Proceedings Fourteenth Workshop on Parallel and Distributed Simulation (2000)
May 28, 2000 to May 31, 2000
David Nicol , Dartmouth College
Jason Liu , Dartmouth College
James Cowie , Cooperating Systems
This paper visits issues that recur in consideration of simulation time-stamps, in the context of building very large simulation models from components developed by different groups, at different times. A key problem here is “safety”, loosely defined to mean that unintended model behavior does not occur due to unpredictable behavior of timestamp generation and comparisons. We revisit the problems of timestamp format and simultaneity, and then turn to the new problem of timestamp inter-operability. We describe how a C++ simulation kernel can support the concurrent evaluation of submodels that internally use heterogeneous timestamps, and evaluate the execution time costs of doing so. We find that use of a safe timestamp format that explicitly allows different time-scales costs less than 10% over a stock 64-bit integer format, whereas support for completely heterogeneous timestamps can cost as much as 50% in execution speed.
parallel simulation, time management, Object-Oriented Programming, Reuse
D. Nicol, J. Liu and J. Cowie, "Safe Timestamps and Large-Scale Modeling," Proceedings Fourteenth Workshop on Parallel and Distributed Simulation(PADS), Bologna, Italy, 2000, pp. 71.