The change in trunk fixes the problem for every class that does not
have a __del__ attribute. Classes that have a __del__ attribute may
cause a memory leak (on cpython, not on jython).
On Jan 7, 11:41 pm, Anthony <abasta...@gmail.com> wrote:
> As far as I can tell, the change in trunk didn't have any effect for me. I'm
> on Windows 7 with Python 2.7.1 (just using the built-in Rocket server). I
> added the following code to the top of default.py (outside any functions) in
> the welcome app:
>
> class Foo(object):
> def __del__(self):
> pass
> foo = Foo()
> foo.payload = [1] * 1000000
>
> I then load the index page of the welcome app and start watching my
> python.exe process memory in the Windows Task Manager. Every time I reload
> the page (by hitting F5), the memory increases by about 7MB, which is
> exactly the same behavior I observe when running the same experiment in
> 1.91.6 (i.e., before gc was added). These large memory increases do not
> occur when I remove the above code from default.py. Am I doing something
> wrong?
>
> I'm also wondering if there may be a small memory leak either in the
> framework or the welcome app, even without the above code. I notice that
> when I reload the welcome app index page (without the above code), I still
> get small memory increases, on the order of a few KB per reload. It's not
> consistent -- sometimes a few KB, sometimes a bit more, sometimes no
> increase at all -- but memory does consistently creep up as I keep reloading
> (both in trunk and in 1.91.6). Is that expected behavior?
>
> Thanks.
>
> Anthony
>
> On Friday, January 7, 2011 7:56:51 PM UTC-5, Massimo Di Pierro wrote:
>
>
>
>
>
>
>
> > Mitsuhiko on reddit brings up a good issue that I was not aware of: a
> > bug in exec.
>
> > code="""
> > class Foo(object):
> > def __del__(self):
> > pass
> > foo = Foo()
> > """
> > while True: exec code in {}
>
> > causes a memory leak. Web2py does this. The memory leak is small in
> > practice and in fact nobody noticed it. Yet it is a concern, in
> > theory.
>
> > So far I have the current solution
>
> > code="""
> > class Foo(object):
> > def __del__(self):
> > pass
> > foo = Foo()
> > """
> > import gc
> > while True:
> > exec code in {}
> > gc.collect()
>
> > It works for me and I cannot reproduce the leak.
> > I patched trunk with this. Give it a try and let me know what you
> > think.
>
> > Massimo
