Function

This exit allows you to gain control whenever JES2 work selection processing has located a pre-execution job for a device. This includes work selected for JES2 and workload management (WLM) initiators. Exit 49 also gets control when the start job ($S J) command is used to start a batch job.

Exit 14, Job Queue Work Select - $QGET is not called for workload management (WLM) initiator work selection. Use this exit to instruct JES2 to accept or not accept such work. Exit 49 is generally easier to implement because it does not require that you copy JES2 decision-making algorithms into your exit routine.

Your exit routine is called by the $QGET routine in HASPJQS, which JES2 uses to acquire control of a job queue element (JQE). This JQE is actually a JQA (an artificial JQE) in update mode; you do not need to verify its update-mode status for calls to $DOGJQE. This JQA represents a job that is "BERT locked" by the PCE calling Exit 49. You can update this JQA without using any $DOGxxx services and therefore avoid disallowed $WAITs for this exit.

The $QGET routine scans the appropriate queue for an element that:

is not held
is not already acquired by a previous request to the job queue service routines
has affinity to the selecting JES2 member
has independent mode set in agreement with the current mode of the selecting member.

If this exit rejects the selected job, the JES2 job queue search routine ($QGET) will continue to search for another job (JQE), which if found will cause this exit to again receive control.

Note: Exit 49 is not called if:

JES2 does not find a job
Exit 14 already selected a job.