[Python-Dev] new unbounded memory leak in exception handling?

[Greg Hewgill]

I've constructed an example program that does not leak memory in Python
2.x, but causes unbounded memory allocation in Python 3.1. Here is the
code:

import gc
import sys

class E(Exception):
    def __init__(self, fn):
        self.fn = fn
    def call(self):
        self.fn()

def f():
    raise E(f)

a = E(f)
while True:
    print(len(gc.get_objects()))
    try:
        a.call()
    except E:
        # get exception value in a python2/3 portable way
        a = sys.exc_info()[1]

Every time through the loop, the length of gc.get_objects() increases
by 7 under Python 3.1. I believe this is a regression error, since
Python 2.x does not exhibit the same behaviour.

Can anybody confirm this?

Greg Hewgill
http://hewgill.com