Session Types for Broadcasting

Abstract

Up to now session types have been used under the assumptions of point to point communication, to ensure the linearity of session endpoints, and reliable communication, to ensure send/receive duality. In this paper we define a session type theory for broadcast communication semantics that by definition do not assume point to point and reliable communication. Our session framework lies on top of the parametric framework of broadcasting ψ-calculi, giving insights on developing session types within a parametric framework. Our session type theory enjoys the properties of soundness and safety. We further believe that the solutions proposed will eventually provide a deeper understanding of how session types principles should be applied in the general case of communication semantics.

Psi-Calculi Revisited: Connectivity and Compositionality

“…Kouzapas et al [KGG14] define a similar reduction context semantics for (broadcast) psi-calculi. Their reduction contexts requires three kinds of numbered holes with complicated side-conditions on how the holes may be filled; we have attempted to simplify the presentation by having only one kind of hole.…”

Polarized Substructural Session Types

“…One approach to these concurrency problems that has been receiving increasing attention is session types [15,16,28,36,42,46,61,62,64,72,75,90,91,99]. Session types take as their conceptual notion of concurrency a collection of processes linked together via channels.…”

“…The first question is invariably answered with only one process, but we can either have a constant process for a channel [39] or a potentially different process for every communication along a channel [41]. The second question allows us to say whether the channel is involved in point-to-point communication, if only one process can receive the information, and the most common choice, or broadcast communication [46], a relatively unexplored space.…”

Broadcast and aggregation in BBC

“…An interesting direction of work is therefore to develop a type system that will allow the same channel to be used non-uniformly in both modes and according to a protocol. This is a variant of binary session types [2] that has been adapted to a setting with broadcast communication by [5]. A further step in this direction is to study multiparty session types [3] and how the projection to local session types can be defined in the setting of BBC.…”