Timing constraint Petri nets and their application to schedulability analysis of real-time system specifications

1995 ◽  
Vol 21 (1) ◽  
pp. 32-49 ◽  
Author(s):  
J.J.P. Tsai ◽  
S. Jennhwa Yang ◽  
Yao-Hsiung Chang
Keyword(s):  
Petri Nets ◽  
Real Time ◽  
Schedulability Analysis ◽  
Time System ◽  
Real Time System ◽  
Timing Constraint

scholarly journals Limited Non-Preemptive EDF Scheduling for a Real-Time System with Symmetry Multiprocessors

Symmetry ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 172 ◽  
Author(s):  
Hoyoun Lee ◽  
Jinkyu Lee
Keyword(s):  
Real Time ◽  
Scheduling Algorithm ◽  
Schedulability Analysis ◽  
Timing Constraints ◽  
Limited Information ◽  
Time System ◽  
Real Time System ◽  
System A ◽  
The Future ◽  
Earliest Deadline

In a real-time system, a series of jobs invoked by each task should finish its execution before its deadline, and EDF (Earliest Deadline First) is one of the most popular scheduling algorithms to meet such timing constraints of a set of given tasks. However, EDF is known to be ineffective in meeting timing constraints for non-preemptive tasks (which disallow any preemption) when the system does not know the future job release patterns of the tasks. In this paper, we develop a scheduling algorithm for a real-time system with a symmetry multiprocessor platform, which requires only limited information about the future job release patterns of a set of non-preemptive tasks, called LCEDF. We then derive its schedulability analysis that provides timing guarantees of the non-preemptive task set on a symmetry multiprocessor platform. Via simulations, we demonstrate the proposed schedulability analysis for LCEDF significantly improves the schedulability performance in meeting timing constraints of a set of non-preemptive tasks up to 20.16%, compared to vanilla non-preemptive EDF.

scholarly journals Schedulability Analysis for Rate Monotonic Algorithm-Shortest Job First Using UML-RT

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
S. Ewins Pon Pushpa ◽  
Manamalli Devasikamani
Keyword(s):  
Real Time ◽  
Early Stage ◽  
Schedulability Analysis ◽  
Target System ◽  
System Modelling ◽  
Modelling Language ◽  
Time System ◽  
Real Time System ◽  
Unified Modelling Language ◽  
Rate Monotonic

System modelling with a unified modelling language (UML) is an active research area for developing real-time system development. UML is widely used modelling language in software engineering community, to specify the requirement, and analyse the target system successfully. UML can be used to provide multiple views of the system under design with the help of a variety of structural and behavioural diagrams at an early stage. UML-RT (unified modelling language-real time) is a language used to build an unambiguous executable specification of a real-time system based on UML concepts. This paper presents a unified modeling approach for a newly proposed rate monotonic scheduling algorithm-shortest job first (RMA-SJF) for partitioned, semipartitioned and global scheduling strategies in multiprocessor architecture using UML-RT for different system loads. As a technical contribution, effective processor utilization of individual processors and success ratio are analyzed for various scheduling principles and compared with EDF and D_EDF to validate our proposal.

Analysis of real-time system conflict based on fuzzy time Petri nets

2014 ◽  
Vol 26 (2) ◽  
pp. 983-991
Author(s):  
Zhao Tian ◽  
Zun-Dong Zhang ◽  
Yang-Dong Ye ◽  
Li-Min Jia
Keyword(s):  
Petri Nets ◽  
Real Time ◽  
Time Petri Nets ◽  
Time System ◽  
Real Time System

scholarly journals Contention-Free Scheduling for Mixed-Criticality Multiprocessor Real-Time System

Symmetry ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1515
Author(s):  
Hyeongboo Baek ◽  
Kilho Lee
Keyword(s):  
Real Time ◽  
Schedulability Analysis ◽  
Multiprocessor Systems ◽  
Real Time Systems ◽  
Time System ◽  
Real Time System ◽  
Scheduling Policy ◽  
And Performance ◽  
Time Systems ◽  
Mixed Criticality

Zero-laxity (ZL) and contention-free (CF) policies have received considerable attention owing to their simplicity and applicability to real-time systems equipped with symmetry multiprocessors. Recently, the ZL policy for mixed-criticality (MC) systems has been proposed and studied, but the applicability to and performance of the CF policy for MC systems have not been investigated yet. In this paper, we propose the CF policy (as a scheduling policy) for MC symmetry multiprocessor systems, referred to as the MC systems tailored CF policy (MC-CF), and a schedulability analysis in support thereof. We define the notion of contention-free slots for two different criticalities (of MC systems) of tasks, propose a technique to limit the amount to be utilized for each task by defining an upper bound, and subsequently explain the way in which the contention-free slots are systematically utilized to improve the schedulability of MC symmetry multiprocessor systems. Following this, we develop a deadline analysis (DA) for MC-CF. Using our experimental results under various environmental settings, we demonstrate that MC-CF can significantly improve the schedulability of fixed-priority scheduling.

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