Aleksey Nogin wrote: > On 31.10.2008 07:57, Martin Jambon wrote: > >> let x = (1, 2);; >> let wa = Weak.create 10;; >> Weak.set wa 0 (Some x);; >> ... >> print_int (fst x);; >> >> (fst x) would certainly cause funny effects if x were GC'ed at an >> arbitrary time after it has been added to the weak array. >> >> An object can be reclaimed by the GC only if there is no reference to >> it. This remains true. Adding an object to a weak array just doesn't >> count as a reference. >> > Martin, > > You are answering the wrong question - you are answering "could x be > GCed too early?" - the answer is obviously "no". However, the initial > question was "could (Some x) be removed from wa too early by GC - before > x is orphaned?" The answer is "we'd hope not", but the documentation is > somewhat ambiguous.
So I checked the implementation and it turns out that x is unboxed from (Some x) before being added to the weak array. x is really the value that matters and of course not keeping any reference to (Some x) has no importance. The weak pointer is x (or a null value), stored as a cell of the weak array. 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
