Deleting events

You can delete an event by discarding both the event and its name. If the event is a subevent, the value of the composite event is that of its predicate, after the subevent is removed from the Boolean expression of the predicate.

About this task

The command you use to delete an event depends on the type of event to be deleted:
  • To delete an input event explicitly, use the DELETE EVENT command.
  • To delete a composite event explicitly, use the DELETE EVENT command. Deleting a composite event does not delete the subevents of the composite event.
  • An activity completion event is implicitly deleted when a response from the completed activity has been acknowledged by a CHECK ACTIVITY command issued by the parent of the activity; or when a DELETE ACTIVITY command is issued.
  • A timer event is implicitly deleted if its associated timer has expired and a CHECK TIMER command is issued by the activity that owns it; or when a DELETE TIMER command is issued.
  • You cannot delete system events.
  • If an activity program issues a RETURN ENDACTIVITY command, CICS automatically deletes all user events other than activity completion events, which must always be deleted with CHECK ACTIVITY or DELETE ACTIVITY commands in the event pool of the activity. See Using the ENDACTIVITY option of the RETURN command.

Table 1 summarizes the commands that can be used to delete each type of event.

Table 1. Commands used to delete events
Event type Deletion commands
Activity completion
  1. CHECK ACTIVITY (if the activity has completed)
  2. DELETE ACTIVITY
Composite
  1. DELETE EVENT
  2. RETURN ENDACTIVITY
Input
  1. DELETE EVENT
  2. RETURN ENDACTIVITY
System Cannot be deleted
Timer
  1. CHECK TIMER (if the timer has expired)
  2. DELETE TIMER
  3. RETURN ENDACTIVITY

Before an activity can complete normally, it must have deleted all the activity completion events in its event pool. This means that it must have dealt with all its child activities, see Activity completion.