Re: .oct files - keeping state across calls

[Christophe Tournery]

Attached is an example .cpp file that can be compile with mkoctfile,  
demonstrating the issue. I have included a simple makefile to compile  
it and create the necessary symlinks.

The code tries to store handles to a library in a map. The key to the  
map is passed back to octave such that the "user" can choose on which  
instance of the library a function is called.

Thanks for testing and I am curious to know if you guys think it is a  
bug in 3.2 or if it was "un-intentionally" working in 3.0.
Christophe Tournery


Testing in Octave 3.0.5:
------------------------

octave:1> h1 = mylib_init()
h1 = 0
octave:2> h2 = mylib_init()
h2 =  1
octave:3> mylib_destroy(h1)
octave:4> mylib_destroy(h2)


Testing in octave 3.2.0:
------------------------

octave:1> h1 = mylib_init()
h1 = 0
octave:2> h2 = mylib_init()
h2 =  1
octave:3> mylib_destroy(h1)
error: mylib_destroy: handle '0' does not exist!
octave:3> mylib_destroy(h2)
error: mylib_destroy: handle '1' does not exist!


On Jul 9, 2009, at 8:41 PM, David Bateman wrote:

> Christophe Tournery wrote:
> > Thanks for the tip, I did not know mlock().
> >
> > However the problem is still there. The list of handles has a  
> > different memory address when calling the mylib_init() function and  
> > when calling the mylib_process() function. Has there been major  
> > changes from 3.0 to 3.2 regarding loading oct files?
> >
> > Do you guys encounter this design problem often or is there a very  
> > simple solution I do not see?
> At this point I'm not sure there is a problem at all. Could you send  
> a complete simple example demonstrating the problem..
>
> D.
>
>
> --
> David Bateman                                address@hidden
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octtest.zip
Description: Zip archive