UiModeManager has a memory leak in Android U

[vgonda]

Reported here: https://issuetracker.google.com/issues/294776102

Found while leak hunting with @joshskeen @helios175 @rjrjr And whoever else was on the call that I couldn't see.

LeakTrace information

┬─── 
│ GC Root: Global variable in native code 
│ 
├─ android.app.UiModeManager$1 instance 
│    Leaking: UNKNOWN 
│    Retaining 2.2 MB in 64692 objects 
│    Anonymous subclass of android.app.IUiModeManagerCallback$Stub 
│    ↓ UiModeManager$1.this$0 
│                      ~~~~~~ 
├─ android.app.UiModeManager instance 
│    Leaking: UNKNOWN 
│    Retaining 2.2 MB in 64691 objects 
│    mContext instance of com.squareup.ui.main.MainActivity with mDestroyed = true 
│    ↓ UiModeManager.mContext 
│                    ~~~~~~~~
╰→ com.squareup.ui.main.MainActivity instance
 ​     Leaking: YES (ObjectWatcher was watching this because com.squareup.ui.main.MainActivity received Activity#onDestroy() callback and Activity#mDestroyed is true)
 ​     Retaining 2.2 MB in 64679 objects
 ​     key = dd32c85b-75ee-4127-b524-ae5bf267ab8a
 ​     watchDurationMillis = 58277
 ​     retainedDurationMillis = 53277
 ​     mApplication instance of com.squareup.development.SposDevApp
 ​     mBase instance of androidx.appcompat.view.ContextThemeWrapper
--

[juliocbcotta]

@pyricau could we get a new release of Leak Canary with the ignored new leaks? I think one is a good candidate to be added.

[pyricau]

Note for pattern matching: the leak is still there in android-14.0.0_r11 but fixed (https://cs.android.com/android/_/android/platform/frameworks/base/+/2bc364179327022d0f60224a1f2420349074c5d2) in android-14.0.0_r16 https://cs.android.com/android/platform/superproject/+/android-14.0.0_r16:frameworks/base/core/java/android/app/UiModeManager.java;bpv=1

[pyricau]

could we get a new release of Leak Canary with the ignored new leaks?

Probably not on 2.x, as I'd rather focus my limited time on 3.x. But 3.x will likely be released as non stable alpha for a while.

Until then, you can easily create & maintain your own list of ignored leaks in your apps.

[hp902]

@pyricau Is this fixed in 3.0-alpha-1?

[pyricau]

@hp902 no this will be fixed in the next release. You can add it manually to your config for now.