What is the behavior of instance variables passed between threads?

I understand that it's not safe to access a shared instance variable between multiple threads (unless the variable is declared volatile and properly synchronized). I'm trying to understand the semantics of passing a shared instance variable to a background thread using Android's AsyncTask.

Consider the following code:

public class Example {
    ContentValues contentValues;

    public void start() {
        contentValues = new ContentValues();
        contentValues.put("one", 1);
        new MyAsyncTask().execute(contentValues);
        contentValues.put("two", 2);
    }


    class MyAsyncTask extends AsyncTask<ContentValues, Void, Boolean> {
        @Override
        public void onPreExecute() {
            contentValues.put("three", 3);
        }

        @Override
        protected Boolean doInBackground(ContentValues... cvs) {
            ContentValues cv = cvs[0];
            return cv == contentValues; 
        }
    }
}

What do we know about the state of the local variable cv in doInBackground()? Specifically,

• Which key-value pairs are guaranteed to be in it.

• Which key-value pairs might be in it?

• What will doInBackground() return?

from What is the behavior of instance variables passed between threads?