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A Taxonomy of Persistent and Nonviolent Steps

Lookup NU author(s): Professor Maciej KoutnyORCiD, Dr Lukasz Mikulski, Dr Marta Koutny



A concurrent system is persistent if throughout its operation no activity which become enabled can subsequently be prevented from being executed by any other activity. This is often a highly desirable (or even absolutely necessary) property, in particular, if the system is to be implemented in hardware. Over the past 40 years, persistence has been investigated and applied in practical implementations assuming that each activity is a single atomic action which can be represented, for example, by a single transition of a Petri net used as a formal representation of a concurrent system. Recently, it turned out that such a notion of persistence is restricted and in dealing with the synthesis of GALS systems one also needs to consider activities represented by steps which are sets of simultaneously executed transitions. Moving into the realm of step based execution semantics creates a wealth of new fundamental problems and intriguing questions. In particular, there are different ways in which the standard notion of persistence could be lifted from the level of sequential semantics to the level of step semantics. Moreover, at a local level, one may consider steps which are persistent and cannot be disabled by other steps, as well as steps which are nonviolent and cannot disableother steps. In this paper, we aim at providing a classification of different types of persistence and nonviolence, both for steps and markings of PT-nets. We also investigate behavioural and structural properties of such notions both for the general PT-nets and their subclasses.

Publication metadata

Author(s): Koutny M, Mikulski L, Pietkiewicz-Koutny M

Publication type: Report

Publication status: Published

Series Title: School of Computing Science Technical Report Series

Year: 2012

Pages: 24

Print publication date: 01/11/2012

Source Publication Date: November 2012

Report Number: 1361

Institution: School of Computing Science, University of Newcastle upon Tyne

Place Published: Newcastle upon Tyne