Robert Boschgmbh

Rolls-royce Corporation

Alan Burns

Gary Morgan

Christos Evripidou

Iain Bate

Method for hosting a multitasking guest on a host system, wherein the guest is allocated a periodic execution server and a deferrable execution server associated with a partition of the system, event-driven tasks of the guest are assigned to the deferrable execution server, time-driven tasks of the guest are assigned to the periodic execution server, a hypervisor of the execution servers is assigned to a first priority group of the system, the deferrable execution server is assigned to a second priority group of the system, the periodic execution server is assigned to a third priority group of the system, and a preemptive task scheduler maintains a descending priority order among the priority groups while the execution servers execute the tasks concurrently.

Method and apparatus for hosting a multitasking guest on a host system

A hybrid control system executes tasks within a transaction which is executed in a given order. The order in which the tasks are executed is inversely proportional to their deadlines. The deadlines are assigned an initial deadline D, an initial maximum end-to-end delay of the transaction is calculated using the initial deadlines D and the given order of the tasks. The deadline of the task with the largest deadline is reduced by an increment to give a new deadline and if the task following it has an increment to give a new deadline. A new end-to-end delay is calculated using the new deadlines and the given order of the tasks. These steps are repeated until the new end-to-end delay does not exceed the desired maximum end-to-end delay.

Growing community of inventors

York, United Kingdom

Alan Burns