How to fix Service Instance Issue?
I am starting a service based on Alarm Manager in every 20 seconds which sends GPS data to my server. The problem is my heap and allocated heap size goes on increasing. When I analysed the heap dump, I found the number of service instances is equal to the number of calls to startService() . How to avoid this issue?
public class SystemBootListener extends BroadcastReceiver {
// Restart service every 30 seconds
private static final long REPEAT_TIME = 1000 * 10;
@Override
public void onReceive(Context context, Intent intent) {
Intent i = new Intent(context, StartLocationServiceAfterReboot.class);
PendingIntent pending = PendingIntent.getBroadcast(context, 0, PendingIntent.FLAG_UPDATE_CURRENT);
// Start 20 seconds after boot completed - so that all providers are initialized by then
Calendar cal = Calendar.getInstance();
cal.add(Calendar.SECOND, 20);
// Trigger every 10 seconds
// InexactRepeating allows Android to optimize the energy consumption
AlarmManager service = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
service.setInexactRepeating(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(), REPEAT_TIME, pending);
}
}
public class StartLocationServiceAfterReboot extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
if(AppSettings.isRouteConfigured(context)){
AppSettings.setServiceRunning(context, Boolean.TRUE);
Intent service = new Intent(context, GPSComputationService.class);
context.startService(service);
}
}
}
public class GPSComputationService extends Service {
private static final int MAX_TIME_TO_FETCH_NEW_LOCATION = 8000;
private final IBinder mBinder = new ServiceBinder();
private Timer timerToFetchLocInfoFromProviders = null;
private LocationManager locationManager = null;
private boolean gpsProviderEnabled=false;
private boolean networkProviderEnabled=false;
private int numberOfSatellites = 0;
private GPSData bestKnownLocation = new GPSData();
private TCPWriter tcpWriter ;
@Override
public void onCreate() {
// TODO Auto-generated method stub
super.onCreate();
tcpWriter= new TCPWriter(this);
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
/*tcpWriter= new TCPWriter(this);*/
computeBestLocation();
return Service.START_STICKY;
}
private void stopGPSComputationService(){
stopSelf();
}
@Override
public IBinder onBind(Intent arg0) {
return mBinder;
}
public class ServiceBinder extends Binder {
public GPSComputationService getService() {
return GPSComputationService.this;
}
}
public GPSData getBestKnownLocation() {
return bestKnownLocation;
}
public void publishBestKnownLocation(GPSData bestKnownLocation) {
this.bestKnownLocation = bestKnownLocation;
sendBestKnownLocationToNMEAServer();
}
public void sendBestKnownLocationToNMEAServer(){
if(getBestKnownLocation() == null){
stopGPSComputationService();
return;
}
TelephonyManager telephonyManager = (TelephonyManager)getSystemService(Context.TELEPHONY_SERVICE);
telephonyManager.getDeviceId();
NMEAData dataPacketToWrite = new NMEAData(
telephonyManager.getDeviceId(),
getBestKnownLocation().getLatitude(),
getBestKnownLocation().getLongitude(),
getBestKnownLocation().getTimeStamp(),
getBestKnownLocation().getSpeed(),
getBestKnownLocation().getNumberOfSatellites()
);
tcpWriter.sendMessage(NMEAServerTypes.MVT600,
dataPacketToWrite);
stopGPSComputationService();
}
public GPSData computeBestLocation() {
Log.d("#############GPSComputation Status", "Running.......");
try{
if(locationManager==null)
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
//Add status listener for satellite count
locationManager.addGpsStatusListener(gpsStatusListener);
Criteria criteria = new Criteria();
criteria.setSpeedRequired(true);
criteria.setBearingRequired(true);
List<String> providers = locationManager.getProviders(criteria, false);
//Capture if the GPS/Network providers have been disabled.
try{
gpsProviderEnabled=providers.contains(LocationManager.GPS_PROVIDER) &&
locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
}catch(Exception e){
}
try{
networkProviderEnabled=providers.contains(LocationManager.NETWORK_PROVIDER) &&
locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
}catch(Exception e){
}
if(!gpsProviderEnabled && !networkProviderEnabled)
return null;
if(gpsProviderEnabled)
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListenerGps);
if(networkProviderEnabled)
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListenerNetwork);
timerToFetchLocInfoFromProviders=new Timer();
timerToFetchLocInfoFromProviders.schedule(new GetLastKnownGoodLocation(), MAX_TIME_TO_FETCH_NEW_LOCATION);
locationManager.removeGpsStatusListener(gpsStatusListener);
//Finally store the data in backend Service
return getBestKnownLocation() ;
}catch(Exception e){
return null;
}
}
LocationListener locationListenerGps = new LocationListener() {
public void onLocationChanged(Location location) {
timerToFetchLocInfoFromProviders.cancel();
publishBestKnownLocation(extractAllGeoInfFromLocation(location));
locationManager.removeUpdates(this);
locationManager.removeUpdates(locationListenerNetwork);
locationManager.removeGpsStatusListener(gpsStatusListener);
gpsStatusListener = null;
}
public void onProviderDisabled(String provider) {
}
public void onProviderEnabled(String provider) {
}
public void onStatusChanged(String provider, int status, Bundle extras) {
}
};
//listen for gps status changes to capture number of satellites.
GpsStatus.Listener gpsStatusListener = new GpsStatus.Listener() {
@Override
public void onGpsStatusChanged(int event) {
if (event == GpsStatus.GPS_EVENT_SATELLITE_STATUS || event == GpsStatus.GPS_EVENT_FIRST_FIX) {
GpsStatus status = locationManager.getGpsStatus(null);
Iterable<GpsSatellite> sats = status.getSatellites();
// Check number of satellites in list to determine fix state
int tempNumberOfSatellites = 0;
for (GpsSatellite sat : sats) {
if(sat.usedInFix())
tempNumberOfSatellites++;
}
numberOfSatellites = tempNumberOfSatellites;
}
}
};
LocationListener locationListenerNetwork = new LocationListener() {
public void onLocationChanged(Location location) {
timerToFetchLocInfoFromProviders.cancel();
publishBestKnownLocation(extractAllGeoInfFromLocation(location));
locationManager.removeUpdates(this);
locationManager.removeUpdates(locationListenerGps);
}
public void onProviderDisabled(String provider) {
}
public void onProviderEnabled(String provider) {
}
public void onStatusChanged(String provider, int status, Bundle extras) {
}
};
class GetLastKnownGoodLocation extends TimerTask {
@Override
public void run() {
locationManager.removeUpdates(locationListenerGps);
locationManager.removeUpdates(locationListenerNetwork);
Location bestKnownNetworkLocation = null, bestKnownGPSLocation=null;
if(gpsProviderEnabled)
bestKnownGPSLocation=locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if(networkProviderEnabled)
bestKnownNetworkLocation=locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if(bestKnownGPSLocation!=null && bestKnownNetworkLocation!=null){
if(bestKnownGPSLocation.getTime()>bestKnownNetworkLocation.getTime())
publishBestKnownLocation(extractAllGeoInfFromLocation(bestKnownGPSLocation));
else
publishBestKnownLocation(extractAllGeoInfFromLocation(bestKnownNetworkLocation));
return;
}
if(bestKnownGPSLocation!=null){
publishBestKnownLocation(extractAllGeoInfFromLocation(bestKnownGPSLocation));
return;
}
if(bestKnownNetworkLocation!=null){
publishBestKnownLocation(extractAllGeoInfFromLocation(bestKnownNetworkLocation));
return;
}
AppLog.logWarningMsg("Bad luck-NO BEST LOCATION AVAILABLE");
publishBestKnownLocation(null);
}
}
private GPSData extractAllGeoInfFromLocation(Location location){
bestKnownLocation = new GPSData();
bestKnownLocation.setLatitude(location.getLatitude());
bestKnownLocation.setLongitude(location.getLongitude());
bestKnownLocation.setTimeStamp(location.getTime());
bestKnownLocation.setSpeed(location.getSpeed()*3.8);
bestKnownLocation.setNumberOfSatellites(numberOfSatellites);
return bestKnownLocation;
}
}
There is only one instance of service. As per the document
Multiple calls to Context.startService() do result in multiple corresponding calls to onStartCommand()), But only one service instance can exist.
On startService(), the Android system calls the service's onStartCommand() method. If the service is not already running, the system first calls onCreate(), then calls onStartCommand().
The only thing that can create this kind of scenario is that you have some kind of memory leak. Your service did it's work and stopped but didn't garbage collected. it probably happen few times and that is why you see many instances of it.
It's hard to find memory leaks but i would suggest you to start from the listeners. check if you unregistered them at the right time.
This link can help you to detect the leak: https://developer.android.com/studio/profile/am-memory.html
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