Formal Methods for Dependable Distributed Software

摘要

This work has developed a powerful concept in evaluating formal specificationsconcurrently with distributed program execution for the purposes of error detection, fault tolerance, and security. This concept is realized in the CCSP evaluation system for axiomatic proofs, for interval temporal formulae, and for a security calculus. We have validated this concept through nontrivial examples of distributed programs including a dynamic group membership protocol, a distributed database scheduler, of a responsive system modeling railroad trains on intersecting tracks, and of a secure warehouse management system. Temporal subsumption has been developed as a way of making these programs efficient. Moreover, the spinoff technologies from this work, in of themselves have become useful. CCSP can also be used as a debugging tool for distributed programs. Temporal Subsumption functions as a quick and powerful proof checker for Hoare triples. Both of these achievements may help to bring more use of formal methods into the mainstream.