Type Specialization and Coordination

Declarative models and language concepts for the coordination in parallel and distributed systems attract increasing attention because of their simplicity and expressiveness. In this paper, type specialization is proposed as a declarative, object-oriented programming and coordination model. A simple execution mechanism repeatedly specializes types of entities (variables) and thereby collects knowledge about the objects represented by these entities. Concurrently running specialization processes communicate through logically shared entities and by writing specialization requests (which create further processes) to a shared blackboard. The entities' specialization degrees determine if and when a specialization request is executable atomically. Coordination is usually implicit in the data dependencies of the program and need not be speciied explicitly.