Time- and space-conscious omniscient debugging of parallel DEVS

Current Parallel DEVS simulation tools provide a wide set of debugging features. Omniscient debugging, or debugging backwards in time, is only rarely implemented, presumably due to its high resource consumption. Outside of DEVS simulation, omniscient debugging implementations are often lossy: some parts of the model or code are ignored, or they consider only a time window of most recent events. In this paper, we consider efficient and lossless omniscient debugging, particularly in the context of Parallel DEVS. We take inspiration from optimistic synchronization protocols, which can roll back simulation. We investigate how this technique can be tailored to omniscient debugging of Parallel DEVS models. Our algorithm limits simulation overhead and memory consumption, while remaining lossless. We compare the traditional approach with our approach. Our approach significantly decreases time and space overhead, at the cost of slightly slower debugging operations.