Formal Modeling and Verification of Timed Connectors in IoT with Z3

The Internet of Things (IoT) is rapidly advancing and reshaping the whole world. Coordination models and languages, like Reo and Orc, provide connectors that interconnect components in IoT applications and organize their interactions in distributed environments. In this paper, we propose a method for formally modeling and verifying the properties of timed connectors using Z3, an SMT (Satisfiability Modulo Theories) solver. We use Z3 Python-bindings to construct the models and carry out experiments. The formal model in Z3 clearly reflects the original structure of connectors. With the definition in Z3, we can automatically verify time-related properties of connectors, and automatically construct counter-examples when the properties do not hold.