Invalid heap address and fatal signal 11

Question

Every so often my app will crash and my log will read:

@@@ ABORTING: INVALID HEAP ADDRESS IN dlfree
Fatal signal 11 (SIGSEGV) at 0xdeadbaad (code=1)

Sometimes code=2, but always Fatal signal 11 and invalid heap address.

I've tried researching what this means and how to fix it. This thread has been the most helpful; however, I'm still without a solution.

The error occurs when I run a couple of AsyncTasks to download several images.

This is my main AsyncTask

public class FetchArtistImages extends AsyncTask<Void, Integer, String[]> implements Constants {

private final WeakReference<Context> contextReference;

public FetchArtistImages(Context context) {
    contextReference = new WeakReference<Context>(context);
}

@Override
protected String[] doInBackground(Void... params) {
    String[] projection = new String[] {
            Audio.Artists._ID, Audio.Artists.ARTIST
    };
    String sortOrder = Audio.Artists.DEFAULT_SORT_ORDER;
    Uri uri = Audio.Artists.EXTERNAL_CONTENT_URI;
    Cursor c = contextReference.get().getContentResolver()
            .query(uri, projection, null, null, sortOrder);
    ArrayList<String> artistIds = new ArrayList<String>();
    if (c != null) {
        int count = c.getCount();
        if (count > 0) {
            final int ARTIST_IDX = c.getColumnIndex(Audio.Artists.ARTIST);
            for (int i = 0; i < count; i++) {
                c.moveToPosition(i);
                artistIds.add(c.getString(ARTIST_IDX));
            }
        }
        c.close();
        c = null;
    }
    return artistIds.toArray(new String[artistIds.size()]);
}

@Override
protected void onPostExecute(String[] result) {
    for (int i = 0; i < result.length; i++) {
            new LastfmGetArtistImages(contextReference.get()).executeOnExecutor(
                    AsyncTask.THREAD_POOL_EXECUTOR, result[i]);
    }
    super.onPostExecute(result);
}

Even though I've tried researching what's up with this, I still find myself lost when it comes to fixing it. If anyone has some insight, I'd definitely appreciate seeing it. The error isn't thrown every time I execute my AsyncTasks, but I can't find much of a pattern to help isolate why this is occurring. There are a couple of other threads on SO about fatal signal 11, but they don't provide much help in my case.

Answer 1

I just ran into the same issue and had it at a re-producable state. This is the error I was getting:

08-04 17:37:05.491: A/libc(4233): @@@ ABORTING: INVALID HEAP ADDRESS IN dlfree 08-04 17:37:05.491: A/libc(4233): Fatal signal 11 (SIGSEGV) at 0xdeadbaad (code=1)

What it boiled down to is a function call being made from two different threads at the same time.

More specifically, this function was BluetoothSocket's close() method.

I checked the source code at this website , and the call is not synchronized (not sure if this changed since it is from Android 2.1).

At any rate, do you maybe have a similar scenario where a function call is made from multiple threads? Can't say for sure from the source code you're showing.

Also have you tried not using THREAD_POOL_EXECUTOR? According to the android dev guide:

When first introduced, AsyncTasks were executed serially on a single background thread. Starting with DONUT, this was changed to a pool of threads allowing multiple tasks to operate in parallel. Starting with HONEYCOMB, tasks are executed on a single thread to avoid common application errors caused by parallel execution.