gistfile1.clj

(defn ^::blocking get-url
  [{:keys [^BlockingQueue queue] :as state}]
  (let [url (as-url (.take queue))]
    (try
      (if (@crawled-urls url)
        state
        {:url url
         :content (slurp url)
         ::t #'process})
      (catch Exception e
        state)
      (finally (run *agent*)))))


(defn run
  ([] (doseq [a agents] (run a)))
  ([a]
     (when (agents a)
       (send a (fn [{transition ::t :as state}]
                 (when-not (paused? *agent*)
                   (let [dispatch-fn (if (-> transition meta ::blocking)
                                       send-off
                                       send)]
                     (dispatch-fn *agent* transition)))
                 state)))))