Re: [PATCH v4 1/3] coreaudio: Commit the result of init in the end

[Christian Schoenebeck <qemu_oss@crudebyte.com>]

On Friday, January 17, 2025 7:47:00 AM CET Akihiko Odaki wrote:
> init_out_device may only commit some part of the result and leave the
> state inconsistent when it encounters a fatal error or the device gets
> unplugged during the operation, which is expressed by
> kAudioHardwareBadObjectError or kAudioHardwareBadDeviceError. Commit the
> result in the end of the function so that it commits the result iff it
> sees no fatal error and the device remains plugged.
> 
> With this change, handle_voice_change can rely on core->outputDeviceID
> to know whether the output device is initialized after calling
> init_out_device.
> 
> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
> ---
>  audio/coreaudio.m | 49 +++++++++++++++++++++++++++----------------------
>  1 file changed, 27 insertions(+), 22 deletions(-)
> 
> diff --git a/audio/coreaudio.m b/audio/coreaudio.m
> index cadd729d5053..b9e1a952ed37 100644
> --- a/audio/coreaudio.m
> +++ b/audio/coreaudio.m
> @@ -355,7 +355,10 @@ static OSStatus audioDeviceIOProc(
>  static OSStatus init_out_device(coreaudioVoiceOut *core)
>  {
>      OSStatus status;
> +    AudioDeviceID deviceID;
>      AudioValueRange frameRange;
> +    UInt32 audioDevicePropertyBufferFrameSize;
> +    AudioDeviceIOProcID ioprocid;

So you said 'outDeviceID' was 'too verbose', ... but
'audioDevicePropertyBufferFrameSize' is not? :-)

/Christian

>      AudioStreamBasicDescription streamBasicDescription = {
>          .mBitsPerChannel = core->hw.info.bits,
> @@ -368,20 +371,19 @@ static OSStatus init_out_device(coreaudioVoiceOut *core)
>          .mSampleRate = core->hw.info.freq
>      };
>  
> -    status = coreaudio_get_voice(&core->outputDeviceID);
> +    status = coreaudio_get_voice(&deviceID);
>      if (status != kAudioHardwareNoError) {
>          coreaudio_playback_logerr (status,
>                                     "Could not get default output Device\n");
>          return status;
>      }
> -    if (core->outputDeviceID == kAudioDeviceUnknown) {
> +    if (deviceID == kAudioDeviceUnknown) {
>          dolog ("Could not initialize playback - Unknown Audiodevice\n");
>          return status;
>      }
>  
>      /* get minimum and maximum buffer frame sizes */
> -    status = coreaudio_get_framesizerange(core->outputDeviceID,
> -                                          &frameRange);
> +    status = coreaudio_get_framesizerange(deviceID, &frameRange);
>      if (status == kAudioHardwareBadObjectError) {
>          return 0;
>      }
> @@ -392,31 +394,31 @@ static OSStatus init_out_device(coreaudioVoiceOut *core)
>      }
>  
>      if (frameRange.mMinimum > core->frameSizeSetting) {
> -        core->audioDevicePropertyBufferFrameSize = (UInt32) frameRange.mMinimum;
> +        audioDevicePropertyBufferFrameSize = (UInt32) frameRange.mMinimum;
>          dolog ("warning: Upsizing Buffer Frames to %f\n", frameRange.mMinimum);
>      } else if (frameRange.mMaximum < core->frameSizeSetting) {
> -        core->audioDevicePropertyBufferFrameSize = (UInt32) frameRange.mMaximum;
> +        audioDevicePropertyBufferFrameSize = (UInt32) frameRange.mMaximum;
>          dolog ("warning: Downsizing Buffer Frames to %f\n", frameRange.mMaximum);
>      } else {
> -        core->audioDevicePropertyBufferFrameSize = core->frameSizeSetting;
> +        audioDevicePropertyBufferFrameSize = core->frameSizeSetting;
>      }
>  
>      /* set Buffer Frame Size */
> -    status = coreaudio_set_framesize(core->outputDeviceID,
> -                                     &core->audioDevicePropertyBufferFrameSize);
> +    status = coreaudio_set_framesize(deviceID,
> +                                     &audioDevicePropertyBufferFrameSize);
>      if (status == kAudioHardwareBadObjectError) {
>          return 0;
>      }
>      if (status != kAudioHardwareNoError) {
>          coreaudio_playback_logerr (status,
>                                      "Could not set device buffer frame size %" PRIu32 "\n",
> -                                    (uint32_t)core->audioDevicePropertyBufferFrameSize);
> +                                    (uint32_t)audioDevicePropertyBufferFrameSize);
>          return status;
>      }
>  
>      /* get Buffer Frame Size */
> -    status = coreaudio_get_framesize(core->outputDeviceID,
> -                                     &core->audioDevicePropertyBufferFrameSize);
> +    status = coreaudio_get_framesize(deviceID,
> +                                     &audioDevicePropertyBufferFrameSize);
>      if (status == kAudioHardwareBadObjectError) {
>          return 0;
>      }
> @@ -425,11 +427,9 @@ static OSStatus init_out_device(coreaudioVoiceOut *core)
>                                      "Could not get device buffer frame size\n");
>          return status;
>      }
> -    core->hw.samples = core->bufferCount * core->audioDevicePropertyBufferFrameSize;
>  
>      /* set Samplerate */
> -    status = coreaudio_set_streamformat(core->outputDeviceID,
> -                                        &streamBasicDescription);
> +    status = coreaudio_set_streamformat(deviceID, &streamBasicDescription);
>      if (status == kAudioHardwareBadObjectError) {
>          return 0;
>      }
> @@ -437,7 +437,6 @@ static OSStatus init_out_device(coreaudioVoiceOut *core)
>          coreaudio_playback_logerr (status,
>                                     "Could not set samplerate %lf\n",
>                                     streamBasicDescription.mSampleRate);
> -        core->outputDeviceID = kAudioDeviceUnknown;
>          return status;
>      }
>  
> @@ -451,20 +450,24 @@ static OSStatus init_out_device(coreaudioVoiceOut *core)
>       * Therefore, the specified callback must be designed to avoid a deadlock
>       * with the callers of AudioObjectGetPropertyData.
>       */
> -    core->ioprocid = NULL;
> -    status = AudioDeviceCreateIOProcID(core->outputDeviceID,
> +    ioprocid = NULL;
> +    status = AudioDeviceCreateIOProcID(deviceID,
>                                         audioDeviceIOProc,
>                                         &core->hw,
> -                                       &core->ioprocid);
> +                                       &ioprocid);
>      if (status == kAudioHardwareBadDeviceError) {
>          return 0;
>      }
> -    if (status != kAudioHardwareNoError || core->ioprocid == NULL) {
> +    if (status != kAudioHardwareNoError || ioprocid == NULL) {
>          coreaudio_playback_logerr (status, "Could not set IOProc\n");
> -        core->outputDeviceID = kAudioDeviceUnknown;
>          return status;
>      }
>  
> +    core->outputDeviceID = deviceID;
> +    core->audioDevicePropertyBufferFrameSize = audioDevicePropertyBufferFrameSize;
> +    core->hw.samples = core->bufferCount * core->audioDevicePropertyBufferFrameSize;
> +    core->ioprocid = ioprocid;
> +
>      return 0;
>  }
>  
> @@ -548,7 +551,9 @@ static OSStatus handle_voice_change(
>          fini_out_device(core);
>      }
>  
> -    if (!init_out_device(core)) {
> +    init_out_device(core);
> +
> +    if (core->outputDeviceID) {
>          update_device_playback_state(core);
>      }