Re: [patch] Rework of Pango integration

On Wed, Jun 09, 2004 at 10:56:14AM -0400, Owen Taylor wrote:
> On Wed, 2004-06-09 at 10:02, Jody Goldberg wrote:
> > On Thu, Jun 03, 2004 at 08:54:58PM -0400, Owen Taylor wrote:
> > > I've been working recently on redoing the Pango support in gnome-print;
> > > here's a first pass at a patch.
> > > 
> > > It's actually not that conceptually different from what Jean did
> > > with gnome_print_pango_layout_print() ... it doesn't create a new
> > > Pango backend, but simply uses the FT2 backend and converts
> > > PangoFont to GnomeFont when creating the GnomeGlyphList structures.
> > 
> > Actually one other consideration.
> >     http://bugzilla.gnome.org/show_bug.cgi?id=143542
> > This leak seems to be at the pango level.  It looks likely that the
> > patch would trigger the problem.
> 
> Well, my guess is that virtually all people using this stuff will
> be using the global-singleton, which there isn't even a way to free,
> so it's not especially relevant.
> 
> I don't think fixing 143542 is that hard; you'd need to make 
> fcfont->fontmap a weak reference and then make the font do some
> harmless fallback if it is NULL. (Or just make accessing a font
> after the fontmap has been freed illegal.)

That is not the core of the problem.  Portions of the related
layouts remain behind.  We're seeing things like :

MLK: 192 bytes leaked in 6 blocks
  * This memory was allocated from:
	malloc         [rtlib.o pc=0x6a3c8]
	g_malloc       [gmem.c:136 pc=0xf9e56888]
	pango_ft2_font_render_glyph [pangoft2.c:314 pc=0xfb03afb8]
	pango_ft2_render [pangoft2.c:384 pc=0xfb03b45c]
	pango_ft2_render_layout_line [pangoft2.c:790 pc=0xfb03c3ac]
	pango_ft2_render_layout [pangoft2.c:884 pc=0xfb03ca98]

Even when the layout has been unrefed.  If it was just the global
singleton this would be less significant.