[Qt-jambi-interest] Memory Leaks - any updates?

[Gunnar Sletta]

Curt Nowak wrote:
> Hi Gunnar,
>  
> thanks for you detailed explanation. You saw it coming: I'm having
> follow-up questions. 

I did, actuall ;)

> It looks as though you are not referring to my
> code. You see, my example code (mail sent October 8th) did not
> contain inner classes. It was all about creating a lot of top-level
> widgets at runtime. Those widgets do not seem to get gc-ed. Invoking
> dispose() on each of them does make a big difference but leaves a
> small memory leak nevertheless. How come?

Hm... Before I entered this into our task tracker I played a bit with 
the code, and I entered my modifierd version into the task tracker as it 
still reproduced the problem but contained a lot of debug info, among 
them the inner class.

The problem is still the same though, just with a few levels of 
indirection.

When you do

   button.clicked.connect(this, "create()");

you create a reference from the signal to back to the toplevel and you 
have a circular reference that is inpenetrable for the garbage collector.

This is in fact a huge problem, and hopefully we can minimize some of 
the impact using weak java references in connections, but that will 
introduce regressions in cases where references to the target objects 
are not being kept.

Given this happens with all connections, it seems that one must 
explicitly dispose all toplevels.

best regards,
Gunnar