[Insight-developers] Issue with types (unsigned) long and Visual Studio x64

[Gaëtan Lehmann]

Le 13 janv. 11 à 18:39, maquette a écrit :

> Hi All,
>
> I have a question about some Issue that was discussed on insight- 
> users back in 2007:
>
> http://www.itk.org/pipermail/insight-users/2007-February/021069.html
>
> The thread faded without a real solution to an "Allocate > 4GB on  
> Windows x64" Problem. Luis told us patience and to wait for fixes in  
> ITK 3.xx. Now I have still problems as soon as an image chunk with >  
> 2GB is used in the output of the ResamplingFilter. To review:
> - Problems back in 2007 were suspected to stem from using "long" and  
> "unsigned long" in stead of size_t and ptrdiff_t for pixel amounts,  
> pixel offsets, etc. Some user tried to replace (unsigned) long in  
> the basic files itkImage.h -ImageBase.h -Index.h -Size.h -Offset.h  
> but got into trouble elsewhere, so stopped "fixing" this  
> crosscutting issue.
>
> -Today I'm encountering some strange issues as well, but not while  
> an Image is Allocated, but rather when using the Resample Filter  
> multithreaded (16 threads, no problem with 1 thread, why??). The  
> outIt iterator in LinearThreadedGenerateData(...) happens to fall  
> into way too low memory, when it is expected to work on one of the  
> "upper" portions of the large Output Image (in my case the Image was  
> 1541^3 x 2Byte). So allocation works fine, no exception raised, just  
> some pointer miscalculation somewhere. Looks like an overrun of a  
> 4byte "unsigned long". Visual Studio uses 4Byte for long even in  
> 64bit mode! So theres no problem on GCC I suppose.
>
> -As the Iterators Regions are using 4byte it cannot work like that.  
> => tried to do the replacements in itkImage.h -ImageBase.h -Index.h - 
> Size.h -Offset.h and some itk...Iterator.h files (offset table) as  
> well ... and running into trouble elsewhere. The files all use  
> "long" and "unsigned long" even in 3.18 so there has been no fix so  
> far?
>
> => I think this is worth beeing resolved, as memory is cheap, Win is  
> widespread (would rather use unix though, but the boss says...) 3D  
> Images are Big, and interesting Algorithms are not local ;)
>
> => In my subjective opinion "long" and "unsigned long" should not be  
> used for Pixel Indexes, which can get really big, if images are big  
> and not nicely cube-shaped. E.g. if one pixel has 1Byte, and the  
> Image has only 1 dimension one would need the whole range of size_t  
> and ptrdiff_t to navigate a [1,1,5000000000] Image.
>
> Do you think, that ITK 3.xx can be fixed by:
> 1) replacing all integers which can amount to memory chunk size by  
> either size_t (unsigned) or ptrdiff_t (signed)? The symptom now is  
> IMHO that I can allocate an Image without failure/exception which  
> causes the pipeline to fail without a noticable exception. But is it  
> good enough to look for anything related to a pixel position/ 
> difference or memory position/difference and change the types? This  
> is rather a design decision than a lokalized bug fix.
>
> 2) starting in Code/Common first? Of course this will lead to many  
> failures in other ITK classes which follow the policy "memorysize is  
> long" BUT would at least remove the flaw from Core, and make the  
> rest fixable by the more specialized developers (outside Common).
>
> 3) telling you where the crash happens exactly, and why its only in  
> multithreaded? Well, I think it can not work on a Platform where  
> sizeof(long) < sizeof(ptrdiff_t).
>
> I did my best to search for some successor of the old thread,  
> because I was almost sure that this issue is treated somewhere,  
> perhaps in ITK 4. So please don't be upset that I put it here, but  
> teach me to do better (only a user so far...)
>
> _____


Hi,

ITK v4 should be able to work with large images on MS Windows 64 bit  
now. I think should give it a try and report any problem you may found  
on this mailing list.
The code is available from a git repository — the instructions are  
available on that page

   http://www.itk.org/Wiki/ITK/Git

Regards,

Gaëtan

-- 
Gaëtan Lehmann
Biologie du Développement et de la Reproduction
INRA de Jouy-en-Josas (France)
tel: +33 1 34 65 29 66    fax: 01 34 65 29 09
http://voxel.jouy.inra.fr  http://www.itk.org
http://www.mandriva.org  http://www.bepo.fr

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