Aspect-Oriented Customization of the Scheduling Algorithms and the Resource Access Protocols of a Real-Time Operating System Family

Various embedded systems are used in a smart city and the required functionalities of real-time operating systems (RTOS) are different depending on applications. Most RTOSs adopt just fixed priority scheduling. Some applications, however, require dynamic scheduling algorithms. The paper presents a method to customize the scheduling algorithm and the resource access protocol of an OSEK OS using aspect-oriented programming (AOP). We define aspects to replace the fixed priority scheduling mechanism of the OSEK OS with an Earliest Deadline First (EDF) scheduling mechanism or a Rate Monotonic Critical Laxity (RMCL) scheduling mechanism. We also define aspects to customize the resource access protocol for EDF scheduling and RMCL scheduling. By using the aspects, we can customize the scheduling algorithm and the resource access protocol without modifying the original source code. This improves the maintainability of the RTOS family. The evaluation results show that the overhead of AOP is small enough.