Comment 9 for bug 1648280

              libsystem_kernel.dylib`__psynch_mutexdrop+0xa
              CoreFoundation`CFRunLoopWakeUp+0xf0
              QtGui`QEventDispatcherMac::wakeUp()+0x30
              QtCore`QCoreApplication::postEvent(QObject*, QEvent*, int)+0x12f
              QtCore`QMetaObject::activate(QObject*, QMetaObject const*, int, void**)+0x55a
              mixxx`ControlDoublePrivate::valueChanged(double, QObject*)+0x4a
              mixxx`ControlDoublePrivate::set(double, QObject*)+0x8e
              mixxx`EngineBuffer::updateIndicators(double, int)+0x110
              mixxx`EngineMaster::processChannels(int)+0x6b3
              mixxx`EngineMaster::process(int)+0x135
              mixxx`SoundDevicePortAudio::callbackProcessClkRef(unsigned int, float*, float const*, PaStreamCallbackTimeInfo const*, unsigned long)+0x661
              mixxx`(anonymous namespace)::paV19CallbackClkRef(void const*, void*, unsigned long, PaStreamCallbackTimeInfo const*, unsigned long, void*)+0x23
              libportaudio.2.dylib`AdaptingOutputOnlyProcess+0xe7
              libportaudio.2.dylib`PaUtil_EndBufferProcessing+0x1c4
              libportaudio.2.dylib`AudioIOProc+0x392
              CoreAudio`AUConverterBase::RenderBus(unsigned int&, AudioTimeStamp const&, unsigned int, unsigned int)+0x2c5
              CoreAudio`AUBase::DoRenderBus(unsigned int&, AudioTimeStamp const&, unsigned int, AUOutputElement*, unsigned int, AudioBufferList&)+0x9a
              CoreAudio`AUBase::DoRender(unsigned int&, AudioTimeStamp const&, unsigned int, unsigned int, AudioBufferList&)+0x1f8
              CoreAudio`AUHAL::AUIOProc(unsigned int, AudioTimeStamp const*, AudioBufferList const*, AudioTimeStamp const*, AudioBufferList*, AudioTimeStamp const*, void*)+0x6f2
              CoreAudio`HALC_ProxyIOContext::IOWorkLoop()+0x9e7
  syscall duration ns
           value ------------- Distribution ------------- count
            2048 | 0
            4096 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 16
            8192 |@@@@ 2
           16384 | 0