Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.lang.python > #86602
| From | Dennis Lee Bieber <wlfraed@ix.netcom.com> |
|---|---|
| Subject | Re: Future of Pypy? |
| Date | 2015-02-27 18:47 -0500 |
| Organization | IISS Elusive Unicorn |
| References | (5 earlier) <871tlgaxi7.fsf@jester.gateway.pace.com> <mailman.19113.1424743389.18130.python-list@python.org> <87mw43apmf.fsf@jester.gateway.pace.com> <54ec20d0$0$11103$c3e8da3@news.astraweb.com> <878ufj824g.fsf@jester.gateway.pace.com> |
| Newsgroups | comp.lang.python |
| Message-ID | <mailman.19325.1425080856.18130.python-list@python.org> (permalink) |
On Fri, 27 Feb 2015 13:40:15 -0800, Paul Rubin <no.email@nospam.invalid>
declaimed the following:
>Steven D'Aprano <steve+comp.lang.python@pearwood.info> writes:
>> An interesting point of view: threading is harmful because it removes
>> determinism from your program.
>> http://radar.oreilly.com/2007/01/threads-considered-harmful.html
>
>Concurrent programs are inherently nondeterministic because they respond
>to i/o events that can happen in any order. I looked at the paper cited
And that aspect (nondeterministic) applies whether one is using threads
or processes to handle the I/O -- except, possibly, in the types of
architectures used for aircraft systems: fixed time slices for "partitions"
(which /may/ run threads internally on a partition OS, but the entire
partition gets scheduled as a chunk by an overarching OS); no dynamic
memory allocations (and no freeing either) once the system transitions from
"startup" to "running" (any message queues have all "entries" pre-allocated
in a list); dedicated message queues for data transfer between partitions
vs within a partition, etc. Oh, and some designs require a partition to
essentially complete all processing within some total period of CPU time
(say, three partition time slices) and then, in effect, start over from the
beginning.
>Hmm, I see there's a Wikipedia article "Kahn process networks" about PN
>networks as mentioned, so I guess I'll look at it. I see it claims a
>KPN is deterministic on its inputs, while I think CSP's might not be.
>
Oddly, KPN wouldn't fit the hard realtime of aircraft systems -- it
fails on the "unbounded FIFOs".
Wikipedia gives "deterministic" as (paraphrased) same inputs give the
same outputs -- but does not take into account the timing of the system.
KPN> Hence, timing of the processes does not affect outputs of the system.
Deterministic /timing/ is a factor in aircraft systems.
--
Wulfraed Dennis Lee Bieber AF6VN
wlfraed@ix.netcom.com HTTP://wlfraed.home.netcom.com/
Back to comp.lang.python | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Future of Pypy? Dave Farrance <DaveFarrance@OMiTTHiSyahooANDTHiS.co.uk> - 2015-02-22 12:45 +0000
Re: Future of Pypy? jkn <jkn_gg@nicorp.f9.co.uk> - 2015-02-22 04:58 -0800
Re: Future of Pypy? Dave Farrance <DaveFarrance@OMiTTHiSyahooANDTHiS.co.uk> - 2015-02-22 15:30 +0000
[OT] - BASIC is still not a bad choice, was Re: Future of Pypy? Michael Torrie <torriem@gmail.com> - 2015-02-23 17:24 -0700
Re: Future of Pypy? Laura Creighton <lac@openend.se> - 2015-02-22 14:27 +0100
Re: Future of Pypy? Dave Farrance <DaveFarrance@OMiTTHiSyahooANDTHiS.co.uk> - 2015-02-22 15:36 +0000
Re: Future of Pypy? Laura Creighton <lac@openend.se> - 2015-02-22 18:22 +0100
Re: Future of Pypy? Paul Rubin <no.email@nospam.invalid> - 2015-02-22 11:02 -0800
Re: Future of Pypy? Laura Creighton <lac@openend.se> - 2015-02-22 20:51 +0100
Re: Future of Pypy? Paul Rubin <no.email@nospam.invalid> - 2015-02-22 12:14 -0800
Re: Future of Pypy? Laura Creighton <lac@openend.se> - 2015-02-22 23:13 +0100
Re: Future of Pypy? Paul Rubin <no.email@nospam.invalid> - 2015-02-22 18:45 -0800
Re: Future of Pypy? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-02-23 12:18 +1100
Re: Future of Pypy? Paul Rubin <no.email@nospam.invalid> - 2015-02-22 18:04 -0800
Re: Future of Pypy? Chris Angelico <rosuav@gmail.com> - 2015-02-23 13:16 +1100
Re: Future of Pypy? Ryan Stuart <ryan.stuart.85@gmail.com> - 2015-02-23 03:16 +0000
Re: Future of Pypy? Paul Rubin <no.email@nospam.invalid> - 2015-02-22 19:45 -0800
Re: Future of Pypy? Ryan Stuart <ryan.stuart.85@gmail.com> - 2015-02-23 04:00 +0000
Re: Future of Pypy? Paul Rubin <no.email@nospam.invalid> - 2015-02-22 22:13 -0800
Re: Future of Pypy? Ryan Stuart <ryan.stuart.85@gmail.com> - 2015-02-23 07:32 +0000
Re: Future of Pypy? Paul Rubin <no.email@nospam.invalid> - 2015-02-23 16:11 -0800
Re: Future of Pypy? Chris Angelico <rosuav@gmail.com> - 2015-02-24 11:31 +1100
Re: Future of Pypy? Paul Rubin <no.email@nospam.invalid> - 2015-02-23 17:50 -0800
Re: Future of Pypy? Chris Angelico <rosuav@gmail.com> - 2015-02-24 13:03 +1100
Re: Future of Pypy? Paul Rubin <no.email@nospam.invalid> - 2015-02-23 20:40 -0800
Re: Future of Pypy? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-02-24 17:57 +1100
Re: Future of Pypy? Paul Rubin <no.email@nospam.invalid> - 2015-02-27 13:40 -0800
Re: Future of Pypy? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2015-02-27 18:47 -0500
Are threads bad? - was: Future of Pypy? Ryan Stuart <ryan.stuart.85@gmail.com> - 2015-02-24 00:35 +0000
Re: Are threads bad? - was: Future of Pypy? Paul Rubin <no.email@nospam.invalid> - 2015-02-23 21:27 -0800
Re: Are threads bad? - was: Future of Pypy? Chris Angelico <rosuav@gmail.com> - 2015-02-24 16:57 +1100
Re: Are threads bad? - was: Future of Pypy? Paul Rubin <no.email@nospam.invalid> - 2015-02-23 22:23 -0800
Re: Are threads bad? - was: Future of Pypy? Marko Rauhamaa <marko@pacujo.net> - 2015-02-24 10:08 +0200
Re: Are threads bad? - was: Future of Pypy? Paul Rubin <no.email@nospam.invalid> - 2015-02-24 15:53 -0800
Re: Are threads bad? - was: Future of Pypy? Marko Rauhamaa <marko@pacujo.net> - 2015-02-25 07:25 +0200
Re: Are threads bad? - was: Future of Pypy? Marcos Almeida Azevedo <marcos.al.azevedo@gmail.com> - 2015-02-25 13:34 +0800
Re: Are threads bad? - was: Future of Pypy? Marko Rauhamaa <marko@pacujo.net> - 2015-02-25 07:46 +0200
Re: Are threads bad? - was: Future of Pypy? Chris Angelico <rosuav@gmail.com> - 2015-02-25 16:54 +1100
Re: Are threads bad? - was: Future of Pypy? Marcos Almeida Azevedo <marcos.al.azevedo@gmail.com> - 2015-02-25 13:58 +0800
Re: Are threads bad? - was: Future of Pypy? Ian Kelly <ian.g.kelly@gmail.com> - 2015-02-24 23:02 -0700
Re: Are threads bad? - was: Future of Pypy? Chris Angelico <rosuav@gmail.com> - 2015-02-25 17:07 +1100
Re: Are threads bad? - was: Future of Pypy? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-02-25 16:37 +0000
Re: Are threads bad? - was: Future of Pypy? Ian Kelly <ian.g.kelly@gmail.com> - 2015-02-25 10:00 -0700
Re: Are threads bad? - was: Future of Pypy? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-02-25 17:16 +0000
Re: Are threads bad? - was: Future of Pypy? Chris Angelico <rosuav@gmail.com> - 2015-02-26 04:22 +1100
Re: Are threads bad? - was: Future of Pypy? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2015-02-25 19:44 -0500
Re: Are threads bad? - was: Future of Pypy? Ryan Stuart <ryan.stuart.85@gmail.com> - 2015-02-25 00:59 +0000
Re: Are threads bad? - was: Future of Pypy? Paul Rubin <no.email@nospam.invalid> - 2015-02-26 21:55 -0800
Re: Future of Pypy? Chris Angelico <rosuav@gmail.com> - 2015-02-23 14:25 +1100
Re: Future of Pypy? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-02-23 18:41 +1100
Re: Future of Pypy? Marko Rauhamaa <marko@pacujo.net> - 2015-02-23 10:16 +0200
Re: Future of Pypy? Chris Angelico <rosuav@gmail.com> - 2015-02-23 20:19 +1100
Re: Future of Pypy? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-02-24 17:56 +1100
Re: Future of Pypy? Chris Angelico <rosuav@gmail.com> - 2015-02-24 18:16 +1100
Re: Future of Pypy? wxjmfauth@gmail.com - 2015-02-23 23:57 -0800
Re: Future of Pypy? Ethan Furman <ethan@stoneleaf.us> - 2015-02-23 11:39 -0800
Re: Future of Pypy? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-02-24 13:15 +1100
Re: Future of Pypy? Paul Rubin <no.email@nospam.invalid> - 2015-02-23 17:47 -0800
Re: Future of Pypy? Marko Rauhamaa <marko@pacujo.net> - 2015-02-24 10:12 +0200
Re: Future of Pypy? Emile van Sebille <emile@fenx.com> - 2015-02-24 09:57 -0800
Re: Future of Pypy? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-02-23 01:05 +1100
Re: Future of Pypy? Dave Farrance <DaveFarrance@OMiTTHiSyahooANDTHiS.co.uk> - 2015-02-22 15:44 +0000
Re: Future of Pypy? Dave Farrance <DaveFarrance@OMiTTHiSyahooANDTHiS.co.uk> - 2015-02-22 19:20 +0000
Re: Future of Pypy? Laura Creighton <lac@openend.se> - 2015-02-22 22:45 +0100
Re: Future of Pypy? Dave Farrance <DaveFarrance@OMiTTHiSyahooANDTHiS.co.uk> - 2015-02-23 14:04 +0000
Re: Future of Pypy? Laura Creighton <lac@openend.se> - 2015-02-23 17:16 +0100
Re: Future of Pypy? Terry Reedy <tjreedy@udel.edu> - 2015-02-23 01:34 -0500
Re: Future of Pypy? Dave Cook <davecook@nowhere.net> - 2015-02-23 11:36 +0000
Re: Future of Pypy? Dave Farrance <DaveFarrance@OMiTTHiSyahooANDTHiS.co.uk> - 2015-02-23 14:13 +0000
Cython - was: Future of Pypy? Stefan Behnel <stefan_ml@behnel.de> - 2015-02-23 16:43 +0100
Re: Future of Pypy? Dave Cook <davecook@nowhere.net> - 2015-02-23 23:23 +0000
csiph-web