(receive (in-a out-a in-b out-b) (unix-pair)
  (write-json '((hello . "world")) out-a)
  (flush-output out-a)
  (thread-start!
    (make-thread
      (lambda ()
        (thread-sleep! 3)
        (print (read-json in-b consume-trailing-whitespace: #f)))))
  (close-output-port out-a))


;; after 3 seconds...
#;8> ((hello . world))