I think you are concentrating on the case where a new thread is created.  But don't forget, any time a signal is delivered (either synchronously or asynchronously), 'eiffel_signal_handler' can be called; EVEN IF THE THREAD IS NOT EIFFEL.  In that case you should check 'rt_globals' to see if it is NULL.  At that point I'm not sure what to do.  I guess it would be nice to know that the problem was in a non-Eiffel thread.