2009/3/20 Joel Pitt <[email protected]>: > On Sat, Mar 21, 2009 at 3:13 AM, Linas Vepstas <[email protected]> wrote: >>> (I've discover this is the source of some tests failing on buildbot >>> and for random people ... >> >> well, technically speaking, checking for a null pointer is >> the wrong thing to do. The tests should have checked for >> undefined handle. > > The problem I have is that if I have a set Handles, and then during > the life of Handle, some become invalid through removals (and not just > the expected one, because removals can recursively remove others). I > could probably hack around to avoid this, but I think it'd be a bigger > problem, especially when things get multithreaded and distributed.
Well, but that's exactly the point. If some other thread deletes an atom, then calling TLB::IsInvalidHandle() is guaranteed to give you the correct answer. By contrast, some pointer to atom might be stale: it may be pointing at some atom that no longer exists. Perhaps you meant this: (NULL == TLB::getAtom(hand)) Then that's OK, since it is exactly identical to TLB::IsInvalidHandle(hand) ... err, *should be identical*. After code review, I see that its not, and that is a bug. Should I fix it? Do you want to do this? I also see that TLB.h still has traces of "non-real atom" code in it. I presume its OK to remove this now? --linas _______________________________________________ Mailing list: https://launchpad.net/~opencog-dev Post to : [email protected] Unsubscribe : https://launchpad.net/~opencog-dev More help : https://help.launchpad.net/ListHelp
