@kushal, thanks for your replies.
before i wrote the email, i've already read the python docs carefully. i need the proof from code, i mean python source code. i tried to prove some of my assumptions that lead the loop quit, and i traced back to Queue.py, threading.py, dummy_thread.py, now i need some hints to help me understanding the sample from python source code. -- http://mail.python.org/mailman/listinfo/python-list
