Greg Ewing wrote: > Martin Devera wrote: > >> As I've written in "Big reader lock" paragraph of the original >> proposal, these >> objects could be handled by not blocking in read path > > But as was just pointed out, because of refcounting, > there's really no such thing as read-only access to > an object. What *looks* like read-only access at the > Python level involves refcount updates just from the > act of touching the object. >
Yes I was thinking about atomic inc/dec (locked inc/dec in x86) as used in G.Stein's patch. I have to admit that I haven't measured its performance, I was hoping for decent one. But from http://www.linuxjournal.com/article/6993 it seems that atomic inc is rather expensive too (75ns on 1.8GHz P4) :-( Greg, what change do you have in mind regarding that "3 instruction addition" to refcounting ? thanks, Martin _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
