Mailboxer:Early Detection of Erlang Communication Errors- Phil Trinder & Duncan P. Attard |Code BEAM

CodeSync · May 3, 2025, 1:00pm

This talk was recorded at Code BEAM Europe in October 2024. If you’re curious about our upcoming event, check https://codebebeameurope.com

The talk presents and demonstrates a new communication checking tool for Erlang codebases: Mailboxer.

If a developer annotates parts of an Erlang codebase with expected message types Mailboxer can statically detect many communication errors in the annotated processes. So errors like unreceived messages, some deadlocks, protocol violations, typos in message tags etc. Finding errors early in development reduces debugging and development times.

Existing session type checkers for Erlang and Elixir enforce channel, rather than mailbox, based communication. In contrast, Mailbox types check communication using idiomatic mailbox communication. Currently, Mailboxer targets Erlang, but the type theory and checking technology apply to other actor languages with mailboxes, so Elixir, Scala/Akka and others.

Erlang will be the first production language to benefit from a radically new communication-checking tool.

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