Develop Reference

Android 6: App uses more memory each time it's started

Samsung Galaxy S6 with Android 6.0.0 and 6.0.1
My app runs fine, code analysis shows no mem leaks. SmartManager shows that the app uses ~40MB of memory. I kill the app (using the "currently running apps" overview--- not sure how that's called in English, sorry. The key on the bottom left of the phone, that shows a list of miniatures of all running apps...), then start it again.
Now SmartManager no longer shows ~40MB of memory for my app, but ... more. 50. 100. 400. It varies, but growing each time. After awhile, my app actually crashes with an OutOfMemoryException. Sometimes even with "out-of-memory while trying to throw an OutOfMemoryException"...
I have to de-install and re-install the app in order to reset its memory consumption. The same APK behaves correctly on all other phones I've tested with (e.g. S5 with Android 5.0). No idea what's causing this. No idea what could be causing this! Any help/hints/suggestions...?
Edit: Same behaviour on S5 with Android 6.0.1, but not on S5 with Android 5.0!
Edit2: Thanks, everyone who contributed. I still don't have an answer that I'm satisfied with, but a few ideas were mentioned that I will look into. Most people were focusing on the MemLeak issue, and while that sounds reasonable I'd like to stress that there is no leak occuring on Android 4 or 5, only 6. (I have yet to test 7.) Also, the leak only occurs when I forcefully kill the app (which I need to do at times to test proper shutdown and re-start behaviour), and only without a debugger attached (which makes testing/debugging this behaviour a pain in the backside).
The app starts one service as a bound service. Bound to the application context--- which according to the docs should clean itself up when the app stops.
Unfortunetely, time for this bounty is running out. So far, the above mentioned service seems to be the most likely source of my problem. As such, I will award Qamar the bounty, as he was the first to mention this both in the comments and his answer. The rest of you, a big THANK YOU and up-vote.

In Android Studio, click Android Monitor at the bottom of your screen. Click the tab Monitors. You see a graph of the memory that your app uses. Now click the item Dump Java Heap which is next to the garbage van. The system starts collecting the info and creates a dump file. You can open the file in the Analyze Tasks tab in the upper right of your Android Studio window. Press the green arrow to find classes that leak memory. When you click a leaking activity, you'll see a window Reference Tree. Go through the tree, finding the member that has depth zero. That's the memory leak.

Analyse your code and images if anything wrong you are doing itself. Like very large images of drawables. make sure you correctly implement recycler or list views.
The following links may helpful to you.
Use leakcanary library to detect and make sure there is not leaks
Detect when user kill app from reccent apps
Invoke gc from memory monitor comes with Android Studio for correct value of memory usage cause gc not run frequently.
Use large heap size. <application android:largeHeap="true" in manifest
Use app context to start servicesstartService(new Intent(getApplicationContext(),MyService.class));

Your application has some threads are timer tasks that are creating again and again and they are utilizing many resources related to networks so your heap size is consistently increasing and at sometime your app is out of memory and crashes.

Some people think that task killers are important on Android. By closing apps running in the background, you’ll get improved performance and battery life – that’s the idea, anyway. In reality, task killers can reduce your performance.Android isn’t Windows and doesn’t manage processes like Windows does. Unlike on Windows, where there’s an obvious way to close applications, there’s no obvious way to “close” an Android application. This is by design and isn’t a problem.When you leave an Android app, going back to your home screen or switching to another app, the app stays “running” in the background. In most cases, the app will be paused in the background, taking up no CPU or network resources. Some apps will continue using CPU and network resources in the background, of course – for example, music players, file-downloading programs, or apps that sync in the background.When you go back to an app you were recently using, Android “unpauses” that app and you resume where you left off. This is fast because the app is still stored in your RAM and ready to be used again,hence consuming no further resources.
Task killers like smart manager think they know better than Android. They run in the background, automatically quitting apps and removing them from Android’s memory. They may also allow you to force-quit apps on your own, but you shouldn’t have to do this normally.If a task killer removes an app from your RAM and you open that app again, the app will be slower to load as Android is forced to load it from your device’s storage.Further s6 has Smart Manager and could be used as a widget or shortcut to battery and storage settings,however you should avoid using the Clean All optimization feature. This feature is said to improve device performance – as the Clean Master app aims to do – but its actual impact is questionable.
Meaning while still sometimes you kill an app it can still leave the traces on heap so next time when you start it ,it will show varyingly more amount of storage used which also fails the notion of default maxMemory() and the app ultimately might crash.Further such leaks are difficult to track as they aren't directly associated to app you killed in first instance.But still sometimes even after killing app, certain features like resources attained may keep running in background without even the app even knowing about them.i.e unnoticeable leaks.Thus you may want to use maxMemory()
which can be invoked (e.g., in your main activity's onCreate() method) as follows:
Runtime rt = Runtime.getRuntime();
long maxMemory = rt.maxMemory();
Log.v("onCreate", "maxMemory:" + Long.toString(maxMemory));
This method tells you how many total bytes of heap your app is allowed to use.
Optimal Behaviour:
An app can stay "running" in the background without any processes eating up your phone's resources. Android keeps the app in its memory so it launches more quickly and returns to its prior state. When your phone runs out of memory, Android will automatically start killing tasks on its own, starting with ones that you haven't used in awhile.
What You Should Do Instead
That said, not all apps are created equal. Many of you have used task killers in the past and actually found that after freeing up memory, your phone works a bit better. It's more likely that this is because you've killed a bad app that was poorly coded, and (for example) keeps trying to connect to the internet even when it shouldn't. Any performance increase you experience is more likely because you killed the right app, not because you freed up loads of memory (or, in many cases, it's just placebo). Instead of killing all those apps, find out which ones are actually causing the problems.using a task killer to deal with a misbehaving app is like using a shotgun to kill a fly – you may fix your problem, but you’re inflicting a lot of other damage in the process.Now
since S6 has 3 gigs of ram,it should'nt have problems,however implementation of smart manager can cause problems with some apps and isnt necessarily android version dependent.Also bare that heapsize tends to be based more on screen resolution, as higher-resolution screens tend to want to manipulate larger bitmaps.
Instead of using a task killer in this situation, you should identify the bad app and uninstall it,or debug it, replacing it with an app that works properly. To pin down the app that’s misbehaving, you can try the
Watchdog Task Manager app
– it will show you which apps are actually using CPU in the background, not which apps are harmlessly being stored in memory.
Captivating Fact:
CyanogenMod, the popular community-developed Android ROM, won’t even
accept bug reports from users using task killers, saying that they
cause more problems than they solve.
A probable cause of issue
if you can try following at once,first of all go to settings >sounds and notifications > App notifications > select smart manager and select hide content on lock screen
then again back to settings go to lockscreen and security >Device security >Disable KNOX active protection and deactivate the anti malware option below KNOX active protection
in lock screen and security go to other security settings > disable send security reports and go down to ussage data access> disable smart manager so after that restart your device.Now see if the app works Also see performace concerns with s6

Is there somethign similar to the Windows Task Manager for the android emulator

I was studying some tutorials on Android programming and I realized that pressing the Home button on the emulator takes me tot he phones Desktop, but my sample that was running at the time only goes to the background and does not get destroyed. However, if I press the return button, the app is destroyed as well. So I am assuming there might be other apps running int he background as well, those which I am not aware of. Is there something in the android emulator resembling the task manager from windows, which shows what apps are currently running on the phone? I don't have a smartphone with me, but I remember seeing something like that on my friend's smartphone a few days ago. It wasn't an external app but was something built into the phone, I could access it by going to Settings or something.
Is there a task manager built into the android emulator, or is there any other way I can see such things through the SDK debugger?

Inside the settings, there is a list of currently running processes.

First , Leaving the activity does not mean the process ends, It is just not invisible . When the Os needs more memory ,it will be recovered.
If you want to have a backup process, you can start a back service.
http://developer.android.com/reference/android/app/Service.html

Here is how I end a process (only works on Android 4.0+).
Instead of pressing home, press recent and swipe away the process you want to end. Then press home (or back).
You can also use this to close those nasty apps that prevent you from closing them by not allowing back button to work on their main screens.
This is much quicker than having to go to settings, etc.

Android application seems to continue running after exiting

This might be a bit of a stupid question but my application seems to stay running even after I have stopped it. I close it by holding down the home key and dragging the application off to the left. However, I still see logcat output, it only stops if I go to settings-->Apps-->Running Apps and stop it this way. Is this a bug in my application or is this expected android behavior?

This is expected . Android behaviour
Unlike many other Operating Systems, Android does by default not have a dedicated button to close an application manually. This is because Android is designed to manage the running applications itself and close them as needed.
By design, Android handles the memory and time assigned to applications. This ensures that applications that are left opened do not cause the smartphone to slow down or run out of memory.
When pressing Home button, your app will go to the background and Android O/S will close it when low on memory. If not and you open the application again, it resumed where you left off.
Unless you specifically create a method in your application that closes (finishes) your app.

Android app auto reset on minimize

We have designed an hybrid app which is a bit heavy (9 MB). Problem is that at times, minimizing this app (home button) makes the app reset in background i.e. its app cache is lost and app reloads from splash screen. After minimizing we worked with other apps in tablet (Galaxy 800).
We saw this problem only if we tried to launch app from the icon in launcher. This problem did not happen when we tried to launch it from the minimized list(recent apps button).
This problem is not specific to the tab. It also happened in Galaxy 3 and Droid Razr also.
Any guidance?

Problem is that at times, minimizing this app (home button) makes the app reset in background i.e. its app cache is lost and app reloads from splash screen.
This is perfectly normal.
Computers, phones, and tablets do not have infinite RAM. Android's approach to this problem is to keep your process around for a while after the user has left it, but eventually Android will terminate your process to free up RAM for other applications and their processes. You can read more about the Android process model in the documentation.

It can be possible that ‘deep clean' option is enabled by mistake on your phone. What deep clean does is, whenever you minimize an app , it releases all the memory associated with that app, and hence when you again open that app, it will start as if it is new. To check the 'deep clean' option,
go to the
Developer options -> 'Don't keep activities' -> disable it
If it is not disable please disable it.

Disabling the notification tray

A little background first. I'm developing an application for corporate devices running on the Android platform. It won't be distributed on the Play store and thus, is unavailable to the general public. The devices are owned by the company and its only purpose is to run this application. So accessing the home screen/notifications/application history/ app drawer are unnecessary and in fact we want to focus the user experience directly on this application.
The current problem I'm facing is preventing access to the notification tray. Simply making the application full screen is not a solution. We do actually need to see the status bar. It's the easiest way to provide network,gps and battery status information to the user.
So far my research has only turned up one solution, which is to go full screen (again, not a solution for this problem,I need the status bar to be visible). I know there's a number of lock screen apps that are able to do this so there must be a way. I just haven't found it yet.

I am not sure, but probably that you can't just lock notification bar from the application level. Android app is isolated from the Operating System and another apps, so it is not able to lock OS features.
Solution that came into my head is to make app fullscreen and create Your own status bar with battery level, current time and network status. It is not hard.
Another solution would be to prepare Your own Android distribution :)
Moreover probably You would like to override all buttons (home, back, search) so user is not able to leave your app.

Very likely is not going to be possible on a Stock device, you'd have to root and potentially install your own version of the OS to allow for this behavior. The system was purposefully made to disallow applications from having this type of behavior. The creators of the OS had the general public in mind as users, and they wanted to prevent applications from being able to "lock" the user out of portions of the device.
Much easier solution like #Jacek states is go full screen and make your own View to display whatever info that you do want from the Notifications bar, AFAIK there are public APIs to access all of that information.