A Tag Contract Framework for Modeling Heterogeneous Systems

International audienceDevelopment of distributed systems can be supported effectively by a contract-based methodology as contracts can ensure interoperability of components and adherence to specifications. Such development can become very complex since distributed systems can consist of components which are heterogeneous in terms of computational and interactive model. Several frameworks, both operational and denotational, have been proposed to handle heterogeneity using a variety of approaches. However, the application of those frameworks to contract-based design has not yet been investigated. In this work, we adopt the operational mechanism of tag machines to represent heterogeneous systems and construct a full contract model. We introduce heterogeneous composition, refinement, dominance and compatibility between contracts, altogether enabling a formalized and rigorous design process for heterogeneous systems. Besides, we also develop a method to synthesize or refine the component models so that their composition satisfies a given contract

A Tag Contract Framework for Modeling Heterogeneous Systems

In the distributed development of modern IT systems, contracts play a vital role in ensuring interoperability of components and adherence to specifica- tions. The design of embedded systems, however, is made more complex by the heterogeneous nature of components, which are often described using different models and interaction mechanisms. Composing such components is generally not well-defined, making design and verification difficult. Sev- eral denotational frameworks have been proposed to handle heterogeneity using a variety of approaches. However, the application of heterogeneous modeling frameworks to contract-based design has not yet been investigated. In this work, we develop an operational model with precise heterogeneous denotational semantics, based on tag machines, that can represent hetero- geneous composition, and provide conditions under which composition can be captured soundly and completely. The operational framework is imple- mented in a prototype tool which we use for experimental evaluation. We then construct a full contract model and introduce heterogeneous compo- sition, refinement, dominance, and compatibility between contracts, alto- gether enabling a formalized and rigorous design process for heterogeneous systems. Besides, we also develop a generic algebraic method to synthe- size or refine a set of contracts so that their composition satisfies a given contract