PSE

This Note describes the Persistent Simulation Environment (PSE), which combines object-oriented simulation with a persistent object repository and domain-dependent object prefetching facilities. The goals of PSE are (1) to augment a contemporary object-oriented programming language with discrete event and process-based simulation facilities equaling those found in simulation languages such as Simscript and Simula; (2) to tightly couple an object-oriented simulation language with a secondary storage facility to achieve the persistence of simulation objects; and (3) to improve the swapping of persistent simulation objects between main memory and secondary storage through the use of object prefetching. The authors present the simulation facilities supported by PSE, including examples that demonstrate the use of events, processes, and resources. They discuss the persistent object system within PSE and describe the methodology they developed for object prefetching. Finally, they consider two PSE applications and identify limitations and areas for future work.