ACTORS · Adaptivity and Control of Resources in Embedded Systems

ACTORS addresses design of resource-constrained software-intensive embedded systems with high requirements on adaptivity and efficiency. Three techniques will be combined: virtualization, feedback-based resource scheduling, and data-flow programming models. Virtualization techniques such as reservation-based scheduling provide spatial and temporal separation of concerns and enforce dependability and predictability. Reservations can be composed, are easier to develop and test, and provide security support. Using feedback-based resource management, the resource allocation is based on a comparison of the actual resource utilization of, e.g., a set of activities or tasks, with the desired resource utilization. The difference is used for deciding how the resources should be dynamically allocated. Feedback control makes it possible to deal with uncertainties and variations in a controlled way and provides adaptivity to on-line changes in objectives, external conditions and use cases. By combining feedback control with resource reservations it is possible to handle incorrect reservations, reclaim and redistribute unused resources, and adjust to dynamic changes in resource requirements. Execution efficiency and development efficiency require abstractions on a higher level than what is provided with C and threads/priorities. Data-flow models such as actor models provide the proper foundation for implementation of efficient, component based, and adaptive algorithms for both multimedia applications in consumer electronics and industrial control systems and signal processing applications. In ACTORS a design methodology will be developed that combines virtualization, feedback-scheduling and actor programming. Two demonstrators will be used: multimedia processing on cellular phone terminals and embedded control. The ACTORS project contains the ideal mix of large companies, SMEs, and universities required to fulfil these objectives.