Temporal properties of the timed d-graphs of distributed processes

Abstract

Some concepts and tools used to verify the time boundaries of sequential software for hard-real-time applications are based on program control flow and the execution time of instructions or blocks. The paper extends a structural approach from sequential to distributed software. It is conceptually and practically based on timed Concurrent Graphs, TCGs, which extend the concept of sequential program d-graphs. The properties of the concurrent exploration of a 'system' of timed concurrent d-graphs are considered, and TCGs are shown to be useful tools for predicting the initial and the steady state worst temporal behaviours of life-time critical distributed static or dynamic systems of messaging only processes, in the maximum pure parallel model. The semantics of Ada-like tasking and communication models are considered. Also, obstacles to predictability are identified and predictable solutions are provided. The proposed approach holds for different tasking and communication models, as shown by an included CSP-like case-study.<>