•Two
M:N associations could relate an EventType
with all allowable sending and receiving
ActiveClasses for this ET. This would
be a class-level constraint on the source and destination classes
that could communicate by means of any runtime EventType
(inter-Class Collaboration Diagram).
•Another
pair of M:N associations between AI and ET (not shown) would
constrain specific Active Instances that could communicate by
means of this EventType (object
instance wiring diagram).
•These
constraints are runtime-checkable by the Event Dispatcher at any
site in the system where an Event Instance que (EI table) is managed
(all such EIs have two ActiveInstance foreign keys which
identify its AIid1_sender and AIid2_receiver).