anchor.diff:  (defun enqueue (task &optional (queue (current-queue)))
     (declare (type task-designator task)
              (type queue queue))
  -  (with-mutex ((queue-lock queue))
  -    (assert (alive-p queue))
  -    (sb-queue:enqueue task (queue-queue queue))
  -    (condition-broadcast (queue-cvar queue)))
  +  (assert (alive-p queue))
  +  (sb-queue:enqueue task (queue-queue queue))
  +  (condition-broadcast (queue-cvar queue))
     nil)
   
   (defun enqueue-all (tasks &optional (queue (current-queue)))
     (declare (type queue queue))
  -  (with-mutex ((queue-lock queue))
  -    (assert (alive-p queue))
  -    (let ((queue (queue-queue queue)))
  -      (map nil (lambda (task)
  -                 (sb-queue:enqueue task queue))
  -           tasks))
  -    (condition-broadcast (queue-cvar queue)))
  +  (assert (alive-p queue))
  +  (let ((queue (queue-queue queue)))
  +    (map nil (lambda (task)
  +               (sb-queue:enqueue task queue))
  +         tasks))
  +  (condition-broadcast (queue-cvar queue))
     nil)
   
   (defun push-self (task &optional (queue (current-queue)))
  
positive.code: (in-package "WORK-QUEUE")
  
  (defstruct (queue
              (:constructor %make-queue
                  (nthread state queue stacks threads)))
    (lock    (make-mutex)  :type mutex
                           :read-only t)
    (cvar    (make-waitqueue) :type waitqueue
                           :read-only t)
  
negative.code:           (try)
            (unless (condition-wait cvar lock :timeout timeout)
              (grab-mutex lock))
            (setf timeout (min 1.0 (* timeout 1.1))))))))
  
  (defun %make-worker (wqueue i &optional binding-names binding-compute)
    (let* ((locks  (queue-locks  wqueue))
           (cvar   (queue-cvar   wqueue))
           (state  (queue-state  wqueue))
           (queue  (queue-queue  wqueue))
  