Abstract: Coordinated composition of third-party components and services into more complex systems
requires a formal model of concurrency that treats interaction as a first-class concept. Contemporary
formalisms for composition of component and services generally rely on endogenous action-centric
models and/or impose severe restrictions on the behavior of the components and services and their compositions.
Reo is an exogenus coordination language based on an interaction-centric model of concurrency where
protocols manifest as connectors. Reo allows arbitrary user-defined primitives, arbitrary mix of synchrony
and asynchrony, and relational constraints between input and output of components. These features make
Reo more expressive than, e.g., dataflow models, Kahn networks, workflow models, stream processing
languages, Petri nets, and synchronous languages. In Reo combining a small set of user-defined synchronous
and asynchronous primitives, yields connectors that implement arbitrarily complex concurrency protocols for
coordinated composition of distributed black-box components and servives.
Short Bio: Farhad Arbab is Emeritus Professor of computer science, at Leiden University (LIACS),
and a former senior researcher at the Dutch national research Center for Mathematics and Computer Science
(CWI) in Amsterdam, the Netherlands. Dr. Arbab received his PhD in Computer Science from the University
of California, Los Angeles (UCLA) in 1982, and is internationally known as a leader in coordination models
and languages, concurrency theory, component-based and service oriented software engineering.
