"Simon Marlow"
Now the association becomes associate (Foo _ ref) bar = atomicModifyIORef ref (\lst -> (touchForeignPtr bar : lst, ()))
Isn't that equivalent to using addForeignPtrFinalizer? I don't think this fixes anything: the finalizer for bar can still run before the finalizer for foo.
foo has a single finalizer which is defined like: fooFinalizer cfoo ref = do cdeleteFoo cfoo vs <- readIORef ref mapM_ (\c -> c) vs and foo is created like createFoo ptr = do ref <- newIORef [] fp <- newForeigPtr ptr (fooFinalizer ptr ref) return (Foo fp ref) As the finalizer of foo references the IORef which contains the list of actions containing the "touchForeignPtr bar" the finalizer of foo is run first. The finalizer to bar should be able to run only when the touchForeignPtr has been executed in the mapM_ which only happens after foo has been cleaned up - if I understand things correctly. - Einar Karttunen