Reconfiguration of Reo Connectors Triggered by Dataflow

Reo is a language for coordinating autonomous components in dis- tributed environments. Coordination in Reo is performed by circuit-like connectors, which are constructed from primitive, mobile channels with well-defined behaviour. While the structure of a connector can be modeled as a graph, its behaviour is com- positionally defined using that of its primitive constituents. In previous work, we showed that graph transformation techniques are well-suited to model reconfigu- rations of connectors. In this paper, we investigate how the connector colouring semantics can be used to perform dynamic reconfigurations. Dynamic reconfigu- rations are triggered by dataflow in the connector at runtime, when certain struc- tural patterns enriched with dataflow annotations occur. For instance we are able to elegantly model dynamic Reo circuits, such as just-in-time augmentation of single- buffered channels to a circuit that models a channel with an unbounded buffer. Addi- tionally we extend Reo's visual notation and the Reo animation language to describe and animate dynamically reconfiguring connectors.