research-article

Weakly Hard Real-Time Systems

Authors:

Guillem Bernat,

Albert LlamosiAuthors Info & Claims

IEEE Transactions on Computers, Volume 50, Issue 4

Pages 308 - 321

https://doi.org/10.1109/12.919277

Published: 01 April 2001 Publication History

Abstract

In a hard real-time system, it is assumed that no deadline is missed, whereas, in a soft or firm real-time system, deadlines can be missed, although this usually happens in a nonpredictable way. However, most hard real-time systems could miss some deadlines provided that it happens in a known and predictable way. Also, adding predictability on the pattern of missed deadlines for soft and firm real-time systems is desirable, for instance, to guarantee levels of quality of service. We introduce the concept of weakly hard real-time systems to model real-time systems that can tolerate a clearly specified degree of missed deadlines. For this purpose, we define four temporal constraints based on determining a maximum number of deadlines that can be missed during a window of time (a given number of invocations). This paper provides the theoretical analysis of the properties and relationships of these constraints. It also shows the exact conditions under which a constraint is harder to satisfy than another constraint. Finally, results on fixed priority scheduling and response-time schedulability tests for a wide range of process models are presented.

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Published In

cover image IEEE Transactions on Computers

IEEE Transactions on Computers Volume 50, Issue 4

April 2001

95 pages

ISSN:0018-9340

Editors:
Jean-Luc Gaudiot
Univ. of Southern California, Los Angeles
,
Fabrizio Lombardi
Northeastern Univ., Boston, MA

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Copyright © Copyright © 2001 IEEE. All Rights Reserved.

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IEEE Computer Society

United States

Publication History

Published: 01 April 2001

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Cited By

Pimentel AGrelck CMiedema LSapra DVölp MLucchetti FMatovic AMaggio MVreman NAltmeyer SHaas FCasimiro ACecílio JJäger GEspindola ASkalistis SKouwer JLange GAlmeida JBlasum HBrotz MWagner SNovobílský P(2024)The ADMORPH Approach for Adaptively Morphing Embedded SystemsACM SIGAda Ada Letters10.1145/3672359.367237243:2(78-83)Online publication date: 7-Jun-2024
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Niu LRawat DZhu DMusselwhite JGu ZDeng Q(2024)Energy Management for Fault-tolerant (m,k)-constrained Real-time Systems That Use Standby-SparingACM Transactions on Embedded Computing Systems10.1145/364836523:3(1-36)Online publication date: 21-Feb-2024
https://dl.acm.org/doi/10.1145/3648365
Adhikary SKoley IGhosh SGhosh SDey S(2024)Revisiting Dynamic Scheduling of Control Tasks: A Performance-Aware Fine-Grained ApproachIEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems10.1109/TCAD.2024.344300743:11(3662-3673)Online publication date: 1-Nov-2024
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