He visto una serie de otros hilos con títulos similares, y ninguno parece cubrir mi problema. Así que, aquí va.

Estoy usando la biblioteca y el código de muestra de los archivos de expansión del mercado de Google (apkx), con algunas modificaciones. Este código se basa en recibir devoluciones de llamada de un servicio que maneja la descarga en segundo plano, la verificación de licencias, etc.

Tengo un error donde el servicio no se adjunta correctamente, lo que resulta en un bloqueo lógico. Para hacer que esto sea menos útil, este error nunca ocurre en algunos dispositivos, sino que ocurre aproximadamente dos tercios del tiempo en otros dispositivos. Creo que es independiente de la versión de Android, ciertamente tengo dos dispositivos que ejecutan 2.3.4, uno de los cuales (un Nexus S) no tiene el problema, el otro (un HTC Evo 3D) sí.

Para intentar conectarse al servicio, se llama a bindService y devuelve true. A continuación, OnBind recibe la llamada como se esperaba y devuelve un valor razonable pero (cuando se produce el error) onServiceConnected no ocurre (he esperado 20 minutos por si acaso).

¿Alguien más ha visto algo como esto? Si no, ¿alguna conjetura de lo que podría haber hecho para causar tal comportamiento? Si nadie tiene ningún pensamiento, mañana publicaré algún código.

EDITAR: Aquí está el código relevante. Si me he perdido algo, por favor pregunte.

Al agregar este código, encontré un error menor. Arreglarlo causó que la frecuencia del problema que estoy tratando de resolver cambie de 2 veces en 3 a 1 vez en 6 en el teléfono en el que lo estoy probando; No tengo idea acerca de los efectos en otros teléfonos. Esto sigue sugiriéndome una condición de carrera o similar, pero no tengo idea de con qué.

OurDownloaderActivity.java (copiado y modificado del código de ejemplo de Google)

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    ...

    //Test the licence is up to date
    //if (current stored licence has expired)
    {
        startLicenceCheck();
        initializeDownloadUI();
        return;
    }

    ...
}

@Override
protected void onResume() {
    if (null != mDownloaderClientStub) {
        mDownloaderClientStub.connect(this);
    }
    super.onResume();
}

private void startLicenceCheck()
{
    Intent launchIntent = OurDownloaderActivity.this
            .getIntent();
    Intent intentToLaunchThisActivityFromNotification = new Intent(OurDownloaderActivity
            .this, OurDownloaderActivity.this.getClass());
    intentToLaunchThisActivityFromNotification.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK |
            Intent.FLAG_ACTIVITY_CLEAR_TOP);
    intentToLaunchThisActivityFromNotification.setAction(launchIntent.getAction());

    if (launchIntent.getCategories() != null) {
        for (String category : launchIntent.getCategories()) {
            intentToLaunchThisActivityFromNotification.addCategory(category);
        }
    }

    // Build PendingIntent used to open this activity from Notification
    PendingIntent pendingIntent = PendingIntent.getActivity(OurDownloaderActivity.this,
            0, intentToLaunchThisActivityFromNotification,
            PendingIntent.FLAG_UPDATE_CURRENT);

    DownloaderService.startLicenceCheck(this, pendingIntent, OurDownloaderService.class);
}

initializeDownloadUI()
{
    mDownloaderClientStub = DownloaderClientMarshaller.CreateStub
            (this, OurDownloaderService.class);

    //do a load of UI setup
    ...
}

//This should be called by the Stub's onServiceConnected method
/**
 * Critical implementation detail. In onServiceConnected we create the
 * remote service and marshaler. This is how we pass the client information
 * back to the service so the client can be properly notified of changes. We
 * must do this every time we reconnect to the service.
 */
@Override
public void onServiceConnected(Messenger m) {
    mRemoteService = DownloaderServiceMarshaller.CreateProxy(m);
    mRemoteService.onClientUpdated(mDownloaderClientStub.getMessenger());
}

DownloaderService.java (en la biblioteca de expansión del mercado de Google, pero algo editado)

//this is the onBind call that happens fine; the value it returns is definitely not null
@Override
public IBinder onBind(Intent paramIntent) {
    return this.mServiceMessenger.getBinder();
}

final private IStub mServiceStub = DownloaderServiceMarshaller.CreateStub(this);
final private Messenger mServiceMessenger = mServiceStub.getMessenger();

//MY CODE, derived from Google's code
//I have seen the bug occur with a service started by Google's code too,
//but this code happens more often so is more repeatably related to the problem
public static void startLicenceCheck(Context context, PendingIntent pendingIntent, Class<?> serviceClass)
{       
    String packageName = serviceClass.getPackage().getName();
    String className = serviceClass.getName();

    Intent fileIntent = new Intent();
    fileIntent.setClassName(packageName, className);
    fileIntent.putExtra(EXTRA_LICENCE_EXPIRED, true);
    fileIntent.putExtra(EXTRA_PENDING_INTENT, pendingIntent);
    context.startService(fileIntent);
}

@Override
protected void onHandleIntent(Intent intent) {
    setServiceRunning(true);
    try {
        final PendingIntent pendingIntent = (PendingIntent) intent
            .getParcelableExtra(EXTRA_PENDING_INTENT);

        if (null != pendingIntent)
        {
            mNotification.setClientIntent(pendingIntent);
            mPendingIntent = pendingIntent;
        } else if (null != mPendingIntent) {
            mNotification.setClientIntent(mPendingIntent);
        } else {
            Log.e(LOG_TAG, "Downloader started in bad state without notification intent.");
            return;
        }

        if(intent.getBooleanExtra(EXTRA_LICENCE_EXPIRED, false))
        {
            //we are here due to startLicenceCheck
            updateExpiredLVL(this);
            return;
        }
    ...
    }
}

//MY CODE, based on Google's, again
public void updateExpiredLVL(final Context context) {
    Context c = context.getApplicationContext();
    Handler h = new Handler(c.getMainLooper());
    h.post(new LVLExpiredUpdateRunnable(c));
}

private class LVLExpiredUpdateRunnable implements Runnable
{
    LVLExpiredUpdateRunnable(Context context) {
        mContext = context;
    }

    final Context mContext;

    @Override
    public void run() {
        setServiceRunning(true);
        mNotification.onDownloadStateChanged(IDownloaderClient.STATE_LVL_UPDATING);
        String deviceId = getDeviceId(mContext);

        final APKExpansionPolicy aep = new APKExpansionPolicy(mContext,
                new AESObfuscator(getSALT(), mContext.getPackageName(), deviceId));

        // Construct the LicenseChecker with a Policy.
        final LicenseChecker checker = new LicenseChecker(mContext, aep,
                getPublicKey() // Your public licensing key.
        );
        checker.checkAccess(new LicenseCheckerCallback() {
            ...
        });
    }
}

DownloaderClientMarshaller.java (en la biblioteca de expansión del mercado de Google)

public static IStub CreateStub(IDownloaderClient itf, Class<?> downloaderService) {
    return new Stub(itf, downloaderService);
}

y la clase Stub del mismo archivo:

private static class Stub implements IStub {
    private IDownloaderClient mItf = null;
    private Class<?> mDownloaderServiceClass;
    private boolean mBound;
    private Messenger mServiceMessenger;
    private Context mContext;
    /**
     * Target we publish for clients to send messages to IncomingHandler.
     */
    final Messenger mMessenger = new Messenger(new Handler() {
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case MSG_ONDOWNLOADPROGRESS:                        
                    Bundle bun = msg.getData();
                    if ( null != mContext ) {
                        bun.setClassLoader(mContext.getClassLoader());
                        DownloadProgressInfo dpi = (DownloadProgressInfo) msg.getData()
                                .getParcelable(PARAM_PROGRESS);
                        mItf.onDownloadProgress(dpi);
                    }
                    break;
                case MSG_ONDOWNLOADSTATE_CHANGED:
                    mItf.onDownloadStateChanged(msg.getData().getInt(PARAM_NEW_STATE));
                    break;
                case MSG_ONSERVICECONNECTED:
                    mItf.onServiceConnected(
                            (Messenger) msg.getData().getParcelable(PARAM_MESSENGER));
                    break;
            }
        }
    });

    public Stub(IDownloaderClient itf, Class<?> downloaderService) {
        mItf = itf;
        mDownloaderServiceClass = downloaderService;
    }

    /**
     * Class for interacting with the main interface of the service.
     */
    private ServiceConnection mConnection = new ServiceConnection() {

        //this is the critical call that never happens

        public void onServiceConnected(ComponentName className, IBinder service) {
            // This is called when the connection with the service has been
            // established, giving us the object we can use to
            // interact with the service. We are communicating with the
            // service using a Messenger, so here we get a client-side
            // representation of that from the raw IBinder object.
            mServiceMessenger = new Messenger(service);
            mItf.onServiceConnected(
                    mServiceMessenger);
            mBound = true;                
        }

        public void onServiceDisconnected(ComponentName className) {
            // This is called when the connection with the service has been
            // unexpectedly disconnected -- that is, its process crashed.
            mServiceMessenger = null;
            mBound = false;
        }
    };

    @Override
    public void connect(Context c) {
        mContext = c;
        Intent bindIntent = new Intent(c, mDownloaderServiceClass);
        bindIntent.putExtra(PARAM_MESSENGER, mMessenger);
        if ( !c.bindService(bindIntent, mConnection, 0) ) {
            if ( Constants.LOGVV ) {
                Log.d(Constants.TAG, "Service Unbound");
            }
        }

    }

    @Override
    public void disconnect(Context c) {
        if (mBound) {
            c.unbindService(mConnection);
            mBound = false;
        }
        mContext = null;
    }

    @Override
    public Messenger getMessenger() {
        return mMessenger;
    }
}

DownloaderServiceMarshaller.java (en la biblioteca de expansión del mercado de Google, sin cambios)

private static class Proxy implements IDownloaderService {
    private Messenger mMsg;

    private void send(int method, Bundle params) {
        Message m = Message.obtain(null, method);
        m.setData(params);
        try {
            mMsg.send(m);
        } catch (RemoteException e) {
            e.printStackTrace();
        }
    }

    public Proxy(Messenger msg) {
        mMsg = msg;
    }

    @Override
    public void requestAbortDownload() {
        send(MSG_REQUEST_ABORT_DOWNLOAD, new Bundle());
    }

    @Override
    public void requestPauseDownload() {
        send(MSG_REQUEST_PAUSE_DOWNLOAD, new Bundle());
    }

    @Override
    public void setDownloadFlags(int flags) {
        Bundle params = new Bundle();
        params.putInt(PARAMS_FLAGS, flags);
        send(MSG_SET_DOWNLOAD_FLAGS, params);
    }

    @Override
    public void requestContinueDownload() {
        send(MSG_REQUEST_CONTINUE_DOWNLOAD, new Bundle());
    }

    @Override
    public void requestDownloadStatus() {
        send(MSG_REQUEST_DOWNLOAD_STATE, new Bundle());
    }

    @Override
    public void onClientUpdated(Messenger clientMessenger) {
        Bundle bundle = new Bundle(1);
        bundle.putParcelable(PARAM_MESSENGER, clientMessenger);
        send(MSG_REQUEST_CLIENT_UPDATE, bundle);
    }
}

private static class Stub implements IStub {
    private IDownloaderService mItf = null;
    final Messenger mMessenger = new Messenger(new Handler() {
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case MSG_REQUEST_ABORT_DOWNLOAD:
                    mItf.requestAbortDownload();
                    break;
                case MSG_REQUEST_CONTINUE_DOWNLOAD:
                    mItf.requestContinueDownload();
                    break;
                case MSG_REQUEST_PAUSE_DOWNLOAD:
                    mItf.requestPauseDownload();
                    break;
                case MSG_SET_DOWNLOAD_FLAGS:
                    mItf.setDownloadFlags(msg.getData().getInt(PARAMS_FLAGS));
                    break;
                case MSG_REQUEST_DOWNLOAD_STATE:
                    mItf.requestDownloadStatus();
                    break;
                case MSG_REQUEST_CLIENT_UPDATE:
                    mItf.onClientUpdated((Messenger) msg.getData().getParcelable(
                            PARAM_MESSENGER));
                    break;
            }
        }
    });

    public Stub(IDownloaderService itf) {
        mItf = itf;
    }

    @Override
    public Messenger getMessenger() {
        return mMessenger;
    }

    @Override
    public void connect(Context c) {

    }

    @Override
    public void disconnect(Context c) {

    }
}

/**
 * Returns a proxy that will marshall calls to IDownloaderService methods
 * 
 * @param ctx
 * @return
 */
public static IDownloaderService CreateProxy(Messenger msg) {
    return new Proxy(msg);
}

/**
 * Returns a stub object that, when connected, will listen for marshalled
 * IDownloaderService methods and translate them into calls to the supplied
 * interface.
 * 
 * @param itf An implementation of IDownloaderService that will be called
 *            when remote method calls are unmarshalled.
 * @return
 */
public static IStub CreateStub(IDownloaderService itf) {
    return new Stub(itf);
}