I have a service in my android application and I need that it never stop.
How to mark my service so the user could never stop it?
If the user goes to: "Setting - Applications - Running Services - My Service" and click on STOP, my service should not be stopped.
How can I do this?
You cannot prevent stopping a service. The same way you cannot prevent somebody from force closing your app. Even if it were possible, the user could still kill your service by uninstalling your app. Why do you want the service not to be stopped?
On second thought you could have two services that monitor each other periodically by checking ActivityManager.getRunningServices(). When one service is killed the other could restart it. This would probably be considered malicious activity on your part, and you would likely receive very negative reviews.
I'm going to sidestep the obvious question:
Why would you want to do this?
and give you a workable answer. You need two services. Each one monitors the other. If the user kills service A, service B restarts it. If the user kills service B, service A restarts it.
The services will have to be very quick to respond and relaunch the service. This would prevent the user from killing them both at once. So you'll need to design a very quick heartbeat service, but it should be possible. Of course, this will not prevent the user from simply uninstalling your app.
"I fight for the users".
I would be frustrated with an app that didn't let me cancel a service it was running.
I can't think of a use case in which an app (not something in the system) should prevent the user from cancelling something. You should, of course, notify users if the service isn't running, and provide an easy way to restart it.
Related
This is similar to another question I asked where I was wondering how other apps like drupe dialer keep their service running forever when it is not in foreground. Because I've used job services, alarm manager, START_STICKY and everything else to try to keep my service alive but it always gets stopped by the OS.
You can run the service as "Foreground" and it will be not candidate to be killed by the system under low memory conditions. The gotcha is that you will need to show that behavior to the user with a notification. This is the way that music players uses to go background and alive when you start another apps.
Foreground Services
The app you mentioned (Drupe Dialer) is a Dialer. It might be listening to broadcasts and turning the service up every time by checking whether its up.
To answer your question, you need to keep the service started as START_STICKY to make it restart after the OS kills it. But AlarmManager does not work at device sleep states, and doze will stop it from running in the background nevertheless.
The real question is; WHY you want to keep it running? That might answer your question on HOW you want to do that.
If its a communication type app, you will need to use something like
GCM.
If its running background work based on some event, you might
want to start the service inside the BroadcastReceiver.
etc.
it depends on what app you're writing.
I have started a service from my application and from that service a worker thread is started .I want my service to run even application goes background and until the user kills/exits the application.
But some cases my service got killed due to low memory ,then used sticky service or making the app to foreground to restart the service.
My issue is I dont want to lose the data between service ending and restarting time ,so is it possible to start another thread from service ondestroy method, but in this case how we can control that thread.
Please let me know is it the right approach ,and is this usecase achievable
I want my service to run even application goes background and until the user kills/exits the application.
This is not possible. The user can always get rid of your app, via Force Close in Settings, or via some device's version of the recent-tasks list.
But some cases my service got killed due to low memory
No, your process is terminated for low memory.
My issue is I dont want to lose the data between service ending and restarting time ,so is it possible to start another thread from service ondestroy method
No, because your process is being terminated.
Please let me know is it the right approach
Probably not. Very few apps need a service that runs constantly, which is why Android, and its users, go to great lengths to control such services. I would recommend that you try to find some solution to whatever your problem is that does not need a service running constantly.
I want to perform action/event when application killed from task manager or any other app. Is there any to perform action when application killed. My application is running in background like service. If i terminate the application then main service stop . I want to start it again.
No, there's no reliable way to know if your application was killed by a another process. The whole point of "killing" an app is to terminate it as soon as possible, without letting it run any code.
== Do not actually use the following suggestions in production application. They are here purely as potential technical solutions, but in general are not a good idea for apps running on end user devices. ==
It might be possible to use IBinder.linkToDeath() from a secondary application, which acts as a monitor for your primary one. However, you will have to convince the user to install the secondary app as well. If you can do it, you could establish two-side monitoring between the two apps, and have one of them restart the other if the second is killed.
You could also attempt to set an alarm through the AlarmManager that fires every so often, to restart your application if it happens to be killed. However, if your alarm period is too big, you risk having certain period of time where your app is not running. And if your time period is too small, most likely your app will not be allowed by Google in the Google Play Store, and the malware app analysis on the phone (JB+) might kick in. Also, alarms that kick in too often will keep the device awaken, and drain the battery very fast.
If you kill some process, you just kill it, so it stops working immediately. There is no event sent to the application.
I looked for the same thing and the answer that i found is : NO, the application does not go to OnDestroy() or anything like that.
What happens to a service started by BOOT_COMPLETE after system kills it for memory?
Will it ever be restarted without rebooting the phone? Is it possible to restart it somehow?
What is the best practice to avoid as much as possible an important service from being killed?
Will it ever be restarted without rebooting the phone?
Possibly. If it truly was because "system kills it for memory", and you return an appropriate value from onStartCommand() (e.g., START_STICKY), it should be restarted at some point in the future. If the service was killed due to user action (e.g., Force Stop in the Manage Services screen in Settings), it will not be restarted.
What is the best practice to avoid as much as possible an important service from being killed?
First, design your application to not rely on an everlasting service like this. 99.44% of Android applications do not need a service that runs continuously, let alone one that starts doing so at boot time. Android device users hate developers who think that their apps are sooooooooooooo important that they have services running all the time -- that's why we have task killers, Force Stop, and Android killing services due to old age. For example, if you are checking for new email every 15 minutes, use AlarmManager and an IntentService, not a service that runs forever.
If you can demonstrate -- to me and to your users -- that yours is among the 0.56% of applications that really do need a service that starts at boot time and runs forever, you can use startForeground(). This will indicate to the OS that your service is part of the foreground user experience. You will have to display a Notification, ideally to allow the user to shut down your service cleanly if and when the user no longer feels that it is justified.
If you need to restart the service then you should use AlarmManager to check up on the service in a separate BroadcastReceiver, but nominally when a service is killed by the system for memory it will not get automatically restarted.
You may want to take a look at START_STICKY
Use the AlarmManager to periodically send an Intent-- receive the intent and make sure your service is running.
My app runs a geolocalisation service that the user can active or disactive by a toggleButton. To check the status of the service, I write a boolean in the Shared Preferences. I listen the beginning of the service and the end of it thanks to the onDestroy() of my service.
My problem is that: When the user kill the service with the "advanced task killer", I can't know that the service is killed, the onDestroy is not called !
How can I deal with that?
Thanks for your help.
Florent
When a process is killed (using ATK or android's own force stop button, or the function here), it is immediately purged from memory (if the kernel allows it). This means there's no chance for any additional code to run, meaning there is no way to really deal with a "force kill" sent to your application.
If you want to handle this, you have 2 options (that I can think of):
Publish a disclaimer telling users to add your app to the "ignore" list of ATK.
Find some way to maintain functionality without relying on the onDestroy() method.
EDIT:
If you want to check for your process from a list of currently-running processes, look into getRunningAppProcesses().
onDestroy()
If you want to restart the service, you can restart in onDestroy().