CODEWITHSUNDEEP
javamacosjavasound
akarnokd
akarnokd

Reputation: 70007

SourceDataLine.drain() hangs on OSX

My game plays back sound via the usual method:

sdl.open();
sdl.start();
sdl.write(data, 0, data.length);
sdl.drain();
sdl.stop();
sdl.close();

And the user may cancel the playback (asynchronously):

sdl.stop();

This cancellation works nicely under Windows, but for one user running OSX 10.5.8 with Java 6 the program hangs. Threaddump shows the playback thread is inside drain(): com.sun.media.sound.MixerSourceLine.nDrain. If the user doesn't interrupt the sound, it completes nicely and the application continues.

My questions are:

Edit: I found this bug report with similar effects, but the page says it is fixed.

Upvotes: 2

Views: 1009

Answers (1)

trashgod
trashgod

Reputation: 205875

For reference, this example using close() exits normally under either Java 5 or 6.

Invoking stop(), rather than close(), on the EDT hangs both Java 5 and 6 unless the line has already been closed normally on the initial thread. This appears to be the expected result of drain() blocking, as a stopped line can't drain.

import java.awt.EventQueue;
import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.LineUnavailableException;
import javax.sound.sampled.SourceDataLine;
import javax.swing.JOptionPane;

/**
 * @see https://stackoverflow.com/questions/7803310
 * @see https://stackoverflow.com/questions/2065693
 */
public class Tone {

    public static void main(String[] args) throws LineUnavailableException {
        final AudioFormat af =
            new AudioFormat(Note.SAMPLE_RATE, 8, 1, true, true);
        final SourceDataLine line = AudioSystem.getSourceDataLine(af);
        EventQueue.invokeLater(new Runnable() {

            public void run() {
                JOptionPane.showMessageDialog(null, "Halt");
                //line.stop(); // stops and hangs on drain
                line.close();
            }
        });
        line.open(af, Note.SAMPLE_RATE);
        line.start();
        for (Note n : Note.values()) {
            play(line, n, 500);
            play(line, Note.REST, 10);
        }
        line.drain();
        line.close();
    }

    private static void play(SourceDataLine line, Note note, int ms) {
        ms = Math.min(ms, Note.SECONDS * 1000);
        int length = Note.SAMPLE_RATE * ms / 1000;
        int count = line.write(note.data(), 0, length);
    }
}

Requires Note.

Upvotes: 1

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