I just started working with Android recently, so I don't know for sure, but I think this might be because the timer used by Handlers is only incremented when the CPU is running. When your phone becomes inactive, the Android OS might shut down the CPU (this was mentioned in one of the Google I/0 2008 talks: Android Anatomy and Physiology: http://www.youtube.com/watch?v=G-36noTCaiA) which prevents the timer used by your handler from being incremented.
Brian のメッセージ: > I rarely post to groups, because I can usually find the answer > somewhere on the web. So I apologize in advance if I have violated any > ettiquette. But this time I am truly stumped, and would appreciate any > help, insight, or suggestion from a more experienced Android > developer. > > I've written a test service to understand how android implements a > service. I believe I understand the difference between > Context.startService and Context.bindService. If I am not mistaken, > Context.startService will tell android to keep the service running, > even after the Activity that started it has ended. > > While testing the service, I have come across something unexpected. > > The service appears to sleep or pause for a few hours, run a short > time, and then sleep for a few more hours, then run a short time, etc > when the phone has become inactive. In other words, when I am doing > things on the phone the service is doing what it is supposed to. But > after I have finished doing things on the phone and the screen goes > blank the service appears to sleep or pause. I don't know if I have > implemented the service wrong or if this is how Android services work. > > The test service I have written simply sets a postDelayed handler to > increment++ a variable in the Runnable every minute, and then write > the value of that variable and a timestamp to a file (log.txt) on the > sd card. This how I know that the service appears to sleep. Because > there are gaps in the timstamp that correspond to when the phone was > inactive. If the service were truly active the whole time, there > should be a line item in the log.txt file every minute. > > From the log.txt file below you can see that over an eleven hour > period there are only 36 line items with time stamps ranging from > 10:27 PM through 9:23 AM. If the service was running and active the > whole time there should be over 600 lines in the text file. The phone > was on AC power the whole time so Android should not have tried to > stop services due to power issues. The phone was not used or touched > from about midnight to 9 the next morning, so there should not have > been a low resource clean up. > > I have spent several days looking for an answer and everything I can > find seems to validate that when a service is started and not bound, > it will stay running (http://code.google.com/android/reference/android/ > app/Service.html). However, it appears it does not. Unless I have > completely missed the ball on this. > > I have included the service.java and activity.java as well as the log > file. Any help/ideas would be greatly appreciated. I am truly > stumped... > > > > > Here is the log.txt file > > 02/05/2009 10:27:02 PM: Service Created. > 02/05/2009 10:27:02 PM: Service Started. > 02/05/2009 10:27:07 PM: iCount = 1 > 02/05/2009 10:28:07 PM: iCount = 2 > 02/05/2009 10:29:07 PM: iCount = 3 > 02/05/2009 11:20:49 PM: iCount = 4 > 02/05/2009 11:31:11 PM: iCount = 5 > 02/05/2009 11:32:11 PM: iCount = 6 > 02/05/2009 11:33:16 PM: iCount = 7 > 02/05/2009 11:34:16 PM: iCount = 8 > 02/05/2009 11:35:16 PM: iCount = 9 > 02/05/2009 11:36:16 PM: iCount = 10 > 02/05/2009 11:37:16 PM: iCount = 11 > 02/05/2009 11:38:16 PM: iCount = 12 > 02/05/2009 11:39:16 PM: iCount = 13 > 02/05/2009 11:40:16 PM: iCount = 14 > 02/05/2009 11:41:16 PM: iCount = 15 > 02/05/2009 11:42:16 PM: iCount = 16 > 02/05/2009 11:43:17 PM: iCount = 17 > 02/05/2009 11:44:17 PM: iCount = 18 > 02/05/2009 11:45:17 PM: iCount = 19 > 02/05/2009 11:46:17 PM: iCount = 20 > 02/05/2009 11:47:17 PM: iCount = 21 > 02/05/2009 11:48:17 PM: iCount = 22 > 02/05/2009 11:55:58 PM: iCount = 23 > 02/06/2009 01:06:56 AM: iCount = 24 > 02/06/2009 03:07:41 AM: iCount = 25 > 02/06/2009 04:38:32 AM: iCount = 26 > 02/06/2009 06:54:49 AM: iCount = 27 > 02/06/2009 08:03:14 AM: iCount = 28 > 02/06/2009 08:57:50 AM: iCount = 29 > 02/06/2009 08:58:50 AM: iCount = 30 > 02/06/2009 08:59:50 AM: iCount = 31 > 02/06/2009 09:05:24 AM: iCount = 32 > 02/06/2009 09:06:24 AM: iCount = 33 > 02/06/2009 09:07:24 AM: iCount = 34 > 02/06/2009 09:08:24 AM: iCount = 35 > 02/06/2009 09:23:09 AM: iCount = 36 > 02/06/2009 09:23:17 AM: Service Destroyed. > > > > > > > > Here is the service java file: > > Java: > > package bSoft.bService; > > > import java.io.FileWriter; > import java.text.SimpleDateFormat; > import java.util.Calendar; > > import android.app.Service; > import android.content.Intent; > import android.os.Binder; > import android.os.Handler; > import android.os.IBinder; > > public class bService extends Service > { > private long _iCount = 0; > > > private Handler objHandler = new Handler(); > > > > @Override > public void onCreate() > { > super.onCreate(); > > SaveStatusData("Service Created.\n\n"); > } > > @Override > public void onDestroy() > { > super.onDestroy(); > > objHandler.removeCallbacks(doMonitoringTasks); > > SaveStatusData("Service Destroyed.\n\n"); > } > > > @Override > public void onStart(Intent intent, int startId) > { > SaveStatusData("Service Started.\n\n"); > > objHandler.postDelayed(doMonitoringTasks, 5000); > } > > @Override > public IBinder onBind(Intent intent) > { > return binder; > } > > > private final IBinder binder = new MyBinder(); > > public class MyBinder extends Binder > { > bService getService() > { > return bService.this; > } > } > > > private Runnable doMonitoringTasks = new Runnable() > { > public void run() > { > _iCount++; > > SaveStatusData("iCount = " + String.valueOf(_iCount)); > > objHandler.postDelayed(doMonitoringTasks, 60000); > } > }; > > > public boolean SaveStatusData(String strTextToWrite) > { > FileWriter objFileWriter = null; > > try > { > Calendar objCalendar = Calendar.getInstance(); > SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy > hh:mm:ss a"); > String strDate = sdf.format(objCalendar.getTime > ()); > > StringBuilder objStringBuilder = new StringBuilder(); > > objStringBuilder.append(strDate); > objStringBuilder.append(": "); > objStringBuilder.append(strTextToWrite); > objStringBuilder.append("\n"); > > objFileWriter = new FileWriter("/sdcard/log.txt", true); > objFileWriter.write(objStringBuilder.toString()); > objFileWriter.flush(); > objFileWriter.close(); > } > catch (Exception e) > { > try > { > objFileWriter.close(); > } > catch (Exception e2) { /*Do Nothing*/ } > > return(false); > } > > return(true); > } > } > > > > > Here is the Activity java: > > Java: > > package bSoft.bService; > > > > import android.app.Activity; > import android.content.ComponentName; > import android.content.Context; > import android.content.Intent; > import android.os.Bundle; > import android.view.Gravity; > import android.view.View; > import android.widget.Button; > import android.widget.Toast; > > public class bServiceGUI extends Activity > { > private boolean blnServiceConnected = false; > > > @Override > public void onCreate(Bundle icicle) > { > > super.onCreate(icicle); > setContentView(R.layout.main); > > > > //Just started testing different ways to start the service. > Intent objIntent = new Intent(); > objIntent.setClassName("bSoft.bService", > "bSoft.bService.bService"); > this.startService(objIntent); > // this.startService(new Intent(this.get, bService.class)); > > > } > > > private void ShowNotification(String strMsg, String strPosition) > { > Context context = getApplicationContext(); > > Toast toast = Toast.makeText(context, strMsg, 100); > > if (strPosition.equals("BOTTOM")) > { > toast.setGravity(Gravity.BOTTOM, 0, 0); > } > > toast.show(); > } > > > / > ****************************************************************************************** > SERVICE STUFF > ******************************************************************************************/ > > private void startMyService() > { > ComponentName service = startService(new Intent(this, > bService.class)); > > ShowNotification("Service Started", "BOTTOM"); > } > > private void stopMyService() > { > try > { > Intent i = new Intent(); > i.setClassName( "bSoft.bService", > "bSoft.bService.bService" ); > stopService( i ); > > ShowNotification("Service Stopped", "BOTTOM"); > } > catch (Exception e){ /* Do Nothing */ } > } > } --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Android Developers" group. 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