anchor.diff:    ;; Current thread's state has been saved, restore the new-thread's state.
     ;; Update run-time meters.
     (let ((now (get-high-precision-timer)))
  -    ;; TODO: Account for potential wrap-around of the timer
  -    ;; if (< start now) wrapped...
  -    (incf (thread-%run-time current-thread)
  -          (high-precision-time-units-to-internal-time-units
  -           (- now (thread-switch-time-start current-thread))))
  +    (update-run-time current-thread now)
       (setf (thread-switch-time-start new-thread) now))
     ;; Switch threads.
     (set-current-thread new-thread)
  
positive.code:   ;; Jump to common function.
    (%%switch-to-thread-common current-thread next-thread))
  
  (defun thread-run-time (thread)
    (when (eql thread (current-thread))
      ;; Update the run-time variable so it is as accurate as possible.
      (safe-without-interrupts ()
        (let ((self (current-thread))
              (now (get-high-precision-timer)))
          (incf (thread-%run-time self)
                (high-precision-time-units-to-internal-time-units
                 (- now (thread-switch-time-start self))))
          (setf (thread-switch-time-start self) now))))
    (thread-%run-time thread))
  
  
negative.code:   "Called very early after boot to reset the initial thread."
    (let* ((thread (current-thread)))
      (setf *world-stopper* thread)
      (setf (thread-state thread) :active)
      (setf (thread-switch-time-start thread) (get-high-precision-timer))))
  
  (defun finish-initial-thread ()
    "Called when the boot code is done with the initial thread."
  