FWD » Core Development » User Interface

FWD emits a beep sound to indicate invalid user input (e.g., pressing a disallowed key in a FILL-IN widget). When the underlying audio system cannot play the sound, FWD logs warnings and ignores specific exceptions.

The relevant code is in the AbstractDriver.playBeep method:

try
{
   ...
   clip.open(audioStream);
   ...
}
catch (LineUnavailableException | IOException | UnsupportedAudioFileException e)
{
   LOG.warning("Cannot play beep sound file " + BEEP_FILE_PATH, e);
   return null;
}

On Linux (at least with Java 8), the underlying audio implementation in icedtea-sound.jar uses Java assert statement in the Stream.disconnect() method:

/**
 * Disconnect a stream from a source/sink.
 */
void disconnect() {
    int returnValue = native_pa_stream_disconnect();
    assert (returnValue == 0);
}

During automated tests, an assertion failure in disconnect() triggers a java.lang.AssertionError, causing an immediate application abend. The stack trace is as follows:

Caused by: java.lang.AssertionError
    at org.classpath.icedtea.pulseaudio.Stream.disconnect(Stream.java:560)
    at org.classpath.icedtea.pulseaudio.PulseAudioDataLine.connect(PulseAudioDataLine.java:271)
    at org.classpath.icedtea.pulseaudio.PulseAudioDataLine.open(PulseAudioDataLine.java:101)
    at org.classpath.icedtea.pulseaudio.PulseAudioDataLine.open(PulseAudioDataLine.java:283)
    at org.classpath.icedtea.pulseaudio.PulseAudioClip.open(PulseAudioClip.java:402)
    at org.classpath.icedtea.pulseaudio.PulseAudioClip.open(PulseAudioClip.java:453)
    at com.goldencode.p2j.ui.client.driver.AbstractDriver.playBeep(AbstractDriver.java:408)
    at com.goldencode.p2j.ui.client.gui.driver.swing.SwingGuiDriver.beep(SwingGuiDriver.java:308)
    at com.goldencode.p2j.ui.client.OutputManager.beep(OutputManager.java:817)
    at com.goldencode.p2j.ui.client.FillIn.validateDisplayValue(FillIn.java:3562)
    at com.goldencode.p2j.ui.client.FillIn.processKeyEvent(FillIn.java:1709)
    at com.goldencode.p2j.ui.client.gui.FillInGuiImpl.processKeyEvent(FillInGuiImpl.java:1373)
    at com.goldencode.p2j.ui.chui.ThinClient.processProgressEvent(ThinClient.java:22455)
    at com.goldencode.p2j.ui.client.FocusManager.focusChange(FocusManager.java:1583)
    at com.goldencode.p2j.ui.chui.ThinClient.nextTabStop(ThinClient.java:25172)
    at com.goldencode.p2j.ui.client.FillIn.processKeyEvent(FillIn.java:1852)
    at com.goldencode.p2j.ui.client.gui.FillInGuiImpl.processKeyEvent(FillInGuiImpl.java:1373)

Recommended Fix

Add java.lang.AssertionError to the list of caught exceptions in AbstractDriver.playBeep.

Greg, I know we've had a debate about the use of assertions in our code base. Was the conclusion that using assert is discouraged?

Hynek Cihlar wrote:

Greg, I know we've had a debate about the use of assertions in our code base. Was the conclusion that using assert is discouraged?

Using assert is disallowed. It must be removed.

Greg Shah wrote:

Hynek Cihlar wrote:

Greg, I know we've had a debate about the use of assertions in our code base. Was the conclusion that using assert is discouraged?

Using assert is disallowed. It must be removed.

You cannot do this in 3-rd party software.

We would have to catch (AssertionError ae) in that case.

Greg Shah wrote:

We would have to catch (AssertionError ae) in that case.

This is exactly what the fix does.

Hynek Cihlar wrote:

Vladimir Tsichevski wrote:

Greg Shah wrote:

Hynek Cihlar wrote:

Greg, I know we've had a debate about the use of assertions in our code base. Was the conclusion that using assert is discouraged?

Using assert is disallowed. It must be removed.

You cannot do this in 3-rd party software.

Sorry, I was browsing the dissassembly assuming this was our code :-).

The changes are good. I suppose no more testing is needed?

I suppose no testing is needed.

Hynek Cihlar wrote:

Please merge 10751a to trunk.

Branch 10751a was merged into trunk as rev. 16287 and archived.