It leaks when I startLeScan in onCreate and stopLeScan in onDestroy - memory-leaks

Question

I run my code and rotate the phone couple of times, then dump memory and analyze it.
Below is my code:
private BluetoothAdapter.LeScanCallback mLeScanCallback = new BluetoothAdapter.LeScanCallback() {
#Override
public void onLeScan(BluetoothDevice device, int rssi, byte[] scanRecord) {
LogUtils.e("111");
}
};
private boolean mScanning = false;
private BluetoothManager bm;
private void scanLeDevice(final boolean enable) {
LogUtils.e(enable);
try {
if (enable) {
mScanning = true;
if(bm.getAdapter()!=null)bm.getAdapter().startLeScan(mLeScanCallback);
} else {
mScanning = false;
if(bm.getAdapter()!=null)bm.getAdapter().stopLeScan(mLeScanCallback);
}
invalidateOptionsMenu();
}catch (Throwable e){
}
}
#Override
protected void onDestroy() {
super.onDestroy();
scanLeDevice(false);
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
initStage();
}
#Override
protected void initStage() {
bm = (BluetoothManager)getSystemService(Context.BLUETOOTH_SERVICE);
scanLeDevice(true);
}
The java heap:

Answer 1

The LeScanCallback is holding a reference to the Activity. I just ran into this when testing the BluetoothLeGatt sample provided by Google. I copied the scanning code into my app and I suddenly found massive leaks occurring.
I solved it by wrapping the scan callback into a static class which then holds a weak reference to the activity. Much like Google reccomends when using a Handler. Like this:
private final BluetoothAdapter.LeScanCallback mLeScanCallback = new LeScanCallbackClass(this);
private static final class LeScanCallbackClass implements BluetoothAdapter.LeScanCallback {
private String TAG = makeLogTag(LeScanCallbackClass.class.getName());
private final WeakReference<TrackActivity> mAct;
public LeScanCallbackClass(TrackActivity act) {
mAct = new WeakReference<>(act);
}
#Override
public void onLeScan(final BluetoothDevice device, int rssi, byte[] scanRecord) {
LOGI(TAG, String.format("BLE LeScan Result: %s", device.getAddress()));
final TrackActivity act = mAct.get();
act.runOnUiThread(new Runnable() {
#Override
public void run() {
mLeDeviceListAdapter.addDevice(device);
mLeDeviceListAdapter.notifyDataSetChanged();
}
});
act.sendNotification();
}
}