guv

(def time (ffi-fn libc "time" [] CInt))

(defmacro timing [& body]
  `(let [start# (time),
         result# (do ~@body),
         end# (time)]
     (printf (str "Elapsed time: " (- end# start#)))
     result#))

guv

(defn use-only-tls
  [^Server jetty]
  (let [protocols (into-array String ["TLSv1.1" "TLSv1.2"])]
    (doseq [con (->> jetty
                  .getConnectors
                  (filter #(instance? org.eclipse.jetty.server.ssl.SslSelectChannelConnector %)))]
      (.setIncludeProtocols (.getSslContextFactory con) protocols))))

(jetty/run-jetty routes {... :configurator use-only-tls})

guv

(let [signal (promise),
      ; create waiting threads
      future-coll (vec
                    (for [some-val some-coll]
                      (future
                        (deref signal)
                        (do-something some-val))))]
  ; signal start to all threads
  (deliver signal true)
  ; wait for all threads to finish

guv

(def ^:private resolve-symbol-lock (Object.))

(defn- ns-loaded?
  [ns]
  (get (loaded-libs) ns))

(defn- provide-ns
  "Thread-safe version of (require ns)."
  [ns]
  (when-not (ns-loaded? ns)

guv

(defn ping
  ([ip, port]
    (ping ip, port, 1000))
  ([ip, port, timeout]
    (try
      (let [addr (java.net.InetSocketAddress. ^String ip, (int port))]
        (with-open [s (java.net.Socket.)]
          (if timeout
            (.connect s, addr, (int timeout))
            (.connect s, addr))))

guv

(defmacro plet [bindings & body]
  (let [bindings (partition-all 2 bindings)
        destruct-exprs (map first bindings)
        expressions (map second bindings)
        vars (repeatedly (count bindings) gensym)]
    `(let [~@(mapcat (fn [var expr] `[~var (future ~expr)]) vars expressions)
           ~@(mapcat (fn [destr var] `[~destr (deref ~var)]) destruct-exprs vars)]
       ~@body)))

guv

(ns functions.primitive
  (:require
    [clojure.string :as string]))


(defn- print-warning
  [form, s]
  (binding [*out* *err*]
    (println (format "Warning, invoke-primitive at %s:%s: %s" *file* (:line (meta form)) s))))

guv

(ns rebindable-thread-pool
  (:import (java.util.concurrent Executors ExecutorService ThreadPoolExecutor ArrayBlockingQueue TimeUnit)))


; fixed thread pool as default
(def ^{:dynamic true} 
  *thread-pool* (Executors/newFixedThreadPool (+ 2 (.availableProcessors (Runtime/getRuntime)))))


(defn future-call+