Alarm Manager is sometimes very long to run the intent - android

I got a problem with the AlarmManager. When the alarm is set, if the alarm's hour has already passed the intent is started which is great. But sometimes there is a very long time (from 30 secondes to 3 minutes) before the intent is started. If anyone knows why, I'm curious to understand.
Here is my code :
public static void setAlarm()
{
Intent intent = new Intent(Application.Context, typeof(AlarmReceiver));
intent.SetAction("ExchangeGo");
PendingIntent pendingIntent = PendingIntent.GetBroadcast(Application.Context, 0, intent, PendingIntentFlags.CancelCurrent);
Calendar dayCalendar = Calendar.GetInstance(Java.Util.TimeZone.Default);
dayCalendar.Set(CalendarField.HourOfDay, 8);
dayCalendar.Set(CalendarField.Minute, 30);
dayCalendar.Set(CalendarField.Second, 0);
dayCalendar.Set(CalendarField.Millisecond, 0);
AlarmManager alarm = Application.Context.GetSystemService(Context.AlarmService).JavaCast<AlarmManager>();
alarm.Cancel(pendingIntent);
alarm.SetRepeating(AlarmType.RtcWakeup, dayCalendar.TimeInMillis, AlarmManager.IntervalDay, pendingIntent);
}
And here the intent :
[BroadcastReceiver]
public class AlarmReceiver : BroadcastReceiver
{
private String SOMEACTION = "ExchangeGo";
public override void OnReceive(Context context, Intent intent)
{
String action = intent.Action;
if (SOMEACTION.Equals(action))
{
Intent intentService = new Intent(context, typeof(ExchangeService2));
context.StartService(intentService);
}
}
}
There is no problem with manifest cause it works, just a bit too long sometimes. And the problem is not from my second intent because I put a breakPoint just before and the waiting time is before the break point.
Anyone ?
Thanks for reading me.

As setRepeating() doesn't guarantee that it will happen at precise time.
That's why you are getting delay of 30 secondes to 3 minutes.
Replace setRepeating() with setExact() refer documentation from Here
manager.setExact(AlarmManager.RTC, startTime.getTimeInMillis(), operation);
To repeat this what you can do is, to schedule this alarm again after executing your current event. So when your 1st intent gets executed schedule alarm for 2nd event using setExact() only. This will guarantee the time accuracy you are expecting

Related

Alarm isn't executed on Android

I have an android app where I try to set an alarm. My code inside activity:
fun setAlarm() {
alarmManager = getSystemService(Context.ALARM_SERVICE) as AlarmManager
val intent = Intent(this, NotificationReceiver::class.java)
pendingIntent = PendingIntent.getBroadcast(this, 0, intent, PendingIntent.FLAG_IMMUTABLE)
alarmManager!!.set(AlarmManager.RTC_WAKEUP, /*calculateAlarmTime()*/1, pendingIntent)
Timber.i("setAlarm executed")
}
I set this alarm, calling setAlarm method. This is my NotificationReceiver class:
public class NotificationReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
Timber.i("onReceive called");
}
}
Why I have only "setAlarm executed" in logcat, and not "onReceive called"? I set alarm to 1 millisecond and it should trigger immeditately. Why nothing happens?
Your second parameter is wrong. It isn't how long from now you want the alarm to occur, it's the Unix timestamp of when you want it to occur. So 1 would have happened back in 1970. You would need to, at minimum, go System.currentTimeMillis()+1. Although that may well cause race conditions, I wouldn't count on an alarm being set for less than a second in the future working.
You set the AlarmManager with RTC_WAKEUP, so you should supply the exact date and time. Instead you set the time to 1 ms, which is interpreted as 1ms after 1-1-1970, 00h00m00s.
If you want to use an relative time from setting the alarmManager you should get the current RTC time, add a few seconds and set the alarmManager with that time. As this method is inexact, allow a few seconds leeway.
See here for description RTC_WAKEUP

How to keep a service alive using AlarmManager.setInexactRepeating()?

I have some existing code that spawns a service intent which does a bunch of stuff in the background. This code does work...
Intent serviceIntent = new Intent(context, APMService.class);
serviceIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startService(serviceIntent);
My question is: how to change this to use the AlarmManager.setInexactRepeating(...) methods?
I have changed the above code to this:
Intent serviceIntent = new Intent(context, APMService.class);
serviceIntent.putExtra("STARTED_BY", starter);
serviceIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
//Set up recurring alarm that restarts our service if
// it crashes or if it gets killed by the Android OS
AlarmManager am = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
PendingIntent pi = PendingIntent.getService(context, 0, serviceIntent, 0);
//am.cancel(pi);
am.setInexactRepeating(
AlarmManager.ELAPSED_REALTIME_WAKEUP //wake up the phone if it's asleep
, cal.getTimeInMillis()
, 10000
, pi);
And I have added these permissions to AndroidManifest.xml...
<uses-permission android:name="com.android.alarm.permission.SET_ALARM"/>
<uses-permission android:name="com.android.alarm.permission.WAKE_LOCK"/>
My understanding is that this is supposed to start the service immediately and then try to restart it again every 10 seconds. But this code isn't working properly.
Using this new code, the service never starts at all and I cannot see why not. To complicate matters the debugger never seems to attach to the app in time to see what's going on.
Can anyone see what I'm doing wrong?
Put AlarmManager code under onDestroy() function of service to schedule start of service as below:
#Override
public void onDestroy() {
/**
* Flag to restart service if killed.
* This flag specify the time which is ued by
* alarm manager to fire action.
*/
final int TIME_TO_INVOKE = 5 * 1000; // try to re-start service in 5 seconds.
// get alarm manager
AlarmManager alarms = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(context, AutoStartServiceReceiver.class);
PendingIntent pendingIntent = PendingIntent
.getBroadcast(context, 0, intent, PendingIntent.FLAG_CANCEL_CURRENT);
// set repeating alarm.
alarms.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() +
TIME_TO_INVOKE, TIME_TO_INVOKE, pendingIntent);
}
And handle starting of your service in AutoStartServiceReceiver as below:
public class AutoStartServiceReceiver extends BroadcastReceiver {
private static final String TAG = AutoStartServiceReceiver.class.getSimpleName();
#Override
public void onReceive(Context context, Intent intent) {
// check broadcast action whether action was
// boot completed or it was alarm action.
if (intent.getAction().equals(AppConstants.ACTION_ALARM_INTENT)) {
context.startActivity(new Intent(context, YourActivity.class));
// handle service restart event
LockerServiceHelper.handleServiceRestart(context);
}
}
}
Kindly note that, your service will not restart if you stop it manually from settings-apps-running apps-your app.
Your service is not starting because of AlarmManager.ELAPSED_REALTIME_WAKEUP, while it should be using AlarmManager.RTC_WAKEUP
If you want to run every 10s keep in mind that above API 21 alarm intervals below 60s are rounded up to 60s.
Also, consider using WakefulIntentService
https://github.com/commonsguy/cwac-wakeful

start repeating alarm from AlarmManager

I want to start a service every day from 8am to 6pm. I am using 3 alarms.
For starting alarm2 everyday at 8am.
For starting service every 1 min.
To stop alarm2.
Is it the proper way? Also I am unable to start alarm2 from alarm1.
This is code for alarm 1:
public class AlarmReceiver1 extends BroadcastReceiver {
int interval;
#Override
public void onReceive(Context context, Intent intent) {
AlarmManager manager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
Intent in=new Intent(this,AlarmReceiver2);
PendingIntent startingIntent = PendingIntent.getBroadcast(context, 0,in, 0);
long duration = interval * 60 * 1000;
manager.setRepeating(AlarmManager.RTC_WAKEUP,timeOn.getTimeInMillis(), 86400000,startingIntent);
}
}
Far from enough code to tell if it has been set up properly. There is a good example here on how you should set up the AlarmManager. I'd recommend looking it through if there is something you've missed.
Also as you can see in the example you gotta reset the Alarms every time the phone is rebooted. If you don't the services will not run.

AlarmManager only lets one Service through when used with setRepeating in Android

I've been struggling with this for a couple of days. What I want to do is run a service periodically, about 2-3 minutes apart. I have an Activity that is responsible for the interface and setting up the first alarm.
The alarm is configured by a BroadcastReceiver which looks like this:
public class Receiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
String message = "Alarm worked";
Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
setAlarm(context);
}
public void setAlarm(Context context){
AlarmManager am = (AlarmManager) context.
getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(context, Receiver.class);
PendingIntent pi = PendingIntent.getBroadcast(context,
0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
Intent dailyUpdater = new Intent(context, DiscoveryService.class);
context.startService(dailyUpdater);
am.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis()
+ (1000 * 30) , pi);
}
}
I've tried using setRepeating for AlarmManager, but it still has the same effect. What happens is that the AlarmManager works how it should, it fires an Intent which the receiver gets and executes onReceive periodically, as it should. However, it executes the service only the first time. After the first time, the alarms still go off, but the service is not executed.
I read some threads from people with similar problems, and one of them mentioned that PendingIntent lasts for only one send. Thus, I opted out to setting the alarm every time so I can set pendingIntent flag for updating every time.
I tried making my service an intentService, which is fine, but then my bluetooth scanner inside the service does not work because intentService thread terminates without waiting for my bluetooth discovery to finish.
Anyone have any idea what can help me?
Here is part of my service:
public class DiscoveryService extends Service {
public void onCreate() {
super.onCreate();
Toast.makeText(this, "MyAlarmService.onCreate()",
Toast.LENGTH_LONG).show();
findEverything();
}
}
EDIT: This is the code that I currently have.
public void onReceive(Context context, Intent intent) {
String message = "Alarm worked";
Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
Intent dailyUpdater = new Intent(context, DiscoveryService.class);
context.startService(dailyUpdater);
}
public void setAlarm(Context context){
// get a Calendar object with current time
AlarmManager am=(AlarmManager)context.
getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(context, Receiver.class);
PendingIntent pi = PendingIntent.getBroadcast(context, 0, intent,
PendingIntent.FLAG_UPDATE_CURRENT);
am.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(),
(1000 * 30) , pi);
}
What happens is that the AlarmManager works how it should, it fires an Intent which the reciever gets and executes onReceive periodically, as it should. However, it executes the service only the first time. After the first time, the alarms still go off, but the service is not executed.
You are calling startService() once when you are scheduling the alarm. You are not calling startService() at all from your BroadcastReceiver. Yet you are scheduling the alarm via the BroadcastReceiver. Hence, when the alarm goes off, the service will not be sent a command, because you are not sending it a command.
I read some threads from people with similar problems, and one of them mentioned that PendingIntent lasts for only one send.
That is only if you use FLAG_ONE_SHOT.
Anyone have any idea what can help me?
Call startService() from your onReceive() method, instead of from your setAlarm() method. Also, add in all the WakeLock management logic, since you are using a _WAKEUP alarm and you are not able to use my WakefulIntentService.

Update service on boot with timer/alarmclock

I have an update service that starts at boot. The thing is I want it to make a check and then wait for a period of time and restart itself. I did this with alarm clock when my service was tied to an application but now it is independent and I only use a broadcast receiver to start it at boot. The problem is that now for some reason I can't integrate my alarm clock with it.
I only have my UpdateService class and my broadcastreceiver class.My code so far in the broadcastreceiver is this, but I want to put the alarm clock here to say schedule the service to start every 30 seconds. I really need this.
#Override
public void onReceive(Context context, Intent intent) {
Intent startServiceIntent = new Intent(context, UpdateService.class);
context.startService(startServiceIntent);
}
Any suggestions are welcome. Thanks in advance.
I found the answer to my problem:
private boolean service_started=false;
private PendingIntent mAlarmSender;
#Override
public void onReceive(Context context, Intent intent) {
if(!service_started){
// Create an IntentSender that will launch our service, to be scheduled
// with the alarm manager.
mAlarmSender = PendingIntent.getService(context,
0, new Intent(context, UpdateService.class), 0);
//We want the alarm to go off 30 secs from now.
long firstTime = SystemClock.elapsedRealtime();
// Schedule the alarm!
AlarmManager am = (AlarmManager)context.getSystemService(context.ALARM_SERVICE);
am.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP,
firstTime,30*1000, mAlarmSender);
service_started=true;
}
}
Eventually,my problem was that I didn't get the context right as follows:
(AlarmManager)getSystemService(ALARM_SERVICE);
changed to
(AlarmManager)context.getSystemService(context.ALARM_SERVICE);

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