Resource-Predictable and Efficient Monitoring of Events

iAbstract We present a formally specified event specification language (Solicitor). So-licitor is suitable for real-time systems, since it results in resource-predictable and efficient event monitors. In event monitoring, event expressions defined in an event specification language control the monitoring by matching in-coming streams of event occurrences against the event expressions. When an event expression has a complete set of matching event occurrences, the ev-ent type that this expression defines has occurred. Each event expression is specified by combining contributing event types with event operators such as sequence, conjunction, disjunction; contributing event types may be primi-tive, representing happenings of interest in a system, or composite, specified by event expressions. The formal specification of Solicitor is based on a formal schema that separates two important aspects of an event expression; these aspects are event operators and event contexts. The event operators aspect addresse