On the Construction of Live Timed Systems

Bornot, Sébastien; Gößler, Gregor; Sifakis, Joseph

doi:10.1007/3-540-46419-0_9

Cited by 20 publications

(20 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The framework consists of a priority system, where an action a i has (dynamic) priority over another action a j once a condition c ij is satisfied together with the enabledness of actions. In the same way, [11] defines a dynamic priority on actions, where an action a i has a priority on an action a j during a certain time interval. In fact, such dynamic priority relations are a partial function because they are only applied under the satisfaction of an extra condition on comparable actions.…”

Section: Related Workmentioning

confidence: 98%

“…However, a compositional framework merging different priority systems is still relatively lacking. Several works of Sifakis [11], [18], [3], Cleaveland [9], [15] and UPPAAL team [16], [17] have focused on the modeling and synthesis of timed systems with priorities. They represent a common theoretical basis for the modeling with priorities.…”

Section: Related Workmentioning

confidence: 99%

“…However, a compositional framework with high-level concepts like variables, communication and priorities is still lacking. Several works [11], [16], [22], [13] have focused on this subject by analyzing thoroughly the problem and criticizing existing solutions. In fact, this paper is a follow up of [12] where we have revisited the composition of timed systems, without priorities, and proposed a new communication mechanism for UPPAAL timed automata.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Compositional Refinement for Real-Time Systems with Priorities

Boudjadar

Bodeveix

Filali

2012

2012 19th International Symposium on Temporal Representation and Reasoning

View full text Add to dashboard Cite

High-level requirements of real-time systems like as time constraints, communications and execution schedulability make the verification of real-time models arduous, where a system is the interaction of a possibly unbounded set of components. Priorities have been introduced to resolve execution conflicts, and by that, prevent the combinatorial explosion of state space. In this paper, we are interested in the composition and refinement of timed systems by considering static and dynamic priorities. Firstly, we propose a revised definition of the product of extended timed transition systems with static and dynamic priorities associated to individual transitions. Afterwards, we study the (compositional) refinement of compound extended timed systems. Without sacrificing compositionality, we instantiate this framework for the case of UPPAAL networks of timed automata with static priority Committedness, dynamic priority between channels and priority between processes. Moreover, we show how to associate an Extended Timed Transition System (ETTS) to timed automata (TA), where an unique generalized dynamic priority system of ETTS is derived from both dynamic priority orders: priority between channels and priority between processes.

show abstract

Section: Related Workmentioning

confidence: 98%

Section: Related Workmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Compositional Refinement for Real-Time Systems with Priorities

Boudjadar

Bodeveix

Filali

2012

2012 19th International Symposium on Temporal Representation and Reasoning

View full text Add to dashboard Cite

show abstract

“…Urgency types are used to specify the need for an action to progress when it is enabled (i.e. when its clock constraint is true) [7]. Lazy actions (i.e.…”

Section: Preliminariesmentioning

confidence: 99%

Model-Based Implementation of Parallel Real-Time Systems

Triki

Combaz

Bensalem

et al. 2013

Fundamental Approaches to Software Engineering

Self Cite

View full text Add to dashboard Cite

Abstract.One of the main challenges in the design of real-time systems is how to derive correct and efficient implementations from platformindependent specifications.We present a general implementation method in which the application is represented by an abstract model consisting of a set of interacting components. The abstract model executes sequentially components interactions atomically and instantaneously. We transform abstract models into physical models representing their execution on a platform. Physical models take into account execution times of interactions and allow their parallel execution. They are obtained by breaking atomicity of interactions using a notion of partial state. We provide safety conditions guaranteeing that the semantics of abstract models is preserved by physical models. These provide bases for implementing a parallel execution engine coordinating the execution of the components. The implementation has been validated on a real robotic application. Benchmarks show net improvement of its performance compared to a sequential implementation.

show abstract

“…We call this situation a deadlock. Henceforth, we consider abstract models M = (A, Q, X, −→) such that any circuit in the graph −→ has at least a clock that is reset and tested against a positive lower bound, that is, M is structurally non-zeno [7]. This class of abstract models does not have time-locks, that is, time always eventually progresses.…”

Section: Abstract Modelmentioning

confidence: 99%

Model-based implementation of real-time applications

Abdellatif

Combaz

Sifakis

2010

Proceedings of the Tenth ACM International Conference on Embedded Software

Self Cite

View full text Add to dashboard Cite

Correct and efficient implementation of general real-time applications remains by far an open problem. A key issue is meeting timing constraints whose satisfaction depends on features of the execution platform, in particular its speed. Existing rigorous implementation techniques are applicable to specific classes of systems e.g. with periodic tasks, time deterministic systems.We present a general model-based implementation method for real-time systems based on the use of two models.• An abstract model representing the behavior of real-time software as a timed automaton. The latter describes user-defined platform-independent timing constraints. Its transitions are timeless and correspond to the execution of statements of the real-time software. • A physical model representing the behavior of the realtime software running on a given platform. It is obtained by assigning execution times to the transitions of the abstract model.A necessary condition for implementability is time-safety, that is, any (timed) execution sequence of the physical model is also an execution sequence of the abstract model. Timesafety simply means that the platform is fast enough to meet the timing requirements. As execution times of actions are not known exactly, time-safety is checked for worst-case execution times of actions by making an assumption of timerobustness: time-safety is preserved when speed of the execution platform increases. We show that as a rule, physical models are not timerobust and show that time-determinism is a sufficient condition for time-robustness.For given real-time software and execution platform corresponding to a time-robust model, we define an Execution Engine that coordinates the execution of the application software so as to meet its timing constraints. Furthermore, in case of non-robustness, the Execution Engine can detect violations of time-safety and stop execution.Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. EMSOFT'10, October 24-29, 2010, Scottsdale, Arizona, USA. Copyright 2010 ACM 978-1-60558-904-6/10/10 ...$10.00.We have implemented the Execution Engine for BIP programs with real-time constraints. We have validated the implementation method for an adaptive MPEG video encoder. Experimental results reveal the existence of timing anomalies seriously degrading performance for increasing platform execution speed.

show abstract

On the Construction of Live Timed Systems

Cited by 20 publications

References 12 publications

Compositional Refinement for Real-Time Systems with Priorities

Compositional Refinement for Real-Time Systems with Priorities

Model-Based Implementation of Parallel Real-Time Systems

Model-based implementation of real-time applications

Contact Info

Product

Resources

About