android - How can I see which wakelocks are active

Question

For some reason my Android phone won't go to sleep. I assume that a wakelock is keeping it awake, but there is no way to tell which wakelocks are active. The running services doesn't list anything suspicious, and certainly nothing different from usual. So my questions are:

1. Does Android definitely release wakelocks when a process ends? Is it possible an app was badly written and didn't release a wakelock before exiting?

2. Is there any way to see the active wakelocks?

This is what dumpsys power shows:

$ dumpsys power
Power Manager State:
  mIsPowered=true mPowerState=0 mScreenOffTime=226093 ms
  mPartialCount=0
  mWakeLockState=
  mUserState=
  mPowerState=
  mLocks.gather=
  mNextTimeout=91922738 now=92136117 -213s from now
  mDimScreen=true mStayOnConditions=0
  mScreenOffReason=3 mUserState=0
  mBroadcastQueue={-1,-1,-1}
  mBroadcastWhy={0,0,0}
  mPokey=1 mPokeAwakeonSet=false
  mKeyboardVisible=false mUserActivityAllowed=false
  mKeylightDelay=6000 mDimDelay=47000 mScreenOffDelay=7000
  mPreventScreenOn=false  mScreenBrightnessOverride=-1  mButtonBrightnessOverride=-1
  mScreenOffTimeoutSetting=60000 mMaximumScreenOffTimeout=2147483647
  mLastScreenOnTime=0
  mBroadcastWakeLock=UnsynchronizedWakeLock(mFlags=0x1 mCount=0 mHeld=false)
  mStayOnWhilePluggedInScreenDimLock=UnsynchronizedWakeLock(mFlags=0x6 mCount=0 mHeld=false)
  mStayOnWhilePluggedInPartialLock=UnsynchronizedWakeLock(mFlags=0x1 mCount=0 mHeld=false)
  mPreventScreenOnPartialLock=UnsynchronizedWakeLock(mFlags=0x1 mCount=0 mHeld=false)
  mProximityPartialLock=UnsynchronizedWakeLock(mFlags=0x1 mCount=0 mHeld=false)
  mProximityWakeLockCount=0
  mProximitySensorEnabled=false
  mProximitySensorActive=false
  mProximityPendingValue=-1
  mLastProximityEventTime=0
  mLightSensorEnabled=false
  mLightSensorValue=-1.0 mLightSensorPendingValue=-1.0
  mLightSensorScreenBrightness=35 mLightSensorButtonBrightness=255 mLightSensorKeyboardBrightness=0
  mUseSoftwareAutoBrightness=true
  mAutoBrightessEnabled=false
  mScreenBrightness: animating=false targetValue=-1 curValue=0.0 delta=-1.3333334

mLocks.size=0:

mPokeLocks.size=1:
    poke lock 'PhoneApp': POKE_LOCK_IGNORE_CHEEK_EVENTS

Answer 1

In new versions of Android you can see list of wakelocks here:

adb shell "cat /sys/kernel/debug/wakeup_sources"