A real-time virtual resource is an abstraction for resource sharing where the application task groups sharing a resource must meet timing constraints in the absence of knowledge of all the timing requirements of all the task groups, thus prohibiting a global schedulability analysis. RTVR addresses the issues of application isolation in the open system environment, as well as satisfying the timeliness requirements of all the task groups. Based on the theoretical framework in previous work, we present in this paper the first implementation of a real-time virtual resource for the CPU. We shall describe two real-time virtual resource (RTVR) prototypes that are based on the Linux 2.4.18.3 kernel. The first RTVR implementation uses a static resource level scheduler which can be applied to systems with predefined application task sets. The second implementation has a novel dynamic resource level scheduler under which task groups (temporal partitions) can join and leave dynamically. We shall report some experimental results on measuring system performance in various aspects such as the effect of the scheduling quantum size, interrupt request response time and scheduling overhead. The experiments demonstrate that RTVR can be efficiently implemented while satisfying its theoretical properties.

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