Scheduling Real-Time Embedded Systems Based on TCPNIA

摘要

TCPNIA (Timed Colored Petri Nets with Inhibitor Arcs, TCPNIA) is a model for specifying real-time embedded systems. It integrates features of colored Petri nets, timed Petri nets and inhibitor arcs. The methods for modeling modules of systems using TCPNIA are proposed. A depth-first scheduling algorithm for TCPNIA is proposed. The system level resource’s influence to schedulable path is considered. Different data in tokens will change an execution path and call different data operational functions. The influence from data operational functions is considered in the scheduling algorithm. The time requirement upper bound of a schedulable path can be calculated in the algorithm. Tasks’ parallel executions have been considered when the time upper bound of the path is calculated. The soundness of the algorithm is proved. The time and space complexities of the algorithm are also analyzed. The compositional conditions and method for composing schedulable path are given. A case study shows the applicability and feasibility of the method.