serial I/O with blocking queue and trampoline

serial.clj

(defn serial-processor
  "Given BlockingQueue q, returns a map of two functions, :process and :stop.

  :process takes a constant function (presumably for side effects) and
  adds it to the queue, where it is invoked serially with respect to
  other functions added via :process.

  :stop takes a non-function value to return, blocks on the completion
  of remaining process functions, and returns the value."
  [^java.util.concurrent.BlockingQueue q]
  (let [processor (future (trampoline (.take q)))]
    {:process (fn [f] (.put q (fn [] (f) (.take q))))
     :stop (fn [eoq] (.put q eoq) @processor)}))

(let [{:keys [process stop]} (serial-processor (java.util.concurrent.LinkedBlockingQueue.))]
  ;; shovel work into the queue
  (dotimes [i 10]
    (future (process #(println i))))

  ;; block on completion
  (println (stop "all done")))