No abstract

Increasing the connectivity of systems at various levels gives rise to potential benefits that is addressed by trends such as the Internet of Things, Cyber-Physical Systems and Cyber-Biosphere. It is inevitable that the vast global network will consist of computationally constrained units. The ability of such systems to adapt while being connected to a global network presents new opportunities. Qualities such as fault tolerance and load sharing may be extended to nodes in the network that initially were devoid of them. On the other hand, an open adaptable system that does not limit its adaptation to pre-defined and pre-containing states needs to be connected to one or more sources that may provide the necessary behavioral units to switch to the new state. Extending computationally constrained nodes with the ability to adapt is in itself challenging, which increases when timely behavior is required due to real-time requirements. The system must then guarantee all deadlines implying the need for deterministic adaptation. The question of when to adapt becomes an important one with real-time deadlines involved. We present our work on a framework that aims to achieve deterministic runtime adaptation on single processor systems thereby enabling such computationally constrained systems to extend their functionality and non-functional qualities.

Modern systems are designed to have various non-functional attributes such as fault tolerance, robustness, et cetera. The ability of systems to adapt while being connected to a global network as in Cyber Physical Systems, presents new opportunities. Extra-functional qualities may be extended to nodes in the network that initially were devoid of them. It is inevitable that such vast global networks will consist of computationally constrained units. Extending such computationally constrained nodes with the ability to adapt is already a difficult challenge, which becomes more difficult when added with the constraint of timely behavior. In this chapter, the authors present an approach to tackle the issue of runtime adaptation on computationally constrained systems with real-time constraints. The focus is on systems with only a single general purpose processor, with the responsibility to run the system and application software. The authors introduce their framework towards this aim, followed by the architecture and a case study.