813 research outputs found
A Modular Formalization of Reversibility for Concurrent Models and Languages
Causal-consistent reversibility is the reference notion of reversibility for
concurrency. We introduce a modular framework for defining causal-consistent
reversible extensions of concurrent models and languages. We show how our
framework can be used to define reversible extensions of formalisms as
different as CCS and concurrent X-machines. The generality of the approach
allows for the reuse of theories and techniques in different settings.Comment: In Proceedings ICE 2016, arXiv:1608.0313
Causal Consistency for Reversible Multiparty Protocols
In programming models with a reversible semantics, computational steps can be
undone. This paper addresses the integration of reversible semantics into
process languages for communication-centric systems equipped with behavioral
types. In prior work, we introduced a monitors-as-memories approach to
seamlessly integrate reversible semantics into a process model in which
concurrency is governed by session types (a class of behavioral types),
covering binary (two-party) protocols with synchronous communication. The
applicability and expressiveness of the binary setting, however, is limited.
Here we extend our approach, and use it to define reversible semantics for an
expressive process model that accounts for multiparty (n-party) protocols,
asynchronous communication, decoupled rollbacks, and abstraction passing. As
main result, we prove that our reversible semantics for multiparty protocols is
causally-consistent. A key technical ingredient in our developments is an
alternative reversible semantics with atomic rollbacks, which is conceptually
simple and is shown to characterize decoupled rollbacks.Comment: Extended, revised version of a PPDP'17 paper
(https://doi.org/10.1145/3131851.3131864
Retractable Contracts
In calculi for modelling communication protocols, internal and external
choices play dual roles. Two external choices can be viewed naturally as dual
too, as they represent an agreement between the communicating parties. If the
interaction fails, the past agreements are good candidates as points where to
roll back, in order to take a different agreement. We propose a variant of
contracts with synchronous rollbacks to agreement points in case of deadlock.
The new calculus is equipped with a compliance relation which is shown to be
decidable.Comment: In Proceedings PLACES 2015, arXiv:1602.0325
Controlling Reversibility in Reversing Petri Nets with Application to Wireless Communications
Petri nets are a formalism for modelling and reasoning about the behaviour of
distributed systems. Recently, a reversible approach to Petri nets, Reversing
Petri Nets (RPN), has been proposed, allowing transitions to be reversed
spontaneously in or out of causal order. In this work we propose an approach
for controlling the reversal of actions of an RPN, by associating transitions
with conditions whose satisfaction/violation allows the execution of
transitions in the forward/reversed direction, respectively. We illustrate the
framework with a model of a novel, distributed algorithm for antenna selection
in distributed antenna arrays.Comment: RC 201
Reversible Barbed Congruence on Configuration Structures
A standard contextual equivalence for process algebras is strong barbed
congruence. Configuration structures are a denotational semantics for processes
in which one can define equivalences that are more discriminating, i.e. that
distinguish the denotation of terms equated by barbed congruence. Hereditary
history preserving bisimulation (HHPB) is such a relation. We define a strong
back and forth barbed congruence using a reversible process algebra and show
that the relation induced by the back and forth congruence is equivalent to
HHPB, providing a contextual characterization of HHPB.Comment: In Proceedings ICE 2015, arXiv:1508.0459
Reversibility in session-based concurrency: A fresh look
Much research has studied foundations for correct and reliable communication-centric software systems. A salient approach to correctness uses verification based on session types to enforce structured communications; a recent approach to reliability uses reversible actions as a way of reacting to unanticipated events or failures. In this paper, we develop a simple observation: the semantic machinery required to define asynchronous (queue-based), monitored communications can also support reversible protocols. We propose a framework of session communication in which monitors support reversibility of (untyped) processes. Main novelty in our approach are session types with present and past, which allow us to streamline the semantics of reversible actions. We prove that reversibility in our framework is causally consistent, and define ways of using monitors to control reversible actions.
Keyword
Process Calculi Abstractions for Biology
Several approaches have been proposed to model biological systems by means of the formal techniques and tools available in computer science. To mention just a few of them, some representations are inspired by Petri Nets theory, and some other by stochastic processes. A most recent approach consists in interpreting the living entities as terms of process calculi where the behavior of the represented systems can be inferred by applying syntax-driven rules. A comprehensive picture of the state of the art of the process calculi approach to biological modeling is still missing. This paper goes in the direction of providing such a picture by presenting a comparative survey of the process calculi that have been used and proposed to describe the behavior of living entities. This is the preliminary version of a paper that was published in Algorithmic Bioprocesses. The original publication is available at http://www.springer.com/computer/foundations/book/978-3-540-88868-
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