Synnefo » snf-ganeti

import logging

def ResetTempfileModule():

  """Resets the random name generator of the tempfile module.

  This function should be called after C{os.fork} in the child process to

  ensure it creates a newly seeded random generator. Otherwise it would

  generate the same random parts as the parent process. If several processes

  race for the creation of a temporary file, this could lead to one not getting

  a temporary name.

  """

  # pylint: disable-msg=W0212

  if hasattr(tempfile, "_once_lock") and hasattr(tempfile, "_name_sequence"):

    tempfile._once_lock.acquire()

    try:

      # Reset random name generator

      tempfile._name_sequence = None

    finally:

      tempfile._once_lock.release()

  else:

    logging.critical("The tempfile module misses at least one of the"

                     " '_once_lock' and '_name_sequence' attributes")