A hierarchical pre-runtime scheduling for hard real-time systems considering fault-tolerance

The scientific community has devoted attention to virtualization in hard real-time systems, motivating the development of many hierarchical scheduling techniques for dealing with stringent timing constraints for such systems. Most techniques are based on runtime scheduling methods and they provide important results concerning schedulability analysis. However, there are situations in which runtime methods may fail in finding a feasible schedule, and intertask relations as well as overheads are neglected by several approaches. This paper proposes a hierarchical pre-runtime scheduling for hard real-time systems taking into account intertask relations and overheads. A formal model based on time Petri net (TPN) is adopted to provide a basis for precise schedule generation.