How is this handled in gtk perl?

[Ari Jolma <ari jolma tkk fi>]

Hi,

I'm working in the GDAL developers group and writing the Perl port of 
swig bindings for GDAL. There is an issue of references, which is 
perhaps best shown in an example:

$layer = gdal::Open('datafile').GetLayer(1);

$layer is not usable after this since the data source was only a 
temporary and when it was destroyed, the actual layer was also and thus 
$layer is left without anything real and using it causes a segfault.

There is a reference count system in the underlying C++ system for data 
source class and we could utilize it to delay deletion of the actual 
data source until the $layer object is destroyed. The problem is, the 
$layer object would need a pointer to the data source object and I don't 
know how to manage that. Also the chain could be longer that just data 
source -> layer.

Is this issue an issue in gtk-perl bindings and/or how it was fixed or 
dealt with? Do you have any recommendations/ideas? Of course the swig is 
an added complication and the need to support more languages that Perl.

Ari

--
Prof. Ari Jolma
Kartografia ja Geoinformatiikka / Cartography and Geoinformatics
Teknillinen Korkeakoulu / Helsinki University of Technology
POBox 1200, 02015 TKK, Finland
Email: ari.jolma at tkk.fi URL: http://www.tkk.fi/~jolma