An Event-Based Architecture Definition Language

| This paper discusses general requirements for architecture deenition languages, and describes the syntax and semantics of the subset of the Rapide language that is designed to satisfy these requirements. Rapide is a concurrent event-based simulation language for deening and simulating the behavior of system architectures. Rapide is intended for modelling the architectures of concurrent and distributed systems, both hardware and software. In order to represent the behavior of distributed systems in as much detail as possible, Rapide is designed to make the greatest posi-ble use of event-based modelling by producing causal event simulations. When a Rapide model is executed it produces a simulation that shows not only the events that make up the model's behavior, and their timestamps, but also which events caused other events, and which events happened independently. The architecture deenition features of Rapide are described here: event patterns, interfaces, architectures and event pattern mappings. The use of these features to build causal event models of both static and dynamic architec-tures is illustrated by a series of simple examples from both software and hardware. Also we give a detailed example of the use of event pattern mappings to deene the relationship between two architectures at diierent levels of abstraction. Finally, we discuss brieey how Rapide is related to other event-based languages.