Hello!! Is there a way to measure the rendering time of Composables, or what is equivalent of `on...

# compose

[Gagan Deep]

Hello!!
Is there a way to measure the rendering time of Composables, or what is equivalent of onGlobalLayout in Compose world?

[Gagan Deep]

@Will Shelor any thoughts!!
I have gone through your article
https://engineering.premise.com/measuring-render-performance-with-jetpack-compose-c0bf5814933
but we are not using any Fragments, so cant use onResume to measure when view is rendered

[Will Shelor]

Sure! onGlobalLayout is still called with Compose with basically the same timing as the view world

[Will Shelor]

But if you want to get more accurate, Perfetto and the Android Studio profiler are probably the way to go. If you haven’t used it, Perfetto gives you very accurate real-world data from more recent devices. Using it, you can pretty easily look at your composition from a higher level and see how long your rendering is taking, what is taking so much time, and whether jit compilation is happening. (jit compilation will be slightly better on production devices because the play store will download profiles for your most commonly used code)

[Gagan Deep]

ok, i will give it a try, but my use-case is slightly different, we want to calculate page-rendering time and send it for analytics, and our pages are composables 🙂
, so was figuring how to measure the render time

[Will Shelor]

if you want more specifics as to what is taking up so much time in your perfetto profile, I’ve also had luck with the Android Studio profiler. You can sample method traces, which allows you to see exactly what is happening with a ton of detail- but it also completely messes that performance up, meaning that what you’re seeing is not that accurate

[Will Shelor]

Ah! Calculating it in the wild is a much more difficult problem. It’s a problem in XML too, as both recyclerviews and lazycolumns can cause onGlobalLayout to call multiple times

[Gagan Deep]

yes, thats what i am struggling at, i tried using LaunchedEffect to calculate as it is called one time during composition

[Gagan Deep]

but the numbers are not correct

[Will Shelor]

onGlobalLayout should be just as accurate as it was with XML. In my testing I saw it firing twice, once for the base layout and once for the recyclerview- with the same being true for both xml and Compose

[Will Shelor]

https://developer.android.com/studio/profile/jankstats this library released the other day, I wonder if it could provide any tools?

[Gagan Deep]

ok.. thanks for the info, i will take look 🙂

[Will Shelor]

The problem with measuring something like rendering is that the system renders a lot, for a lot of reasons, so it’s not really a one-time thing; but what we want to measure here is something more specific. IMO it makes a great microbenchmarking/macrobenchmarking test, but it’s hard to do in the wild.

[Gagan Deep]

you are right, its more suitable for macrobenchmarking

[Gagan Deep]

ohhk, thanks for the advice 👍