[Haskell-cafe] Re: Are handles garbage-collected?

Malcolm Wallace Malcolm.Wallace at cs.york.ac.uk
Tue Oct 26 05:41:45 EDT 2004

"Simon Marlow" <simonmar at microsoft.com> writes:

> I didn't mean fully synchronous, just "more synchronous".  For example,
> the finalization routine could be run directly after garbage collection.
> Hugs & nhc98 already do this, because they don't support Haskell
> finalizers.

Actually, nhc98 supports both C and Haskell finalisers, with the same
signatures as in ghc:

    newForeignPtr     :: FinalizerPtr a -> Ptr a -> IO (ForeignPtr a)
    newConcForeignPtr :: IO ()          -> Ptr a -> IO (ForeignPtr a)

C finalisers are run during garbage collection, Haskell finalisers
are run immediately afterwards.  In fact, you cannot run a Haskell
finaliser during GC, because you don't have a valid heap to run it in.


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