Wakelock "DoNotSleep" Continue to crash..

Question

From my last question : My app crashes just because wakelock "DoNotSleep"

I added the line : wakeLock.acquire();

But my problem continue... :

Thats my logcat :

05-15 12:46:29.316: E/AndroidRuntime(2066): FATAL EXCEPTION: main

05-15 12:46:29.316: E/AndroidRuntime(2066): java.lang.RuntimeException: WakeLock under-locked DoNotSleep

05-15 12:46:29.316: E/AndroidRuntime(2066):     at android.os.PowerManager$WakeLock.release(PowerManager.java:945)

05-15 12:46:29.316: E/AndroidRuntime(2066):     at android.os.PowerManager$WakeLock.release(PowerManager.java:916)

05-15 12:46:29.316: E/AndroidRuntime(2066):     at com.example.iw84u.GpsTracker.UpdateWithNewLocation(GpsTracker.java:190)

05-15 12:46:29.316: E/AndroidRuntime(2066):     at com.example.iw84u.GpsTracker.access$0(GpsTracker.java:169)

05-15 12:46:29.316: E/AndroidRuntime(2066):     at com.example.iw84u.GpsTracker$MyLocationList.onLocationChanged(GpsTracker.java:213)

05-15 12:46:29.316: E/AndroidRuntime(2066):     at android.location.LocationManager$ListenerTransport._handleMessage(LocationManager.java:261)

05-15 12:46:29.316: E/AndroidRuntime(2066):     at android.location.LocationManager$ListenerTransport.access$000(LocationManager.java:189)

05-15 12:46:29.316: E/AndroidRuntime(2066):     at android.location.LocationManager$ListenerTransport$1.handleMessage(LocationManager.java:206)

05-15 12:46:29.316: E/AndroidRuntime(2066):     at android.os.Handler.dispatchMessage(Handler.java:99)

05-15 12:46:29.316: E/AndroidRuntime(2066):     at android.os.Looper.loop(Looper.java:137)

05-15 12:46:29.316: E/AndroidRuntime(2066):     at android.app.ActivityThread.main(ActivityThread.java:5293)

05-15 12:46:29.316: E/AndroidRuntime(2066):     at java.lang.reflect.Method.invokeNative(Native Method)

05-15 12:46:29.316: E/AndroidRuntime(2066):     at java.lang.reflect.Method.invoke(Method.java:511)

05-15 12:46:29.316: E/AndroidRuntime(2066):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)

05-15 12:46:29.316: E/AndroidRuntime(2066):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)

05-15 12:46:29.316: E/AndroidRuntime(2066):     at dalvik.system.NativeStart.main(Native Method)

And in my code:

public void onCreate() {
        super.onCreate();
        PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
        wakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "DoNotSleep");
        wakeLock.acquire();
}
public void onDestroy() {
    // TODO Auto-generated method stub
    super.onDestroy();



    }
public int onStartCommand(Intent intent, int flags, int startId) {
    // Here there's some calculations with the intent

        return START_REDELIVER_INTENT;

    }
private void UpdateWithNewLocation(final Location loc) {
 wakeLock.release();
//Some commands and then .....
 stopSelf(); 
}

Note: I changed the wakeLock.release(); And put that at the start of the function UpdateWithNewLocation(final Location loc) Because otherwise it doesnt stop.

Now my problem is that I still get error message.

Answer 1

This exception occurs if a lock is released more times than it was acquired (source):

    public void release()
    {
        synchronized (mToken) {
            if (!mRefCounted || --mCount == 0) {
                try {
                    mService.releaseWakeLock(mToken);
                } catch (RemoteException e) {
                }
                mHeld = false;
            }
            if (mCount < 0) {
                throw new RuntimeException("WakeLock under-locked " + mTag);
            }
        }
    }

You acquire the lock only once (in onCreate) but release it multiple times (in UpdateWithNewLocation)

So, instead of locking it in onCreate() and releasing it in UpdateWithNewLocation(), you should probably acquire it in the beginning of UpdateWithNewLocation() and release it in its end.