- From: Miles Sabin <msabin@cromwellmedia.co.uk>
- Date: Thu, 12 Nov 1998 10:51:28 -0000
- To: "'John Cowan'" <cowan@locke.ccil.org>, "'DOM list'" <www-dom@w3.org>
John Cowan wrote, > Miles Sabin wrote: > > > > Actually I *was* thinking of invalidating all iterators, on > > > the assumption that the number of iterators is typically small, > > > even if we can't (due to garbage-collection considerations) > > > determine its actual value. > > > > It's precisely because of GC that we *can't* assume that the > > number of iterators is small. > > For "iterators" read "active iterators". Yes, but how can an implementation tell whether or not an iterator is active? The only way is for it to wait for it to become unreferenced, and the only way of knowing that is to wait for it to be GC'd and have it's finalize method called ... weak references work in more or less the same way: there's a bit of JVM support, but the mechanism is still dependent on GC. The upshot is that whatever you as the programmer might think of as the number of "active" iterators, the implemenations idea of the number of active (or, equivalently, not known to be inactive) iterators could be significantly greater ... potentially unnacceptably so. Cheers, Miles -- Miles Sabin Cromwell Media Internet Systems Architect 5/6 Glenthorne Mews +44 (0)181 410 2230 London, W6 0LJ msabin@cromwellmedia.co.uk England
Received on Thursday, 12 November 1998 05:54:03 UTC