A Gravitational Task Model for Target Sensitive Real-Time Applications

Guerrra, R.; Fohler, Gerhard

doi:10.1109/ecrts.2008.25

Cited by 11 publications

(6 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The developer can decide among different scheduling algorithms, as fixed priorities (FPs) and earliest deadline first (EDF) [17]. To test the system near the limit conditions, the period of task 1 has been set to the maximum value allowed by Equation (13), that is…”

Section: Software Implementationmentioning

confidence: 99%

See 1 more Smart Citation

Design and analysis of target-sensitive real-time systems

Buttazzo

Franco

Marinoni

2015

Softw. Pract. Exper.

View full text Add to dashboard Cite

A significant number of real-time control applications include computational activities where the results have to be delivered at precise instants, rather than within a deadline. The performance of such systems significantly degrades if outputs are generated before or after the desired target time. This work presents a general methodology that can be used to design and analyze target-sensitive applications in which the timing parameters of the computational activities are tightly coupled with the physical characteristics of the system to be controlled. For the sake of clarity, the proposed methodology is illustrated through a sample case study used to show how to derive and verify real-time constraints from the mission requirements. Software implementation issues necessary to map the computational activities into tasks running on a real-time kernel are also discussed to identify the kernel mechanisms necessary to enforce timing constraints and analyze the feasibility of the application. A set of experiments are finally presented with the purpose of validating the proposed methodology

show abstract

Section: Software Implementationmentioning

confidence: 99%

“…To schedule overlapping events generated around the same target time, Guerra and Fohler [13,14] presented an algorithm based on gravitational field. In their approach, every task is considered as a mass denoting a different importance level, free to oscillate on a pendulum hanged at the desired target time.…”

Section: Introductionmentioning

confidence: 99%

Design and analysis of target-sensitive real-time systems

Buttazzo

Franco

Marinoni

2015

Softw. Pract. Exper.

View full text Add to dashboard Cite

show abstract

“…The presence of non-preemptive regions in the task code, however, creates a potential blocking time (δ) to higher priority tasks that need to be taken into account in the feasibility analysis, as shown in Section III. This also affects the bounds for the safety region, because δ has to be added to ε t in Equation (12), so ∆θ max becomes:…”

Section: ) Estimating the Target Velocitymentioning

confidence: 99%

“…Guerra and Fohler [12], [11] proposed a gravitational model to schedule overlapping events around the same time instant. To do that, each task is assigned a different importance value, considered as a mass hanging on a pendulum centered at the desired time and used to compute the mass distribution along the timeline based on the equilibrium state.…”

Section: Introductionmentioning

confidence: 99%

Target-sensitive systems: Analysis and implementation issues

Buttazzo

Franco

Marinoni

2012

Proceedings of 2012 IEEE 17th International Conference on Emerging Technologies &Amp; Factory Automation (ETFA 2012)

View full text Add to dashboard Cite

Several real-time applications include tasks in which the output must be produced at precise time instants, rather than "within" a deadline, and the overall system performance significantly degrades when the task is executed too late or too early with respect to the desired time.This paper illustrates one of such applications and takes it as a reference case study to propose a general approach to show how to derive the timing constraints from the application requirements, how to implement the application on top of a realtime kernel, identifying the operating system features necessary to enforce such constraints, and how to analyze the schedulability of the task set. A set of experimental results are also presented to validate the proposed approach.

show abstract

“…In this paper we present a novel task model, called gravitational task model (Guerra and Fohler 2008), which is based on a physical system: the pendulum. A pendulum is an object that is attached to a pivot point and can swing freely.…”

mentioning

confidence: 99%

A gravitational task model with arbitrary anchor points for target sensitive real-time applications

Guerra

Fohler

2009

Real-Time Syst

Self Cite

View full text Add to dashboard Cite

Classic task models for real-time systems focus on execution windows expressing earliest start times and deadlines of tasks for feasibility. Only within these windows the execution of tasks is feasible, and it is considered of uniform utility.Some tasks, however, have target demands in addition: a task should preferably execute at a specific target point within its execution window, but can execute around this point, albeit at lower utility. Examples of such applications include control and media processing.In this paper, we present a task model based on a gravitational analogy to address these issues. Tasks are considered as massive bobs hanging on a pendulum: a single task, left to itself, will execute at the bottom, the target point. If a force, such as the weight of other tasks, is applied, it can be shifted around this point. Thus, tasks' importance and their utility around target points can be expressed. Since the execution of a task cannot be mapped to a point in time, the model allows tasks to express an arbitrary point with its execution to represent the whole execution. This point is called the anchor point.Moreover, we show an example of a scheduling algorithm for this model which finds an approximation to the best compromise of tasks' interests based on the equilibrium state of a pendulum. Nonetheless, this task model is not restricted to a particular scheduling algorithm.Results from a simulation study show the effectiveness of the approach. This is an extended version of the ECRTS'08 paper (Guerra and Fohler 2008).

show abstract

A Gravitational Task Model for Target Sensitive Real-Time Applications

Abstract: The commonly used task models for real - Results from a simulation study show the effectiveness of the approach.

Cited by 11 publications

References 11 publications

Design and analysis of target-sensitive real-time systems

Design and analysis of target-sensitive real-time systems

Target-sensitive systems: Analysis and implementation issues

A gravitational task model with arbitrary anchor points for target sensitive real-time applications

Contact Info

Product

Resources

About