Comment #9 on issue 871 by pekka.klarck: Timeout speed optimization http://code.google.com/p/robotframework/issues/detail?id=871
In addition to GIL problems mentioned in issue 497, timeouts in Robot are slow because the thread stopping hack we use is based on sys.settrace. From the article I linked in the previous comment:
"""Other non-solutions include using sys.settrace in the thread. In addition to making the thread code horribly slow, this will also fail to work when the thread calls into C functions."""
