Abstract

The simple notion of soft real-time processing has fractured into a spectrum of diverse soft real-time types with a variety of different resource and time constraints. Schedulers have been developed for each of these types, but these are essentially point solutions in the space of soft real-time and no single scheduler has previously been offered that can simultaneously manage all types. More generally, no detailed unified definition of soft real-time has been provided that includes all types of soft real-time processing. We present a complete real-time taxonomy covering the spectrum of processes from best-effort to hard real-time. The taxonomy divides processes into nine classes based on their resource and timeliness requirements and includes four soft real-time classes, each of which captures a group of soft real-time applications with similar characteristics. We exploit the different features of each of the soft realtime classes to integrate all of them into a single scheduler together with hard real-time and best-effort processes and present results showing their performance.

Citations