停止Clojure中的线程声音循环

Question

我有一个线程循环声音剪辑：

(def f
  (future
    (let [sound-file (java.io.File. "/path/to/file.wav")
          sound-in (javax.sound.sampled.AudioSystem/getAudioInputStream sound-file)
          format (.getFormat sound-in)
          info (javax.sound.sampled.DataLine$Info. javax.sound.sampled.Clip format)
          clip (javax.sound.sampled.AudioSystem/getLine info)]
      (.open clip sound-in)
      (.loop clip javax.sound.sampled.Clip/LOOP_CONTINUOUSLY))))

问题是，当我试图杀死线程时：

(future-cancel f)

它不会停止这段永远播放的剪辑。我发现停止它的唯一方法是显式调用(.stop clip)。我的问题是：做这件事的最佳/惯用方式是什么？我对Clojure还很陌生，所以到目前为止我只尝试了future，但也许agent更适合这种情况？

更新：考虑到.loop函数是非阻塞的（如下所述），我通过去掉最初的future:简化了设计

(defn play-loop [wav-fn]
    (let [sound-file (java.io.File. wav-fn)
          sound-in (javax.sound.sampled.AudioSystem/getAudioInputStream sound-file)
          format (.getFormat sound-in)
          info (javax.sound.sampled.DataLine$Info. javax.sound.sampled.Clip format)
          clip (javax.sound.sampled.AudioSystem/getLine info)]
      (.open clip sound-in)
      (.loop clip javax.sound.sampled.Clip/LOOP_CONTINUOUSLY)
      clip))

以及控制atom:

(def ^:dynamic *clip* (atom nil))

我用它开始循环：

(when (nil? @*clip*)
  (reset! *clip* (play-loop "/path/to/file.wav")))

并停止它：

(when @*clip*
  (future (.stop @*clip*) ; to avoid a slight delay caused by .stop
          (reset! *clip* nil)))

Answer 1

您可以尝试以下操作：

(def f
  (future
    (let [sound-file (java.io.File. "/path/to/file.wav")
          sound-in (javax.sound.sampled.AudioSystem/getAudioInputStream sound-file)
          format (.getFormat sound-in)
          info (javax.sound.sampled.DataLine$Info. javax.sound.sampled.Clip format)
          clip (javax.sound.sampled.AudioSystem/getLine info)
          stop (fn [] (.stop clip))]
      (.open clip sound-in)
      (.loop clip javax.sound.sampled.Clip/LOOP_CONTINUOUSLY)
       stop)))
(def stop-loop @f)
(stop-loop)