Is this normal for CfD apps The drop is when I quit the app

Question

David W · Answer

I ran visualvm on it and it s very possible I m not interpreting the results right but it seems like it s just CfD doing non stop rendering

David W · Answer

This is with the app just sitting doing nothing

Kirill Grouchnikov · Answer

Depends on how you set up your data flow It might look like it s doing nothing while in fact it s recomposing the entire UI on every frame

David W · Answer

I ll try sprinkling breakpoints around and seeing if they re hit

David W · Answer

haven t had any success getting useful information from VisualVM or Mission Control

Colton Idle · Answer

If you just create a simple hello world app do you see the same usage on your machine

David W · Answer

I suppose that is the real question for some reason it seemed like more work to do that checking

David W · Answer

lol fresh project gt gt BUG exception in phase semantic analysis in source unit BuildScript Unsupported class file major version 61

David W · Answer

don t try to use jdk 17

David W · Answer

Whatever the issue is it s something in my app pensive

David W · Answer

mine

David W · Answer

empty sample app

David W · Answer

feels like maybe something is launching a new coroutine every frame

David W · Answer

i went through and checked all of my `launch`es

David W · Answer

no culprits

David W · Answer

time to start commenting out giant swathes of code i guess

David W · Answer

the tried and true debugging method

David W · Answer

of the desperate

David W · Answer

got it

David W · Answer

``` val infiniteTransition = rememberInfiniteTransition val angle by infiniteTransition animateFloat initialValue = 0F targetValue = 360F animationSpec = infiniteRepeatable animation = tween 1000 easing = FastOutLinearInEasing Icon painter = painterResource refresh svg modifier = Modifier graphicsLayer if areModsLoading rotationZ = angle contentDescription = Refresh ```

David W · Answer

commenting this out drops the single core usage down to relatively nothing

David W · Answer

gt A graphicsLayer should be used when the content updates independently from anything above it to minimize the invalidated content

David W · Answer

solution ``` Icon painter = painterResource refresh svg modifier = Modifier run if areModsLoading val infiniteTransition = rememberInfiniteTransition val angle by infiniteTransition animateFloat initialValue = 0F targetValue = 360F animationSpec = infiniteRepeatable animation = tween 1000 easing = FastOutLinearInEasing this graphicsLayer rotationZ = angle else this contentDescription = Refresh ```

David W · Answer

Before

David W · Answer

After

David W · Answer

and also single core CPU usage went from being pegged to 10 15

David W · Answer

specifically the issue was using `infiniteTransition animateFloat` outside of the conditional that when true made the icon spin which was presumably causing the area to recompose even though the `graphicsLayer` code that used it was never called

Dominaezzz · Answer

Hmm if nothing is dependent on it then recomposition shouldn t happen Hmm

Colton Idle · Answer

Yeah I can t say I m following but I d open a bug on either compose google issuetracker or jb compose github