anchor.diff:  
            (queue-sort timeouts #'< #'event-abs-timeout)
   
  -         :when (or only-once
  -                   exit-p
  -                   (event-base-empty-p event-base))
  +         :when (or only-once exit-p
  +                   (and exit-when-empty (event-base-empty-p event-base)))
            :do (loop-finish)))))
   
   
  
positive.code:   (defvar *available-multiplexers* nil)
    (defvar *best-available-multiplexer* nil))
  
  ;;;
  ;;; Event-Base
  ;;;
  
negative.code: 
  
  (defmethod event-dispatch ((event-base event-base) &key timeout only-once)
    (with-accessors ((mux mux-of) (fds fds-of)
                     (exit-p exit-p) (exit-when-empty exit-when-empty-p)
                     (timeouts timeouts-of)) event-base
      (let* ((min-event-timeout (events-calc-min-rel-timeout timeouts))
             (actual-timeout (calc-min-timeout min-event-timeout timeout))
             (before nil)
  