Handling aperiodic tasks in diverse real-time systems via plug-ins

Functionality for various services of scheduling algorithms is typically provided as extensions to a basic algorithm. A similar approach dominates operating system functionality: implementation of the actual real-time scheduling algorithm. In this paper, we propose the use of a plug-in approach to add functionality to existing scheduling schemes and provide for easy, replacement on the operating system level. In particular, we present an architecture to disentangle actual real-time scheduling from dispatching and other kernel routines with a small API, suited for a variety of scheduling schemes as plug-ins. We detail two plug-ins for aperiodic task handling and how they can extend two target systems, table-driven and earliest deadline first scheduling, using the approach presented.