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The octahedron abstract domain
- In Static Analysis Symposium (2004
, 2004
"... NOTICE: This is the author’s version of a work that was accepted for publication in Science of Computer Programming. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this docu ..."
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Cited by 58 (1 self)
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NOTICE: This is the author’s version of a work that was accepted for publication in Science of Computer Programming. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. A definitive version was subsequently published in Science of Computer Programming, 64(2007):115-139.
Behavioral cartography of timed automata
- In RP, volume 6227 of LNCS
, 2010
"... Abstract. We aim at finding a set of timing parameters for which a given timed automaton has a “good ” behavior. We present here a novel approach based on the decomposition of the parametric space into behavioral tiles, i.e., sets of parameter valuations for which the behavior of the system is unifo ..."
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Cited by 17 (6 self)
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Abstract. We aim at finding a set of timing parameters for which a given timed automaton has a “good ” behavior. We present here a novel approach based on the decomposition of the parametric space into behavioral tiles, i.e., sets of parameter valuations for which the behavior of the system is uniform. This gives us a behavioral cartography according to the values of the parameters. It is then straightforward to partition the space into a “good ” and a “bad ” subspace, according to the behavior of the tiles. We extend this method to probabilistic systems, allowing to decompose the parametric space into tiles for which the minimal (resp. maximal) probability of reaching a given location is uniform. An implementation has been made, and experiments successfully conducted. 1
Timing analysis of an embedded memory: SPSMALL
- In 10th WSEAS International Conference on Circuits
, 2006
"... Abstract: This paper proposes a high-level formalism, called Abstract Functional and Timing Graph (AFTG), for describing a memory architecture, which combines logical functionality and timing. After translation of the AFTG into the form a timed automaton, we are able to compute the response times of ..."
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Cited by 6 (5 self)
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Abstract: This paper proposes a high-level formalism, called Abstract Functional and Timing Graph (AFTG), for describing a memory architecture, which combines logical functionality and timing. After translation of the AFTG into the form a timed automaton, we are able to compute the response times of the modeled memory, and check their consistency with the values specified in the datasheet. We also address the problem of finding optimal values of setup timings.
Synthesizing Parametric Constraints on Various Case Studies Using IMITATOR (Preliminary Version)
"... We consider in this report systems modeled by timed automata. The timing bounds involved in the action guards and location invariants of our timed automata are not constants, but parameters. Those parametric timed automata allow to model various kinds of timed systems, e.g. communication protocols ..."
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Cited by 4 (4 self)
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We consider in this report systems modeled by timed automata. The timing bounds involved in the action guards and location invariants of our timed automata are not constants, but parameters. Those parametric timed automata allow to model various kinds of timed systems, e.g. communication protocols
Hazard Checking of Timed Asynchronous Circuits Revisited
"... This paper proposes a new approach for the hazard checking of timed asynchronous circuits. Previous papers proposed either exact algorithms, which suffer from statespace explosion, or efficient algorithms which use a (conservative) approximation to avoid state-space explosion but can result in the r ..."
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This paper proposes a new approach for the hazard checking of timed asynchronous circuits. Previous papers proposed either exact algorithms, which suffer from statespace explosion, or efficient algorithms which use a (conservative) approximation to avoid state-space explosion but can result in the rejection of designs which are valid. In particular, [7] presents a timed extention of the work in [1] which is very efficient but is not able to handle circuits with internal loops, which prevents its use in some cases. We propose a new approach to the problem in order to overcome the mentioned limitations, without sacrificing efficiency. To do so, we first introduce a general framework targeted at the conservative checking of safety failures. This framework is not restricted to the checking of timed asynchronous circuits. Secondly, we propose a new (conservative) semantics for timed circuits, in order to use the proposed framework for hazard checking of such circuits. Using this framework with the proposed semantics yields an efficient algorithm that addresses the limitations of the previous approaches. 1
Safety Properties (full version)
, 2011
"... Abstract. Safety properties are crucial when verifying real-time concurrent systems. When reasoning parametrically, i.e., with unknown constants, it is of high interest to infer a set of parameter valuations consistent with such safety properties. We present here algorithms based on the “inverse met ..."
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Abstract. Safety properties are crucial when verifying real-time concurrent systems. When reasoning parametrically, i.e., with unknown constants, it is of high interest to infer a set of parameter valuations consistent with such safety properties. We present here algorithms based on the “inverse method ” for parametric timed automata: given a reference parameter valuation, it infers a constraint such that, for any valuation satisfying this constraint, the system behaves the same as under the reference valuation in terms of traces, i.e., alternating sequences of locations and actions. Those algorithms do not guarantee the equality of traces, but are significantly quicker, synthesize larger sets of parameter valuations than the original inverse method, and still preserve various properties including safety properties. Those algorithms have been implemented in Imitator II and applied to examples of circuits and protocols. 1
Case Studies Using Imitator II
, 2010
"... Timed automata [1] are finite control automata equipped with clocks, which are real-valued variables which increase uniformly. This model is useful for reasoning about real-time systems with a dense representation of time, because one can specify quantitatively the interval of time during which the ..."
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Timed automata [1] are finite control automata equipped with clocks, which are real-valued variables which increase uniformly. This model is useful for reasoning about real-time systems with a dense representation of time, because one can specify quantitatively the interval of time during which the transitions can occur,
An Inverse Method for Parametric . . .
, 2009
"... We consider in this paper systems modeled by timed automata. The timing bounds involved in the action guards and location invariants of our timed automata are not constants, but parameters. Those parametric timed automata allow the modelling of various kinds of timed systems, e.g. communication prot ..."
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We consider in this paper systems modeled by timed automata. The timing bounds involved in the action guards and location invariants of our timed automata are not constants, but parameters. Those parametric timed automata allow the modelling of various kinds of timed systems, e.g. communication protocols or asynchronous circuits. We will also assume that we are given an initial tuple π0 of values for the parameters, which corresponds to values for which the system is known to behave properly. Our goal is to compute a constraint K0 on the parameters, satisfied by π0, guaranteeing that, under any parameter valuation satisfying K0, the system behaves in the same manner: for any two parameter valuations satisfying K0, the behaviors of the timed automata are (time-abstract) equivalent, i.e., the traces of execution viewed as alternating sequences of actions and locations are identical. We present an algorithm InverseMethod that terminates in the case of acyclic models, and discuss how to extend it in the cyclic case. We also explain how to combine our method with classical synthesis methods which are based on the avoidance of a given set of bad states. A prototype implementation has been done, and various experiments are described.
