A timeout is a special event that signals that a specified amount of time has elapsed since a state was entered. The entry point for timeout scheduling is an active object, which creates the timeout and passes it to the timeout manager, an instance of class OMTimerManager. Each time OMTimerManager is notified by its timer, it examines the collection of timeouts and queues the due timeouts in the appropriate manager (the active object), where they are treated for dispatching like any other event. The timeout objects themselves are passive in the sense that they do not contain timers.
The ID of a timeout event is always Timeout_Event_id. This ID allows event consumers to distinguish timeouts from other events. Timeouts can be distinguished from one another by a special ID called timeoutId.