"Simon Marlow" <[EMAIL PROTECTED]> writes: > You might be able to find more information on this in the mailing list > archives. It's true that touchForeignPtr isn't enough to enforce an > ordering on the running of finalizers, but it *can* be used to express a > liveness relationship between one ForeignPtr and another (ForeignPtr A > is alive if ForeignPtr B is alive). This should be enough if you're > dealing with pointer relationships between memory objects, for example, > where it doesn't matter which one gets freed first when they're both > unreferenced.
The order of the cleanup functions is significant in this case, so that does not unfortunately help. > If you really do need ordering, maybe it would be possible to use > reference counting in your case? I ended up using the following design, which seems to work fine: data Foo = Foo (ForeignPtr Foo) (IORef [IO ()]) Each ForeignPtr Foo has a single finalizer which first calls the C-side cleanup function for Foo and then executes all the IO-actions inside the IORef. Now the association becomes associate (Foo _ ref) bar = atomicModifyIORef ref (\lst -> (touchForeignPtr bar : lst, ())) - Einar Karttunen _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
