[Gambas-user] Runaway memory consumption not released until program exit

[Richard]

Hi everybody,

I am using Gambas 2.20.0 on Mandriva 2010.0. The desktop is LXDE and the gui 
toolkit might possibly be GTK.

I have written a button event handler to process hundreds or thousands of .png 
images in a directory. The main memory available when the program starts is 
around 1.8 GBytes. After processing just 744 images (in testing) this falls 
to about 74 MBytes. The memory is not freed on exit from the event handler, 
only when I exit from the program.

I use only 1 Image object; a variable called "frame". I have tried declaring 
this as a local in the event handler and as a class-visible variable with no 
apparent change in the way memory is eaten and never disgorged.

I do three things with my frame variable in a loop which iterates for all 
frames in a directory; 

1. I load it from an image on disc
2. I "stretch" it to make its width smaller(!)
3. I save the altered frame to a different directory

Specifically the significant lines of code look like;

frame = Image.Load(SourceImage)
frame.Stretch(NewWidth, NewHeight)
frame.Save(DestinationImage)

Outside the loop I now do frame = NULL, but this has no effect.

Is it possible that my code is allocating multiple "anonymous" frame objects 
and not releasing them? I have read Benoit's explanation in this list of 
Gambas memory management (Re: [Gambas-user] Memory Management, on  
08/09/2007 09:19).

I turned to Gambas to program this function because my first choice, 
imagemagick, would always run out of memory without processing a single 
frame. The Gambas solution works, but no more work can be done without 
killing the program and restarting it - not very convenient. I anticipate 
that typical uses of the program will have to handle 10-30 thousand png 
images at a time.

Can anyone suggest how I find out what is so hungry for my memory, and 
hopefully how to suppress its appetite? 

Richard