Real-Time Distributed Discrete-Event Execution with Fault Tolerance

We build on PTIDES, a programming model for distributed embedded systems that uses discrete-event (DE) models as program specifications. PTIDES improves on distributed DE execution by allowing more concurrent event processing without backtracking. This paper discusses the general execution strategy for PTIDES, and provides two feasible implementations. This execution strategy is then extended with tolerance for hardware errors. We take a program transformation approach to automatically enhance DE models with incremental checkpointing and state recovery functionality. Our fault tolerance mechanism is lightweight and has low overhead. It requires very little human intervention. We incorporate this mechanism into PTIDES for efficient execution of fault- tolerant real-time distributed DE systems.