clozure cl haven't implements condition-variable. so..

(defun bt:make-condition-variable ()

  (ccl:make-semaphore))

but, condition-variable and semaphore are different. right?

It can cause problems, I think.

Perhaps, It's make meaningless loop.

I just wonder why something like this that you have not implemented in bordeaux-threads

(in-package #:bordeaux-threads)

(defclass condition-variable ()

  ((sem-count :initform 0 :accessor sem-count)

   (semaphore :initform (ccl:make-semaphore) :reader semaphore)))

(defun make-condition-variable ()

  (make-instance 'condition-variable))

(defun condition-wait (condition-variable lock)

  (unwind-protect (progn (incf (sem-count condition-variable))

(release-lock lock)

(ccl:wait-on-semaphore (semaphore condition-variable)))

    (acquire-lock lock)))

(defun condition-notify (condition-variable)

  (when (> (sem-count condition-variable) 0)

    (decf (sem-count condition-variable))

    (ccl:signal-semaphore (semaphore condition-variable))))

I don't know about it....