Interval control EXEC interface sample exit program: DFH$ICCN
DFH$ICCN is an interval control EXEC interface sample exit program. It is designed to be invoked at the XICEREQ exit.
About DFH$ICCN
DFH$ICCN is for use in a distributed routing environment, where you want to cancel a previously-issued interval control request but have no way of knowing to which region to direct the CANCEL. For examples of situations with which DFH$ICCN is designed to cope, see Canceling interval control requests.
DFH$ICCN is invoked before the CANCEL command is executed. It performs the following processing:
- Checks:
- It has been invoked for a CANCEL command.
- The SYSID option was not specified on the command.
- The identifier of the request to be canceled does not begin with 'DF'. ('DF' indicates a request issued internally by CICS.)
- The name of the transaction that issued the CANCEL command does not begin with 'C'—that is, that the transaction is not a CICS internal transaction, nor a CICS-supplied transaction such as CECI.
If one or more of these conditions are not met—for example, if it was invoked for a RETRIEVE command—DFH$ICCN does nothing and returns.
- Instructs CICSPlex® SM to:
- Search every CICS region that it knows about for an interval control request with the identifier (REQID) specified on the CANCEL command.
- On each region, cancel the first request (with the specified identifier)
that it finds.Notes:
- Requests might be canceled on more than one region.
- If a particular region contains more than one request with the specified identifier, only the first request found by CICSPlex SM is canceled.
- You must ensure that CICSPlex SM has UPDATE access to the transaction ID of the transaction associated with the CANCEL request.