Hi all,
I've tried to learn how to properly use Weak collections for purposes of
circular references, but I'm not sure I fully understand -- not enough
to actually use it in my implementation.
I made a fairly large project a couple of years ago where I ended up
with a lot of stale information in the image because I had circular
references keeping objects from being cleared by GC. I learned my
lesson, and addressed the situation by building a 'release' mechanism
and explicitly tearing down objects when I was done with them.
From what I understand, the Weak collection hierarchy will keep
references to objects but not in such a way that the GC won't clear them.
If I have, say, an ArchiveItem object, and the ArchiveItem has
ArchivedFiles, but I want ArchivedFiles to know which ArchiveItem they
belong to, then I've set myself up with a circular reference situation.
I understand I could have a separate object which allows ArchivedFiles
to *ask* which ArchiveItem they belong to, instead of storing it within
themselves.
But I also understand that I could potentially use, say, a WeakSet in
ArchiveItem, which will hold weakly onto ArchivedFiles since the
ArchivedFiles themselves refer back to the ArchiveItem. I get the
impression that this approach would free me from having to build out a
complete 'release' mechanism or from doing other explicit clearing and
removal of references. But I don't understand if I could find myself in
a situation where an ArchiveItem thinks it doesn't have any
ArchivedFiles because they got GCed before I was truly through with them.
Can anyone recommend any approach or any materials on this subject?
Thanks,
Tim
