[Twisted-Python] Serious performance problem of twisted

[davy zhang]

a very simple server and multi-process code, I found there's about 500
milliseconds delay for every msg I sent to client I just don't why,
did I made something wrong ?

the code below using a process to handle the data and in the shared
taskList, after done put the data to the shared msgList,  a thread in
main process to read the msg and send to the clients.

the msg delay is significant, you can even see it with your eyes in
telnet client I checked the time in the client, it's approximate to
0.5 secs

first I tested in java using the same logic with MINA, BlockingQueue
stuff, the msg traveled from client to server and back is 0, so I
pretty much sure the problem here is in the  server side

then I printed time in the server code, I found everything is as fast
as it suppose to be, until the c.transport.write. After the write
operation the client need 0.5secs to get the msg


the code is below

#!/usr/bin/env python
#coding=utf-8

from twisted.internet.protocol import Factory,Protocol
from twisted.internet import reactor
from twisted.internet import error
import cPickle
import time
from processing import Manager,Process
import thread
from time import time

"""flash policy file request"""
policyRequest = "<policy-file-request/>" + chr(0)
policyReturn = """<cross-domain-policy>
                <allow-access-from  domain="*"  to-ports="*"  />
                </cross-domain-policy>""" + chr(0)

def handler(taskList,msgList):
    while 1:
        item = cPickle.loads(taskList.get())
        print time()
        print 'item before handle ', item
        item['msg'] += ' hanlded done \r\n'
        msgList.put(cPickle.dumps(item))

def sender():
    global msgList
    while 1:
        item = cPickle.loads(msgList.get())
        print time()
        c = clients[item['cid']]
        c.transport.write(item['msg'] )

class DTProtocol(Protocol):
    global clients
    def connectionMade(self):
        clients.append(self)
        print "a new customer!"

    def dataReceived(self, data):
        global clients
        global taskList
        print 'msg received ',data
        if data == policyRequest:
            self.transport.write(policyReturn)
            self.transport.loseConnection()
        else:
            d = {'cid':clients.index(self),'msg':data,'done':False,'sent':False}
            taskList.put(cPickle.dumps(d))
            print time()
            #self.transport.write(data)

    def connectionLost(self, reason):
        print reason
        if self in clients:
            clients.remove(self)
        print "bye!"

    def message(self,msg):
        self.transport.write(msg)

class DTFactory(Factory):
    protocol  = DTProtocol

if __name__ == '__main__':

    port = 80
    reactor.listenTCP(80,DTFactory())

    clients = []
    manager = Manager()

    taskList = manager.Queue()
    msgList = manager.Queue()


    h = Process(target=handler,args=(taskList,msgList))
    h.start()

    thread.start_new_thread(sender,())

    print 'server is runing at ',port
    reactor.run()