Specification Composition for the Verification of Message Passing Program Composition

We present a specification composition technique, for improving the reliability of message passing applications composed by the Ensemble methodology. In Ensemble, applications are built by composing reusable executable program components designed with scalable communication interfaces. The composition is controlled by scripts. We define reusable specification components associated to program components, as well as their composition directed by the same Ensemble scripts, thus obtaining specifications of applications. We propose an extension of coloured Petri nets, which is used to define specification components. Composed specifications and applications may be validated or verified by available tools. Keywords: Message Passing Composition, Specification Composition, Reusable Program Component, Reusable Specification Component, Software Reliability, Coloured Petri Net.