Re: [Haskell-cafe] Rewrite NetBSD kernel driver using Ajhc Haskell compiler

[Johnny Billquist <bqt%update.uu.se@localhost>]

On 2014-02-19 16:30, Kiwamu Okabe wrote:
> Hi Johnny, I had forgotten important point.
>
> > On Wed, Feb 19, 2014 at 11:57 PM, Johnny Billquist <bqt%update.uu.se@localhost> 
> > wrote:
> > > Maybe someone with more insight could explain to an idiot like me how
> > > Haskell garbage collection is handled when running in the kernel?
>
> Running a simple logic in the kernel, it doesn't call GC.
>
> http://www.slideshare.net/master_q/20140117-11th-wocs2/19
>
> Ajhc Haskell compiler creates program binary that has "context local heap".
> A lot of binaries have only one global heap.
> If C language code calls Haskell code, Ajhc runtime create new arena for GC.
> Sometime Haskell code runs allocator (s_alloc()),
> then the runtime allocates Heap area.
> Haskell context gets the end of life, the arena and heap are recovered
> by the runtime.
>
> In the kernel, the recover is called before the GC.
> But I think my custom kernel is ready to call GC in interrupt handler.

Thanks. Not sure I followed this, though.

Are you saying that you essentially avoid GC by creating a large fresh 
heap every time you call something written in Haskell, and then delete 
the heap when the Haskell function returns? And that the current piece 
of code running in Haskell is short enough that GC never is done?

        Johnny

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