The Implementation and Use of a Generic Dataflow Behaviour in Erlang Christopher Meiklejohn Peter Van Roy Basho Technologies, Inc. Universite´ catholique de Louvain Bellevue, WA, United States Louvain-la-Neuve, Belgium
[email protected] [email protected] Abstract concurrent programming: developers author code that adheres to a 2 We propose a new “generic” abstraction for Erlang/OTP that aids in specific “behaviour” and these abstractions then provide a com- the implementation of dataflow programming languages and mod- mon way to supervise, manage, and reason about processing con- els on the Erlang VM. This abstraction simplifies the implemen- current messages to a single actor. tation of “processing elements” in dataflow languages by provid- We propose a new Erlang/OTP “generic” abstraction for dataflow ing a simple callback interface in the style of the gen server and programming on the Erlang VM called gen flow. This abstraction gen fsm abstractions. We motivate the use of this new abstraction allows for the arbitrary composition of stateful actors into larger by examining the implementation of a distributed dataflow pro- dataflow computations. This abstraction is sufficiently generic to gramming variant called Lasp. aid in the implementation of an arbitrary dataflow language in Erlang/OTP: we motivate the use of gen flow through the im- Categories and Subject Descriptors D.1.3 [Programming Tech- plementation of a deterministic distributed dataflow variant called niques]: Concurrent Programming; E.1 [Data Structures]: Dis- Lasp. [14, 15] tributed data structures This paper contains the following contributions: Keywords Dataflow Programming, Erlang, Concurrent Program- • gen flow abstraction: We propose gen flow, a new abstrac- ming tion in the style of the “generic” abstractions provided by Er- lang/OTP for building dataflow “processing elements.” 1.