A shared Sense-and-Respond infrastructure that is embedded into a physical environment requires considerable run-time support to facilitate the dynamic dispatch and execution of new service instances. Such an infrastructure must also be able to statically analyze new services in order to verify their safety and derive their specific resource requirements (i.e., prior to dispatch). Toward this goal we have developed a multi-dimensional type system for our pervasive sensory service composition language; this formalism extracts implicit constraints from service instances to verify an expanded notion of type safety. While our formal system is rigorous, it is light-weight and essentially transparent to a service programmer. The type-system automatically infers data types that are annotated with a vector of type specific attributes and uses these annotations to establish and verify a range of resource constraints (bounds for computation and memory usage, camera resolution requirements, etc.). In this paper we present an overview of our formal methodology, provide concrete examples of how these formalisms are used in practice (through service logic examples and derived constraint sets) and discuss the details of our implementation.
['Michael J. Ocean', 'A. J. Kfoury', 'Azer Bestavros']
A formal type-centric framework for verification and resource allocation in pervasive Sense-and-Respond systems