Zeroconf.py 文件源码

def __init__(self, bindaddress=None):
        """Creates an instance of the Zeroconf class, establishing
        multicast communications, listening and reaping threads."""
        globals()['_GLOBAL_DONE'] = 0
        self.intf = bindaddress
        self.group = ('', _MDNS_PORT)
        self.socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        try:
            self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
            self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT, 1)
        except Exception:
            # SO_REUSEADDR should be equivalent to SO_REUSEPORT for
            # multicast UDP sockets (p 731, "TCP/IP Illustrated,
            # Volume 2"), but some BSD-derived systems require
            # SO_REUSEPORT to be specified explicity.  Also, not all
            # versions of Python have SO_REUSEPORT available.  So
            # if you're on a BSD-based system, and haven't upgraded
            # to Python 2.3 yet, you may find this library doesn't
            # work as expected.
            #
            pass
        self.socket.setsockopt(socket.SOL_IP, socket.IP_MULTICAST_TTL, 255)
        self.socket.setsockopt(socket.SOL_IP, socket.IP_MULTICAST_LOOP, 1)
        try:
            self.socket.bind(self.group)
        except Exception:
            # Some versions of linux raise an exception even though
            # the SO_REUSE* options have been set, so ignore it
            #
            pass

        if self.intf is not None:
            self.socket.setsockopt(socket.SOL_IP, socket.IP_MULTICAST_IF, socket.inet_aton(self.intf) + socket.inet_aton('0.0.0.0'))
        self.socket.setsockopt(socket.SOL_IP, socket.IP_ADD_MEMBERSHIP, socket.inet_aton(_MDNS_ADDR) + socket.inet_aton('0.0.0.0'))

        self.listeners = []
        self.browsers = []
        self.services = {}

        self.cache = DNSCache()

        self.condition = threading.Condition()

        self.engine = Engine(self)
        self.listener = Listener(self)
        self.reaper = Reaper(self)