Dealing with global guards in a distributed simulation of colored Petri nets

摘要

Petri nets are commonly used for modeling of computer, communication, logistics and manufacturing systems. Powerful grid and cluster computers allow efficient distributed simulation of such models to speed up execution. Optimistic parallel simulation techniques have been developed for different Petri net classes. Different notions of time have been proposed to detect occurring causality violations. However, global guards in timed colored Petri nets restrict state transitions based on global conditions. Furthermore those nets may contain vanishing states and transition priorities. Those properties require an extended logical time scheme and an efficient monitoring mechanism to capture global conditions over time. The paper presents an appropriate logical time scheme that guarantees correct ordering of global states in a distributed timed colored Petri net simulation. A new mirrored state mechanism is proposed to verify global conditions without limiting the optimistic simulation behavior. Some Petri net examples are used to present performance values on a cluster computer.