Sound clip plays only once in Java backend

[guillerodriguez]

In some configurations, sound clips can only be played once.

• My environment: OpenJDK 1.8.0_141 on Ubuntu 14.04.5.
• IcedTea/PulseAudio sound provider (default for OpenJDK in Ubuntu)
• PlayN 2.1-SNAPSHOT

Sample code:

public class SoundTest extends SceneGame {
  boolean playAgain = true;
  playn.core.Sound sound;

  public SoundTest (final Platform plat) {
    super(plat, 33); // update our "simulation" 33ms (30 times per second)

    // create and add background image layer
    Image bgImage = plat.assets().getImage("images/bg.png");
    ImageLayer bgLayer = new ImageLayer(bgImage);
    // scale the background to fill the screen
    bgLayer.setSize(plat.graphics().viewSize);
    rootLayer.add(bgLayer);
    
    sound = plat.assets().getSound("sounds/drop");
    sound.play();
  }
  
  public void update(Clock t) {
    if (playAgain && plat.tick() > 5000) {
      sound.play();
      playAgain = false;
    }
  }
}

This may be related to the following:

• https://bugs.openjdk.java.net/browse/JDK-8077019
• https://ubuntuforums.org/showthread.php?t=1903727