Re: Why do we put GMP allocations on GHC heaps?

On 24/10/13 09:41, Simon Peyton-Jones wrote:

| This is true, but I would add that C finalizers are rather more prompt | and reliable than Haskell finalizers, since we added special support for | them a couple of versions ago. C finalizers are run directly by the GC | rather than in separate threads, and we run all the outstanding ones | before the program terminates.

Great. Is this difference documented? I couldn't find my way to this info.

I tried Hoogling for "final", and got this link http://hackage.haskell.org/package/base-4.6.0.1/docs/Foreign-ForeignPtr.html... but it is dead.

This seems to be a problem caused by the fact that Foreign.ForeignPtr is in both base and haskell2010. Ticket: http://ghc.haskell.org/trac/ghc/ticket/8475

I wonder if it would be worth summarising in the user manual the main facilities offered, with pointers to the Haddock docs that describe them?

http://www.haskell.org/ghc/docs/latest/html/libraries/haskell2010-1.1.1.0/Fo... We probably ought to have a bit more there, yes. Cheers, Simon

Simon

| -----Original Message----- | From: ghc-devs [mailto:ghc-devs-bounces@haskell.org] On Behalf Of Simon | Marlow | Sent: 24 October 2013 09:24 | To: Bryan O'Sullivan; Gergely Risko | Cc: ghc-devs@haskell.org | Subject: Re: Why do we put GMP allocations on GHC heaps? | | On 23/10/13 17:08, Bryan O'Sullivan wrote: | > | > On Wed, Oct 23, 2013 at 4:31 AM, Gergely Risko mailto:gergely@risko.hu> wrote: | > | > I can understand that this may be slower in CPU, but can you | please | > elaborate why would it be worse in memory, how the frees wouldn't | happen | > in a "timely manner"? I thought finalisers are called when the | > referencee is GCd, so if we free the mpz in the callback, then | where are | > we going wrong? | > | > | > There is no guarantee that finalizers will be called at all, much less | > that they will be called in a timely manner. This is a general and | > well-known property of all garbage collectors, not something unique to | GHC. | | This is true, but I would add that C finalizers are rather more prompt | and reliable than Haskell finalizers, since we added special support for | them a couple of versions ago. C finalizers are run directly by the GC | rather than in separate threads, and we run all the outstanding ones | before the program terminates. | | Cheers, | Simon | | | _______________________________________________ | ghc-devs mailing list | ghc-devs@haskell.org | http://www.haskell.org/mailman/listinfo/ghc-devs