Hello, I rewriting a audio driver that was created in IOKit to a new one based on AudioDriverKit. I would like to block possibility to connect multiple devices to the computer so that driver support just one device. In IOKit it was done by overriding IOAudioEngine::getLocalUniqueID() method and I cannot find anything similar in AudioDriverKit (IOUserAudioDevice). Do you know how to do it? Best Regards

Hi, Example code of AudioDriverKit from WWDC2021 stopped to work correctly for me. It builds and loads but when I want to record sine wave immediately after startIO function stopIO is called. It happens on both MacBook Air and Mac mini with macOS 12.0.1. I discovered it because my audio driver also stopped to work correctly - exactly the same problem I described above. Earlier I was testing both example code and my audio driver on macOS 12 public beta and everything was ok. Below I paste logs from console when I start recording: default 12:54:19.161261+0100 kernel StartIO: Start IO: device 2 default 12:54:19.161274+0100 kernel StartIO: Start IO: device 2 default 12:54:19.161092+0100 coreaudiod HALS_IOEngine2::StartIO: starting IO on device SimpleAudioDevice-UID default 12:54:19.161279+0100 kernel StartIO: Start IO: device 2 default 12:54:19.161138+0100 coreaudiod HALS_IOEngine2::_StartIO(435) on Context 443 state: Prewarm: 0 Play: 0 State: Stopped default 12:54:19.161374+0100 CAReportingService CAReportingService.mm:157 service type 9 set for reporter 897648164879 default 12:54:19.161437+0100 coreaudiod HALS_IOEngine2::_StartIO(435) on Context 443 state: Prewarm: 0 Play: 1 State: Running default 12:54:19.161761+0100 coreaudiod HALS_Device::_GetCombinedVolumeScalar: client 246 (pid 517) is not present and has a combined volume scalar is 1.000000 default 12:54:19.161798+0100 coreaudiod HALS_Device::_GetCombinedVolumeScalar: client 246 (pid 517) is not present and has a combined volume scalar is 1.000000 default 12:54:19.161808+0100 coreaudiod HALS_IOUADevice::HandlePropertiesChanged: Object: 431: SimpleAudioDevice-UID default 12:54:19.162034+0100 coreaudiod 'goin', 'glob', 0 default 12:54:19.162580+0100 coreaudiod CAReportingClient.mm:508 message { "device_is_aggregate" = 0; "input_avail_phys_formats" = "{ [16/48000/1 lpcm], [16/44100/1 lpcm] }"; "input_avail_virt_formats" = "{ [32/48000/1 lpcm], [32/44100/1 lpcm] }"; "input_bits_per_channel" = 32; "input_bytes_per_frame" = 4; "input_bytes_per_packet" = 4; "input_channels_per_frame" = 1; "input_device_source_list" = Unknown; "input_device_transport_list" = BuiltIn; "input_device_uid_list" = "SimpleAudioDevice-UID"; "input_format_id" = lpcm; "input_frames_per_packet" = 1; "input_num_tap_streams" = 0; "input_scalar_volume" = "1.000000"; "io_buffer_size" = 15; message = StartHardware; "output_num_tap_streams" = 0; "output_scalar_volume" = "1.000000"; "sample_rate" = 48000; }: ( 897648164879 ) error 12:54:19.163011+0100 coreaudiod 206515 HALS_IOUAUCDriver.cpp:500 Throwing Exception: ret != kIOReturnSuccess Failed to register event link error 12:54:19.163100+0100 coreaudiod 206515 HALS_IOUAEngine.cpp:157 Failed to register io thread! default 12:54:19.163950+0100 kernel StopIO: Stop IO: device 2 default 12:54:19.163968+0100 kernel StopIO: Stop IO: device 2 default 12:54:19.163974+0100 kernel StopIO: Stop IO: device 2 default 12:54:19.163166+0100 coreaudiod HALS_IOContext_Legacy_Impl::IOWorkLoop: failed to register io thread error 12:54:19.163310+0100 coreaudiod 206515 HALS_IOUAEngine.cpp:180 Throwing Exception: error != 0 Failed to disassociate event link 22 error 12:54:19.163482+0100 coreaudiod 206515 HALS_IOUAEngine.cpp:187 Failed to unregister io thread! default 12:54:19.163613+0100 coreaudiod HALS_IOEngine2::StopIO: stopping IO on device SimpleAudioDevice-UID default 12:54:19.163744+0100 coreaudiod HALS_IOEngine2::_StopIO(435) on Context 443 state: Prewarm: 0 Play: 1 State: Running default 12:54:19.164082+0100 coreaudiod HALS_IOUADevice::HandlePropertiesChanged: Object: 431: SimpleAudioDevice-UID default 12:54:19.164134+0100 coreaudiod 'goin', 'glob', 0 default 12:54:19.164289+0100 coreaudiod CAReportingClient.mm:480 stopping ( 897648164879 ) default 12:54:19.164542+0100 coreaudiod CAReportingClient.mm:508 message { "session_duration" = "0.003519058227539062"; }: ( 897648164879 ) error 12:54:19.165611+0100 Audacity HALC_ProxyIOContext::IOWorkLoop: the server failed to start, Error: 0x77686174 default 12:54:19.165045+0100 coreaudiod IO Stopped Context 443 after 0 frames. default 12:54:19.165199+0100 coreaudiod HALS_IOContext_Legacy_Impl::IOThreadEntry: 443 SimpleAudioDevice-UID (SimpleAudioDevice-UID): stopping with error 2003329396 default 12:54:19.165220+0100 coreaudiod HALB_PowerAssertion::Release: releasing power assertion ID 34859 of type 'PreventUserIdleSystemSleep' with name: 'com.apple.audio.context443.preventuseridlesleep' on behalf of 517 error 12:54:19.165390+0100 coreaudiod HALS_IOContext_Legacy_Impl::StartIOThread: the IO thread failed to start, Error: 2003329396 (what) Any advice? Thank you and regards