Re: Using the ImageMagick backend seems to leak memory

[joakim@verona.se]

Tassilo Horn <tassilo@member.fsf.org> writes:

> Miles Bader <miles@gnu.org> writes:
>
>>>> I just noticed that my emacs uses up more than a gigabyte memory.
>>>> It is because of doc-view with ImageMagick backend.
>>>> 
>>> I met same issue.
>>
>> My impression is that in general, ImageMagick does not aim at memory
>> efficiency (that's why I don't want to use its libraries for my own
>> image I/O needs, event though doing so would be pretty convenient).
>
> Well, not being memory efficiency and not giving back memory at all is a
> minor difference. ;-)
>
> I've just opened a doc-view page-x.png with ImageMagick's display tool.
> The behavior is identical, e.g., it reserves ~30MB per PNG and only
> gives back memory when I close the program.  So I presume, ImageMagick
> has some cache that gets at least cleared when the process is killed.
> I'm sure, there's some C function you can call to clear it...
>
> Looking at the API, there's
>
> ClearMagickWand() clears resources associated with the wand.
> The format of the ClearMagickWand method is:
>
>   void ClearMagickWand(MagickWand *wand)
>
> A description of each parameter follows:
> wand
>   the magick wand.
>
> In the emacs sources, that function's never called.  So that's probably
> the source of the leak.

Hmm. We can try.

Anyway i asked the IM team:
http://www.imagemagick.org/discourse-server/viewtopic.php?f=1&t=17819

Some other things:
- Do you see the issue only when scaling?
- Only with PNG? Or also JPG?

> Bye,
> Tassilo

-- 
Joakim Verona