Benjamin Goldberg writes: > Juergen Boemmels wrote: > > Benjamin Goldberg <[EMAIL PROTECTED]> writes: > > > > > The pobject_weakref function first checks if the 'weakref' argument > > > has been marked as alive -- if so, nothing happens. Then, it adds the > > > Pobj* to a lookup table, pointing from the Pobj*, to a list of > > > registered callbacks for that Pobj*. > > > > This is far to complicated. Each object has a list of > > destroy-functions, one of them is the costom-destroy function the > > others are the weakref-callbacks. > > But suppose that at the end of DoD, the object we're weakly referring to > gets marked as alive? Now, we would need to look through that object's > list of destroy-functions, and remove all of the weakref-callbacks. > > But if the weakref-callbacks are stored in a seperate data structure, > created during DoD, then there's no problem; this data structure will > get re-created for each DoD pass, and thus always start empty. > > Also, by keeping them seperate, we can walk all the callback functions > before destructing the dead objects. > > (But you're right -- it is too complicated to do a lookup table. A > simple linked list should do fine.)
I may be missing the problem that you are talking about, but it seems to me that since we have PMCs which mark themselves instead of being automatically marked, a WeakRef PMC would be trivial... I don't think it needs to be any more fundamental than a PMC. Luke
