THe DEVS(discrete event system specification) formalism specifies a discrete event system in a hierachical, modular form. DEVSIM++ is a C++ based general purpose DEVS abstract simulator which can simulate systems modeled by the DEVS formalism in a sequential environment. This paper describes P-DEVSIM++ which is a parallel version of DEVSIM++. In P-DEVSIM++, the external and internal event of DEVS models can be processed in prallel. For such processing, we propose a prallel, distributed optimistic simulation algorithm based on the Time Warp approach. However, the proposed algorithm localizes the rollback of a model within itself, not possible in the standard Time Warp approach. An advantage of such localization is that the simulation time may be reduced.
To evaluate its performance, we simulate a single bus builtiprocessor architecture system with an external common memory. Simulation result shows that significant speed up is made possible with our algorithm in a parallel environment.