private void checkDead() {
        if (decoderThread.getState() == Thread.State.TERMINATED) {
            throw new IllegalStateException("Decoding thread is terminated");
        }
    }
Checks if the audio thread has terminated unexpectedly.
@throws IllegalStateException if the decoding thread is terminated.
jme3-core/src/main/java/com/jme3/audio/openal/ALAudioRenderer.java