Re: [PATCH 0/1] MR4187: mfmediaengine: Be a bit more conservative with locks in engine Shutdown.

[Yuxuan Shui (＠yshui)]

On Fri Nov  3 18:14:45 2023 +0000, Yuxuan Shui wrote:
> Adding to point (2), even if we can fix this now by not holding grabber
> lock while calling `OnProcessSample`, we might introduce more deadlocks
> of the same kind in the future. This MR is more future proof in that sense.

I was able to block engine shutdown by injecting a media source via `IMFMediaEngineExtension`. While the engine shutdown is blocked, I was able to call engine shutdown again from a different thread, and the second shutdown returns `MF_E_SHUTDOWN` immediately.

This mean either engine lock is not held; or engine shutdown flag is not protected by a lock, maybe an atomic. I think this is more evidence this MR should be accepted.