[Date Prev][Date Next][Thread Prev][Thread Next]
- Subject: Re: how to use lmem.h ?
- From: M Joonas Pihlaja <jpihlaja@...>
- Date: Sun, 22 Feb 2009 17:02:08 +0200 (EET)
On Sat, 21 Feb 2009, Mark Hamburg wrote:
> You can avoid the error problem by using a userdata and letting the GC collect
> it. That gets expensive relative to malloc/free if you do it every time since
> the GC is necessarily more expensive than the free. We could work around that,
> however, by doing the following:
Chucking together a simple microbenchmark to test userdata overhead,
I'm seeing a well tuned GC running at ~ 1.6x the speed of explicitly
doing malloc/free, and even the default tuned GC running at ~ 3.2x.
It only takes a handful of table lookups or string-intern checks to
dwarf that overhead. The take home message for me is that full
userdatas are the way to go for almost all allocation, especially
taking into account how much easier they make writing lua-exception
safe C code.