asyncMulticast.py 文件源码

def __init__(self, port, callback_obj, ttl=1, enable_loopback=False, bind_addr=''):
        asyncore.dispatcher.__init__(self)
        # self.lock = threading.RLock()
        self.MAX_MTU = 1500
        self.callback_obj = None
        self.port = port
        self.multicastSet = Set([])
        self.lock = threading.RLock()
        self.ttl = ttl
        self.enable_loopback = enable_loopback
        if callback_obj is not None and isinstance(callback_obj, IUdpCallback):
            self.callback_obj = callback_obj
        else:
            raise Exception('callback_obj is None or not an instance of IUdpCallback class')
        try:
            self.create_socket(socket.AF_INET, socket.SOCK_DGRAM)
            self.set_reuse_addr()
            try:
                socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT, 1)
            except AttributeError:
                pass  # Some systems don't support SO_REUSEPORT

            # for both SENDER and RECEIVER to restrict the region
            self.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_TTL, self.ttl)
            # for SENDER to choose whether to use loop back
            if self.enable_loopback:
                self.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_LOOP, 1)
            else:
                self.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_LOOP, 0)

            self.bind_addr = bind_addr
            if self.bind_addr is None or self.bind_addr == '':
                self.bind_addr = socket.gethostbyname(socket.gethostname())
                # for both SENDER and RECEIVER to bind to specific network adapter
            self.setsockopt(socket.SOL_IP, socket.IP_MULTICAST_IF, socket.inet_aton(self.bind_addr))

            # for RECEIVE to receive from multiple multicast groups
            self.bind(('', port))
        except Exception as e:
            print e
            traceback.print_exc()
        self.sendQueue = Queue.Queue()  # thread-safe queue
        AsyncController.instance().add(self)
        if self.callback_obj is not None:
            self.callback_obj.on_started(self)

    # Even though UDP is connectionless this is called when it binds to a port