That's what exceptions are for, no? If a connection dies an exception is thrown that would propagate up to the top of the thread stack. You'd then catch it and sit in a loop re-establishing the SSH connection, or terminating with a signal to whatever thread started the monitoring thread that it was dying. The act of unwinding the stack would pass through the finally handlers, closing open resources and cleaning up, before the loop starts again.

The failure domain here isn't precisely defined because shared data is allowed (but not required). You could define it as "anything reachable from the thread/fiber stack".