~pythonregexp2.7/python/issue2636-12

Committer: armin.rigo
Date: 2008-04-25 09:35:18 UTC
Revision ID: svn-v3-trunk1:6015fed2-1504-0410-9fe1-9d1591cc4771:python%2Ftrunk:62497

A new crasher.

added added

removed removed

# The cycle GC collector can be executed when any GC-tracked object is

# allocated, e.g. during a call to PyList_New(), PyDict_New(), ...

# Moreover, it can invoke arbitrary Python code via a weakref callback.

# This means that there are many places in the source where an arbitrary

# mutation could unexpectedly occur.

# The example below shows list_slice() not expecting the call to

# PyList_New to mutate the input list. (Of course there are many

# more examples like this one.)

import weakref

class A(object):

pass

def callback(x):

del lst[:]

keepalive = []

for i in range(100):

lst = [str(i)]

a = A()

a.cycle = a

keepalive.append(weakref.ref(a, callback))

del a

while lst:

keepalive.append(lst[:])