ioloop.py 文件源码

def set_blocking_signal_threshold(self, seconds, action):
        """Sends a signal if the ioloop is blocked for more than s seconds.

        Pass seconds=None to disable.  Requires python 2.6 on a unixy
        platform.

        The action parameter is a python signal handler.  Read the
        documentation for the python 'signal' module for more information.
        If action is None, the process will be killed if it is blocked for
        too long.
        """
        if not hasattr(signal, "setitimer"):
            logging.error("set_blocking_signal_threshold requires a signal module "
                       "with the setitimer method")
            return
        self._blocking_signal_threshold = seconds
        if seconds is not None:
            signal.signal(signal.SIGALRM,
                          action if action is not None else signal.SIG_DFL)