def WaitEvent(event):
  """Waits for an event without timeout, without blocking signals.

  event.wait() masks all signals until the event is set; this can be used
  instead to make sure that the signal is delivered within 100 ms.

  Returns:
    True if the event is set (i.e., always, since there is no timeout).  This
      return value is used so that this method behaves the same way as
      event.wait().
  """
  while not event.is_set():
    event.wait(0.1)
  return True