The Design, Implementation, and Use of a Sporadic Tasking Model

This paper describes the design, implementation, and use of a model of sporadic tasks in the Real-Time Mach kernel (MK83) [15]. The purpose of this exercise was two-fold. First, was our desire to provide a programming model in real-Time Mach (RT-Mach) that was better suited to the demands and requirements of applications that must execute in response to non-periodic, but repetitive events. Examples of such applications include those that manipulate live multimedia data, such as videoconferencing systems, and those that need to control asynchronous devices such as local-area network adaptors, to implement real-time communications protocols. Second, we wanted to study the issues involved in applying recent scheduling theory results for sporadic tasks in the context of a general purpose kernel such as the Mach kernel.