scholarly journals Real Time Properties for Interrupt Timed Automata

Author(s):  
Beatrice Berard ◽  
Serge Haddad ◽  
Mathieu Sassolas
Keyword(s):  
2021 ◽  
Vol 20 (5s) ◽  
pp. 1-26
Author(s):  
Jinghao Sun ◽  
Nan Guan ◽  
Rongxiao Shi ◽  
Guozhen Tan ◽  
Wang Yi

Research on modeling and analysis of real-time computing systems has been done in two areas, model checking and real-time scheduling theory. In model checking, an expressive modeling formalism such as timed automata (TA) is used to model complex systems, but the analysis is typically very expensive due to state-space explosion. In real-time scheduling theory, the analysis techniques are highly efficient, but the models are often restrictive. In this paper, we aim to exploit the possibility of applying efficient analysis techniques rooted in real-time scheduling theory to analysis of real-time task systems modeled by timed automata with tasks (TAT). More specifically, we develop efficient techniques to analyze the feasibility of TAT-based task models (i.e., whether all tasks can meet their deadlines on single-processor) using demand bound functions (DBF), a widely used workload abstraction in real-time scheduling theory. Our proposed analysis method has a pseudo-polynomial time complexity if the number of clocks used to model each task is bounded by a constant, which is much lower than the exponential complexity of the traditional model-checking based analysis approach (also assuming the number of clocks is bounded by a constant). We apply dynamic programming techniques to implement the DBF-based analysis framework, and propose state space pruning techniques to accelerate the analysis process. Experimental results show that our DBF-based method can analyze a TAT system with 50 tasks within a few minutes, which significantly outperforms the state-of-the-art TAT-based schedulability analysis tool TIMES.


2012 ◽  
Vol 23 (04) ◽  
pp. 831-851 ◽  
Author(s):  
GUOQIANG LI ◽  
XIAOJUAN CAI ◽  
SHOJI YUEN

Timed automata are commonly recognized as a formal behavioral model for real-time systems. For compositional system design, parallel composition of timed automata as proposed by Larsen et al. [22] is useful. Although parallel composition provides a general method for system construction, in the low level behavior, components often behave sequentially by passing control via communication. This paper proposes a behavioral model, named controller automata, to combine timed automata by focusing on the control passing between components. In a controller automaton, to each state a timed automaton is assigned. A timed automaton at a state may be preempted by the control passing to another state by a global labeled transition. A controller automaton properly extends the expressive power because of the stack, but this can make the reachability problem undecidable. Given a strict partial order over states, we show that this problem can be avoided and a controller automaton can be faithfully translated into a timed automaton.


2003 ◽  
Vol 10 (49) ◽  
Author(s):  
Marius Mikucionis ◽  
Kim G. Larsen ◽  
Brian Nielsen

In this paper we present a framework, an algorithm and a new tool for online testing of real-time systems based on symbolic techniques used in UPPAAL model checker. We extend UPPAAL timed automata network model to a test specification which is used to generate test primitives and to check the correctness of system responses including the timing aspects. We use timed trace inclusion as a conformance relation between system and specification to draw a test verdict. The test generation and execution algorithm is implemented as an extension to UPPAAL and experiments carried out to examine the correctness and performance of the tool. The experiment results are promising.


Author(s):  
N. Belala ◽  
D.E. Saїdouni ◽  
R. Boukharrou ◽  
A.C. Chaouche ◽  
A. Seraoui ◽  
...  

The design of real-time systems needs a high-level specification model supporting at the same time timing constraints and actions duration. The authors introduce in this paper an extension of Petri Nets called Time Petri Nets with Action Duration (DTPN) where time is associated with transitions. In DTPN, the firing of transitions is bound to a time interval and transitions represent actions which have explicit durations. The authors give an operational semantics for DTPN in terms of Durational Action Timed Automata (DATA). DTPN considers both timing constraints and durations under a true-concurrency semantics with an aim of better expressing concurrent and parallel behaviours of real-time systems.


Author(s):  
Fateh Latreche ◽  
Faiza Belala

Web services are very dynamic, they are all around us and we use them every day without even knowing it. In this paper, the authors define a formal model for dynamic Web services composition and they investigate how it can be used to specify and analyse backward recovery procedures, updating partner services in case of failure. First, they propose Recursive and Dynamic Timed Automata (RDTA) model, interpreted over composite service configurations, which provide a natural way to design stateful and dynamic Web services. Then, the authors define the concurrent semantics of this timed automata extension in terms of real-time rewrite theories. Analysis of the model is carried out in the Real-Time Maude system, based on checking relevant properties.


1995 ◽  
Vol 2 (2) ◽  
Author(s):  
Francois Laroussinie ◽  
Kim G. Larsen ◽  
Carsten Weise

One of the most successful techniques for automatic verification is that<br />of model checking. For finite automata there exist since long extremely<br />efficient model-checking algorithms, and in the last few years these algorithms have been made applicable to the verification of real-time automata using the region-techniques of Alur and Dill.<br />In this paper, we continue this transfer of existing techniques from the<br />setting of finite (untimed) automata to that of timed automata. In particular, a timed logic L is put forward, which is sufficiently expressive that we for any timed automaton may construct a single characteristic L formula uniquely characterizing the automaton up to timed bisimilarity. Also, we prove decidability of the satisfiability problem for L with respect to given bounds on the number of clocks and constants of the timed automata to be constructed. None of these results have as yet been succesfully accounted for in the presence of time.


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