This is an issue that I see very infrequently, but have seen a few times. It has impacted some important customers, causing them to miss calls. I'd like to further my understanding of what could be happening here.
In the problematic scenarios, there appears to be a long delay (even up to 30 seconds!) when initializing an IAudioClient. The logs also indicate that all WASAPI calls succeeded. The flow is as follows:
hr = pAudioClient->GetMixFormat((WAVEFORMATEX **)&pMixFormatEx);
if (FAILED(hr)) {
// Log and error
}
// Log the mix format (LOG #1)
hr = pAudioClient->Initialize(
AUDCLNT_SHAREMODE_SHARED,
AUDCLNT_STREAMFLAGS_EVENTCALLBACK,
100 * 10000,
0,
&pMixFormatEx->Format,
NULL);
if (FAILED(hr)) {
// Log and error
}
// Log that the device was initialized (LOG #2)
This works without fail 99.9% of the time. However, this last time, we saw a 30 second interval between LOG #1 and LOG #2 (before the Initialize() call and after the Initialize() call).
Is it possible that something in the Initialize() call is blocking or causing this horrendous hang?
There was no mention of a system hang or any other issue with running applications when the issue was encountered.
- Windows 7
- Microphone (Realtek High Definition Audio), mix format 48 KHz 32-bit float
Please let me know if there is something I can look into, or if there is other information I can provide.
