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

Sneezles

https://digitalcommons.library.umaine.edu/mmb-me/1800/thumbnail.jp

The Kings Breakfast

https://digitalcommons.library.umaine.edu/mmb-me/1795/thumbnail.jp

Causal-Consistent Replay Debugging for Message Passing Programs

Debugging of concurrent systems is a tedious and error-prone activity. A main issue is that there is no guarantee that a bug that appears in the original computation is replayed inside the debugger. This problem is usually tackled by so-called replay debugging, which allows the user to record a program execution and replay it inside the debugger. In this paper, we present a novel technique for replay debugging that we call controlled causal-consistent replay. Controlled causal-consistent replay allows the user to record a program execution and, in contrast to traditional replay debuggers, to reproduce a visible misbehavior inside the debugger including all and only its causes. In this way, the user is not distracted by the actions of other, unrelated processes

Static versus dynamic reversibility in CCS

The notion of reversible computing is attracting interest because of its applications in diverse fields, in particular the study of programming abstractions for fault tolerant systems. Most computational models are not naturally reversible since computation causes loss of information, and history information must be stored to enable reversibility. In the literature, two approaches to reverse the CCS process calculus exist, differing on how history information is kept. Reversible CCS (RCCS), proposed by Danos and Krivine, exploits dedicated stacks of memories attached to each thread. CCS with Keys (CCSK), proposed by Phillips and Ulidowski, makes CCS operators static so that computation does not cause information loss. In this paper we show that RCCS and CCSK are equivalent in terms of LTS isomorphism

A state-space partitioned time integration algorithm for real-time hybrid simulation with nonlinear numerical subdomains

This paper describes a state-space partitioned algorithm for real-time hybrid simulation. The state-space modeling is proposed to represent nonlinear numerical substructures. The effectiveness of the proposed method is demonstrated for a virtual bridge case study equipped with seismic isolation devices

On Observing Dynamic Prioritised Actions in SOC

We study the impact on observational semantics for SOC of priority mechanisms which combine dynamic priority with local pre-emption. We define manageable notions of strong and weak labelled bisimilarities for COWS, a process calculus for SOC, and provide alternative characterisations in terms of open barbed bisimilarities. These semantics show that COWS’s priority mechanisms partially recover the capability to observe receive actions (that could not be observed in a purely asynchronous setting) and that high priority primitives for termination impose specific conditions on the bisimilarities

The Reversible Temporal Process Language

Reversible debuggers help programmers to quickly find the causes of misbehaviours in concurrent programs. These debuggers can be founded on the well-studied theory of causal-consistent reversibility, which allows one to undo any action provided that its consequences are undone beforehand. Till now, causal-consistent reversibility never considered time, a key aspect in real world applications. Here, we study the interplay between reversibility and time in concurrent systems via a process algebra. The Temporal Process Language (TPL) by Hennessy and Regan is a well-understood extension of CCS with discrete-time and a timeout operator. We define revTPL, a reversible extension of TPL, and we show that it satisfies the properties expected from a causal-consistent reversible calculus. We show that, alternatively, revTPL can be interpreted as an extension of reversible CCS with time

A MAPE-K Approach to Autonomic Microservices

Microservices are an emerging architectural style advocating for small loosely-coupled services in order to maximize scalability and adaptability. In order to help IT personnel, adaptability can be put (completely or partially) under the responsibility of the system using autonomic techniques, e.g., underpinned by a MAPE-K control loop. This paper discusses possible trade-offs, challenges and support techniques for soft-ware architects involved in building autonomic microservice-based systems

A Process Calculus for Dynamic Networks

In this paper we propose a process calculus framework for dynamic networks in which the network topology may change as computation proceeds. The proposed calculus allows one to abstract away from neighborhood-discovery computations and it contains features for broadcasting at multiple transmission ranges and for viewing networks at different levels of abstraction. We develop a theory of confluence for the calculus and we use the machinery developed towards the verification of a leader-election algorithm for mobile ad hoc networks