Signal 11: SIGSEGV when using AudioProcessorValueTreeState::Listener

General JUCE discussion
1

I had an AudioProcessorValueTreeState object in PluginProcessor and AudioPluginAudioProcessorEditor inherited from AudioProcessorValueTreeState::Listener. The parameter is attached to a slider using another AudioProcessorValueTreeState::SliderAttachment object.

I tested it in the stand alone mode and it works fine. If opening the VST using JUCE’s AudioPluginHost though, once changing the parameter the program crashed. The error was: Process finished with exit code 139 (interrupted by signal 11: SIGSEGV). The line trigger the error was from line 151 of juce_AudioProcessorValueTreeState.cpp

void parameterValueChanged (int, float) override
    {
        const auto newValue = denormalise (parameter.getValue());

        if (unnormalisedValue == newValue && ! listenersNeedCalling)
            return;

        unnormalisedValue = newValue;
    --> listeners.call ([this] (Listener& l) { l.parameterChanged (parameter.paramID, unnormalisedValue); });
        listenersNeedCalling = false;
        needsUpdate = true;
    }

I noticed the message in the parameterChanged(const juce::String &parameterID, float newValue) callback was printed successfully though. Any suggestions?

PluginEditor.cpp (1.0 KB)
PluginEditor.h (1.0 KB)
PluginProcessor.cpp (6.6 KB)
PluginProcessor.h (2.2 KB)

1 Like
2

If you add a parameter listener in the editor’s constructor, you need to remove the listener in the editor’s destructor (or as soon as the listener is no longer required).

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3

Thank you for the help.