Parallel, hardware-supported interrupt handling in an event-triggered real-time operating system

A common problem in event-triggered real-time systems is caused by low-priority tasks that are implemented as interrupt handlers interrupting and disturbing high-priority tasks that are implemented as threads. This problem is termed rate-monotonic priority inversion, and current software-based solutions are restricted in terms of more sophisticated scheduler features as demanded for instance by the AUTOSAR embedded–operating-system specification. We propose a hardware-based approach that makes use of a coprocessor to eliminate the potential priority inversion. By evaluating a prototypical implementation, we show that our approach both overcomes the restrictions of software approaches and introduces only a slight processing overhead in exchange for increased predictability. Categories and Subject Descriptors C.3 [Special-purpose and Application-based Systems]: Real-time systems and embedded systems; D.4.1 [Operating Systems]: Process Management—Threads; D.4.7 [Operating Systems]: ...

• Type: Conference
• Year: 2009
• Where: CASES
• Authors: Fabian Scheler, Wanja Hofer, Benjamin Oechslein, Rudi Pfister, Wolfgang Schröder-Preikschat, Daniel Lohmann
• Keywords: CASES 2009, Communications, Priority Inversion, Rate-monotonic Priority Inversion, Real-time Systems