Warren Harris wrote: > I'd like to understand better how ocaml's weak pointers operate. First, > although it doesn't seem to be specified in the documentation, I assume > that weak pointers will *not* be reclaimed (e.g. from a weak hash table) > if the program retains some other reference to the object. I.e. the weak > pointer must be the last remaining pointer to the object for reclamation > to occur.
Yes, otherwise the program would crash. > My second question relates specifically to my application. I would like > to have a primary cache of objects, and a secondary index into > sub-objects referenced from the primary cache. I.e. CacheA references > objects of type A; objects of type A reference objects of type B; CacheB > references objects of type B. I would like to guarantee that weak > references in CacheB are not flushed unless the corresponding reference > from CacheA is first flushed. I assume will be the case if a non-weak > reference from A to B is maintained. Can anyone verify? Weak pointers are useful for data that should be shared by several independent "users" and discarded when the number of users drops to zero. I wouldn't call your CacheB a cache if it is a weak array or a weak hash table. It is a table of shared objects. These objects of type B are shared by objects of type A and possibly other users of CacheB. Martin -- http://mjambon.com/ _______________________________________________ Caml-list mailing list. Subscription management: http://yquem.inria.fr/cgi-bin/mailman/listinfo/caml-list Archives: http://caml.inria.fr Beginner's list: http://groups.yahoo.com/group/ocaml_beginners Bug reports: http://caml.inria.fr/bin/caml-bugs
