On the Expressiveness of Relative-Timed Coordination Models

Abstract

Although very simple and elegant, Linda-style coordination models lack the notion of time, and are therefore not able to precisely model real-life coordination applications. Nevertheless, industrial proposals such as TSpaces and JavaSpaces, inspired from Linda, have incorporated time constructs. This paper aims at a systematic study of the introduction of relative time in coordination models. It builds upon previous work to study the expressiveness of Linda, Linda extended with a delay mechanism and Linda primitives extended to support the duration of tuples and of the suspension of communication operations.

On the expressiveness of timed coordination models

“…In order to keep the size of this paper within reasonable limits, only the most difficult proofs have been done. We refer the interested reader to [20] where all the results are demonstrated. Finally, in section 5 we draw our conclusion and discuss related work.…”

On Distributed Density in Tuple-based Coordination Languages

“…Technically this is achieved by associating a positive number, called density, to a finite list of tokens and to distribute this density among the tokens of the list. Our work builds upon previous work by some of the authors [7,8,[13][14][15]. We have essentially followed the same lines and in particular have used de Boer and Palamidessi's notion of modular embedding to compare the families of sublanguages of Dense Bach and Dense Bach with Distributed Density.…”

“…We are now in a position to define what we want to observe from the computations. Following previous work by some of the authors (see eg [7,8,[13][14][15]), we shall actually take an operational semantics recording the final state of the computations, this being understood as the final store coupled to a mark indicating whether the considered computation is successful or not. Such marks are respectively denoted as δ + (for the successful computations) and δ − (for failed computations).…”

Fully abstract models and refinements as tools to compare agents in timed coordination languages

“…The expressiveness of these families has been studied in [16,[20][21][22]. Two interesting conclusions may be extracted from these papers.…”

“…In our recent work [16,[20][21][22], we have proposed different ways of introducing time in coordination languages. For that purpose, we have used the classical two-phase functioning approach to real-time systems and have proved that this approach was effective for modeling coordination in reactive systems.…”