From: Uriel <uriel99@gmail.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 17:32:56 +0200 [thread overview]
Message-ID: <5d375e920909030832i17c62bc7mbb1afc55708e059a@mail.gmail.com> (raw)
In-Reply-To: <3e1162e60909020807t3164e42fvee3b6e5e4671743b@mail.gmail.com>
So libthread must be a figment of 9fan's imagination...
Of course, for Apple (or anyone else) to learn from Plan 9 would be
impossible, so instead they had to add a new 'feature' to C.
uriel
On Wed, Sep 2, 2009 at 5:07 PM, David Leimbach<leimy2k@gmail.com> wrote:
> Has anyone actually looked at the spec or is this just armchair philosophy?
> I've actually looked at these, and used em a little bit. They're not at all
> as bad as I once thought they could be, and the reason they're there is to
> work with a concurrency framework onto which blocks can be scheduled to run
> on various queues, to do concurrent programming.
> If you're running Snow Leopard, they're being used all over the place for
> thread management.
> Here's my objective and actually informed review:
> Can something go horribly wrong with these blocks if you don't use them
> properly? You bet! Imagine many concurrently running blocks playing with
> shared global pointers... Luckily the serial queues are able to prevent that
> exact thing from happening. :-)
> Does it make the code easier to read? So far my answer is no, not at all.
>
> Does it succeed in the goal of making it possible to do lockless programming
> of concurrent applications? Yes, there's several rather interesting
> examples showing the concurrent computation of all the cells in Conway's
> Life for example. I'd say this beats the snot out of coding with pthreads.
> However, if I want real concurrency programming, I would NEVER use C over
> Erlang or Haskell by choice (or Limbo if it's available).
> Blocks themselves are really not terribly useful, you need the libdispatch
> library to make the real value in them come out, which does all the queue
> management by talking to the subsystem of Snow Leopard called "Grand Central
> Dispatch".
> Dave
>
> On Wed, Sep 2, 2009 at 4:40 AM, Eris Discordia <eris.discordia@gmail.com>
> wrote:
>>
>> Perl people love closures. It's one of their common programming
>> techniques. Closures in C? Way to screw its clarity and closeness to the
>> real (or virtual) machine. And in the end closure or no closure doesn't
>> change how the binary looks but allows programmers to pepper source with
>> brain-teasers (now, what does _that_ evaluate to?). Not good at all.
>>
>> --On Wednesday, September 02, 2009 10:04 +0200 Anant Narayanan
>> <anant@kix.in> wrote:
>>
>>> Mac OS 10.6 introduced a new C compiler frontend (clang), which added
>>> support for "blocks" in C [1]. Blocks basically add closures and
>>> anonymous functions to C (and it's derivatives). Full details with
>>> examples are in the linked article. I think the feature is quite elegant
>>> and might be useful in cases where you want map/reduce like functionality
>>> in C.
>>>
>>> How much effort would it be to support a feature similar to blocks in 8c
>>> (and family)? What are your thoughts on the idea in general?
>>>
>>> --
>>> Anant
>>>
>>> [1] http://arstechnica.com/apple/reviews/2009/08/mac-os-x-10-6.ars/10
>>>
>>
>>
>>
>>
>>
>
>
next prev parent reply other threads:[~2009-09-03 15:32 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
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 [this message]
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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