Protocol animation based on event-driven visualization scenarios in real-time LOTOS

In this paper, we propose a method for animating behavior of communication protocols/systems based on event-driven visualization scenarios (VSs) described in a subclass of E-LOTOS called real-time LOTOS. In the proposed method, first we pick up some interesting events in the original specification of the protocol, and then describe a VS for those events so that the corresponding animations are executed just after their execution. We execute the original specification and its VS in parallel under a multi-way synchronization mechanism so that the corresponding animation is activated when each event in the original specification is executed. To describe animations in real-time LOTOS, we have defined some primitive animation operations as ADT functions. The pair of the original specification and its VS is converted into a multi-threaded Java program using our real-time LOTOS compiler where animation primitives described as ADT functions are replaced in the corresponding methods, implemented as Java class libraries. In our visualization method, we can specify the VS without modifying the original specification, and we can derive a Java program which animates the original specification in real-time. We have carried out an experiment to visualize a real-time LOTOS specification of a prioritized queuing mechanism of the differentiated service where two types of VSs for algorithm animation and performance evaluation are used for visualization.