(use mailbox srfi-18)
(use miscmacros thread-utils)

(define (log-mailbox mbx)
(printf "((current-thread: ~S) (mailbox-waiting? ~S) (mailbox-waiting? ~S) (mailbox-count ~S))~N"
           (thread-name (current-thread)) (mailbox-waiting? mbx) (mailbox-waiters mbx) (mailbox-count mbx)))

(let* ((my-box (make-mailbox))
       (proc   (lambda () (fprintf (current-error-port) "Hello from ~S!~N" (current-thread))
                          (fprintf (current-error-port) "Message ~S was received by ~S~N" (mailbox-receive! my-box) (current-thread))
                          (log-mailbox my-box)))
       (thread (thread-start! (make-thread proc))))

  ; Ensure thread is running.
  (while (thread-ready? thread) (pp (thread-state thread)) (thread-yield!))

  (log-mailbox my-box)

  ; Check to see if thread is actually watching the mailbox.
  (if (mailbox-waiting? my-box)
    (begin (mailbox-send! my-box "any data")
           (log-mailbox my-box)

           (while (mailbox-waiting? my-box) (thread-yield!))
           (log-mailbox my-box)))

  ; Now listen for messages ourselves
  (proc))

(use mailbox srfi-18)
(use miscmacros thread-utils)

(define (log-mailbox mbx)
(printf "((current-thread: ~S) (mailbox-waiting? ~S) (mailbox-waiting? ~S) (mailbox-count ~S))~N"
           (thread-name (current-thread)) (mailbox-waiting? mbx) (mailbox-waiters mbx) (mailbox-count mbx)))

(let* ((my-box (make-mailbox))
       (proc   (lambda ()
		 (fprintf (current-error-port)
			  "Hello from ~S!~N" (current-thread))
		 (fprintf (current-error-port)
			  "Message ~S was received by ~S~N"
			  (mailbox-receive! my-box) (current-thread))
		 (log-mailbox my-box)))
       (thread (thread-start! (make-thread proc))))

					; Ensure thread is running.
  (while (thread-ready? thread)
	 (print "state" thread)
	 (pp (thread-state thread))
	 (thread-yield!))

  (log-mailbox my-box)

					; Check to see if thread is actually watching the mailbox.
  (if (mailbox-waiting? my-box)
      (begin (mailbox-send! my-box "any data")
	     (log-mailbox my-box)

	     (while (mailbox-waiting? my-box) (thread-yield!))
	     (log-mailbox my-box)))

					; Now listen for messages ourselves
  (proc)
  (use posix)
  (let lp []
    (log-mailbox my-box)
    (thread-yield!)
    (sleep 1)
    (lp))
  )

state#<thread: thread93>
ready
Hello from #<thread: thread93>!
((current-thread: primordial) (mailbox-waiting? #t) (mailbox-waiting? (#<thread: thread93>)) (mailbox-count 0))
((current-thread: primordial) (mailbox-waiting? #f) (mailbox-waiting? ()) (mailbox-count 1))
((current-thread: primordial) (mailbox-waiting? #f) (mailbox-waiting? ()) (mailbox-count 1))
Hello from #<thread: primordial>!
Message "any data" was received by #<thread: primordial>
((current-thread: primordial) (mailbox-waiting? #f) (mailbox-waiting? ()) (mailbox-count 0))
; loading library posix ...
((current-thread: primordial) (mailbox-waiting? #f) (mailbox-waiting? ()) (mailbox-count 0))
((current-thread: primordial) (mailbox-waiting? #t) (mailbox-waiting? (#<thread: thread93>)) (mailbox-count 0))
((current-thread: primordial) (mailbox-waiting? #t) (mailbox-waiting? (#<thread: thread93>)) (mailbox-count 0))
((current-thread: primordial) (mailbox-waiting? #t) (mailbox-waiting? (#<thread: thread93>)) (mailbox-count 0))