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Integrating Unbounded Software Components into Hard Real-Time Systems

  • N. C. Audsley
  • A. Burns
  • R. I. Davis
  • A. J. Wellings
Chapter
Part of the The Springer International Series in Engineering and Computer Science book series (SECS, volume 318)

Abstract

The incorporation of unbounded components (i.e. software modules that cannot be analysed to produce realistic worst case execution times) into hard real-time applications has been recognised as a key issue for the next generation of real-time systems. In this paper, we present a system model that caters for the three main approaches to integrating unbounded components: milestone methods, sieve functions and multiple versions. This model is feasible because it is supported by schedulability tests that will guarantee the bounded tasks. These test are defined in the paper. Further, only a simple run-time system that uses pre-emptive priority-based dispatching is required. The wide-spread use of techniques such as imprecise computation will only happen if they are integrated into standard software engineering methods, we therefore also show how the techniques can be realised in Ada 9X.1

Keywords

Busy Period Spare Capacity Sporadic Task Schedulability Analysis Schedulability Test 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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Copyright information

© Kluwer Academic Publishers 1995

Authors and Affiliations

  • N. C. Audsley
    • 1
  • A. Burns
    • 1
  • R. I. Davis
    • 1
  • A. J. Wellings
    • 1
  1. 1.Real-Time Systems Research Group, Department of Computer ScienceUniversity of YorkUK

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