Software process enactment in Oikos

Abstract

Despite much research work in progress to model the different facets of software process enactment from different approaches, there are no models yet generally recognized as adequate, and there is need for more experimentation. We describe the Oikos environment and its coordination language ESP: they provide an infrastructure in which experiments may be performed and evaluated. Oikos predefines a number of services offering basic facilities, like access to data bases, workspaces, user interfaces etc.. Services are customizable, in a declarative way that matches naturally the way ESP defines and controls the software process. ESP allows to define services, to structure them in a dynamic hierarchy, and to coordinate them according to the blackboard paradigm. The concepts of environment and of software process and their interplay are naturally characterized in Oikos, in terms of sets of services and of the hierarchy. In the paper, an example taken from a real project (the specification of a small language and the implementation of its compiler) shows how Oikos and ESP are effective for software process enactment. As it is, ESP embeds Prolog as its sequential component, and combines it smoothly to the blackboard approach to deal with concurrency and distribution. Anyway, most of the concepts used to model and enact software processes are largely independent of logic programming.