tcp.py 文件源码

def doConnect(self):
        """I connect the socket.

        Then, call the protocol's makeConnection, and start waiting for data.
        """
        if not hasattr(self, "connector"):
            # this happens when connection failed but doConnect
            # was scheduled via a callLater in self._finishInit
            return

        err = self.socket.getsockopt(socket.SOL_SOCKET, socket.SO_ERROR)
        if err:
            self.failIfNotConnected(error.getConnectError((err, os.strerror(err))))
            return


        # doConnect gets called twice.  The first time we actually need to
        # start the connection attempt.  The second time we don't really
        # want to (SO_ERROR above will have taken care of any errors, and if
        # it reported none, the mere fact that doConnect was called again is
        # sufficient to indicate that the connection has succeeded), but it
        # is not /particularly/ detrimental to do so.  This should get
        # cleaned up some day, though.
        try:
            connectResult = self.socket.connect_ex(self.realAddress)
        except socket.error, se:
            connectResult = se.args[0]
        if connectResult:
            if connectResult == EISCONN:
                pass
            # on Windows EINVAL means sometimes that we should keep trying:
            # http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winsock/winsock/connect_2.asp
            elif ((connectResult in (EWOULDBLOCK, EINPROGRESS, EALREADY)) or
                  (connectResult == EINVAL and platformType == "win32")):
                self.startReading()
                self.startWriting()
                return
            else:
                self.failIfNotConnected(error.getConnectError((connectResult, os.strerror(connectResult))))
                return

        # If I have reached this point without raising or returning, that means
        # that the socket is connected.
        del self.doWrite
        del self.doRead
        # we first stop and then start, to reset any references to the old doRead
        self.stopReading()
        self.stopWriting()
        self._connectDone()