I expect the reading option may block the thread with "buffering: #f".

For example:
(let ((chan (open-vector '(buffering: #f))))
  (thread-start!
    (make-thread
      (lambda ()
        (write "Value" chan)
        (pp "Write done"))))
  (thread-start!
    (make-thread
      (lambda ()
        (thread-sleep! 1)
        (pp "Start reading")
        (pp (read chan)))))
  (thread-sleep! 5))

My expectation:
Outputs:
"Start reading"
"Write done" or "Value", in any order.

Result for 4.6.3, osx 10.6.7:
Outputs:
"Write done"
"Start reading"
"Value"

Obviously, the "read" option doesn't block the spawned thread even "buffering" is set to #f.
Did I misunderstand it?
-- 
Meng Zhang
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