(11.1-beta2) Compositor not always releasing DXGI mutex in Image interop about avalonia

[kekekeks]

This issue only occurs in beta2, beta 1 works as expected.

481 changed files with 15,759 additions and 6,408 deletions.

Could you bisect a bit further?

[amwx]

This is what I got

eee71a62718653583f6b2e96f873a8f945701eaf is the first bad commit
commit eee71a62718653583f6b2e96f873a8f945701eaf
Author: Steven Kirk <[email protected]>
Date:   Sat Apr 20 03:29:12 2024 +0300

    Fix input starvation issues on resource-constrained devices. (#15137)

    * Use 0.2 seconds for input starvation cutoff.

    1 second was too long when running on resource-constrained devices.

    * Allow input starvation code to run.

    Using `ScheduleRender(true)` here prevented the input starvation code from running.

    * Add DispatcherOptions.

    And allow setting the input starvation timeout there.

 src/Avalonia.Base/Media/MediaContext.Compositor.cs |  2 +-
 src/Avalonia.Base/Media/MediaContext.cs            | 13 ++++++++++---
 src/Avalonia.Base/Threading/DispatcherOptions.cs   | 21 +++++++++++++++++++++
 3 files changed, 32 insertions(+), 4 deletions(-)
 create mode 100644 src/Avalonia.Base/Threading/DispatcherOptions.cs

Edit: Adding this seems to make the deadlock less likely to happen (though it still can):
new DispatcherOptions { InputStarvationTimeout = TimeSpan.FromSeconds(10) }

[kekekeks]

That particular PR has changed the way composition batches are being scheduled on the UI thread.

Are you sure that you aren't trying to call _mutex->AcquireSync before the latest UpdateWithKeyMutexAsync is completed?

[kekekeks]

I. e. the input starvation logic can enforce all input to be handled before scheduled render pass. So if you aren't awaiting the latest task it would indeed result in a deadlock once that kicks in.

[amwx]

Ok, I've gotten it fixed by ensuring the Task completed before attempting to render again.

I used the GpuInterop sample as reference for this and on the surface, the only place the LastPresent task is used in the sample is in the Dispose method, I had to go hunting elsewhere to find that it is actually checked before another pass.