type _ t = | Heartbeater_timeout : worker M.t Async.Deferred.t t | (** A "heartbeater" connection is established between the worker and its master. The
worker shuts itself down when |
| Disconnect : (connection_state_init_arg:connection_state_init_arg ‑> Connection.t M.t Async.Deferred.t) t | (** An initial connection to the worker is established. The worker shuts itself down
when |
| Called_shutdown_function : worker M.t Async.Deferred.t t | (** WARNING! Worker's spawned with this variant do not shutdown when the master process exits. The worker only shuts itself down on an explicit shutdown request. *) |