Language Constructsand Support Systems for Distributed Computing

This paper describes language constructs and system support functions intended to facilitate the programming of reliable distributed systems. The new conceptual tool proposed is called an "activity. " A model based on activities has been developed to provide a terminology for describing the relationships among objects involved in a distributed task. We outline the design of a system that uses the activity structure of a program to manage its execution network-wide. A preliminary set of high level language constructs for specifying activity-related control features is presented. Finally, the power of this approach is illustrated in an example of a distributed application