anchor.diff:    (mt:list-threads))
   
   (defun interrupt-thread (thread function)
  -  (mt:thread-interrupt thread function))
  -
  -(defun destroy-thread (thread)
  -  (signal-error-if-current-thread thread)
  -  (mt:thread-kill thread))
  +  (mt:thread-interrupt thread :function function))
   
   (defun thread-alive-p (thread)
     (mt:thread-active-p thread))
  
positive.code:   (mt:mutex-unlock lock))
  
  (defmacro with-lock-held ((place) &body body)
    `(mt:with-lock (,place) ,@body))
  
  (defun make-recursive-lock (&optional name)
    (mt:make-mutex :name name :recursive-p t))
  
negative.code: ;;; balanced
  
  (defmacro with-recursive-lock-held ((place) &body body)
    `(mt:with-mutex-lock (,place) ,@body))
  
  ;;; Resource contention: condition variables
  
  