Synchronization expressed in types of communication channels

Abstract

Static typing and subtyping are useful concepts in objectoriented programming languages. Unfortunately, current type models for concurrent object-oriented languages are not yet as expressive as they should be: Clients have to rely on synchronization behavior not expressed in the objects' types. In the type model proposed in this paper, types of communication channels make synchronization constraints explicit. Static type-checking ensures that messages are sent only if the receivers can deal with the messages at the time when they are received, although the set of accepted messages can change dynamically.