μChoices: an object-oriented multimedia operating system

The paper describes the design of the μChoices object-oriented multimedia operating system. μChoices provides an architecture for interconnecting different OS subsystems, with these subsystems realized as separate modules. The modules are implemented as independent object-oriented frameworks. Frameworks interact through exported abstract interfaces. The sub-classing of components within frameworks enables application and media-specific customization. μChoices also provides a unified scheme for memory handling and passing across, as well as between, all OS subsystems. This allows buffer transfers and manipulation within and between operating system modules without copying, while allowing subsystems to specialize their views of memory buffers for efficient handling of problem-specific behavior. Interpreted agents may be embedded in the kernel that can control system level processing of multimedia streams without interference, eliminating excessive system call overhead. Operating system support for authentication, encryption, and delegation is transparently provided via an extensible framework that customizes interfaces to operating system resources. A new networking subsystem based on an asynchronous transfer mode network environment allows quality of service guarantees within the network protocol stack. These features are combined in μChoices to give an environment that supports high bandwidth multimedia streams