#coding: utf-8import ctypes as _ctypesfrom ctypes import wintypes as _wtypesimport threadingimport timeimport structfrom udt4py import *fd = udt_socket()ret = udt_connect(fd,"127.0.0.1",9000)if ret == 0:    print("connect success")else:    print("connect fail")    import os    os._exit(0)        size = 100000data = Nonefor i in range(0,10000):    for j in range(0,10):        if data is None:            data = struct.pack("B", j+1 )        else:            data += struct.pack("B", j +1)def worker(param):    global ssize    print("SendRate(Mb/s)\tRTT(ms)\tCWnd\tPktSndPeriod(us)\tRecvACK\t\tRecvNAK")    while  True:        monitor = udt_monitor(param)        print("%.1f\t\t%.1f\t%.1f\t%.1f\t\t\t%d\t\t%d"%(monitor.mbpsSendRate,                                          monitor.msRTT,                                          monitor.pktCongestionWindow,                                          monitor.usPktSndPeriod,                                          monitor.pktRecvACK,                                          monitor.pktRecvNAK                                          ))                time.sleep(1)    returnt = threading.Thread(target=worker,args=(fd,))t.start()    for i in  range(0,size):    ssize = 0    ss=0    while ssize < size:        ss = udt_send(fd,data[ssize:size],size - ssize)        if ss < 0:            print("socket_send error")            break;         ssize += ss            if (ssize < size):        break;