Hi Edward, Thank you for your reply!
On Mon, Mar 11, 2013 at 8:17 PM, Edward Z. Yang <ezy...@mit.edu> wrote: > I was under the impression that foreign pointers finalizers were only > ordered with respect to multiple finalizers on a single object. So if > you can show your implementation preserves same-object ordering, that > should be sufficient. (Nota bene: I haven't CR'd your code.) Yes I understand that. However my understanding is that addForeignPtrFinalizer creates a fresh WEAK object with just one finalizer. So in order to maintain the same-object ordering of C finalizers, I still somehow need to deal with ordering between multiple WEAK objects. > > Edward > > Excerpts from Akio Takano's message of Mon Mar 11 03:17:48 -0700 2013: >> Hi, >> >> I'm working on implementing per-generation lists of weak pointers to >> speed up garbage collection in programs that allocate a lot of weak >> pointers. I have a patch [1] that validates and gives a 3x speed up on >> a benchmark. However I'd like to ask for some advise before finishing >> and submitting the patch. >> >> [1] >> https://github.com/takano-akio/ghc/commit/c7345c68eaa1e7f9572e693b5e352e386df7d680 >> >> The problem is that since my patch splits the weak pointer list >> between generations, it no longer maintains the right order of weak >> pointers. This could cause finalizers added with >> addForeignPtrFinalizer to run in the wrong order. >> >> I can think of one way to fix it; to make sure that when a WEAK object >> gets promoted, it is always added to the front of the new list. So my >> questions are: >> >> - Would it be a correct fix? >> - If so, is it an acceptable fix? For example, is it too fragile a >> reasoning to rely on? >> >> Thank you in advance, >> >> Takano Akio >> _______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://www.haskell.org/mailman/listinfo/ghc-devs
