Periodic processing in hard real-time systems: Assessment of different design models in Ada

Abstract

Hard real-time systems are characterized by their stringent timing constraints. The software handles several periodic and aperiodic tasks which must start at a required time and achieve before a deadline. Important issues of the schedubality theory are to provide off-line tests to ensure a system meets all its deadlines. Furthermore, optimal algorithms, such as the Rate Monotonic Scheduling (RMS) are proved to yield an efficient processor utilization.

Applying theorical outcomes to embedded software is fully attractive but many designers wonder how suitable to Ada implementations it is. Their primary concern is to foresee a right real-time design then to check the final product.

An assessment of different models affords selection among designs with a high timing behaviour predictability. On the other hand, it allows to realize actual boundaries in schedulability practice.