The threshold of event simultaneity

We revisit the notion of event simultaneity in the context of parallel and distributed simulation. Although the simulation community has recognized this problem for years, it has focused mainly on the mechanics of breaking event-time ties and has neither measured its extent nor considered its implications. Exant simulators (both serial and parallel) prohibit simultaneity either by user-specified event priorities or by an arbitrary (but well-documented) tie-breaking mechanism. We show, theoretically and empirically, that these strategies may lead to an invalid simulation. In doing so, we introduce the threshold of event simultaneity and use it to understand the semantics of simultaneity.

[1]  Richard M. Fujimoto,et al.  Dynamic virtual logical processes , 1998, Workshop on Parallel and Distributed Simulation.

[2]  Thomas J. Schriber,et al.  Simulation Using GPSS , 1974 .

[3]  Bernard P. Zeigler,et al.  Parallel DEVS: a parallel, hierarchical, modular modeling formalism , 1994, Proceedings of Winter Simulation Conference.

[4]  Frederick Wieland,et al.  A distributed simulation model of air traffic in the national airspace system , 1995, WSC '95.

[5]  Robert G. Sargent,et al.  Simultaneous events and distributed simulation , 1990, 1990 Winter Simulation Conference Proceedings.

[6]  R. M. Fujimoto,et al.  Parallel discrete event simulation , 1989, WSC '89.

[7]  Frederick Wieland,et al.  Parallel Discrete-Event Simulation (PDES): a case study in design, development, and performance using SPEEDES , 1995, PADS.

[8]  Bernard P. Zeigler,et al.  The DEVS environment for high-performance modeling and simulation , 1997 .

[9]  B. P. Ziegler,et al.  Theory of Modeling and Simulation , 1976 .

[10]  A. Alan B. Pritsker,et al.  Introduction to simulation and SLAM II , 1979 .

[11]  Richard M. Fujimoto,et al.  GTW: a time warp system for shared memory multiprocessors , 1994, Proceedings of Winter Simulation Conference.

[12]  Frederick Wieland.  Parallel simulation for aviation applications , 1998, 1998 Winter Simulation Conference. Proceedings (Cat. No.98CH36274).

[13]  N. S. Barnett,et al.  Private communication , 1969 .

[14]  Edward C. Russell.  Building Simulation Models with Simscript II.5 , 1999 .