Path: news.mathworks.com!not-for-mail
From: "Gadi Reinhorn" <greinhor@mathworks.com>
Newsgroups: comp.soft-sys.matlab
Subject: Re: Last drop in a user's patience
Date: Tue, 18 Nov 2008 14:34:45 -0500
Organization: The MathWorks, Inc.
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Dpb,



Great question.  I think you are getting the root issue in this thread.



I am one of the people who has been part of making this decision and 
implementing it.



Two of the initial reasons we "demoted" ".dll" to a secondary MEX extension 
on Windows 32 are:

1) There were recurring complaints from customers that NON-MEX DLLs shadowed 
M-files with the same name.  These NON-MEX DLLs were on the MATLAB path and 
were being used as non-MEX libraries.  When the users tried to call their 
M-files with the same name, MATLAB would dispatch to the ".dll" thinking it 
was a MEX-file (which have higher precedence).  This issue needed to be 
fixed.  We considered other ways to make the dispatcher differentiate 
non-MEX DLLs and MEX DLLs, but we found that the performance cost was 
debilitating.

2) With the introduction of Windows 64, we wanted to differentiate between 
the two types of DLLs.  We needed to avoid this architecture 
incompatibility.



To address issue (1) and for consistency in issue (2) we introduced the MEX 
extension ".mexw32" for Windows 32.  For backwards compatibility we left 
".dll" as a secondary MEX extension.  We felt that leaving this 
functionality for a few years and slowly phasing it out was a soft rasition 
for users.




The main reason we have slowly moved to removing the use of the DLL 
extension is that in order to continue innovating we are always looking for 
ways to improve our code base.  We carefully balance performance 
improvements and features with quality and compatibility.  In this case we 
feel we can simplify our infrastructure by removing this functionality. 
Since we strongly encourage users to rebuild their MEX-files every release, 
we believe that by now ".dll" MEX-files are starting to become obsolete.  We 
have been thoughtful and careful about this process.  We have also attempted 
to be transparent.  We have been warning about this transition for several 
years and are now approaching the final stages.




I hope this explanation clarifies why we have gone down this path.



If you have further concerns, please report them to our support department. 
They will capture your feedback and help us find a way to improve this 
situation and other issues like this in the future.

http://www.mathworks.com/support/contact_us/index.html



Thanks,

Gadi