[Image-SIG] ImageDraw leaks unless deleted?

[Fredrik Lundh]

If explicit "del" appears to address a leak that Python's builtin
refcounter doesn't handle, that's more of a bug in Python than in PIL
;-)

I'm not 100% sure, but I think the rationale for including the
explicit "del" in that example is that the draw object holds a
reference to the image you're drawing in; by doing an explicit del,
you minimize the risk that the program hangs on to potentially large
image objects without you noticing.

(I wouldn't rule out a memory leak either, of course; if you can find
a small example that leaks when executed in a loop, let me know).

</F>

On Mon, Nov 3, 2008 at 11:24 PM, Ned Batchelder <ned at nedbatchelder.com> wrote:
> In the docs for ImageDraw
> (http://www.pythonware.com/library/pil/handbook/imagedraw.htm), the example
> includes "del draw".  I don't understand why that line is necessary, since
> when the variable goes out of scope, the object will be deleted.
> But in our unit tests, we had a problem with memory use growing too large to
> complete the tests.  By adding some "del draw" lines into our code, we
> halved the memory requirement.  In all cases, these dels were in places
> where the variable would go out of scope or be overwritten shortly anyway.
>  Why are the dels necessary?  Is this a subtle memory management bug in
> ImageDraw?
>
> --Ned.
> http://nedbatchelder.com
>
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