Tool for task allocation and scheduling in hard real-time systems.

摘要

Techniques and a tool for allocation and scheduling on hard real-time systems are developed. The hard real-time systems are characterized by a set of independent, strictly periodic transactions with hard end-to-end deadlines. Each transaction is composed of a set of tasks with regular or complex precedence relationships among them. A static allocation technique is used for allocating tasks to processors. A reallocation strategy is developed for re-assigning tasks to processors in case priority assignment for a given allocation fails. A fixed priority scheduling technique for hard realtime systems is introduced. Both preemptive scheduling and non-preemptive scheduling are considered. Instead of using explicit scheduling strategies, the priority computation tool generates a description of the system in terms of constraints that are solved by a CLP-BNR solver to produce a feasible priority set.