As far as I'm aware only the incoming set can change... The outgoing set is fixed when you add a link to the AtomSpace/AtomTable.
J On Tue, Sep 30, 2008 at 10:55 AM, Ben Goertzel <[EMAIL PROTECTED]> wrote: > > Also, of course, the ingoing or outgoing set of an Atom may be changed by a > MindAgent ... why is this not a problem for concurrency? > > On Tue, Sep 30, 2008 at 1:51 PM, Linas Vepstas <[EMAIL PROTECTED]> > wrote: >> >> 2008/9/30 Ben Goertzel <[EMAIL PROTECTED]>: >> > >> > Linas, >> > >> > But the truth values, attention values, etc. associated with an Atom are >> > not >> > immutable ... >> > >> > so for instance, a MindAgent could add a new Version within a >> > CompositeTruthValue >> > object associated with an Atom ... >> >> Hmm. Well, if one thread is looking at a truth value while >> another is setting it, then, in today's system, there would be >> a crash (because the old value is deleted, and >> Atom::getTruthValue() returns a reference). >> >> This could be solved by having AtomTruthValue() return >> a copy, instead of a reference; but then one pays the >> penalty of creating a copy, for each and every access. >> (this is "copy-on-read"). >> >> By contrast, in a garbage-collected system, the worst that >> would happen is that someone is looking at an "old, stale" >> truth value; as opposed to crashing. By the principles >> of concurrency, there's "no such thing" as an "old stale >> value" in between synchronization primitives. >> >> --linas > > > > -- > Ben Goertzel, PhD > CEO, Novamente LLC and Biomind LLC > Director of Research, SIAI > [EMAIL PROTECTED] > > "Nothing will ever be attempted if all possible objections must be first > overcome " - Dr Samuel Johnson > > > > _______________________________________________ > Mailing list: https://launchpad.net/~opencog-dev > Post to : [email protected] > Unsubscribe : https://launchpad.net/~opencog-dev > More help : https://help.launchpad.net/ListHelp > > _______________________________________________ Mailing list: https://launchpad.net/~opencog-dev Post to : [email protected] Unsubscribe : https://launchpad.net/~opencog-dev More help : https://help.launchpad.net/ListHelp
