Data base design for real-time adaptations
Abstract The performance of embedded real-time control software depends on its ability to adapt to changing operating conditions in a timely and predictable manner. CHAOS (concurrent hierarchical adaptable object system) has been designed for programming such adaptable real-time applications. Applications in CHAOS are structured as concurrent objects that interact via invocations. The adaptation control system in CHAOS, responsible for monitoring the execution environment, detecting the need for adaptations, and enacting selected adaptations, is structured around an extended entity relationship data base. Here we describe the design of this entity relationship data base, the mapping of objects and their attributes into it, the mechanisms for performing adaptations, and the data base manipulation language interface (used to encode adaptations) to the data base.