Re: LilyPond is excessively slow on Windows Vista

[Han-Wen Nienhuys]

On Thu, Nov 13, 2008 at 9:19 AM, Trevor Daniels <address@hidden> wrote:
> The slowness is certainly not inherently due to Vista
> as LilyPond has always run fine under Vista here.  The
> slowness issue was discussed at some length back in
> March 08 on both -user and -bug when it was determined
> that it was due to font building.  This is almost certainly
> is cause of the recently reported slowness.  Incidentally,
> a similar issue made LilyPond slow under XP too, and this
> was fixed with the 2.11.43 release.

> In the past, one cause was an incorrect version of
> libfontconfig-1.dll but this is unlikely now as the
> appropriate version of this dll is included with
> every binary.  Another possibility is that when this dll
> searches for the font cache it checks for an old cache
> first.  The fonts used to be cached in ~\.fontconfig.
> If such a directory is present it might be worth trying
> deleting it or moving it to another directory.

Trevor is correct.  Every instance of lilypond slowness was caused by
fontconfig caches.  The problem is that there are a bazillion of
windows versions; I'm not talking about XP vs. Vista but rather
distinctions in minor version numbers, and perhaps changes that vendor
do on top of that.  For some versions, the fontconfig cache ends up
not getting written (permission problems?) or getting recreated all
the time.

Once LilyPond has the font caches computed correctly, running times
should differ little between windows, linux and mac.

The problem is that the problem is often hard to diagnose and
reproduce without having the afflicted machine at hand.  In general,
my takeaway from it is that shipping software on top of Windows is a
religious experience. You can never be sure that it works, so you have
to pray a lot.

-- 
Han-Wen Nienhuys - address@hidden - http://www.xs4all.nl/~hanwen