[#41581] Ruby 1.6.7 dieing of segfault — Dossy <dossy@...>

I've got something that's fairly reproducible in 1.6.7. Is

11 messages 2002/06/02
[#41582] Re: Ruby 1.6.7 dieing of segfault — Nobuyoshi Nakada <nobu.nokada@...> 2002/06/02

Hi,

[#41660] dynamic attr_accessor?? — Markus Jais <mjais@...>

hello

16 messages 2002/06/03

[#41755] HTML Parser suggestions wanted — Ned Konz <ned@...>

I've written an HTML parser that builds trees from HTML source. After

13 messages 2002/06/04

[#41809] eval and local variable — "Park Heesob" <phasis@...>

15 messages 2002/06/05

[#41819] mod_ruby and module space — "Sean O'Dell" <sean@...>

It seems that if I execute a script using mod_ruby, I cannot call

18 messages 2002/06/05

[#41867] Pascal-like 'with' statement? — Philip Mak <pmak@...>

Is there something like Pascal's with statement? I'd like to turn this

18 messages 2002/06/06

[#41919] 1-second events — Paul Brannan <pbrannan@...>

I need to create an event that occurs exactly once per second.

15 messages 2002/06/06

[#42086] ANN: REXML 2.3.5 && 2.2.3 — Sean Russell <ser@...>

<posted & mailed>

31 messages 2002/06/09
[#42091] Re: ANN: REXML 2.3.5 && 2.2.3 — Sean Russell <ser@...> 2002/06/09

<posted & mailed>

[#42092] RE: ANN: REXML 2.3.5 && 2.2.3 — <james@...> 2002/06/09

> Well, XMLSchema may be troublesome to interpret, but it isn't

[#42192] ruby-dev summary 17252-17356 — Minero Aoki <aamine@...>

Hi all,

81 messages 2002/06/11
[#42290] Re: a new block parameter/variable notation (Re: ruby-dev summary 17252-17356) — Kent Dahl <kentda@...> 2002/06/12

Not wanting to flog a dead horse, but I just wonder what the final word

[#42295] Re: a new block parameter/variable notation (Re: ruby-dev summary 17252-17356) — matz@... (Yukihiro Matsumoto) 2002/06/12

Hi,

[#42455] Application server & web developement enviroment — "Radu M. Obad磚 <whizkid@...>

Howdy,

14 messages 2002/06/14
[#42459] Re: Application server & web developement enviroment — Austin Ziegler <austin@...> 2002/06/14

On Fri, 14 Jun 2002 15:55:31 +0900, Radu M. Obadwrote:

[#42472] ANN: Programmierung in Ruby — "Juergen Katins" <katins.juergen@...>

Programmierung in Ruby Online gibt es jetzt mit ausfrlichem

14 messages 2002/06/14

[#42504] Are Unix tools just slow? — Chris Gehlker <gehlker@...>

Awhile back I was asking for help with a unixy way to search the mounted

48 messages 2002/06/14
[#42506] Re: Are Unix tools just slow? — Rick Bradley <rick@...> 2002/06/14

* Chris Gehlker (gehlker@fastq.com) [020614 17:18]:

[#42512] Re: Are Unix tools just slow? — Chris Gehlker <gehlker@...> 2002/06/15

On 6/14/02 3:34 PM, "Rick Bradley" <rick@rickbradley.com> wrote:

[#42513] opengl for ruby, please help — ccos <ccos@...> 2002/06/15

unix newby failing miserably here:

[#42516] Re: Are Unix tools just slow? — "Daniel P. Zepeda" <daniel@...> 2002/06/15

On Sat, 15 Jun 2002 07:14:38 +0900

[#42507] mpg123 — Tobias Reif <tobiasreif@...>

Hi,

15 messages 2002/06/14

[#42546] File.new('foo', 0600 , 'wb') — Tobias Reif <tobiasreif@...>

Hi,

21 messages 2002/06/15
[#42552] Re: File.new('foo', 0600 , 'wb') — Tobias Reif <tobiasreif@...> 2002/06/15

Dossy wrote:

[#42591] Kernel#select questions — Wilkes Joiner <boognish23@...>

I'm trying to track down a bug where Kernel#select is returning [[],[],[]] as

12 messages 2002/06/17

[#42617] eRuby on Mac OS X — Jim Menard <jimm@...>

I've searched ruby-talk for this topic, and the only messages I found show

13 messages 2002/06/17

[#42674] REXML in C — "Radu M. Obad磚 <whizkid@...>

Hi,

20 messages 2002/06/18

[#42771] Why is I/O slow? — Clifford Heath <cjh_nospam@...>

Ok, folk, time to try again. It's nothing to do with SHA-1.

61 messages 2002/06/20
[#42831] Re: Why is I/O slow? — Clifford Heath <cjh_nospam@...> 2002/06/21

Yukihiro Matsumoto wrote:

[#42836] RE: Why is I/O slow? — "Mike Campbell" <michael_s_campbell@...> 2002/06/21

> With respect, this doesn't sound like a smart idea. The glibc folk have

[#42838] Re: Why is I/O slow? — Albert Wagner <alwagner@...> 2002/06/21

On Thursday 20 June 2002 10:10 pm, Mike Campbell wrote:

[#42839] Re: Why is I/O slow? — Austin Ziegler <austin@...> 2002/06/21

On Fri, 21 Jun 2002 12:16:24 +0900, Albert Wagner wrote:

[#42928] GOOD DEAL — "DR. ISA BELLO" <dr_isa@...>

FROM:DR ISA BELLO

11 messages 2002/06/22

[#42982] No exceptions from String#to_i — "Hal E. Fulton" <hal9000@...>

I've been bitten by this before... maybe

19 messages 2002/06/24
[#42983] Re: No exceptions from String#to_i — ts <decoux@...> 2002/06/24

>>>>> "H" == Hal E Fulton <hal9000@hypermetrics.com> writes:

[#42986] Re: No exceptions from String#to_i — Nikodemus Siivola <tsiivola@...> 2002/06/24

[#43122] Re: help (ruby-talk ML) — Benjamin Peterson <bjsp123@...>

20 messages 2002/06/27
[#43123] Re: help (ruby-talk ML) — Dave Thomas <Dave@...> 2002/06/27

Benjamin Peterson <bjsp123@yahoo.com> writes:

[#43124] RE: help (ruby-talk ML) — Bob Calco <robert.calco@...> 2002/06/27

Yes, I would gladly volunteer considerable effort to this end. I have

[#43147] Ruby on Mac OS X — Tobias Reif <tobiasreif@...>

Hi,

24 messages 2002/06/28

[#43174] eruby SAFE question — Dylan Northrup <docx@...>

I'm trying to implement a replacement for the standard apache file listings

39 messages 2002/06/28
[#43249] documentation licenses (was: eruby SAFE question) — Tobias Reif <tobiasreif@...> 2002/06/30

Dave Thomas wrote:

[#43250] Re: documentation licenses (was: eruby SAFE question) — Dave Thomas <Dave@...> 2002/06/30

Tobias Reif <tobiasreif@pinkjuice.com> writes:

[#43255] RE: documentation licenses (was: eruby SAFE question) — <james@...> 2002/06/30

>

[#43280] Re: documentation licenses (was: eruby SAFE question) — "Juergen Katins" <juergen.katins@...> 2002/07/01

Tobias Reif wrote

[#43282] Re: documentation licenses (was: eruby SAFE question) — David Alan Black <dblack@...> 2002/07/01

On Mon, 1 Jul 2002, Juergen Katins wrote:

[#43381] RE: documentation licenses (was: eruby SAFE question) — <james@...> 2002/07/02

> From: David Alan Black [mailto:dblack@candle.superlink.net]

Re: 1-second events

From: Christopher Browne <cbbrowne@...>
Date: 2002-06-07 16:36:22 UTC
List: ruby-talk #42005
Centuries ago, Nostradamus foresaw when Paul Brannan <pbrannan@atdesk.com> would write:
> On Fri, Jun 07, 2002 at 10:57:14PM +0900, Dossy wrote:
>> Out of curiousity:  what are you doing that requires such precise
>> periodic execution?  Embedded software for a pacemaker?  :-)
>
> Five milliseconds of drift is a lot of drift, even for a non-real-time
> application, as it only takes 200 iterations to lose a second.  It's not
> so important to me that I have precise periodic execution, but more so
> that over the course of an hour I get exactly 3600 events (with 5 ms of
> drift, I would get roughly 3572 events).  I suppose it's not critical,
> but it makes analyzing my log files a lot easier.

If you strictly _need_ that kind of accuracy, then you'll need to
design your process in keeping with that.

What you'd need would be to have part of that "scheduler" that tracks
how much things are drifting, and waiting/acting-early in order to
adjust for the drift.

If the only granularity that you've got is something that will do
something looking like sleep(1), with resolution of 1 second, you
can'd do anything better than to be within a second.

If, in contrast, you could live with events every 10 seconds, you can
do quite a lot better.  Something with pseudocode sort of like:

# This isn't really ruby, but it's not anything else either...
start = time.stamp() # Measured in milliseconds
interval = 10
next = start + interval
loop do
  now = time.stamp()
  wait_period = Integer(next - now)   # How long do we need to wait?
  next = next + interval
  sleep(wait_period)
  do_whatever()
end

The point of the calculations is that you're always calculating how
long each interval needs to be.  

If there is some regular drift, whereby the average "sleep" needs to
be 9.5 seconds, then it's likely that there will be a rough
alternation between 9 and 10 second intervals.

This actually ought to work _marginally_ acceptably even with 1 second
intervals; what will likely happen is for there to be a set of sleep()
calls with for 0, 1, and _maybe, sometimes_ 2 seconds.  Unfortunately,
with the very low resolution, that'll jitter all around.  

The larger the number of time intervals that you have to work with,
the less jittery it should be.  

- If you can sleep for intervals measured in milliseconds, then you
  can get a pretty steady result when trying to get 1 second
  intervals, as there shouldn't be need to get off by  more than a
  millisecond or two.
 
- If you can sleep for intervals measured in seconds, and want 10
  second intervals, you ought to be able to stay within 1s.  That's
  much less satisfactory than with ms intervals.

- Trying to be within 1s with 1s sleep() intervals is going to be
  highly jittery.
-- 
(concatenate 'string "aa454" "@freenet.carleton.ca")
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Why are men like blenders?
You need one, but you're not quite sure why. 

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