A server framework for scheduling multimedia applications in open system environment

Abstract

We propose methods for scheduling multimedia soft real-time tasks in an open system environment. We discuss two issues, guaranteeing the schedulability of every task in the application and meeting the QoS of multimedia soft real-time tasks. First, when a real-time application is composed of a heterogeneous task set, hard real-time tasks and multimedia soft real-time tasks, the operating system must guarantee the schedulability of each task in the application. These guarantees can be achieved by preserving the CPU bandwidth of each task in the application. We have designed a server framework that preserves the CPU bandwidth of each task in the application. Each task can select its own server that can satisfy its time constraints. Second, when an operating system schedules multimedia soft real-time tasks in an open system, it is important for the operating system not only to support sufficient QoS level for the task, but also to utilize the CPU bandwidth of the system efficiently. We invented a new method of utilizing the CPU bandwidth of the system efficiently while supporting the requested QoS level.