Ensuring that exit routines exist at the time of the association
If the work involved in issuing the ADD request is costly, you
might issue the QUERY request with the QTYPE=ADD parameter to find
out whether any exit routines are associated with the exit. This
step would help you avoid unnecessary processing. Here is an example,
in pseudocode, of using the QUERY request:
QTYPE=ADD:
Issue REQUEST=QUERY with QTYPE=ADD
IF the return code indicates "there are no exit routines" THEN
(perhaps no PROGxx parmlib member associated a exit routine
with this exit)
Add a "default" module to the exit.
ENDIF