Algorithms for analyzing concurrent software systems using derivatives

Abstract

Brzozowski's technique of derivatives of regular expressions, when suitably extended, can be used to answer questions such as whether a given sequence of events can occur during the execution of a concurrent software system. We show how to use derivatives in analyzing concurrent systems in which processes communicate by message transmission, buffered or unbuffered. We present an algorithm which applies to systems in which all interprocess buffers have bounded capacity, and another, in which event expressions are combined with state vectors for increased generality and efficiency, which applies to systems with unbounded buffering. Implementations have been constructed, and experiments have shown that our techniques are computationally competitive with rival techniques based on state transitions.