Sl4a - eventRegisterForBroadcast - CALL_STATE_RINGING

Question

I register a listerner for a CALL_STATE_RINGING broadcast signal. i open up a socket to read for events postet. when you run this command in this line (f.readline()), the Console depends on. i don't know, what i do wrong?

import android
import socket
from json import loads

def parseEvent(line):
    out = loads(line)
    out.update(loads(out["data"]))
    return out

####connected via USB
droid = android.Android()
ACTION="android.telephony.TelephonyManager.CALL_STATE_RINGING"

droid.eventRegisterForBroadcast(ACTION, False)
####at this line, i can see my Action registred
print droid.eventGetBrodcastCategories()

p=droid.startEventDispatcher().result
####at this line, i see the Port
print p
s=socket.socket()
s.connect(('localhost', p))
f=s.makefile()

##Problem
###when you run this command in this line, the Console depends on
print f.readline()

while True:
    print 'test'
    event = parseEvent(f.readline())
    print event
    droid.log(str(event))
    print "got", event

print droid.eventUnregisterForBroadcast(ACTION)
print droid.eventGetBrodcastCategories()