ConnectivityManager leaking, not sure how to resolve

Question

So, I have this method that let's me know if the user has an active internet connection. It works well. However, leak canary has identified a memory leak associated with the connectivityManager. I am presently not closing the connectivityManager anywhere in my code at any time that I know of.

I've tried to close the connectivityManager in onDestroy. Either that isn't an option or I don't know the code. Truth be told, I simply tried to get auto fill to tell me how to do it. No luck.

public static boolean isNetworkAvailable(Context context) {
    ConnectivityManager connectivityManager =(ConnectivityManager)  context.getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo activeNetworkInfo =connectivityManager.getActiveNetworkInfo();
    return activeNetworkInfo !=null && activeNetworkInfo.isConnected();
}

Answer 1

Use this to prevent leak,

ConnectivityManager connectivityManager = (ConnectivityManager) context.getApplicationContext()
                .getSystemService(Context.CONNECTIVITY_SERVICE);

Answer 2

This is a bug on Android M and has been fixed on L.

The reason is that on M, ConnectivityManager holds the first instance as a static object.

When you get it first using an Activity Context, the static object will always have reference to your Activity. Using the Application Context will solve the problem.

Answer 3

None of the above answers worked for me, I tried all of them in 1 form or another.

It turns out what was causing the issue was AdMob's initialization for banner ads MobileAds.initialize(requireContext()) which I used inside one of my fragments.

The fix was to use MobileAds.initialize(MyApplication.myAppContext)

AdMob initialization in Fragment example:

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)

    // MobileAds.initialize(requireContext()) <---- Causes Memory Leak

    MobileAds.initialize(MyApplication.myAppContext) // <---- No Memory Leak
}

MyApplication example:

class MyApplication : Application() {

    companion object {
        lateinit  var myAppContext: Context
    }

    override fun onCreate() {
        super.onCreate()

        myAppContext = applicationContext
    }
}

Answer 4

As @Adi mentioned this might be a library internally using ConnectivityManager, I'm using AdMob SDK this SDK is using activity context for the initializing as they mentioned in their documentation so to fix this use Application context instead of Activity context, if you're using AdMob SDK initialize it like this below.

MobileAds.initialize(this.applicationContext)

Answer 5

Sharing a new answer as there is a catch:

I tried fixing the bug by instantiating ConnectivityManager using the following code in my activity:

ConnectivityManager connectivityManager = (ConnectivityManager) context.getApplicationContext()
            .getSystemService(Context.CONNECTIVITY_SERVICE);

However, this did not fix the memory leak. The problem is that even before my activity is called, some dependent library might be internally using ConnectivityManager in its code which leads to static variable of context being initialized to an activity context. The trick to fix this is to instantiate ConnectivityManager in the Application class just for the sake of it (unused).

public class MyApp extends Application {
    @Override
    public void onCreate() {
         ConnectivityManager cm = (ConnectivityManager) getApplicationContext().getSystemService(Context.CONNECTIVITY_SERVICE);
    }
}