[racket] OPERATING SYSTEM ON A FPGA
I personally think that the low level issues are not so important and
have been playing with the thought of implementing high-level
features of such an OS, i.e. user access control and distributed,
sandboxed applications with reasonable process scheduling and resource
control. However, I have given up on the idea -- too many other things
to do.
Secure, multi-user high-level OS services could be useful even without
the capability of running on bare hardware, e.g. on top of a very small
GNU/Linux.
Best,
Erich
On Wed, 5 Dec 2012 08:29:04 -0800 (PST)
David Blubaugh <davidblubaugh2000 at yahoo.com> wrote:
> Well
>
>
> Is there a way I can obtain help in acquiring funding in developing
> Racket into a real OS?? I would love to see how far we can take this
> concept !!! Apple and MacOS watch out here comes something with more
> powerful features !!!
> David Blubaugh
>
> --- On Wed, 12/5/12, Matthias Felleisen <matthias at ccs.neu.edu> wrote:
>
>
> From: Matthias Felleisen <matthias at ccs.neu.edu>
> Subject: Re: [racket] OPERATING SYSTEM ON A FPGA
> To: "David Blubaugh" <davidblubaugh2000 at yahoo.com>
> Cc: users at racket-lang.org
> Date: Wednesday, December 5, 2012, 11:24 AM
>
>
>
> In the mid 90s, we had this idea to go for a Scheme OS, SOS. As an
> experiment, we asked a student to write a disk driver in Scheme
> (Bigloo) and to see what we could do with it. One of the things he
> was able to do is hot-swap policies for spinning the disk. This
> sounds so quaint in the age of laptops w/o movable parts.
>
> In the late 90s, Matthew spent an afternoon so that we could boot
> Racket (formerly known as PLT Scheme) on raw hardware. Since most of
> us had dual-boot machines already (Linux and the other one), we went
> to ternary-boot machines: Linux, PLT Scheme, and the other one. None
> of us ever had the appetite to add enough device drivers to turn
> Racket into a real OS but nothing stands in its way.
>
> Right now, a Darpa project enables us to experiment with Racket on
> the Router (think RoR, though that acronym has been taken). Again,
> it's systemish work. This email is going thru the DNS service that we
> have built so far.
>
> In short, doable but we haven't done it.
>
>
>
>
>
>
>
>
>
> On Dec 5, 2012, at 11:16 AM, David Blubaugh wrote:
>
> > To All,
> >
> >
> > I was wondering if anyone has ever created a real time operating
> > system with Racket. As well as, create applications within a FPGA
> > device by utilizing racket?? Can racket be a solution to ALL
> > PROBLEMS that is the question.
> >
> >
> > David Blubaugh
> >
> >
> >
> > --- On Wed, 12/5/12, users-request at racket-lang.org
> > <users-request at racket-lang.org> wrote:
> >
> > From: users-request at racket-lang.org <users-request at racket-lang.org>
> > Subject: users Digest, Vol 88, Issue 18
> > To: users at racket-lang.org
> > Date: Wednesday, December 5, 2012, 10:30 AM
> >
> > Send users mailing list submissions to
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> > [Racket Users list:
> > http://lists.racket-lang.org/users]
> >
> >
> > Today's Topics:
> >
> > 1. Re: Whats the difference between a predicate and a flat
> > contract? (Harry Spier)
> > 2. Re: Whats the difference between a predicate and a flat
> > contract? (Robby Findler)
> > 3. Re: DRRacket right-click menu fragility in Linux. (Neil
> >Toronto) 4. Re: minimum spanning tree (Matthias Felleisen)
> >
> >
> > ----------------------------------------------------------------------
> >
> > Message: 1
> > Date: Tue, 4 Dec 2012 21:59:42 -0500
> > From: Harry Spier <vasishtha.spier at gmail.com>
> > To: Robby Findler <robby at eecs.northwestern.edu>
> > Cc: Carl Eastlund <cce at ccs.neu.edu>, users <users at racket-lang.org>
> > Subject: Re: [racket] Whats the difference between a predicate and a
> > flat contract?
> > Message-ID:
> > <CAJ3b0o9_yd-j4U6tbEOQaB+JKWto_A1XwSrh3_xyRTk=Uviy=Q at mail.gmail.com>
> > Content-Type: text/plain; charset=UTF-8
> >
> > Are flat-contract and flat-contract-predicate equivalent?
> >
> > > ((flat-contract 'x) 'x)
> > #t
> > > ((flat-contract-predicate 'x) 'x)
> > #t
> > > ((flat-contract 'x) 'y)
> > #f
> > > ((flat-contract-predicate 'x) 'y)
> > #f
> > >
> >
> > Harry
> >
> > On Tue, Dec 4, 2012 at 9:41 PM, Robby Findler
> > <robby at eecs.northwestern.edu> wrote:
> > > It does that for symbols, but not everything.
> > >
> > > This is the place you should be looking, I think.
> > >
> > > http://docs.racket-lang.org/reference/contracts.html
> > >
> > > Robby
> > >
> > > On Tue, Dec 4, 2012 at 8:38 PM, Harry Spier
> > > <vasishtha.spier at gmail.com> wrote:
> > >> OK I see the docs to flat-contract? but not flat-contract
> > >> http://docs.racket-lang.org/reference/contract-utilities.html#(def._((lib._racket/contract/private/misc..rkt)._flat-contract~3f))
> > >> mention that flat-contracts are more than predicates. Those docs
> > >> don't mention it, but it appears from experimentation that
> > >> (flat-contract something) produces a procedure such that
> > >> ((flat-contract something) x) is #t if something eq? x .
> > >>
> > >> Harry Spier
> > >>
> > >> On Tue, Dec 4, 2012 at 8:57 PM, Robby Findler
> > >> <robby at eecs.northwestern.edu> wrote:
> > >>> On Tue, Dec 4, 2012 at 7:28 PM, Carl Eastlund <cce at ccs.neu.edu>
> > >>> wrote:
> > >>>> On Tue, Dec 4, 2012 at 7:49 PM, Robby Findler
> > >>>> <robby at eecs.northwestern.edu> wrote:
> > >>>>>
> > >>>>> Flat contracts includes more things than contracts. For
> > >>>>> example:
> > >>>>>
> > >>>>> [robby at yanpu] ~/git/plt/collects/scribblings/reference$ racket
> > >>>>> Welcome to Racket v5.3.1.9.
> > >>>>> > (flat-contract? 'x)
> > >>>>> #t
> > >>>>> > (procedure? 'x)
> > >>>>> #f
> > >>>>>
> > >>>>> The flat-contract function is a holdover from the days when
> > >>>>> flat contracts weren't able to be used directly as predicate
> > >>>>> functions.
> > >>>>>
> > >>>>>
> > >>>>> I'll push a clarification to the docs for flat-contract.
> > >>>>
> > >>>>
> > >>>> Isn't that the wrong way around? The flat-contract function
> > >>>> lets you use a predicate as a contract, not a contract as a
> > >>>> predicate. Presumably it's from before predicates could be
> > >>>> used as contracts, although I hadn't realized there was such a
> > >>>> time.
> > >>>
> > >>> There was a time when you had to call 'flat-contract' to turn a
> > >>> predicate into a contract, yep. There was a housecleaning
> > >>> (anyone remember the days when there were multiple suffixes
> > >>> (not just "/c") on the combinators?) and I probably should have
> > >>> gotten rid of it at that time, but I didn't.
> > >>>
> > >>> (Oh and I mean "contracts" where I wrote "preducate functions"
> > >>> above. Oops.)
> > >>>
> > >>> Robby
> >
> >
> > ------------------------------
> >
> > Message: 2
> > Date: Tue, 4 Dec 2012 21:05:45 -0600
> > From: Robby Findler <robby at eecs.northwestern.edu>
> > To: Harry Spier <vasishtha.spier at gmail.com>
> > Cc: Carl Eastlund <cce at ccs.neu.edu>, users <users at racket-lang.org>
> > Subject: Re: [racket] Whats the difference between a predicate and a
> > flat contract?
> > Message-ID:
> > <CAL3TdOMVL4xerBMr9xWqNz3tPjxbSXDfjaiJro2N9j6fxrSrOQ at mail.gmail.com>
> > Content-Type: text/plain; charset=UTF-8
> >
> > Yes ..., I think so (well, eq? probably messes things up, as usual).
> >
> > But that's a funny question! What's really going on there is that
> > flat-contract is coercing the value into a contract, and flat
> > contracts also acts as predicate functions (matching what the
> > contracts match). flat-contract-predicate takes its argument, turns
> > it into the contract and then returns the predicate. This last step
> > is useless, as flat-contracts are now predicates without any
> > coercion (again, not something that was always the case).
> >
> > I'll add a similar note to the docs for this function too.
> >
> > Robby
> >
> > On Tue, Dec 4, 2012 at 8:59 PM, Harry Spier
> > <vasishtha.spier at gmail.com> wrote:
> > > Are flat-contract and flat-contract-predicate equivalent?
> > >
> > >> ((flat-contract 'x) 'x)
> > > #t
> > >> ((flat-contract-predicate 'x) 'x)
> > > #t
> > >> ((flat-contract 'x) 'y)
> > > #f
> > >> ((flat-contract-predicate 'x) 'y)
> > > #f
> > >>
> > >
> > > Harry
> > >
> > > On Tue, Dec 4, 2012 at 9:41 PM, Robby Findler
> > > <robby at eecs.northwestern.edu> wrote:
> > >> It does that for symbols, but not everything.
> > >>
> > >> This is the place you should be looking, I think.
> > >>
> > >> http://docs.racket-lang.org/reference/contracts.html
> > >>
> > >> Robby
> > >>
> > >> On Tue, Dec 4, 2012 at 8:38 PM, Harry Spier
> > >> <vasishtha.spier at gmail.com> wrote:
> > >>> OK I see the docs to flat-contract? but not flat-contract
> > >>> http://docs.racket-lang.org/reference/contract-utilities.html#(def._((lib._racket/contract/private/misc..rkt)._flat-contract~3f))
> > >>> mention that flat-contracts are more than predicates. Those
> > >>> docs don't mention it, but it appears from experimentation that
> > >>> (flat-contract something) produces a procedure such that
> > >>> ((flat-contract something) x) is #t if something eq? x .
> > >>>
> > >>> Harry Spier
> > >>>
> > >>> On Tue, Dec 4, 2012 at 8:57 PM, Robby Findler
> > >>> <robby at eecs.northwestern.edu> wrote:
> > >>>> On Tue, Dec 4, 2012 at 7:28 PM, Carl Eastlund
> > >>>> <cce at ccs.neu.edu> wrote:
> > >>>>> On Tue, Dec 4, 2012 at 7:49 PM, Robby Findler
> > >>>>> <robby at eecs.northwestern.edu> wrote:
> > >>>>>>
> > >>>>>> Flat contracts includes more things than contracts. For
> > >>>>>> example:
> > >>>>>>
> > >>>>>> [robby at yanpu] ~/git/plt/collects/scribblings/reference$
> > >>>>>> racket Welcome to Racket v5.3.1.9.
> > >>>>>> > (flat-contract? 'x)
> > >>>>>> #t
> > >>>>>> > (procedure? 'x)
> > >>>>>> #f
> > >>>>>>
> > >>>>>> The flat-contract function is a holdover from the days when
> > >>>>>> flat contracts weren't able to be used directly as predicate
> > >>>>>> functions.
> > >>>>>>
> > >>>>>>
> > >>>>>> I'll push a clarification to the docs for flat-contract.
> > >>>>>
> > >>>>>
> > >>>>> Isn't that the wrong way around? The flat-contract function
> > >>>>> lets you use a predicate as a contract, not a contract as a
> > >>>>> predicate. Presumably it's from before predicates could be
> > >>>>> used as contracts, although I hadn't realized there was such
> > >>>>> a time.
> > >>>>
> > >>>> There was a time when you had to call 'flat-contract' to turn a
> > >>>> predicate into a contract, yep. There was a housecleaning
> > >>>> (anyone remember the days when there were multiple suffixes
> > >>>> (not just "/c") on the combinators?) and I probably should
> > >>>> have gotten rid of it at that time, but I didn't.
> > >>>>
> > >>>> (Oh and I mean "contracts" where I wrote "preducate functions"
> > >>>> above. Oops.)
> > >>>>
> > >>>> Robby
> >
> >
> > ------------------------------
> >
> > Message: 3
> > Date: Tue, 04 Dec 2012 21:30:23 -0700
> > From: Neil Toronto <neil.toronto at gmail.com>
> > To: users at racket-lang.org
> > Subject: Re: [racket] DRRacket right-click menu fragility in Linux.
> > Message-ID: <50BECDDF.4030508 at gmail.com>
> > Content-Type: text/plain; charset=UTF-8; format=flowed
> >
> > Could what you're experiencing have anything to do with tooltips?
> > It seems my right-click menu doesn't stay up whenever there's a
> > tooltip out. Which is, like, every time I want it.
> >
> > Neil ?
> >
> > On 12/04/2012 07:55 PM, Ray Racine wrote:
> > > Yea, I didn't want to make a big deal out of it, but the up/down
> > > button change did not fix the issue. In fact I'd say no impact
> > > positive or negative.
> > >
> > > It seems to happen when there is additional drawing 'complexity'
> > > in co-occurrence with the pop up drawing area. I.e. the pop up
> > > menu is drawing where arrows are drawn or error highlighting is
> > > occurring etc. Also maybe when the pop up menu area is near the
> > > 'edge' of the Dr window and or pane area. But again the problem
> > > is not consistently reproducible yet happens more often then
> > > not. Its not a once in a blue moon that thing. Sometimes an
> > > attempt to right click pop up menu will fail numerous times in a
> > > row then succeed for no apparent reason.
> > >
> > > On Dec 4, 2012 9:07 PM, "Robby Findler"
> > > <robby at eecs.northwestern.edu
> > > <mailto:robby at eecs.northwestern.edu>> wrote:
> > >
> > > On Tue, Dec 4, 2012 at 6:11 PM, Stephen Chang
> > ><stchang at ccs.neu.edu <mailto:stchang at ccs.neu.edu>> wrote:
> > > > On Fri, Nov 2, 2012 at 9:33 PM, Robby Findler
> > > > <robby at eecs.northwestern.edu
> > > <mailto:robby at eecs.northwestern.edu>> wrote:
> > > >> I've pushed a fix to this. Thanks to Matthew for looking
> > >into it and >> sorting it out and sorry for the delay.
> > > >
> > > > I'm using git head and I'm still seeing this problem
> > >(Ubuntu 11.10). I
> > > > can't reliably reproduce it but in case it helps, it most
> > >recently > happened when I selected tack arrows and now I can't
> > >bring up the menu
> > > > to untack the arrows anymore.
> > > >
> > >
> > > The particular fix Matthew pointed me to is popping up the
> > >menu on a mouse down event, not a mouse up event.
> > >
> > > http://git.racket-lang.org/plt/blobdiff/27aa99944657c5827eee3772f715df7dd971d1e0..0377bda9474f8848a97509ace898174c83361006:/collects/framework/private/keymap.rkt
> > >
> > > So I guess there's something else going on, too (because
> > >that's the code that pops up the menu with the check syntax items).
> > >
> > > Robby
> > >
> > >
> > >
> > > ____________________
> > > Racket Users list:
> > > http://lists.racket-lang.org/users
> > >
> >
> >
> >
> > ------------------------------
> >
> > Message: 4
> > Date: Wed, 5 Dec 2012 10:30:22 -0500
> > From: Matthias Felleisen <matthias at ccs.neu.edu>
> > To: Pierpaolo Bernardi <olopierpa at gmail.com>
> > Cc: Racket mailing list <users at racket-lang.org>
> > Subject: Re: [racket] minimum spanning tree
> > Message-ID: <CE678990-63D0-4400-AF2A-C6B2880E4FFB at ccs.neu.edu>
> > Content-Type: text/plain; charset="iso-8859-1"
> >
> >
> > You are making a very good point here, especially the last one,
> > which in a sense exposes the folly of Perlis's maxim (it is better
> > to have one data type with a 100 operations than 10 data types
> > with 10 operations each). One, the maxim biases programmers
> > and before they know it, they have introduced bad dependences
> > and performance problems and whoknowswhat.
> >
> > ---------------------------------------------------------------
> >
> > Having said that, I think Ian's point is equally good. So here
> > is what I am wondering.
> >
> > Isn't the case of graphs worth a case study where we define
> > a WIDE interface for graphs and their operations, which we
> > can do so with contracts. Then we implement it in several
> > different ways and conduct performance studies (small and
> > large). And we advertise, which library is good for which
> > kind of scenario.
> >
> > I am sure that some data structure person has done this
> > for C++ or some such language. The Saarbr?cken MPI 1 comes
> > to mind. BUT, I am also sure that we don't have it and that
> > we would benefit from having one.
> >
> > NOW: as we conduct this study, we might be able to articulate
> > performance "contracts" (that's probably the wrong word) and
> > possibly learn how to add those to library implementations as
> > a secondary interface. Doing so would once again distinguish
> > Racket from other programming languages.
> >
> > It is probably a dissertation, possibly more.
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > On Dec 4, 2012, at 5:36 AM, Pierpaolo Bernardi wrote:
> >
> > > On Mon, Dec 3, 2012 at 5:07 PM, J. Ian Johnson <ianj at ccs.neu.edu>
> > > wrote:
> > >> Graph algorithms are often meant to be very fast, and different
> > >> algorithms necessitate different representations. Two popular
> > >> representations are adjacency lists and shared structures.
> > >
> > > The representations usually used in general purpose graphs
> > > libraries are adiacency lists and incidence matrices.
> > >
> > > Two good examples that I know of are: Knuth's Stanford GraphBase
> > > (available from his home page and in published book form), and the
> > > Combinatorica library for Mathematica (code available freely on
> > > the net, manual available as a published book "Computational
> > > Discrete Mathematics" by Skiena & Pemmaraju).
> > >
> > >> It also isn't right to call them lists unless you're talking
> > >> about multigraphs. Indeed successor nodes should be treated as a
> > >> set, but Racket's sets have quite a bit of overhead, especially
> > >> for small sets. Should it be fast to compute predecessor nodes?
> > >> There are too many considerations for there to be just one
> > >> blessed representation, IMHO.
> > >
> > > Linked lists made of cons pairs are not the best data structure
> > > for every possible use of a sequence data structure. However, we
> > > find this data structure very useful, don't we? we force them
> > > into uses for which they are not optimal, because of the
> > > convenience of having available a vast library using them. And
> > > when we can't fit them to our purpose we use a more specialized
> > > data structure.
> > >
> > > I think a similar compromise for a graph data structure would be
> > > very useful.
> > >
> > > Cheers
> > > P.
> > >
> > > ____________________
> > > Racket Users list:
> > > http://lists.racket-lang.org/users
> >
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