Real-time interfaces for interface-based design of real-time systems with fixed priority scheduling

Abstract

The central idea behind interface-based design is to describe components by a component interface. In contrast to a component description that describes what a component does, a component interface describes how a component can be used. A well designed component interface provides enough information to decide whether two or more components can work together properly in a system. In this work, we expand the idea of interface-based design to the area of real-time system design. Here, the term of 'working together properly' refers to questions like: Does the composed system satisfy all requested real-time properties such as delay and throughput constraints? For this, we introduce Real-Time Interfaces, that connect the principles of Real-Time Calculus with Interface-based Design. In contrast to traditional real-time system design, in interface-based real-time system design the compliance to real-time constraints is checked at composition time. This leads to faster design processes and partly removes the need for the classical binary search approach to find an economically dimensioned system. Further, interface-based real-time system design also benefits from the properties of incremental design and independent implementability.

WCRT algebra and interfaces for esterel-style synchronous processing

“…Similar restrictions apply to recent work [12], [13] combining network calculus [14], [15] with real-time interfaces. These works are concerned with the compositional modeling of regular execution patterns rather than stabilization processes inside each execution cycle of a synchronous program.…”

“…These works are concerned with the compositional modeling of regular execution patterns rather than stabilization processes inside each execution cycle of a synchronous program. Existing interface theories [11], [12], [13], which aim at the verification of resource constraints for real-time scheduling, handle timing properties such as task execution latency, arrival rates, resource utilization, throughput, accumulated cost of context switches, and so on. However, the dependency on data and control flow is largely abstracted.…”

Designing end-to-end resource reservations in predictable distributed embedded systems

“…The algorithm gives an approximation on the partitions for real-time components. In the same context, the work presented in Wandeler and Thiele (2005) uses real-time calculus to design the servers based on a given interface. The algorithm computes demand and service curves for components in real-time systems.…”

Analysis and Optimisation of Hierarchically Scheduled Multiprocessor Embedded Systems

“…In [Ric02] and [Ric03], the authors model the multiprocessor heterogeneous systems as components that communicate through event streams and propose a technique for integrating different local scheduling policies based on such event-model interfaces. Another compositional approach is presented in [Wan05], where the authors propose real-time interfaces and a component model that support incremental design of real-time systems. Usually, communication protocols allow either static (TT) or dynamic (ET) services, influencing several levels in the design flow and giving more weight in the design output to either flexibility or time-determinism of the system.…”