Consider the following when coding your configuration change exit
routine:
- The exit routine is required to save and restore the contents
of GPR 13.
- The exit routine must reside in common storage.
- The exit routine should not wait for asynchronous work to complete.
Otherwise, system deadlocks might occur.
- Code a different configuration change exit routine for each type
of notification, rather than coding one exit routine to respond to
all notification types.