Synnefo » snf-ganeti » ganeti-local

def WaitForSocketCondition(sock, event, timeout):

  """Waits for a condition to occur on the socket.

  @type sock: socket

  @param sock: Wait for events on this socket

  @type event: int

  @param event: ORed condition (see select module)

  @type timeout: float or None

  @param timeout: Timeout in seconds

  @rtype: int or None

  @return: None for timeout, otherwise occured conditions

  """

  check = (event | select.POLLPRI |

           select.POLLNVAL | select.POLLHUP | select.POLLERR)

  if timeout is not None:

    # Poller object expects milliseconds

    timeout *= 1000

  poller = select.poll()

  poller.register(sock, event)

  try:

    while True:

      # TODO: If the main thread receives a signal and we have no timeout, we

      # could wait forever. This should check a global "quit" flag or

      # something every so often.

      io_events = poller.poll(timeout)

      if not io_events:

        # Timeout

        return None

      for (_, evcond) in io_events:

        if evcond & check:

          return evcond

  finally:

    poller.unregister(sock)