mfmediaengine: Don't send event notify when engine is shutdown.
I've also tried saving a cancel cookie from `BeginCreateObject*` and using it to cancel the
operation in engine shutdown. However there are 2 problems:
1. Callback might still get called after `CancelObjectCreation`. Microsoft's
[own documentation](https://learn.microsoft.com/en-us/windows/win32/api/mfidl/nf-mfidl-imfsourceresolver-cancelobjectcreation)
says as much:
> Because these methods are asynchronous, however, they might be completed before the
> operation can be canceled. Therefore, your callback might still be invoked after you
> call this method.
2. Our implementations of `BeginCreateObject*` are not cancellable. They call either
`MFPutWorkItem` or `IMFByteStream_BeginRead`, neight of which provides cancellation.
(and our `CancelObjectCreation` doesn't actually work. AsyncResult objects aren't added to
`handler->results` list until they are completed, which means any attempts to cancel an
yet-to-be-completed object creation will always fail with `MF_E_UNEXPECTED`)
Showing
Please
register
or
sign in
to comment