Analysis of Clocked Petri Nets Using Stubborn Sets and Time Warp Distributed Simulator

• Main Authors: Tseng, Chung-Liang, 曾中亮
• Other Authors: Yen Hsu-Chun
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/40041455923237692787

碩士 === 國立臺灣大學 === 電機工程學系 === 85 === Petri nets, a useful model for concurrent systems, lack the notion of time which is critical in modeling real-time systems. Thus, Petri nets, in general, are not appropriate for modeling systems on which timing constraints are imposed. Several timed versions of Petri nets have been proposed in theliterature, incorporating timing information into the Petri net model either implicitly or explicitly. Among such extended Petri nets, clocked Petri nets associate each transition with a set of clockconstraints and/or clock reset operations.After we associate timing information with the transitions of thePetri net we can use this enhanced model to effectively model real- time systems. However,since a system's configuration must now include timing information, both the state space and the system complexity increase significantly.To reduce the complexity, weuse the concept of Stubborn set introduced by Antti Valmari. The intuition behind stubborn sets is simply that in each of the reachable states, only portion of the next states will be explored,resulting in a reduced state space. Aside from the above analytical aspect of clocked Petri nets,in this thesis we also implement a Time-Warp distributedsimulator on a distributed shared memory system for simple timedPetri nets. Our empirical results reveal how the "partition" issue affects the performance of our simulation.