Petri nets and components - extending the DAWN approach

The flexibility of Petri nets that allows us the combination of components without restriction to a single general composition operator is an important advantage of Petri nets compared to other formalisms. This flexibility supports many different types of component interaction, reflecting various communication paradigms. We suggest not to define the types of component interaction by adding new constructs to the language but by restricting the legal combinations between components. In this approach, general Petri net analysis techniques can still be applied to the overall model. For each component interaction type, the respective restriction is formulated in a syntactical manner, thus providing suitable communication patterns. A particular communication pattern for message passing interaction is one of the core ingredients of the DAWN approach. DAWN was developed for modeling and verifying distributed message passing algorithms by a suitable composition of components that model components of the algorithm. In DAWN, a distributed algorithm is modeled as an algebraic Petri net and verified by a combination of Petri net techniques and temporal logic. The structure of a net representation as well as the verification techniques employ the particular component structure. The DAWN approach, its underlying class of algebraic Petri nets, its communication pattern, and its verification technique is surveyed and illustrated using a simple distributed algorithm. We finally discuss how to extend the DAWN approach by other interaction paradigms, defining new communication patterns that are also based on algebraic Petri nets.