(in-package :cl-user)

#+NIL
(defun foo ()
  (let ((cv (bt:make-condition-variable))
        (lk (bt:make-lock))
        (k 0)
        (t1 0))
    (prin1 `(internal-time-units-per-second = ,internal-time-units-per-second))
    (terpri)
    (let ((s *standard-output*))
      (bt:make-thread
       (lambda ()
         (let ((*standard-output* s))
           (loop
             (bt:with-lock-held (lk)
               (bt:condition-wait cv lk)
               (prin1 (list k (* 1s0 (/ (- (get-internal-real-time) t1)
                                        internal-time-units-per-second)))))
             (terpri)
             (force-output))))))
    (sleep 1)
    (dotimes (i 10)
      (setq t1 (get-internal-real-time))
      (bt:with-lock-held (lk)
        (incf k)
        (bt:condition-notify cv))
      (sleep 10))))

#+CCL
(defun foo ()
  (prin1 `(internal-time-units-per-second = ,internal-time-units-per-second))
  (terpri)
  (force-output)
  (let ((sem (ccl:make-semaphore))
        (t1 0)
        (k 0))
    (let ((s *standard-output*))
      (ccl:process-run-function
       'aux
       (lambda ()
         (let ((*standard-output* s))
           (loop
             (ccl:wait-on-semaphore sem)
             (format t "~&K = ~D; latency ~Ds~%"
                     k (* 1s0 (/ (- (get-internal-real-time) t1)
                                 internal-time-units-per-second)))
             (force-output))))))
    (sleep 1)
    (dotimes (i 10)
      (setq t1 (get-internal-real-time))
      (incf k)
      (ccl:signal-semaphore sem)
      (prin1 `(sleep ,(expt 1.4 i))) (terpri) (force-output)
      (sleep (expt 1.4 i)))
    nil))

#+SBCL
(defun foo ()
  (prin1 `(internal-time-units-per-second = ,internal-time-units-per-second))
  (terpri)
  (force-output)
  (let ((sem (SB-THREAD:MAKE-SEMAPHORE))
        (t1 0)
        (k 0))
    (let ((s *standard-output*))
      (sb-thread:make-thread
       (lambda ()
         (let ((*standard-output* s))
           (loop
             (sb-thread:wait-on-semaphore sem)
             (format t "~&K = ~D; latency ~Ds~%"
                     k (* 1s0 (/ (- (get-internal-real-time) t1)
                                 internal-time-units-per-second)))
             (force-output))))))
    (sleep 1)
    (dotimes (i 10)
      (setq t1 (get-internal-real-time))
      (incf k)
      (sb-thread:signal-semaphore sem)
      (prin1 `(sleep ,(expt 1.4 i))) (terpri) (force-output)
      (sleep (expt 1.4 i)))
    nil))

(foo)