On-line Monitoring of Real Time Applications for Early Error Detection

Error confinement technologies have proven their efficiency to improve software dependability. Such mechanisms usually require efficient error detectors to swiftly signal any misbehaviour. Real-time systems, due to their timing constraints, require a richer description of correct and/or erroneous states that includes timing aspects. This paper presents real-time error detectors that can be automatically generated from formal models of the expected behaviours of software applications. The considered specifications provide the means to define quantitative temporal constraints on the execution of the application. These detectors check at run-time that the current execution matches its specification. The paper contribution is twofold. Firstly, at the theoretical level, we provide a formal definition of the expected behaviour of such detectors, ensuring a predictable behaviour of the detector system. Secondly, at a practical level, we provide a description of the complete generation process, from the models to the code of the detector.