From: Roman V Shaposhnik <rvs@sun.com>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
Subject: Re: [9fans] "Blocks" in C
Date: Thu, 3 Sep 2009 14:08:36 -0700 [thread overview]
Message-ID: <1252012116.16936.5128.camel@work.SFBay.Sun.COM> (raw)
In-Reply-To: <580135a14ad078bb8223e7c448a5fa2b@quanstro.net>
On Thu, 2009-09-03 at 15:36 -0400, erik quanstrom wrote:
> > > > Apple's using it all over the place in Snow Leopard, in all their native
> > > > apps to write cleaner, less manual-lock code. At least, that's the claim
> > > > :-).
> > >
> > > could someone explain this to me? i'm just missing how
> > > naming a block of code could change its locking properties.
> > >
> > >
> > The explanation is in the manual I linked to earlier in this discussion. If
> > you want to see examples there's two I can think of available for download.
> > One is called DispatchLife the other is DispatchFractal.
> >
> > I've looked at DispatchLife, and there's no explicit locking of state for
> > every cell being concurrently update in Conway's game of life.
>
> i can't find DispatchLife after a few minutes of googling.
> i've read the manual, and it looks like csp to me. clearly
> i am a reprobate outside the apple reality distortion field.
>
> could you explain why this isn't csp
Please define what is it that you refer to as csp. The reason
I'm asking is simple: csp-like things are needed but *not*
sufficient for implementing a nice abstraction for the
parallel framework.
> and why this can't be done
> with regular c (that is why we need the concept of an
> unnamed function pointer) and the thread library?
Anything can be done using regular C and threads. The trick here
is to make everything *scalable* and *painless* enough so that
mere mortals can start benefiting from parallelism in their code.
The other trick here is to find a model that makes things *natural*, and
that means practically no explicit locking, less shared state, etc.
The search for the model is meaningless unless it is used for
solving *practical* challenges. In that respect, one of my
favorite article is how implementation of a chess engine
influenced Cilk framework (which almost has the notion of a "block")
http://supertech.csail.mit.edu/papers/icca99.pdf
Read it, I don't think we can be on the same page (and escape the
armchair philosophy trap) unless we are talking about practical
applications of the framework.
Look at the chess example -- can the same be done with pure C? Sure!
Did Cilk make it less painful? Absolutely!
Thanks,
Roman.
next prev parent reply other threads:[~2009-09-03 21:08 UTC|newest]
Thread overview: 117+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-02 8:04 Anant Narayanan
2009-09-02 9:43 ` Francisco J Ballesteros
2009-09-02 11:00 ` Philippe Anel
2009-09-02 11:13 ` Charles Forsyth
2009-09-03 9:52 ` Greg Comeau
2009-09-02 11:40 ` Eris Discordia
2009-09-02 12:32 ` Uriel
2009-09-02 14:20 ` Devon H. O'Dell
2009-09-03 9:52 ` Greg Comeau
2009-09-03 10:48 ` Akshat Kumar
2009-09-03 11:25 ` Charles Forsyth
2009-09-03 13:59 ` Greg Comeau
2009-09-03 15:15 ` Uriel
2009-09-03 15:44 ` David Leimbach
2009-09-03 16:01 ` Roman V Shaposhnik
2009-09-04 9:15 ` Greg Comeau
2009-09-04 16:49 ` Roman Shaposhnik
2009-09-03 16:02 ` erik quanstrom
2009-09-03 18:56 ` David Leimbach
2009-09-03 18:58 ` erik quanstrom
2009-09-03 19:13 ` David Leimbach
2009-09-03 19:36 ` erik quanstrom
2009-09-03 19:50 ` David Leimbach
2009-09-03 20:30 ` Iruata Souza
2009-09-06 22:35 ` Uriel
2009-09-07 0:41 ` David Leimbach
2009-09-03 21:08 ` Roman V Shaposhnik [this message]
2009-09-03 21:35 ` erik quanstrom
2009-09-03 21:45 ` David Leimbach
2009-09-03 21:49 ` David Leimbach
2009-09-03 21:51 ` David Leimbach
2009-09-03 22:36 ` Roman V Shaposhnik
2009-09-04 9:16 ` Greg Comeau
2009-09-03 22:10 ` Daniel Lyons
2009-09-03 22:07 ` Daniel Lyons
2009-09-04 9:15 ` Greg Comeau
2009-09-04 3:21 ` Anant Narayanan
2009-09-04 3:52 ` erik quanstrom
2009-09-04 4:18 ` David Leimbach
2009-09-04 4:44 ` erik quanstrom
2009-09-04 5:31 ` David Leimbach
2009-09-04 5:35 ` David Leimbach
2009-09-04 7:11 ` Bakul Shah
2009-09-04 7:47 ` David Leimbach
2009-09-04 14:41 ` Bakul Shah
2009-09-04 15:04 ` David Leimbach
2009-09-04 15:58 ` Bakul Shah
2009-09-04 12:14 ` erik quanstrom
2009-09-04 13:52 ` David Leimbach
2009-09-04 13:59 ` matt
2009-09-04 14:20 ` erik quanstrom
2009-09-04 14:56 ` David Leimbach
2009-09-06 23:03 ` Uriel
2009-09-07 0:45 ` David Leimbach
2009-09-04 16:50 ` Roman Shaposhnik
2009-09-04 6:45 ` Bakul Shah
2009-09-04 16:44 ` Roman Shaposhnik
2009-09-04 16:58 ` Iruata Souza
2009-09-04 17:09 ` Roman Shaposhnik
2009-09-04 17:42 ` erik quanstrom
2009-09-04 18:34 ` erik quanstrom
2009-09-04 21:54 ` Roman V Shaposhnik
2009-09-07 9:06 ` Greg Comeau
2009-09-07 9:05 ` Greg Comeau
2009-09-07 9:40 ` Uriel
2009-09-08 15:31 ` David Leimbach
2009-09-08 15:44 ` Uriel
2009-09-08 16:40 ` Bakul Shah
2009-09-11 18:15 ` Iruata Souza
2009-09-11 18:46 ` David Leimbach
2009-09-11 20:36 ` Roman V Shaposhnik
2009-09-11 21:28 ` David Leimbach
2009-09-14 16:07 ` Lawrence E. Bakst
2009-09-12 11:08 ` Anant Narayanan
2009-09-13 19:03 ` David Leimbach
2009-09-17 1:54 ` Lawrence E. Bakst
2009-09-17 8:43 ` Charles Forsyth
2009-09-17 9:12 ` Daniel Lyons
2009-09-17 15:56 ` David Leimbach
2009-09-17 17:38 ` Jack Norton
2009-09-17 20:23 ` Anant Narayanan
2009-09-17 20:26 ` erik quanstrom
2009-09-17 20:31 ` Anant Narayanan
2009-09-17 20:47 ` Akshat Kumar
2009-09-17 21:02 ` erik quanstrom
2009-09-17 22:26 ` Steve Simon
2009-09-17 22:32 ` Roman V Shaposhnik
2009-09-18 2:05 ` Daniel Lyons
2009-09-18 9:30 ` Charles Forsyth
2009-09-18 11:41 ` erik quanstrom
2009-09-17 21:03 ` Uriel
2009-09-03 9:52 ` Greg Comeau
2009-09-02 14:08 ` Rodolfo (kix)
2009-09-03 9:52 ` Greg Comeau
[not found] ` <C56117D7BD9A097270529AAE@192.168.1.2>
2009-09-02 15:07 ` David Leimbach
2009-09-02 15:26 ` Roman V Shaposhnik
2009-09-02 15:45 ` David Leimbach
2009-09-03 15:32 ` Uriel
2009-09-03 15:49 ` Roman V Shaposhnik
2009-09-03 15:54 ` erik quanstrom
2009-09-03 16:20 ` Roman V Shaposhnik
2009-09-03 16:44 ` erik quanstrom
2009-09-04 1:05 ` Roman V Shaposhnik
2009-09-04 1:30 ` Russ Cox
2009-09-04 1:32 ` erik quanstrom
2009-09-03 21:54 ` James Tomaschke
2009-09-06 22:26 ` Uriel
2009-09-04 9:04 ` Greg Comeau
2009-09-02 15:20 ` Roman V Shaposhnik
2009-09-02 17:51 ` Bakul Shah
2009-09-04 1:35 drivers
2009-09-04 1:52 ` erik quanstrom
2009-09-17 9:19 Andrew Simmons
2009-09-17 14:45 ` LiteStar numnums
2009-09-17 17:24 ` Daniel Lyons
2009-09-18 15:50 drivers
2009-09-18 15:56 ` erik quanstrom
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