is there enough information?

castironpi at gmail.com castironpi at gmail.com
Tue Feb 26 19:20:01 CET 2008


On Feb 26, 12:04 pm, Jeff Schwab <j... at schwabcenter.com> wrote:
> castiro... at gmail.com wrote:
> > On Feb 26, 11:37 am, Jeff Schwab <j... at schwabcenter.com> wrote:
> >> castiro... at gmail.com wrote:
> >>> On Feb 26, 10:59 am, Preston  Landers <pland... at gmail.com> wrote:
> >>>> On Feb 26, 1:45 am, castiro... at gmail.com wrote:
> >>>>> Two options occurred to me, which the first showed up in the earlier
> >>>>> extremely skeletal and cryptic post:
> >>>> Perhaps you would be more likely to get the kind of help you seem to
> >>>> want
> >>>> if you refrained from posting "cryptic and skeletal" messages. The
> >>>> fact that many
> >>>> other people have pointed this out to you as of late would tend to
> >>>> suggest
> >>>> you are trolling, i.e. intentionally trying to foster miscommunication
> >>>> and threads
> >>>> that do nothing to advance anyones understanding.
> >>>> And regarding your other recent post about trying to find a "solution"
> >>>> to the "problem"
> >>>> of immutable types...  Due to the above reasons you are unlikely to
> >>>> influence the
> >>>> design of the core language with half-baked stream of consciousness
> >>>> ramblings. These
> >>>> belong in your LiveJournal, not in c.l.python.
> >>>> If you have a problem you need help with, please read this entire
> >>>> document about 3 times
> >>>> before posting anything else:
> >>>>http://catb.org/~esr/faqs/smart-questions.html
> >>>> Specifically this:
> >>>>http://catb.org/~esr/faqs/smart-questions.html#beprecise
> >>>> and this:
> >>>>http://catb.org/~esr/faqs/smart-questions.html#goal
> >>> Ugh, very well.  You call for an explanation.
> >>> Back home, the original post would be interesting, so I wrote it.
> >>> Whatever reactions other people have to them is information that is
> >>> unavailable to me.  I don't know you.  I'm rather irked by a
> >>> proportion of posts, but for my part, it's hard to get me to point a
> >>> finger.
> >>> I am not a troll.  I want a sustainable, healthy, productive,
> >>> educational, informative relationship with frequenters of c.l.p, the
> >>> Python community at large, and anyone who has anything non-negative to
> >>> contribute.  If you are wanting to see how I react to hostility, just
> >>> ask.  I'll fake it for you, but only for a second at a time.
> >> Wow.  I sure hope I don't come across like castiron does here.
>
> >>> Now, what help is it that you believe I seem to want?  All I asked for
> >>> was, ideas.
> >> It's a little difficult for me to interpret your code, partly because I
> >> am nbt very familiar with Python's support for concurrency.  But what
> >> are you trying to a achieve?
>
> >> You mentioned:  "I recently ran into a case (* would that be helpful to
> >> describe here?) where thread1 had to do something, thread2 had to do
> >> something after that, and thread1 had to wait for that, then do
> >> something else, and thread2 again had to wait before starting the first
> >> thing again."
>
> >> This is ordinarily called a Producer-Consumer model.  It is often
> >> implemented using semaphores.  Googling "python semaphore" turns up this
> >> documentation:
>
> >>http://www.python.org/doc/lib/semaphore-objects.html
>
> >> That page, in turn, links to an example of the proper use of semaphores
> >> in Python.  Does that help?- Hide quoted text -
>
> >> - Show quoted text -
>
> > Hi Jeff.  I've enjoyed your recent posts.
>
> > I'm not quite sure a semaphore is exactly the synchronization object
> > I'm looking for, but I'm a little new to concurrency myself.
>
> > In the interface I design, only one with-call can get the result at
> > once.  It was my understanding that semaphores, and many other synch.
> > objs. returned control at random.
>
> I take this to mean that your interface offers a function returns
> immediately, rather than waiting for the work to complete.  Is that correct?
>
> > In fact, in the background, I'm working on something a little more
> > substantial than this, but it's not done, so the only review of it I
> > can perform is of its interface.
>
> The interface is (in my opinion) usually the best place to start the
> code, anyway.
>
> > If someone has a "yes, but in half the lines, at twice the speed,"
> > then tear my posts to shreds.
>
> It is not quite clear what your code is intended to do.  That doesn't
> mean there's necessarily anything wrong with it, but it's hard for most
> Usenetters to take the time to read such long sequences of code.  Would
> it be possible for you to post a complete program, that we can actually
> run?  Wherever your code is not yet ready, just put a line or two of
> "stub" code, and add a comment to explain what should be happening.- Hide quoted text -
>
> - Show quoted text -

Sure.  And honestly, I have no idea what the best way to go about this
is, except keep trying.

th1       th2
set cmd
          run cmd
get result
          acknowledge
continue  continue

th2 won't -run cmd- until th1 completes -set cmd-.  th1 won't -get
result- until th2 completes -run cmd-.  and once -acknowledge-
completes, both can go about their merry ways.  In the example last
night, th2 continued to loop to handle requests in a collection of
threads, but th1 had pressing business elsewhere.

Dated 05:07 PST, the code should be runnable.  But the only thing is,
I developed it in Python 3.0a2.  In particular, line 71 def
thloop( thd ), and line 82 def op100( thd ), should demonstrate that
interface.

Newsgroups: comp.lang.python
From: castiro... at gmail.com
Date: Tue, 26 Feb 2008 05:07:48 -0800 (PST)
Local: Tues, Feb 26 2008 7:07 am
Subject: Re: is there enough information?

The interface is an awesome place to start.



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