[racket] FW: q about code for partitions

Strange: I do not get a segfault when running racket, only when running from
DrRacket.
Jos 

> -----Original Message-----
> From: jensaxelsoegaard at gmail.com 
> [mailto:jensaxelsoegaard at gmail.com] On Behalf Of Jens Axel Søgaard
> Sent: jueves, 17 de julio de 2014 13:12
> To: Jos Koot
> Cc: Vincent St-Amour; Eric Dobson; Matthew Flatt; Racket Users List
> Subject: Re: [racket] FW: q about code for partitions
> 
> What you describe seems more like a bug in partitions than a 
> documentation bug.
> Do you have a small example that provoke a segfault?
> 
> /Jens Axel
> 
> 
> 2014-07-17 12:41 GMT+02:00 Jos Koot <jos.koot at gmail.com>:
> > The documentation of partitions has not yet been updated, 
> as far as I can
> > see in version 6.0.1.13--2014-07-08(7735dd0/a) [3m]. I 
> don't want to hurry
> > up things (there may be other priorities) but when the docs 
> will be updated,
> > I think they should include a warning against calling 
> function partitions
> > from two concurrently running futures or threads. Reason is 
> the non atomic
> > memoization. (let alone calling set-partitions-cache in one 
> process while
> > another one is consulting/updating the cache)
> >
> > Calling partitions from two concurrent futures gives me a 
> segfault. Not a
> > surprise.
> > Up to now calling from two concurrent threads gives me 
> correct results, but
> > slows down vvveeerrryyy much.
> > I assume concurrent threads can lead to the same problems 
> as concurrent
> > futures, though.
> > If I understand places correctly, calling from concurrent 
> places should go
> > well. Do I understand correctly?
> >
> > Jos
> >
> >> -----Original Message-----
> >> From: Vincent St-Amour [mailto:stamourv at ccs.neu.edu]
> >> Sent: domingo, 29 de junio de 2014 22:52
> >> To: Eric Dobson
> >> Cc: Jos Koot; Matthew Flatt; Jens Axel Søgaard; Racket Users List
> >> Subject: Re: [racket] FW: q about code for partitions
> >>
> >> Ah, that explains it. Thanks!
> >>
> >> Vincent
> >>
> >>
> >> At Sun, 29 Jun 2014 12:32:48 -0700,
> >> Eric Dobson wrote:
> >> >
> >> > Vincent: exact-zero? is defined through 'make-predicate' 
> which uses
> >> > contract machinery to generate the function. I filed a
> >> couple of bugs
> >> > tracking some of the slowness issues. There is no `contract` form
> >> > though so I doubt that the coach will find it.
> >> >
> >> >
> >> http://bugs.racket-lang.org/query/?cmd=view%20audit-trail&data
> > base=default&pr=14610
> >> >
> >> http://bugs.racket-lang.org/query/?cmd=view%20audit-trail&data
> > base=default&pr=14611
> >> >
> >> > On Sun, Jun 29, 2014 at 11:53 AM, Jos Koot
> >> <jos.koot at gmail.com> wrote:
> >> > > Great work, Jens. I am glad my approach as been adopted
> >> (and much improved
> >> > > without deviating from the original idea of simpler
> >> recurrence). When can we
> >> > > expect it in the next nightly build?
> >> > >
> >> > > Thanks, Jos
> >> > >
> >> > >> -----Original Message-----
> >> > >> From: jensaxelsoegaard at gmail.com
> >> > >> [mailto:jensaxelsoegaard at gmail.com] On Behalf Of Jens
> >> Axel Søgaard
> >> > >> Sent: domingo, 29 de junio de 2014 12:48
> >> > >> To: Matthew Flatt
> >> > >> Cc: Jos Koot; Racket Users List
> >> > >> Subject: Re: [racket] FW: q about code for partitions
> >> > >>
> >> > >> I have made a new vector version using zero? instead of
> >> exact-zero?.
> >> > >>
> >> > >> To give users a chance to remove the cache after doing
> >> > >> partitions calculations,
> >> > >> I have added set-partitions-cache.
> >> > >>
> >> > >>    Code:
> >> > >>
> >> > >> https://github.com/soegaard/racket/blob/patch-14/pkgs/math-pkg
> >> > > s/math-lib/math/private/number-theory/partitions.rkt
> >> > >>
> >> > >>    Discussion:
> >> > >>     https://github.com/plt/racket/pull/697
> >> > >>
> >> > >> /Jens Axel
> >> > >>
> >> > >>
> >> > >> 2014-06-29 12:44 GMT+02:00 Jens Axel Søgaard
> >> <jensaxel at soegaard.net>:
> >> > >> > 2014-06-29 8:47 GMT+02:00 Matthew Flatt 
> <mflatt at cs.utah.edu>:
> >> > >> >> It looks like "partitions2.rkt" ends up calling a
> >> contract-wrapped
> >> > >> >> variant of `exact-zero?`.
> >> > >> >
> >> > >> > That explains why Eric saw an improvement, when the used #f
> >> > >> instead of
> >> > >> > 0 as the not-cached-yet value.
> >> > >> >
> >> > >> > /Jens Axel
> >> > >>
> >> > >>
> >> > >>
> >> > >> --
> >> > >> --
> >> > >> Jens Axel Søgaard
> >> > >
> >> > >
> >> > > ____________________
> >> > >   Racket Users list:
> >> > >   http://lists.racket-lang.org/users
> >> >
> >> > ____________________
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> >
> >
> > ____________________
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> 
> 
> 
> -- 
> --
> Jens Axel Søgaard