In spite of significant advances in concurrency theory, constructs and models for programming of concurrent applications have essentially stagnated in the past half-century. In contrast to advances in abstractions and constructs for sequential programming, no truly abstract protocol constructs have evolved to raise the level of concurrent programming.

Consequently, programmers today use the same cumbersome, error-prone concurrency constructs of traditional action-centric models of concurrency to express protocols in modern software as they did 50 years ago: processes, threads, locks, semaphores, monitors, rendezvous, etc. Among other disadvantages, the unavailability of high-level protocol constructs in contemporary programming languages hampers full utilization of the enormous potential offered by massively parallel hardware platforms in real-life applications.

In this talk, we motivate the need for interaction-centric models of concurrency, and present Reo as a premier concrete example of such alternatives. Reo offers a language that treats concurrency protocols as explicit first-class constructs, called connector circuits. More complex protocols in Reo result from composition of simpler, and eventually primitive, protocols. Treating protocols as concrete constructs yields a very expressive formal model of concurrency with highly useful software engineering properties, such as fully-compositional construction and verification, scalability, and verbatim reuse. Specifying the protocol of a concurrent system in Reo produces a connector circuit that mirrors the architecture of that system with high fidelity. Moreover, treating such specifications directly as high-level programs opens up new possibilities for compilation and optimization techniques to generate efficient executable code whose performance can meet or beat that of hand-crafted versions of those same protocols programmed in traditional models of concurrency.


Speaker: Prof. Farhad Arbab, CWI and Leiden University, Netherlands


Refreshments will be available from 5.15pm. The talk will start at 6pm.

Composing Protocols - FACS
Date and time
3 April, 6:00pm - 9:00pm
BCS, The Chartered Institute for IT
The Davidson Building
5 Southampton Street
This event is sold out