memory leak

[underworld9]

I have found a memory leak when closing a session. (stopping & destroying the arCore activity)
found using the Android Profiler.
There are some objects with names like "bkm", "big", "bff", etc. that get increased by 2 after a session was opened. So after opening a session 7 times these objects have an allocation count of 14.

I have tested this Memory Leak in several different ArCore samples.
new samples and older ones.
the Memory Leak happens in every single one of them! every time the Activity is destroyed.
it never happens if the Activity is saved and stopped.
i also have created an App that does nothing except
set the content view to: com.google.ar.sceneform.ux.ArFragment
and the Memory Leak happens every time.

every session increases the memory by an average of 3,5 MB.

[claywilkinson]

Thanks for the details. We'll take a look.

[codeniko]

I'd like to add to this which might be relevant. I'm seeing StrictMode violation and that my activity has leaked android.widget.FrameLayout. I'm not using FrameLayout at all on my side, but I do see that ArFragment extends BaseArFragment which does hold a reference to one. I'm guessing that's where the leak is.

This is what I see every time I rotate screen (I do not wish to disable this). I've also tried using WeakReference for holding my ArFragment reference, same thing. I'm using sceneform 1.5.1

2018-11-27 13:50:53.483 23233-23233/com.nfeld E/StrictMode: class com.nfeld.ar.ArSceneActivity; instances=2; limit=1
    android.os.StrictMode$InstanceCountViolation: class com.nfeld.ar.ArSceneActivity; instances=2; limit=1
        at android.os.StrictMode.setClassInstanceLimit(StrictMode.java:1)
2018-11-27 13:50:53.496 23233-23233/com.nfeld E/WindowManager: android.view.WindowLeaked: Activity com.nfeld.ar.ArSceneActivity has leaked window android.widget.FrameLayout{114fb77 V.E...... ......I. 0,0-0,0} that was originally added here
        at android.view.ViewRootImpl.<init>(ViewRootImpl.java:614)
        at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:365)
        at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:100)
        at com.google.ar.sceneform.rendering.ViewAttachmentManager.lambda$onResume$0$ViewAttachmentManager(ViewAttachmentManager.java:64)
        at com.google.ar.sceneform.rendering.ViewAttachmentManager$$Lambda$0.run(Unknown Source:2)
        at android.os.Handler.handleCallback(Handler.java:789)
        at android.os.Handler.dispatchMessage(Handler.java:98)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6938)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:327)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1374)

[malik-at-work]

I am able to reproduce this leak. I'll work on a fix.

[malik-at-work]

I've fixed this in our codebase. This did not make the 1.6.0 release train however so will be in a release after that.

[claywilkinson]

Here is the Pull Request if you want to build an updated version of the ux library.
#461

[underworld9]

@malik-at-work @claywilkinson
I can confirm that 1.7 has fixed a memory leak.
thank you!
however when i tested this i still saw different objects that increase by 1 every session.
this is obviously a different memory leak.
i have created a follow up Issue about this: #538