Использование android.os.Binder для организации асинхронного взаимодействия в Андроиде

public class MiddleActivity extends Activity {

    private Object object;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        if (savedInstanceState == null) {
            object = new Object();
        } else {
            object = ((IdentitySerializable) savedInstanceState.getSerializable(OBJECT_KEY)).getObject();
        }
    }

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putSerializable(OBJECT_KEY, new IdentitySerializable(object));
    }
}

Intent intent = new Intent(this, BActivity.class);
intent.putExtra("AActivityRecord", new IdentityParcelable(
        new WeakReference<?>(getActivityRecord())
));

WeakReference<AActivityRecord> aActivityRecordRef = (WeakReference<AActivityRecord>) ((IdentityParcelable) getIntent().getParcelableExtra("AActivityRecord")).content;

. . .

AActivityRecord aActivityRecord = aActivityRecordRef.get();
if (aActivityRecord != null) {
    aActivityRecord.invalidateTaskResult();
}

<!-- res/layout/length_activity.xml -->

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:layout_width="fill_parent"
              android:layout_height="fill_parent"
              android:orientation="vertical"
        >
    <TextView
            android:id="@+id/statusText"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:freezesText="true"/>
    <EditText
            android:id="@+id/sampleField"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"/>
    <Button android:id="@+id/calculateLengthButton"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Calculate Length"/>
</LinearLayout>