From: Michael Bevilacqua-Linn <michael.bevilacqualinn@...>
Date: 2007-10-09T23:00:35+09:00
Subject: Re: thread problem.....

------=_Part_5905_20481838.1191938429112
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

Um,

All you're doing is creating threads and putting them to sleep...  You're
not doing any actual work.

What are you getting at exactly?

MBL

On 10/9/07, 7stud -- <dolgun@excite.com> wrote:
>
> Michael Bevilacqua-Linn wrote:
> > 1.) The only way threads get you a speedup is when you write your code
> > in
> > such a way that sections of it can be executed in parallel so you can
> > take
> > advantage of multiple cores (or processors).
> >
> > 2.) The current version of Ruby only supports green threads anyhow.  So
> > even
> > if you did have multiple cores, you wouldn't get a speedup.
> >
> > MBL
>
> Then perhaps you could explain the output of this program:
>
> require 'rtiming'  #a simple program that times methods
>
> def test1
>   threads = []
>
>   2.times do |i|
>   threads[i] = Thread.new do
>     sleep(2)
>     puts "task #{i+1} finished"
>   end
>   end
>
>   threads.each do |t|
>     t.join
>   end
> end
>
> def test2
>   sleep(2)
>   puts "task 1 finished"
>
>   sleep(2)
>   puts "task 2 finished"
> end
>
> puts timer(:test1, 1)
> puts timer(:test2, 1)
>
>
> --output:---
> task 2 finished
> task 1 finished
> Method exec time(1 loops): 2.010791 total
> task 1 finished
> task 2 finished
> Method exec time(1 loops): 4.000226 total
> --
> Posted via http://www.ruby-forum.com/.
>
>

------=_Part_5905_20481838.1191938429112--