Improve detection of leaky services

[vanniktech]

Similar to #2091 but for services:

┬───
│ GC Root: Global variable in native code
│
├─ com.vanniktech.meditationtimer.MeditationTimerApplication instance
│    Leaking: NO (Application is a singleton)
│    mBase instance of android.app.ContextImpl
│    ↓ Application.mLoadedApk
│                  ~~~~~~~~~~
├─ android.app.LoadedApk instance
│    Leaking: UNKNOWN
│    Retaining 684.6 kB in 11606 objects
│    mApplication instance of com.vanniktech.meditationtimer.MeditationTimerApplication
│    Receivers
│    ..MeditationTimerApplication@318809616
│    ....EC0@323502664
│    ....ProxyChangeListener$ProxyReceiver@323502720
│    ....O80@323502784
│    ....f@323502848
│    ....w6@323502912
│    ....VisibilityTracker@323502976
│    ....x70@323503048
│    ....p@323503104
│    ....dj@321051072
│    ....am@322244752
│    ....lw@322121976
│    ....q@323503240
│    ....bx@321880120
│    ....s6@323503304
│    ....wq0@323503368
│    ↓ LoadedApk.mServices
│                ~~~~~~~~~
├─ android.util.ArrayMap instance
│    Leaking: UNKNOWN
│    Retaining 675.4 kB in 11535 objects
│    ↓ ArrayMap.mArray
│               ~~~~~~
├─ java.lang.Object[] array
│    Leaking: UNKNOWN
│    Retaining 675.3 kB in 11533 objects
│    ↓ Object[].[4]
│               ~~~
╰→ com.vanniktech.meditationtimer.MeditationTimerMainActivity instance
     Leaking: YES (ObjectWatcher was watching this because com.vanniktech.meditationtimer.MeditationTimerMainActivity
     received Activity#onDestroy() callback and Activity#mDestroyed is true)
     Retaining 673.3 kB in 11511 objects
     key = c10fa223-ffa3-4523-ba85-611e5fab414c
     watchDurationMillis = 218555
     retainedDurationMillis = 213555
     mApplication instance of com.vanniktech.meditationtimer.MeditationTimerApplication
     mBase instance of androidx.appcompat.view.ContextThemeWrapper
METADATA
Build.VERSION.SDK_INT: 30
Build.MANUFACTURER: Google
LeakCanary version: 2.7
App process name: com.vanniktech.meditationtimer
Stats: LruCache[maxSize=3000,hits=4700,misses=97445,hitRate=4%]
RandomAccess[bytes=4984938,reads=97445,travel=46095612296,range=28247320,size=34799969]
Heap dump reason: 3 retained objects, app is not visible
Analysis duration: 5907 ms

[pyricau]

This was necessary for receivers because they prevented the activity from being GCed without appearing in the leaktrace. Do you have a scenario to reproduce that with services as well? If yes please provide sample code.

Closing the issue until then.

[vanniktech]

That was also the case for services.

I have had a scenario - since fixed it. Converting it to something sharable would be non trivial.

[pyricau]

Can you describe the scenario at the high level?

[vanniktech]

In my case the Activity was connecting to a Foreground Service using the Binder mechanism and the Activity did not call unregisterService at any point of time.