I'm using AudioKit (4.11.2) in my app to replay audio files.
When try to start a player after connecting/disconnecting audio hardware, there is often a deadlock in main thread. The same also happens when loading or unloading a player after connecting/disconnecting audio hardware.
Especially, when the connected/disconnected device is an Apple AirPod Pro headset, then it's reproducible by 100%.
See image with call stack on deadlock.
Image with call stack of deadlocks
I know that AudioKit 4.11.2 is not the latest, but it is the latest 4.x release. I cannot yet switch to 5.x due to the breaking change of missing AKPlayer class.
Is there any known issue with deadlocks after connecting/disconnecting audio hardware?
I already switched off AKSettings.enableCategoryChangeHandling and AKSettings.enableRouteChangeHandling, but that didn't help.
P.S: In the mean time I migrated to AudioKit 5.3.2 and use the class AudioPlayer instead of AKPlayer and the issue is still the same.
After many hours and hours of debugging I found that it must be an Apple bug.
Reading lastRenderTime (AKManager.engine.outputNode.lastRenderTime on AudioKit 4 or avEngine.outputNode.lastRenderTime on an instance of AudioEngine on AudioKit 5) causes the problem.
As long as I never read lastRenderTime, I can connect/disconnect the AirPod Pro headset and play the audio file without any problems.
Once I read lastRenderTime, after next connect/disconnect of the AirPod Pro headset the main thread freezes when trying to start the player.
(lastRenderTime on AVAudioNode is an Apple function, not an AudioKit function.)
