If obj foobar. looksup #foobar and fails with DNU, will the next obj foobar repeat the foobar, or is the DNU cached so no repeat lookup (unless cache invalidated)?
Is it likely to be the same in e.g. Gemstone ST?
Thanks - Sophie
On 04.05.2008, at 21:39, itsme213 wrote:
If obj foobar. looksup #foobar and fails with DNU, will the next obj foobar repeat the foobar, or is the DNU cached so no repeat lookup (unless cache invalidated)?
It is not cached in Squeak.
Is it likely to be the same in e.g. Gemstone ST?
In general, even if it was "cached", you should be unable to tell.
- Bert -
10 years back I got trapped in a snow storm in Boston, and spent the evening exploring the existing caching algorithm for method lookup which hasn't changed much over the years. I was curious if the behavior now (well 10 years back) was the same as what was documented in the Green Book, and how Morphic affected things. I found no real difference between my numbers and the documented Green Book numbers, so working on the caching won't buy much.
But, I note you would notice it if you turned caching off.
On May 4, 2008, at 12:39 PM, itsme213 wrote:
If obj foobar. looksup #foobar and fails with DNU, will the next obj foobar repeat the foobar, or is the DNU cached so no repeat lookup (unless cache invalidated)?
Is it likely to be the same in e.g. Gemstone ST?
Thanks - Sophie
-- = = = ======================================================================== John M. McIntosh johnmci@smalltalkconsulting.com Corporate Smalltalk Consulting Ltd. http://www.smalltalkconsulting.com = = = ========================================================================
Hi Sophie, the DNU is cached in the global lookup cache, but not used unless you explicitly send a #doesNotUnderstand: message. (ie: 1 doesNotUnderstand: ....) I sent a fix to the list four years ago but it never went to the VM code. The mail is: http://lists.squeakfoundation.org/pipermail/squeak-dev/2004-December/086322....
Bye, Hernan.
On Sun, May 4, 2008 at 4:39 PM, itsme213 itsme213@hotmail.com wrote:
If obj foobar. looksup #foobar and fails with DNU, will the next obj foobar repeat the foobar, or is the DNU cached so no repeat lookup (unless cache invalidated)?
Is it likely to be the same in e.g. Gemstone ST?
Thanks - Sophie
squeak-dev@lists.squeakfoundation.org
-
Bert Freudenberg -
Hernan Wilkinson -
itsme213 -
John M McIntosh