…r calls will work
responses. Processing controller actions in a separate thread allows us to work around the rack api - we can allow the user to set status and headers, then block until the first bytes are written. As soon as the first bytes are written, the main thread can return the status, headers, and (essentially) a queue for the body.
See the comment in the file activerecord/lib/active_record.rb added by this patch for the rationale.
This require makes the dependency even more clear. In particular we are eager loading the session store but that does not work if AR is used outside Rails, this patch is preliminary work in fixing #7160.