Using atomic data structures for parallel simulation

Abstract

Synchronizing access to shared data structures is a difficult problem for simulation programs. Frequently, synchronizing operations within and between simulation steps substantially curtails parallelism. The paper presents a general technique for performing this synchronization while sustaining parallelism. The technique combines fine-grained, exclusive locks with futures, a write-once data structure supporting producer-consumer parallelism. The combination allows multiple operations within a simulation step to run in parallel; further, successive simulation steps can overlap without compromising serializability or requiring roll-backs. The cumulative effect of these two sources of parallelism is dramatic: the example presented shows almost 20-fold increase in parallelism over traditional synchronization mechanisms.<>