IssueTracker

I have a Foreground Service on which I use a wake lock. My use case is a meditation timer, where for the entire duration of your meditation I have foreground notification which counts down.

I have a wake lock property in my Service:

private var wakeLock: WakeLock? = null`

which I set here:

override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
  ...
  wakeLock = powerManager.newWakeLock(PARTIAL_WAKE_LOCK, "meditationtimer:MeditationBackgroundService")
  wakeLock?.acquire(meditationSessionState.wakeLockTime())
  ...
}

and clean up via:

override fun onDestroy() {
  super.onDestroy()
  wakeLock?.safelyRelease()
  wakeLock = null
}

fun WakeLock.safelyRelease() {
  if (isHeld) {
    release()
  }
}

Yesterday after my meditation, Leak Canary told me that my Service is leaking:

┬───
│ GC Root: System class
│
├─ com.android.tools.profiler.support.energy.WakeLockWrapper class
│    Leaking: NO (a class is never leaking)
│    ↓ static WakeLockWrapper.eventIdMap
│                             ~~~~~~~~~~
├─ java.util.HashMap instance
│    Leaking: UNKNOWN
│    Retaining 176 B in 5 objects
│    ↓ HashMap[key()]
│             ~~~~~~~
├─ android.os.PowerManager$WakeLock instance
│    Leaking: UNKNOWN
│    Retaining 3,1 kB in 58 objects
│    ↓ PowerManager$WakeLock.this$0
│                            ~~~~~~
├─ android.os.PowerManager instance
│    Leaking: UNKNOWN
│    Retaining 3,0 kB in 55 objects
│    mContext instance of com.vanniktech.meditationtimer.MeditationTimerBackgroundService
│    ↓ PowerManager.mContext
│                   ~~~~~~~~
╰→ com.vanniktech.meditationtimer.MeditationTimerBackgroundService instance
​     Leaking: YES (ObjectWatcher was watching this because com.vanniktech.meditationtimer.
​     MeditationTimerBackgroundService received Service#onDestroy() callback and Service not held by ActivityThread)
​     Retaining 2,4 kB in 40 objects
​     key = 37eaefd5-67fa-4142-94a8-cc872a9710ea
​     watchDurationMillis = 5349
​     retainedDurationMillis = 348
​     mApplication instance of com.vanniktech.meditationtimer.MeditationTimerApplication
​     mBase instance of android.app.ContextImpl

METADATA

Build.VERSION.SDK_INT: 33
Build.MANUFACTURER: Google
LeakCanary version: 2.10
App process name: com.vanniktech.meditationtimer
Class count: 33030
Instance count: 236808
Primitive array count: 156415
Object array count: 34886
Thread count: 82
Heap total bytes: 34448465
Bitmap count: 5
Bitmap total bytes: 51147
Large bitmap count: 0
Large bitmap total bytes: 0
Db 1: open /data/user/0/com.vanniktech.meditationtimer/databases/com.google.android.datatransport.events
Db 2: open /data/user/0/com.vanniktech.meditationtimer/databases/MeditationTimer.db
Db 3: open /data/user/0/com.vanniktech.meditationtimer/no_backup/androidx.work.workdb
Stats: LruCache[maxSize=3000,hits=131137,misses=237111,hitRate=35%]
RandomAccess[bytes=11920280,reads=237111,travel=105749540601,range=40253671,size=49542614]
Analysis duration: 5704 ms