Enum Singleton Double Creation

Question

在我的Android应用程序中，我有一个单独的类，如下所示：

public enum AudioManager {
   INSTANCE;

   private final Object mLockLoad = new Object();
   private final Object mSPLockLoad = new Object();

   public void loadFiles(final Context context, final Locale locale) {
       synchronized (mLockLoad) {
          //Load SoundPool and other stuff

         Thread thread = new Thread() {
             @Override
             public void run() {
                 synchronized (mSPLockLoad) {
                     loadAllSounds(context);
                     mSPLockLoad.notify();
                 }
             }
         };
         thread.start();
     }
 }

然后从一个Activity类我用它来调用它：

public static void loadAudioFiles(final Context context, final Locale locale) {
    new Thread(new Runnable() {
        @Override
        public void run() {    
            AudioManager.INSTANCE.loadFiles(
                                 context.getApplicationContext(),
                                 locale);
        }
    }, "AudioManagerInitializeThread").start();
}

在某些时候发生竞争条件并且loadFiles()被调用两次。问题出在哪里？ 如果我在主UI线程上获取实例，我会避免它：

public static void loadAudioFiles(final Context context, final Locale locale) {
    AudioManager manager = AudioManager.INSTANCE;
    new Thread(new Runnable() {
        @Override
        public void run() {    
            manager.loadFiles(context.getApplicationContext(), locale);
        }
    }, "AudioManagerInitializeThread").start();
}