rosjava ListenerGroup causes android memory leak

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I have been developing an Android based application using rosjava and android_core dependencies. I have found an issue with the ListenerDispatch class leaking memory (specifically classes that extend NodeMain). These leaked classes cannot be garbage collected and cause large android applications to crash.

I have created a simple Android application that contains two activities, each of type ROSActivity, one called "Main" and the other called "Second". The "Main" activity starts the "Second" activity which contains a simple Heartbeat class that implements NodeMain. The Heartbeat publishes a Header message every second, and allocates 10MB when it created (to show the leak). In "Second"s onDestroy method, the Heartbeat is shutdown using shutdownNodeMain() provided by the NodeMainExecutor.

@Override
protected void onDestroy() {
    if(mNodeMainExecutor != null)
    {
        if(mHeartbeat != null)
        {
            Log.d(LOG_TAG, "Shutting down Heartbeat");
            mNodeMainExecutor.shutdownNodeMain(mHeartbeat);
        }
    }
    super.onDestroy();
}

To demonstrate the leak, the "second" activity is repetitively navigated into and out of using a button on the "Main" activity and the back button. The Hearbeat is created in the onCreate() call of the "Second" activity, executed in the init() call and is shutdown in onDestroy().

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_second);

    Log.d(LOG_TAG, "Creating a new Heartbeat");
    mHeartbeat = new Heartbeat();
}

@Override
protected void init(NodeMainExecutor nodeMainExecutor) {
    mNodeMainExecutor = nodeMainExecutor;
    mNodeConfiguration = NodeConfiguration.
            newPublic(InetAddressFactory.newNonLoopback().getHostAddress(),getMasterUri());

    if(mNodeMainExecutor != null)
        mNodeMainExecutor.execute(mHeartbeat, mNodeConfiguration);
}

The system memory continues to increase until the application crashes due to the fact that the system garbage collector cannot free memory.

After dumping the application heap and anlazing the data, it seems that the created Heartbeat objects cannot be garbage collected due a reference tree depth of 0 caused by the EventDispatcher in org.ros.concurrent.ListenerGroup.

After inspecting the ListenerGroup source, it seems that the shutdown() method should be called to cancel the EventDispatchers which could be holding up the Heartbeat NodeMain from being garbage collected.

I can't find in any of the source where the ListenerGroup.shutdown() method is called? Has anyone experienced this?

In large Android RosJava applications any class that extends NodeMain will theoretically be leaked. Anyone have any ideas?

Thanks in advance!

Here is a link to the source code used to generate the leak: ROSLeak Source