Re: [Matplotlib-users] Memory leaks in a web application

[A B <pyt...@gm...>]

On Mon, Feb 9, 2009 at 9:59 PM, Jouni K. Seppänen <jk...@ik...> wrote:

> Ryan May <rm...@gm...> writes:
>
> > On Mon, Feb 9, 2009 at 2:37 PM, A B <pyt...@gm...> wrote:
> >
> > If you're using the full OO interface and creating a figure by making an
> > instance of Figure(), then you shouldn't need to close the figure by
> hand.
> > It should be deleted whenever you delete or replace your instance of
> > Figure.  (If I understand correctly.)
>
> Yes, in the OO interface there is no close() because matplotlib does not
> retain any references to the figure object. Garbage collection will take
> care of reclaiming memory once the user code has no more references to
> the object either.
>
> That said, there have been cases of memory leaks caused by circular
> references among objects that have __del__ methods. I think all known
> leaks have been fixed, but if I were deploying a long-lived application
> that creates lots of figures, I would definitely want to watch its
> memory usage in my exact use case.
>
> --
> Jouni K. Seppänen
> http://www.iki.fi/jks
>

Thank you. The reason I asked the question was that with the OO interface, I
still observed growth in memory consumption (more than I saw after I added
pyplot.close() calls). However, at some point (90M which I still think is a
lot) the growth tapered off and eventually seemed to have stopped.
Essentially, what I do is create a figure, then call plot() on it in a loop
to generate multiple curves, then print_png() on the canvas object.