} // end _GuestModeMainWrapper()

        private static int _GuestModeCleanup()
        {
            if (null == sm_altMainThread)
            {
                // Nothing to do. (I guess we were never started.)
                Util.Fail("currently not possible, therefore not tested");
            }
            else
            {
                // We already have an alternate main thread, which is "paused" (blocked),
                // waiting to resume. Before we unblock it, we'll set this bit to let it
                // know that it should actually exit.
                DbgProvider.GuestModeTimeToExitAllTheWay = true;

                DbgProvider.GuestModeResume();

                LogManager.Trace("Waiting for the DbgShell main thread.");
                sm_altMainThread.Join();
                LogManager.Trace("_AltMainThread finished.");

                // Calling GuestModeFinalCleanup works even though we don't fire up the
                // DbgEngThread because the current thread has already been marked as the
                // thread that DbgEngThread's pump runs on, so it just runs synchronously.
                DbgProvider.GuestModeFinalCleanup();
            }

            return(sm_exitCode);
        } // end _GuestModeCleanup()