Abstract: A time-partitioned system for accounting for processor time consumed by operating system services provided on behalf of an application running in a real-time environment. The time utilized by the operating system is treated as being application processing time, rather than viewing the resultant processor time consumed as an operating system overhead. Each application consists of one or more threads. A time budget is assigned to each thread and to each interrupt. The processor time consumed by the operating system when executing on behalf of a thread or interrupt is charged back to the application or interrupt as part of the application's time budget. Operating system overheads and processor interrupts are thus accounted for accurately enough to determine a schedule for the applications which is enforceable by the operating system.

Abstract: A time-efficient inter-process communication method (50, 60) and protocol allowing producers and consumers to execute at any combination of periods, where producers (12) and consumers (14, 16, 18) are isolated from execution ordering variations. The method and protocol is for periodic broadcast-type inter-process communication in a harmonic rate system. The system has a plurality of threads sharing a memory space (42) and including consuming threads and producing threads having potentially different rates. The producing threads have a period and are adapted to produce a message consumable by said consuming threads. The memory space (42) includes a plurality of buffers (44) for messages produced. The method includes the step of writing (58) a copy of said produced message to a buffer in said memory space during said producing thread's period, wherein only one copy of said produced message is written, regardless of the difference in rates between producing and consuming threads.

Abstract: A time-partitioned system for accounting for processor time consumed by operating system services provided on behalf of an application running in a real-time environment. The time utilized by the operating system is treated as being application processing time, rather than viewing the resultant processor time consumed as an operating system overhead. Each application consists of one or more threads. A time budget is assigned to each thread and to each interrupt. The processor time consumed by the operating system when executing on behalf of a thread or interrupt is charged back to the application or interrupt as part of the application's time budget. Operating system overheads and processor interrupts are thus accounted for accurately enough to determine a schedule for the applications which is enforceable by the operating system.