Standalone plug-in: Fixed a mute button race condition

modules/juce_audio_plugin_client/Standalone/juce_StandaloneFilterWindow.h

@@ -42,7 +42,8 @@ namespace juce
     @tags{Audio}
 */
 class StandalonePluginHolder    : private AudioIODeviceCallback,
-                                  private Timer
+                                  private Timer,
+                                  private Value::Listener
 {
 public:
     //==============================================================================
@@ -78,9 +79,11 @@ public:
 
         : settings (settingsToUse, takeOwnershipOfSettings),
           channelConfiguration (channels),
-          shouldMuteInput (! isInterAppAudioConnected()),
           autoOpenMidiDevices (shouldAutoOpenMidiDevices)
     {
+        shouldMuteInput.addListener (this);
+        shouldMuteInput = ! isInterAppAudioConnected();
+
         createPlugin();
 
         auto inChannels = (channelConfiguration.size() > 0 ? channelConfiguration[0].numIns
@@ -158,6 +161,7 @@ public:
     //==============================================================================
     Value& getMuteInputValue()                           { return shouldMuteInput; }
     bool getProcessorHasPotentialFeedbackLoop() const    { return processorHasPotentialFeedbackLoop; }
+    void valueChanged (Value& value) override            { muteInput = (bool) value.getValue(); }
 
     //==============================================================================
     File getLastFile() const
@@ -406,6 +410,7 @@ public:
 
     // avoid feedback loop by default
     bool processorHasPotentialFeedbackLoop = true;
+    std::atomic<bool> muteInput { false };
     Value shouldMuteInput;
     AudioBuffer<float> emptyBuffer;
     bool autoOpenMidiDevices;
@@ -492,9 +497,7 @@ private:
                                 int numOutputChannels,
                                 int numSamples) override
     {
-        const bool inputMuted = shouldMuteInput.getValue();
-
-        if (inputMuted)
+        if (muteInput)
         {
             emptyBuffer.clear();
             inputChannelData = emptyBuffer.getArrayOfReadPointers();