rails--rails/actioncable/CHANGELOG.md

*   Protect against concurrent writes to a websocket connection from
    multiple threads; the underlying OS write is not always threadsafe.

    *Tinco Andringa*

*   Add ActiveSupport::Notifications hook to Broadcaster#broadcast.

    *Matthew Wear*

*   Close hijacked socket when connection is shut down.

    Fixes #25613.

    *Tinco Andringa*


Please check [5-0-stable](https://github.com/rails/rails/blob/5-0-stable/actioncable/CHANGELOG.md) for previous changes.