Coordination via Interaction Constraints I: Local Logic

Dave Clarke
(Dept. Computer Science, Katholieke Universiteit Leuven)
José Proença
(CWI)

Wegner describes coordination as constrained interaction. We take this approach literally and define a coordination model based on interaction constraints and partial, iterative and interactive constraint satisfaction. Our model captures behaviour described in terms of synchronisation and data flow constraints, plus various modes of interaction with the outside world provided by external constraint symbols, on-the-fly constraint generation, and coordination variables. Underlying our approach is an engine performing (partial) constraint satisfaction of the sets of constraints. Our model extends previous work on three counts: firstly, a more advanced notion of external interaction is offered; secondly, our approach enables local satisfaction of constraints with appropriate partial solutions, avoiding global synchronisation over the entire constraints set; and, as a consequence, constraint satisfaction can finally occur concurrently, and multiple parts of a set of constraints can be solved and interact with the outside world in an asynchronous manner, unless synchronisation is required by the constraints. This paper describes the underlying logic, which enables a notion of local solution, and relates this logic to the more global approach of our previous work based on classical logic.

In Filippo Bonchi, Davide Grohmann, Paola Spoletini and Emilio Tuosto: Proceedings 2nd Interaction and Concurrency Experience Structured Interactions (ICE 2009), Bologna, Italy, 31st August 2009, Electronic Proceedings in Theoretical Computer Science 12, pp. 17–39.
Published: 3rd December 2009.

ArXived at: http://dx.doi.org/10.4204/EPTCS.12.2 bibtex PDF

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