async IO + thread pool

core.clj

(ns chat.core
  (:use lamina.core aleph.tcp gloss.core)
  (:gen-class))

(def broadcast-channel (permanent-channel))

(defn chat-handler [ch client-info]
  (receive-all ch #(async (let [value (if (not= "sleep" %)
                                        %
                                        (task (do (Thread/sleep 5000) "I slept!")))]
                            (enqueue broadcast-channel value)
                            )))
  (siphon broadcast-channel ch))

(defn -main [& args]
  (start-tcp-server chat-handler {:port 5000 :frame (string :utf-8 :delimiters ["\r\n"])}))