Vista and font cache

[Dov Isaacs]

Rebecca,
 
We honestly don't know what is causing the problem other than that
deleting
the Windows font cache clears the symptoms at least for a while (where
for
some "a while" is longer than for others). The problem seems to be
shared
by Windows 2000 and XP (which share a tremendous amount of code). 
We did not see it with Windows'9x or Windows NT 4, both of which have 
significantly different text/font handling mechanisms than Windows 2000
and XP. I haven't heard of anyone encountering the problem with Vista,
but that doesn't mean that it is exempt either since the GDI-based text
and font handling is based on that of Windows XP.
 
My observation is that if you indeed encounter the problem even once on
a 
particular system, you should assume that you are likely to encounter it
again
on that system and as such, you should proactively delete the font cache
and
reboot on a regular basis. What is a regular basis? Your guess is as
good as
mine. Of those who have "fixed" the problem by doing the font cache
deletion 
and reboot, I haven't heard of anyone getting the problem back that
quickly
(i.e., within hours or days or even a week). If I was to start seeing
the symptom
occur on my system, I would configure my system to have a system
shutdown
script that would delete the font cache every time the system shutdown
(which
is part of every reboot). Since reboots occur most times you do a
Microsoft
Windows Update (for example, yesterday was "Patch Tuesday"), you would
probably get a clean font cache at least once a month if not more
frequently.
If you shutdown the computer once a day, then you get a clean font cache
daily.
 
What is the cost of having a new font cache? As far as I can determine,
not
much. I have yet to see any performance hit when deleting a font cache
and rebooting other than the time to delete the font cache and reboot.
 
With regards to any "fixes" -- the problem is not readily reproducible
and
as such we can't instrument FrameMaker to look for where we can change
any code to prevent the problem. My comments about old GDI calls is
guesswork on my part based on a few hunches, the technical details of
which I will not bore this list with.
 
            - Dov
 
 
________________________________

From: rebecca officer [mailto:rebecca.officer at alliedtelesis.co.nz] 
Sent: Tuesday, February 13, 2007 6:38 PM
To: Dov Isaacs
Cc: Framers (E-mail); FrameMaker Discussion Forum
Subject: RE: Vista and font cache



	Hi Dov
	
	Are you saying that deleting the font cache and rebooting should
get
	rid of the symptoms for a while, regardless of the size of the
font
	cache after reboot?
	
	My memory of last year's posts was that you had to also reduce
the size
	of the font cache by deleting big unused fonts. I did that a few
months
	ago and my font cache is now around 770 KB. But a document
showed the
	symptoms again a couple of days ago. Is that what you'd expect?
	
	Next time I have a document with symptoms, I'll try just
deleting the
	cache and rebooting.
	
	Also, does your email mean that Adobe are hunting for those "old
	Windows GDI calls made by FrameMaker" to fix the bug?
	
	Thanks, Rebecca
	
	>>> "Dov Isaacs" <isaacs at adobe.com> 14/02/07 10:42 >>>
	The symptom was reported against FrameMaker internally.
	The problem has been seen in printing to PostScript
	printers and as such, cannot be traced in any way to
	Distiller (or the AdobePDF PostScript printer driver
	instance). The symptom is not directly reproducible;
	all we know is that by deleting the FNTCACHE.DAT file
	and rebooting, the problem goes away, at least for a
	while. Since FrameMaker does not and cannot directly
	access or manipulate the FNTCACHE.DAT file, the likely
	cause of the bug are old Windows GDI calls made by
	FrameMaker that are still supported by Windows, but
	in which some bug associated with font caching crept
	in over the years.
	
	        - Dov