Cooperative objects: a concurrent, Petri-net based, object-oriented language

This paper presents an object-oriented language (OOL) designed to allow the easy description of objects with concurrent behavior. In this language, concurrency, objects´ behavior and inter-objects communication are formally described in terms of high-level Petri nets (HLPN). The language relies on a client-server organisation of objects, and retains the most important features common to sequential OOL: classification, encapsulation, inheritance, instantiation and dynamic use relationship. The language allows one to provide both an abstract specification for a class, in the spirit of abstract data types, and one or several executable implementations. Object-oriented notations and PN designs are not kept apart, but on the contrary tightly integrated in a syntactically and semantically coherent framework. The PN theory allows for static analysis of the programs, and provides means for executing them