How can I get the options menu of my Activity?

Be wary of invalidateOptionsMenu(). It recreates the entire menu. This has a lot of overhead and will reset embedded components like the SearchView. It took me quite a while to track down why my SearchView would "randomly" close.

I ended up capturing the menu as posted by Dark and then call onPrepareOptionsMenu(Menu) as necessary. This met my requirement without an nasty side effects. Gotcha: Make sure to do a null check in case you call onPrepareOptionsMenu() before the menu is created. I did this as below:

private Menu mOptionsMenu;

@Override
public boolean onCreateOptionsMenu(final Menu menu) {
    mOptionsMenu = menu
    ...
}

private void updateOptionsMenu() {
    if (mOptionsMenu != null) {
        onPrepareOptionsMenu(mOptionsMenu);
    }
}

Call invalidateOptionsMenu() instead of passing menu object around.