
MQXP_PCOPYPARM7      DS   AL4       Copy of 7th parameter
MQXP_PCOPYPARM8      DS   AL4       Copy of 8th parameter
MQXP_PCOPYPARM9      DS   AL4       Copy of 9th parameter
MQXP_PCOPYPARM10     DS   AL4       Copy of 10th parameter
MQXP_PCOPYPARM11     DS   AL4       Copy of 11th parameter
*
MQXP_COPYPLIST_LENGTH  EQU  *-MQXP_PXPB
                       ORG  MQXP_PXPB
MQXP_COPYPLIST_AREA    DS   CL(MQXP_COPYPLIST_LENGTH)
*

Field MQXP_PXPB points to the exit parameter block, MQXP.

Field MQXP_PCOPYPARM is an array of addresses of the call parameters. For example, if the application issues an MQI call with parameters P1, P2, or P3, the communication area contains:

  PXPB,PP1,PP2,PP3

where P denotes a pointer (address) and XPB is the exit parameter block.

 

Parent topic:

Using the API-crossing exit

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