Wayne M. Loucks

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This paper examines memory management issues associated with Time Warp synchronized parallel simulation on distributed memory machines. The paper begins with a summary of the techniques which have been previously proposed for memory management on various parallel processor memory structures. It then concentrates the discussion on parallel simulation(More)
In Time Warp parallel simulation, the state of each process must be saved (checkpointed) regularly in case a rollback is necessary. Although most existing Time Warp implementations checkpoint after every state transition, this is not necessary, and the checkpoint interval is in reality a tuning parameter of the simulation. Lin and Lazowska[6] proposed a(More)
Optimistically synchronized parallel discrete-event simulation is based on the use of communicating sequential processes. Optimistic synchronization means that the processes proceed under the assumption that a synchronized execution schedule is fortuitous. Periodic checkpointing of the state of a process allows the process to roll back to an earlier state(More)
An approach for high performance parallel logic simulation on a local area network of workstation computers is discussed in this paper. The single, shared transmission medium often found in such networks places limitations on parallel execution, hence a reduction in the frequency of synchronization is pursued by combining a circuit partitioning methodology(More)
Optimistically synchronized parallel discrete-event simulation is based on the use of communicating sequential processes. Optimistic synchronization means that the processes execute under the assumption that synchronization is fortuitous. Periodic checkpointing of the state of a process allows the process to roll back to an earlier state when(More)
The main problem associated with comparing distributed discrete event simulation mechanisms is the need to base the comparisons on some common problem specification. This paper presents a specification strategy and language which allows the same simulation problem specification to be used for both distributed discrete event simulation mechanisms as well as(More)
This paper presents the results of an empirical study of the effects of null message cancellation on the performance of conservatively synchronized distributed simulation. Null message cancellation is an algorithmic modification to the basic conservative synchronization scheme wherein a null message is discarded before receipt when overcome by a message(More)
It has long been recognized that the ability of a logical process (LP) to ''look ahead'' is crucial to the performance of distributed simulation using conservative synchronization. This paper examines previous definitions of lookahead and lookahead ratio — metrics for characterizing the lookahead ability of LPs. These metrics do not reflect the use of null(More)