From: Tim Hunter <TimHunter@...>
Date: 2009-08-28T08:28:31+09:00
Subject: Re: RMagick reacts very oddly to an incorrect file

Pito Salas wrote:
> I am not sure if this is me or Rmagick. I 'accidentally' used an input
> file which was a 40Meg multi-image TIF with 50 or so images and my mac
> os x went totally haywire. As I traced down into the problem I got to
> this:
> 
>     # Initialize new instances
>     def initialize(*filenames, &block)
>         @images = []
>         @scene = nil
>         filenames.each { |f|
>             Magick::Image.read(f, &block).each { |n| @images << n }
>             }
>         if length > 0
>             @scene = length - 1     # last image in array
>         end
>         self
>     end
> 
> Which is near line 1600 of RMagick.rb. And in particular, the line
> 
>             Magick::Image.read(f, &block).each { |n| @images << n }
> 
> Is where things go sour. My disk whirls like crazy, my mac becomes
> totally unresponsive and eventually I figured out that I could locate a
> particular process running ruby and kill it surgically and after a few
> moments things settled back to normal.
> 
> Odder still, if I stepped into the Image.read I found the particular
> call was to @path.dup where things went sour. @path at that moment
> seemed to have an innocuous string in it.
> 
> I assume this is sufficiently arcane that only one person on this list
> will have a comment... But if anyone, especially  TimH can shed some
> light I would appreciate it!
> 
> I want to put some defensive code into my stuff but I am not sure what I
> am checking for. Is it just a very large file or what?
> 
> Thanks!!
> 
> Pito

My guess is that you ran out of memory and OS X started swapping to 
disk. This would explain your disk whirling and your computer getting 
unresponsive. Killing the process freed the memory and things went back 
to normal.

-- 
MagickWand for Ruby - http://magickwand.rubyforge.org/