Specification, Analysis, and Execution of Requirements and Designs for Real-Time Systems

摘要

The goal was to further develop a methodology, language, and tools, based on state machines, for describing, analyzing, and executing requirements and designs for concurrent and distributed real time systems. Using our communicating real time state machine (CRSM) notation , we showed how specifications in the large could be obtained with simple mechanisms for composing CRSMs into subsystems and larger systems, and how assertion checking can be employed to monitor systems changes. Events and data messages that are communicated among distributed components are often time stamped as a way to handle timing constraints, ordering, and causality; the idea of time stamped event histories, i.e., sequences of time stamped events ordered by time, was developed as a new real time programming object and supported by an implementation extension of our CRSM simulator. Our current work is focused on real time communication models that fit naturally into a state machine framework and that can be applied to the many and diverse forms of distributed communication that exist.