K. Azadbakht, F.S. de Boer, N. Bezirgiannis & E.P. de Vink
A Formal Actor-Based Model for Streaming the Future

Asynchronous Actor-based programming has gained increasing attention as a model
of concurrency and distribution. The Abstract Behavioral Specification (ABS)
language is an actor-based programming language that has been developed for
both the modeling and formal analysis of distributed systems. In ABS, actors
are modeled as concurrent objects that communicate by asynchronous method
calls. Return values are also communicated asynchronously via return statements
and so-called futures.

Many modern distributed software applications require a form of continuous
interaction between their components which consists of streaming data from a
server to its clients. In this paper, we extend the ABS language in order to
support the streaming of data. We introduce the notion of `future-based data
streams' by augmenting the syntax, type system, and operational semantics of
ABS. As a proof of concept, we further discuss a prototype implementation for
supporting future-based data streams on top of ABS, and discuss the impact of
the use of these data streams in ABS on the performance in the implementation
of a distributed application for the generation of social networks.