Towards a formalization for COM part i

Abstract

We introduce in this paper a typed calculus intended to capture the execution model of COM. The innovation of this calculus is to model very low-level aspects of the COM framework, specifically the notion of interface pointers. This is handled by specifying an allocation semantics for the calculus, thereby modeling heap allocation of interfaces explicitly. Having an explicit way of talking about interface pointers allows us to model in a reasonable way the notions of interface sharing and object identity. We introduce a type system that can be used to disambiguate between specification and implementation of interfaces. The type system moreover can capture a notion of COM conformance, that is, the legality of COM components. We discuss extensions of the calculus to handle subtyping of interfaces, dynamic interface negotiation and aggregation.