Skip useless tasks in the worker to improve fast scrolling with scanned books (bug 1866296) #17403
+110
−57
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Outdated suggestions cannot be applied.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.
When a page rendering is cancelled, a task is sent to the worker but before it's executed the rendering task is: the cancel task is more or less useless in this case. So in using the fact that draining the message queue has a higher priority than draining the event one, it's possible to get all the current tasks, hence it's possible to cancel some tasks which are before a cancel task.