87 research outputs found
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
Towards Reversible Sessions
In this work, we incorporate reversibility into structured
communication-based programming, to allow parties of a session to automatically
undo, in a rollback fashion, the effect of previously executed interactions.
This permits taking different computation paths along the same session, as well
as reverting the whole session and starting a new one. Our aim is to define a
theoretical basis for examining the interplay in concurrent systems between
reversible computation and session-based interaction. We thus enrich a
session-based variant of pi-calculus with memory devices, dedicated to keep
track of the computation history of sessions in order to reverse it. We discuss
our initial investigation concerning the definition of a session type
discipline for the proposed reversible calculus, and its practical advantages
for static verification of safe composition in communication-centric
distributed software performing reversible computations.Comment: In Proceedings PLACES 2014, arXiv:1406.331
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
Reverse Bisimulations on Stable Configuration Structures
The relationships between various equivalences on configuration structures,
including interleaving bisimulation (IB), step bisimulation (SB) and hereditary
history-preserving (HH) bisimulation, have been investigated by van Glabbeek
and Goltz (and later Fecher). Since HH bisimulation may be characterised by the
use of reverse as well as forward transitions, it is of interest to investigate
forms of IB and SB where both forward and reverse transitions are allowed. We
give various characterisations of reverse SB, showing that forward steps do not
add extra power. We strengthen Bednarczyk's result that, in the absence of
auto-concurrency, reverse IB is as strong as HH bisimulation, by showing that
we need only exclude auto-concurrent events at the same depth in the
configuration
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
Reversible Multiparty Sessions with Checkpoints
Reversible interactions model different scenarios, like biochemical systems
and human as well as automatic negotiations. We abstract interactions via
multiparty sessions enriched with named checkpoints. Computations can either go
forward or roll back to some checkpoints, where possibly different choices may
be taken. In this way communications can be undone and different conversations
may be tried. Interactions are typed with global types, which control also
rollbacks. Typeability of session participants in agreement with global types
ensures session fidelity and progress of reversible communications.Comment: In Proceedings EXPRESS/SOS 2016, arXiv:1608.0269
Compliance for reversible client/server interactions
In the setting of session behaviours, we study an extension of the concept of
compliance when a disciplined form of backtracking is present. After adding
checkpoints to the syntax of session behaviours, we formalise the operational
semantics via a LTS, and define a natural notion of checkpoint compliance. We
then obtain a co-inductive characterisation of such compliance relation, and an
axiomatic presentation that is proved to be sound and complete. As a byproduct
we get a decision procedure for the new compliance, being the axiomatic system
algorithmic.Comment: In Proceedings BEAT 2014, arXiv:1408.556
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