A Pragmatic Behavior Subtyping Relation Based on Both States and Actions

摘要

A behavior preserving relation between Petri-net systems is introduced in this paper, based on the observability of both places and transitions, which is important in mod- eling the dynamic behavior of concurrent object-oriented systems with Petri nets. Each group of closely related attributes of a concurrent object is modeled by the state of a collection of observable places, and each of its methods by a group of observable transitions. The grouping distinguishes the definition in this paper from others, which makes it easy to work together with the static object models, to reuse the models and to dispel the interference among groups, thus relieving the problem of inheritance anomaly by the possibility of diving the synchroniza- tion code into independent parts.