Abstract not found

Reo is an exogenous coordination language for compositional construction of component connectors based on a calculus of channels. Building automated tools to address such concerns as equivalence or containment of the behavior of two given connectors, verification of the behavior of a connector, etc. requires an operational semantic model suitable for model checking. In this paper we introduce constraint automata and propose them as a semantic model for Reo.

We introduce the notion of functional stream derivative, generalising the notion of input derivative of rational expressions (Brzozowski 1964) to the case of stream functions over arbitrary input and output alphabets. We show how to construct Mealy automata from algebraically specified stream functions by the symbolic computation of functional stream derivatives. We illustrate this construction in full detail for various bitstream functions specified in the algebraic calculus of the 2-adic numbers. This work is part of a larger ongoing effort to specify and model component connector circuits in terms of (functions and relations on) streams.

CWI is a founding member of ERCIM, the European Research Consortium for Informatics and Mathematics. CWI's research has a theme-oriented structure and is grouped into four clusters. Listed below are the names of the clusters and in parentheses their acronyms.

The coordination language Reo supports compositional system construction through connectors with real-time properties that exogenously coordinate the interactions among the constituent components into a coherent collaboration. In this paper, we present an operational semantics for the channel-based component connectors of Reo in terms of Timed Constraint Automata and introduce a temporal-logic for specification and verification of their real-time properties.

Abstract. Orchestrating software components, often independently supplied, has assumed a central role in software construction. Actually, as relevant as components themselves, are the ways in which they can be put together to interact and cooperate in order to achieve some common goal. Such is the role of so-called software connectors: external coordination devices which ensure both the flow of data and synchronization restrictions within a component’s network. This paper introduces a new model for software connectors, based on relations extended in time, which aims to provide support for light inter-component dependency and effective external control. 1

CWI is a founding member of ERCIM, the European Research Consortium for Informatics and Mathematics. CWI's research has a theme-oriented structure and is grouped into four clusters. Listed below are the names of the clusters and in parentheses their acronyms.

Reo is a coordination model based on circuit-like connectors which coordinate components through the interplay of data flow, synchronisation and mutual exclusion, state, and context-dependent behaviour. This paper proposes a scheme based on connector colouring for determining the behaviour of a Reo connector by resolving its context dependent synchronisation and mutual exclusion constraints. Colouring a Reo connector in a specific state with given boundary conditions (I/O requests) provides a means to determine the routing alternatives for data flow. Our scheme has the advantage over previous models in that it is simpler to implement and that it models Reo connectors more closely to their envisaged semantics than existing formal models.

Abstract: The basic motivation of component based development is to replace conventional programming by the composition of reusable off-the-shelf units, externally coordinated through a network of connecting devices, to achieve a common goal. This paper introduces a new relational model for software connectors and discusses some preliminary work on its implementation in Haskell. The proposed model adopts a coordination point of view in order to deal with components ’ temporal and spatial decoupling and, therefore, to provide support for looser levels of inter-component dependency and effective external control.

Abstract not found