Question

I have a page what refresh periodically using this script:

from twisted.web.client import getPage
from twisted.internet import reactor, task

def getData():
    dgp = getPage('http://www.google.com/')
    dgp.addCallback(dataLoadOK)
    dgp.addErrback(dataLoadError)

def dataLoadOK(value):
    print value

def dataLoadError(error):
    print error

loop = task.LoopingCall(getData)
loop.start(10, now=True)
reactor.run()

Buy while using this way I got the memory leak. Has any one help me find there is it?

Edit:
I have try to use garbage collection python module, and got this out put:

GARBAGE OBJECTS:
:: <HTTPClientFactory: http://www.google.com/>
        type: <type 'instance'>
referrers: 3
    is class: True
    module: <module 'twisted.web.client' from '/usr/lib/python2.7/site-packages/twisted/web/client.pyc'>

:: {'status': '200', 'cookies': {'PREF': 'ID=d894e510f2ebe263:FF=0:TM=1306053252:LM=1306053252:S=ebpb4ZebRUu_EhiI', 'NID': '47=LxM9fbBBN-bVIeuLPOfvO-fgXOKw1n2suyZ2...
        type: <type 'dict'>
referrers: 3
    is class: True
    module: None

:: InsensitiveDict({})
        type: <type 'instance'>
referrers: 3
    is class: True
    module: <module 'twisted.python.util' from '/usr/lib/python2.7/site-packages/twisted/python/util.pyc'>

:: {'preserve': 1, 'data': {}}
        type: <type 'dict'>
referrers: 3
    is class: True
    module: None

:: <Deferred at 0x29e2cf8 current result: None>
        type: <type 'instance'>
referrers: 3
    is class: True
    module: <module 'twisted.internet.defer' from '/usr/lib/python2.7/site-packages/twisted/internet/defer.pyc'>

:: {'_chainedTo': None, 'called': True, '_canceller': None, 'callbacks': [], 'result': None, '_runningCallbacks': False}
        type: <type 'dict'>
referrers: 3
    is class: True
    module: None

:: <<class 'twisted.internet.tcp.Client'> to ('www.google.com', 80) at 2445090>
        type: <class 'twisted.internet.tcp.Client'>
referrers: 3
    is class: True
    module: <module 'twisted.internet.tcp' from '/usr/lib/python2.7/site-packages/twisted/internet/tcp.pyc'>
    line num: 681
        line: class Client(BaseClient):
        line:     """A TCP client."""
        line: 
        line:     def __init__(self, host, port, bindAddress, connector, reactor=None):
        line:         # BaseClient.__init__ is invoked later
        line:         self.connector = connector
        line:         self.addr = (host, port)
        line: 
        line:         whenDone = self.resolveAddress
        line:         err = None
        line:         skt = None
        line: 
        line:         try:
        line:             skt = self.createInternetSocket()
        line:         except socket.error, se:
        line:             err = error.ConnectBindError(se[0], se[1])
        line:             whenDone = None
        line:         if whenDone and bindAddress is not None:
        line:             try:
        line:                 skt.bind(bindAddress)
        line:             except socket.error, se:
        line:                 err = error.ConnectBindError(se[0], se[1])
        line:                 whenDone = None
        line:         self._finishInit(whenDone, skt, err, reactor)
        line: 
        line:     def getHost(self):
        line:         """Returns an IPv4Address.
        line: 
        line:         This indicates the address from which I am connecting.
        line:         """
        line:         return address.IPv4Address('TCP', *(self.socket.getsockname() + ('INET',)))
        line: 
        line:     def getPeer(self):
        line:         """Returns an IPv4Address.
        line: 
        line:         This indicates the address that I am connected to.
        line:         """
        line:         return address.IPv4Address('TCP', *(self.realAddress + ('INET',)))
        line: 
        line:     def __repr__(self):
        line:         s = '<%s to %s at %x>' % (self.__class__, self.addr, unsignedID(self))
        line:         return s

:: {'_tempDataBuffer': [], 'disconnected': 1, 'dataBuffer': '', '_tempDataLen': 0, 'realAddress': ('74.125.225.81', 80), 'connector': <twisted.internet.tcp.Connect...
        type: <type 'dict'>
referrers: 3
    is class: True
    module: None

:: []
        type: <type 'list'>
referrers: 3
    is class: True
    module: None

:: {'x-xss-protection': ['1; mode=block'], 'set-cookie': ['PREF=ID=d894e510f2ebe263:FF=0:TM=1306053252:LM=1306053252:S=ebpb4ZebRUu_EhiI; expires=Tue, 21-May-2013 0...
        type: <type 'dict'>
referrers: 3
    is class: True
    module: None

:: ['-1']
        type: <type 'list'>
referrers: 3
    is class: True
    module: None

:: ['private, max-age=0']
        type: <type 'list'>
referrers: 3
    is class: True
    module: None

:: ['text/html; charset=ISO-8859-1']
        type: <type 'list'>
referrers: 3
    is class: True
    module: None

:: ['PREF=ID=d894e510f2ebe263:FF=0:TM=1306053252:LM=1306053252:S=ebpb4ZebRUu_EhiI; expires=Tue, 21-May-2013 08:34:12 GMT; path=/; domain=.google.com', 'NID=47=LxM9...
        type: <type 'list'>
referrers: 3
    is class: True
    module: None

:: ['gws']
        type: <type 'list'>
referrers: 3
    is class: True
    module: None

:: ['1; mode=block']
        type: <type 'list'>
referrers: 3
    is class: True
    module: None

:: []
        type: <type 'list'>
referrers: 3
    is class: True
    module: None

:: <twisted.internet.tcp.Connector instance at 0x29e2cb0>
        type: <type 'instance'>
referrers: 3
    is class: True
    module: <module 'twisted.internet.tcp' from '/usr/lib/python2.7/site-packages/twisted/internet/tcp.pyc'>

:: ['Sun, 22 May 2011 08:34:12 GMT']
        type: <type 'list'>
referrers: 3
    is class: True
    module: None

:: {'reactor': <twisted.internet.selectreactor.SelectReactor object at 0x288bd10>, 'state': 'disconnected', 'factoryStarted': 0, 'bindAddress': None, 'factory': <H...
        type: <type 'dict'>
referrers: 3
    is class: True
    module: None

so I saw some unclosed reference inside twisted function, how can I avoid it?

Answer 1

Try some strategies recommended in related questions. However, it is likely that you don’t have a memory leak, you just have memory fragmentation.

It looks like the “Python memory leak detector” has a pretty severe bug. It enables DEBUG_LEAK which prevents all cycles from being collected. Put another way, it creates lots of massive leaks. If you just add some code to your example to report the contents of gc.garbage without enabling DEBUG_LEAK, then it remains empty (gc.garbage will be populated if any objects are actually leaking, even if you don’t enable any gc debug flags).