A system for compositional verification of asynchronous objects

We present a semantics, calculus, and system for compositional verification of Creol, an object-oriented modelling language for concurrent distributed applications. The system is an instance of KeY, a framework for object-oriented software verification, which has so far been applied foremost to sequential Java. Building on KeY characteristic concepts, like dynamic logic, sequent calculus, symbolic execution via explicit substitutions, and the taclet rule language, the presented system addresses functional correctness of Creol models featuring local cooperative thread parallelism and global communication via asynchronous method calls. The calculus heavily operates on communication histories specified by the interfaces of Creol units. Two example scenarios demonstrate the usage of the system. This article extends the conference paper of Ahrendt and Dylla (2009) with a denotational semantics of Creol and an assumption-commitment style semantics of the logic.