情報処理学会 第78回全国大会講演要旨

At present, there is a gap between practical implementations of tasks on popular RTOSs and theoretical real-time scheduling. This is due to overhead required when the RTOS offers advanced features. Yet, implementing advanced scheduling features consumes vast amount of development time. By offering a real-time scheduler library implemented in user space, the user can choose whether to skip the overhead, or use more advanced theories. At the moment there exists already several scheduling frameworks for FreeRTOS. However, they either do not provide advanced scheduling policies, or require high scheduling overhead. This paper proposes an open source scheduler library for FreeRTOS that runs with low overhead. Moreover it provides configurable release time for periodic tasks, Sporadic server that runs aperiodic and sporadic tasks, Priority Ceiling Protocol, dependable Timing-Error-Detection and RMS, DMS, EDF scheduling policies to provide theoretical real-time scheduling features to speed up development of complex projects, and make FreeRTOS friendlier to students who has newly studied real-time scheduling.