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by davesims 5308 days ago
“...a lot of the work we have to do today is because of certain choices made years ago... ...having the UI thread handle animations is the biggest problem...An easy solution would of course to create a new UI toolkit but there are many downsides to this also.”

What would such a re-write look like, from a practical coding point-of-view? Couldn't this be done in a way that is transparent to the calling code, or would there have to be a fundamental re-write of the SDK, i.e., the UI thread no longer be the main thread?
1 comments
patrickgzill 5308 days ago
That jumped out at me as well. I think there would definitely be a way to have most if not all of the underlying API calls set up to do this, without even needing to recompile the application.
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Someone 5308 days ago
If you move code that used to run (and was tested to) on the main thread to another thread, and run that thread in parallel with the main thread, you are creating a huge opportunity for race conditions.

Some applications may run fine, but I bet you will find a lot that do not, even ignoring timing differences that may cause problems with games.

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davesims 5308 days ago
I guess I don't see how that's any different than performing any other blocking operation off the main/UI thread, either on a hand-rolled secondary thread or using a util class like AsyncTask which handles that for you.

It seems to me race conditions are no more or less of a concern for rendering animations than updating data -- and probably less, actually, since there's probably not much contention for animation resources, and if there is contention, synchronization of access to drawables should be straightforward.

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Someone 5307 days ago
The post I replied to speculated that it would be possible to change the system's behavior without recompiling apps.

That would change the rules from "model updates and screen redraws never run concurrently" to "...will typically run concurrently". I think you agree that is asking for problems.

Of course, it is possible to adjust the system to apply different rules to different apps, but then apps would have to be changed to advertise "I am fine with running updates on a different thread". I think newer versions of Android already have some of that.

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