datetime_racecondition.py

"""I suspect that there is a race condition in datetime module.

When I ran the following code in a multi-threading application:

    datetime.datetime.strptime('20120509100335', "%Y%m%d%H%M%S")

I've noticed the following error in the log. 

    Traceback (most recent call last):
      File "/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/threading.py", line 522, in __bootstrap_inner
        self.run()
      File "/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/threading.py", line 477, in run
        self.__target(*self.__args, **self.__kwargs)
      File "a.py", line 18, in f
        datetime.datetime.strptime('20120509100335', "%Y%m%d%H%M%S")
    AttributeError: _strptime

This behavior is not predictable. This program tries to reproduce that behavior.
"""

import sys
import threading
import datetime

def f():
    print "BEGIN", threading.currentThread().getName()
    for i in range(100):
        datetime.datetime.strptime('20120509100335', "%Y%m%d%H%M%S")
    print "END", threading.currentThread().getName()

def main():
    threads = [threading.Thread(target=f) for i in range(10)]
    for t in threads:
        t.start()

    for t in threads:
        t.join()

main()