Flexible cross-domain event delivery for quality-managed multimedia applications

Abstract

To meet end users' quality-of-service (QoS) requirements, online quality management for multimedia applications must include appropriate allocation of the underlying computing platform's resources. Previous work has developed novel operating system (OS) functionality for dynamic QoS management, including multimedia or real-time CPU schedulers and OS extensions for online performance monitoring and for adaptations, as well as QoS-aware applications that adapt their behavior to gain additional benefits from such functionality. This article describes a general OS mechanism that may be used to implement a wide variety of online quality management functions. ECalls is a communication mechanism that implements multiple cross-domain calling conventions that can be customized to the quality management needs of applications. The ECalls mechanism is based on the notions of events, event channels, and event handlers. Using events, applications can share relevant QoS attributes with OS services, and OS-level resource management services can efficiently provide monitoring data to target applications or application managers. Dynamically generated event handlers can be used to customize event delivery to meet diverse application needs, for example, to achieve high scalability for Web servers or small jitter for real-time data delivery.