Slotted priorities: supporting real-time computing within general-purpose operating systems

Slotted Priorities: Supporting Real-Time Computing Within General-Purpose Operating Systems Recent advances in network technologies, processor capabilities, and microcomputer system hardware, coupled with the explosive growth of the Internet and on-line data access, have created new demands on personal computer operating systems and hardware. In large part, these demands are for the ability to acquire, manipulate, display, and store multimedia data. The computational processes that successfully acquire and display multimedia data necessarily have deadlines. That is, the computation must be complete before a speci ed point in time. Currently, no general-purpose operating systems support such real-time processes. We have developed a software architecture, called slotted priorities, that de nes a way to add support for real-time computation to existing general-purpose operating systems for uniprocessor machine architectures. The slotted priorities architecture shares the resources of a computing system between a general-purpose operating system and a real-time kernel. Software components called executives manage how an instance of a resource is shared. Executives ensure that the RTK can gain access to the resource at precise times. The resulting operating system will be able