anchor.diff:  ;;;; WAIT-FOR-OBJECTS and the EVENT primitive.
   
   (defstruct (wfo
  +             (:constructor %make-wfo)
                (:include wait-queue)
                (:area :wired))
     objects
  
positive.code: 
  (sys.int::defglobal *big-wait-for-objects-lock*
      (place-spinlock-initializer))
  
  (defun wfo-wait-1 (sp fp wfo)
    (acquire-place-spinlock *big-wait-for-objects-lock*)
  
negative.code:                      (event object)
                       (timer (timer-event object))
                       (t (get-object-event object)))))
          (setf (cdr tail) (wfo-cons event nil)
                tail (cdr tail))))
      (cdr head)))
  
  