Getting low memory warning but I don't appear to be leaking memory

Issue

My application is closing without any error messages and re-launching automatically after switching activities approximately 20 or 30 times. I'm testing this by tapping a button that relaunches the current activity with different data (and cycles back around to the beginning once the end of the data is reached). The activity is launched with the FLAG_ACTIVITY_CLEAR_TOP flag so there should only ever be one instance of the activity in memory at a time. If I set FLAG_ACTIVITY_NO_HISTORY the problem still occurs.

This appears in the logcat output when the app crashes:

06-28 19:32:10.472: I/ActivityManager(115): Process com.mypackage.myapp (pid 3718) has died.
06-28 19:32:10.476: I/WindowManager(115): WIN DEATH: Window{406d06e0 com.mypackage.myapp/com.mypackage.myapp.welcome.LoginActivity paused=false}
06-28 19:32:10.480: E/InputDispatcher(115): channel '406ade20 com.mypackage.myapp/com.mypackage.myapp.matchup.MatchUpActivity (server)' ~ Consumer closed input channel or an error occurred.  events=0x8
06-28 19:32:10.480: E/InputDispatcher(115): channel '406ade20 com.mypackage.myapp/com.mypackage.myapp.matchup.MatchUpActivity (server)' ~ Channel is unrecoverably broken and will be disposed!
06-28 19:32:10.535: I/WindowManager(115): WIN DEATH: Window{406ade20 com.mypackage.myapp/com.mypackage.myapp.matchup.MatchUpActivity paused=false}
06-28 19:32:10.539: I/WindowManager(115): WIN DEATH: Window{407a8230 com.mypackage.myapp/com.mypackage.myapp.fightcard.FightCardActivity paused=false}
06-28 19:32:10.566: I/ActivityManager(115): Start proc com.mypackage.myapp for activity com.mypackage.myapp/.fightcard.FightCardActivity: pid=3915 uid=10053 gids={3003}
06-28 19:32:10.574: I/ActivityManager(115): Low Memory: No more background processes.

Normally this would tell me that the app is leaking memory, however if I perform this test while watching the DDMS perspective in Eclipse, I can see that the allocated memory is stable, and in fact the app will often crash even when the % used is sitting around 50% (which is where it sits most of the time). The heap size and allocated memory are not increasing.

I have extensively used MAT on the app and while I did find memory leaks previously, I have solved them and can no longer find any other problems with that tool.

I've been able to recreate this problem on a Nexus S running Gingerbread, but it doesn't appear to be reproducible on a Galaxy Nexus running 4.0.4 (however that might be due to the fact that the heap is larger on the Galaxy).

What am I missing?

Solution

David Wasser's suggestion above led me to the solution. I noticed when I ran the command mentioned, I was getting a whole bunch of custom font asset allocations:

zip:/data/app/com.mypackage.myapp-2.apk:/assets/DINNextLTPro-MediumCond.otf: 98K

These allocations appeared to be increasing very quickly as I changed activities. Some googling led me to this link: http://code.google.com/p/android/issues/detail?id=9904

So it appears that there is an Android bug related to using custom fonts. The following workaround was taken from the link above:

public class Typefaces {
    private static final String TAG = "Typefaces";

    private static final Hashtable<String, Typeface> cache = new Hashtable<String, Typeface>();

    public static Typeface get(Context c, String assetPath) {
        synchronized (cache) {
            if (!cache.containsKey(assetPath)) {
                try {
                    Typeface t = Typeface.createFromAsset(c.getAssets(),
                            assetPath);
                    cache.put(assetPath, t);
                } catch (Exception e) {
                    Log.e(TAG, "Could not get typeface '" + assetPath
                            + "' because " + e.getMessage());
                    return null;
                }
            }
            return cache.get(assetPath);
        }
    }
}

Essentially we're caching the instances of the custom font asset so each one only needs to be instantiated a single time.

Answered By - howettl