Memory leak examples

example0.ipy

In [1]: import sys

In [2]: def test():
   ...:     foo = "Hello, world!"
   ...:     try:
   ...:         raise Exception()
   ...:     except Exception, e:
   ...:         trace = sys.exc_info()[2]
   ...:         return trace
   ...:

In [3]: trace = test()

In [4]: trace.tb_frame.f_locals
Out[4]: {'e': Exception(), 'foo': 'Hello, world!', 'trace': <traceback at 0x10c075ab8>}

In [5]: trace == trace.tb_frame.f_locals['trace']
Out[5]: True

example1.py

import urllib3
import objgraph
import time


pm = urllib3.ProxyManager('http://localhost:8000/')
try:
    pm.request('GET', 'https://ianpreston.io/', timeout=0.25)
except Exception, e:
    print 'Exception raised!'
    print e
    del e

# In current master, open og1.png to see the backrefs from the stack frame object
# to ex_socket. In ianpreston/urllib3/fdleak2, the line below will raise IndexError
# because there is no socket._socketobject kept alive.
ex_socket = objgraph.by_type('socket._socketobject')[0]
objgraph.show_backrefs(ex_socket, filename='og1.png')