GuardianOMP: A Framework for Highly Productive Fault Tolerance Via OpenMP Task-Level Replication

Advanced critical real-time embedded systems (CRTES) like autonomous cars impose dependability and highperformance requirements. Parallel architectures are increasingly adopted to cope with the performance needs of these systems. In this context, the OpenMP parallel programming model is becoming popular for effectively exploiting complex hardware due to its productivity and time-predictability, but it lacks the mechanisms to provide fail-operational behaviour. This paper presents GuardianOMP, a complete open-source framework based on extensions to the OpenMP language, compiler and runtime tools built on top of LLVM framework to improve the fault tolerance of critical systems while minimizing overheads. GuardianOMP offers software-based task-level replication and user-directed fault detection to mitigate the impact of transient faults. The proposed framework provides flexibility in defining parameters, such as the number of replicas, the replication type, and the voting method, incurring minimal efforts to provide programmability and adaptability. Moreover, it exploits the available parallel resources of shared memory systems to minimize the impact on the system's overall performance. This work evaluates GuardianOMP in terms of accuracy, performance, and programmability by employing BOTS (Barcelona OpenMP Task Suite) benchmarks, showing the elimination of false positives, a slight reduction in overhead and an enhancement in the programmability and flexibility compared to the state-of-the-art. The framework is also evaluated in a real-world railway obstacle detection application, reinforcing its effectiveness. Furthermore, this work contributes with a new open-source fault injector tool that simulates software transient faults in processes memory and hardware registers and enables the evaluation of this work and its further use and extension.