I have implemented Android Speech Recognition as a service on Android 4.1 & 4.2 recognition solution in my application, with some minor modification(e.g: 1500ms countdown, mute beep), which works basically fine.
I would like to run this service for hours. I tested a lot this solution and i experienced unexpected stops.
The recognition is running in the background, notification icon is displayed, which indicates, when the recognition service is on. After 10-15 minutes continuous listening without any exception the whole applications stops. (But it happened, after 8 recognition periods as well, after 30 secs.) When it happens, I was able to trace one thing, one more time the thread enters the extended Application class' onCreate() method, where the logs are printed out, but nothing else works. The displayed notification can't be removed.
I don't have leak related exception during listening or any suspicious log message.
Is anyone experienced similar stops? Is anyone has any idea why it happens?
I've tried to restart the service after every 20th (handler) starts to avoid this behaviour, so the service is not running for that long. But the situation is the same.
If you have any suggestion what are the possibilities to run the service for many hours, please share.
BEFORE READING THE FIX BELOW, PLEASE BE AWARE THAT
Keeping a service on for a long time and not allowing the system to kill is a bad idea. The phone has limited battery and the Service runs even when is sleep mode.
Android will kill different services based on the memory state, so on devices with more memory it might not stop. But make it not stop you need to tell the OS that your service is important and, quote from android reference, it can't "be killed without too much harm". To tell the system that you want your service when it can be killed and when it cannot, take a look at startForeground and stopForeground methods, described below.
Start Foreground
It makes the service run in the foreground, making the system prefer to kill other services other than yours to free memory. But, even if you use this method, it is not guaranteed that your service will not stop. It may stop if the phone is on very low memory. Also:
You can set this flag if killing your service would be disruptive to the user, such as if your service is performing background music playback, so the user would notice if their music stopped playing.
Stop foreground
Remove this service from foreground state, allowing it to be killed if more memory is needed.
Links to documentations:
Start Foreground method
Stop Foreground method
Related
I have written an VPN using android's VPNService and it works perfectly. When I run it, it creates a foreground service and sends all traffic through my VPN server. It also has an internal reconnecting mechanism to reconnects VPN server if it disconnects for any reason without stopping service itself.
I like to have this VPN service working all the time. But my problem is that this VPN service is stopped occasionally after a completely random period(sometime it takes just 10 minutes, but other times it works for 2-3 days before stopping).
Since the stopping time is completely random and I cannot find any place in code that creates this situation (I have been debugging for weeks), I thought maybe android OS itself stops my VPNService for some reason. I wonder if there is a way to detect if system has stopped my service from outside or not. Any idea?
Unfortunately, Android OS still can terminate the service in low memory and possibly other situations, even if it's a background running service !
It is not only Android, but all Mobile Operating Systems optimize RAM usage by killing background apps.
This is done so that the foreground app can be given top priority. It ensures smooth functioning of the current app and reduces load on the system.
There's are two approaches as mentioned in this post: Background Service getting killed in android
If you are implementing the service, override onStartCommand() and
return START_STICKY as the result. It will tell the system that even
if it will want to kill your service due to low memory, it should
re-create it as soon as memory will be back to normal.
If you are not sure 1st approach will work - you'll have to use
AlarmManager
http://developer.android.com/reference/android/app/AlarmManager.html
. That is a system service, which will execute actions when you'll
tell, for example periodically. That will ensure that if your service
will be terminated, or even the whole process will die(for example
with force close) - it will be 100% restarted by AlarmManager.
I had this issue previously and I've solved it by creating the service running forever even if it's killed manually or from the system it recreates itself.
I'm creating an app that captures location every 30 seconds. To do so, I've a foreground service and a handler in it that gets the latest location every 30 seconds. The app is working just fine for many devices with stock OS. But, on some devices like OnePlus, Panasonic, Vivo etc. the foreground service gets killed by the OS(sometimes the app too) even after changing the battery optimization status and the doze mode. I know that it is not possible to create a service in Android that does not die. Is there any way I can achieve what I'm trying to? Please let me know. Thanks!
First of all, yes you are right the operating system will stop services when resources are limited, so to get around this you state the type of the services while creating them as the following:
START_STICKY, START_NOT_STICKY, START_REDELIVER_INTENT...
read the last part of this article it talks about when to use which of them
https://android-developers.googleblog.com/2010/02/service-api-changes-starting-with.html
Service.onStartCommand() callback that allows the service to better control how the system should manage it. The key part here is a new result code returned by the function, telling the system what it should do with the service if its process is killed while it is running.
Android app that I am working on reads from near by beacons(devices) using bluetooth. It works fine when the app is in the foreground (tested it for 20 minutes). However, few minutes after app goes to background it stops reading.
I notice when app goes to background, onpause() method is executed; still my app reads for few minutes and then simply stops reading anything (when I manually bring the app to foreground, oncreate method is executed and app continuous normally).
Why is my app stopped reading few minutes after it went to background. My app is an activity and not service.
should convert the activity to service or
should I create intentservice or
should I create foregroundserive
I donot understand the difference between above 3 types of services and if any of them would help me.
Though slightly older threads, I reviewed Prevent that the app get stopped or paused by the OS and How can we prevent a Service from being killed by OS? and my app killed by android system when it running in background
But I am lost. Any discussion is appreciated
EDIT
As I understand from #davidgyoung answer, I have to write a service. I assume GUI portion of my app goes into mainactivity; then how I can ensure my mainactivity/GUI is still active in memory and was not killed by Android by the time service tries to broadcast/notify GUI
/EDIT
An Activity is not designed to run for long periods in the background. The Android OS will destroy activities that are not visible as memory is needed for other functions. While a Service is the proper alternative, even a service will be destroyed under memory pressure by the OS, so you still need to restart the service if it is killed by the OS and you continue to want to do beacon scanning.
All of these issues came up when we built the Android Beacon Library, and we settled on these solutions to keep scanning going:
Use a Service to scan for beacons in the background. It does not have to be an IntentService, but that is a reasonable option.
Use an AlarmManager to restart the scanning service 5 minutes in the future in case it gets killed. (This delay allows the OS to time to recover from a temporary need for extra memory.) If the scanning service is still running, just reschedule the alarm.
Register for OS level events (boot, power connect/disconnect) to restart the scanning service at a later time if the user kills the app with the task switcher.
All of this is built for you if you decide to use the Android Beacon Library (and we welcome contributions, too!) If you want to roll your own, you may want to look at the source code to see how these things were built. Feel free to copy and modify, too. That's the beauty of open source!
Full disclosure: I am the lead developer on the Android Beacon Library open source project.
I've been looking through many questions about services, but I couldn't find one that suited me.
I need a service that both starts on BOOT_COMPLETED (not bound to an Activity) and runs ALL the time (therefore I can't user AlarmReceiver). I know it might drain my battery but so far I don't care. It is just for research purposes.
I have a service that monitors sensor's data. What I managed to do so far was: either start the service as a regular Activity, but it runs only for +-20s and it is stopped (I think the SO cuts it down to release its memory); or start a service that runs in foreground. It worked to keep the process running, however the class that actually runs the service somehow was not started, besides an annoying notification which is required.
The code I refered as the one that runs the service in foreground was taken from here:
Implement startForeground method in Android
I mean, how does an app like WhatsApp run constantly? Is it running in foreground? Because looking at Settings it seems the service is very stable, and it does not show any permanent notification, since it is not possible for a foreground service run without one.
( How to startForeground() without showing notification? )
Any advice?
You can use a WakeLock. But please remember, with great power comes great responsibility (to release them again and not over-use them).
But for now, just acquire a hefty WakeLock and only release it until you are done. This should keep your device's screen and CPU awake and allow you to do whatever it is you want to do.
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.