Fix frames that are marked as discarded incorrectly #435
+11
−1
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
The way PresentMon marks the completion of frames is to first mark frames as 'Presented' when it receives MMIO MPO flip call and then once Win32k providers’ (running within DWM process) TokenStateChange(TokenState::Discarded) event is received it is marked as completed.
In certain cases, like when there are short bursts of presents, we get multiple back-to-back flips and token tracking thread ends up marking the second frame in the burst as dropped. To fix this issue, we mark the frame as discarded only if the frame already doesn’t have valid ScreenTime.
ETL file: https://drive.google.com/file/d/1uVnWiT9An-p5_BanYQB8e_-FCPd61qXP/view?usp=sharing