Re: [Texmacs-dev] efficiency of improved Qt port

[Joris van der Hoeven]

On Sat, Dec 27, 2008 at 12:37:39AM +0100, David Allouche wrote:
> > Yes, more or less. You indeed have 1Mb increase in memory usage
> > for every four or five iterations. Now the magic scheme command is '(gc)'
> > and you will have to redo your thirty iterations before noticing
> > further increase. So maybe it is just the gc which is not well synchronized.
> > You may try to see whether doing a '(gc)' also solves the problem with
> > the increase in memory usage during idle time.
> 
> Dunno if that changed in the past years, but when I looked at the
> Guile glue, the "memory size" information was wrong for complex
> objects such as trees and lists.
> 
> Typically, the size reported to Guile for a tree structure was the
> size of a single node. Admittedly, it is difficult to report a
> significant size, because different trees that are visible as
> different objects to Guile can share common subtrees. The only way to
> report the correct size for such shared structures would be to build
> the entire structure as Guile objects.
> 
> This memory size information is critical to guile's garbage
> collection. It lets guile know when to trigger a gc. Not reporting
> correct sizes for guile-visible objects leads to systemic memory leaks
> caused by insufficiently frequent garbage collection.
> 
> That might be related to what you are observing now.

Thanks for recalling this fact which slept out of my mind.
However: why do we only observe the strange behaviour for the Qt-version,
and not the X11-version...?

--Joris