From: Robert Klemme <shortcutter@...>
Date: 2010-10-22T22:11:05+09:00
Subject: Re: Strange consumption CPU for a quite small program

On Fri, Oct 22, 2010 at 2:58 PM, Guillaume Ebuprofen
<guillaume.dorchies@gmail.com> wrote:
> Hello,
>
> Below my little program for Linux (because I use ps command)
>
> <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
> require 'socket'
>
> Thread.abort_on_exception=true
>
> pid=Process.fork do
>  ##Processus 1
>  thread=Thread.new do
>    tcp_server = TCPServer.new('0.0.0.0',10000)
>    socket = tcp_server.accept
>  end
>  thread.join
> end
>
> #Porcessus 2
> while true
>  output=''
>  IO.popen("ps -p #{pid} -o pcpu,size") do |pipe|
>    output=pipe.read
>  end
>  puts output
>  sleep(1)
> end
> <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
>
> When I execute this program (with ruby 1.8.7 or 1.9.2) and after 10
> steps, I can see process 1 consumes CPU, why ?

I see

15:08:16 Temp$ ruby19 so.rb
so.rb:8: [BUG] native_mutex_unlock return non-zero: 1
ruby 1.9.1p429 (2010-07-02 revision 28523) [i386-cygwin]

-- control frame ----------
c:0005 p:---- s:0015 b:0015 l:000014 d:000014 CFUNC  :initialize
c:0004 p:---- s:0013 b:0013 l:000012 d:000012 CFUNC  :new
c:0003 p:0019 s:0008 b:0008 l:000764 d:000007 BLOCK  so.rb:8
c:0002 p:---- s:0004 b:0004 l:000003 d:000003 FINISH
c:0001 p:---- s:0002 b:0002 l:000001 d:000001 TOP
---------------------------
-- Ruby level backtrace information-----------------------------------------
so.rb:8:in `initialize'
so.rb:8:in `new'
so.rb:8:in `block (2 levels) in <main>'

[NOTE]
You may encounter a bug of Ruby interpreter. Bug reports are welcome.
For details: http://www.ruby-lang.org/bugreport.html


Btw, why don't you just do

require 'socket'

Thread.abort_on_exception=true

pid=fork do
 tcp_server = TCPServer.new('0.0.0.0',10000)
 socket = tcp_server.accept
end

#Porcessus 2
loop do
 system "ps", "-p", pid.to_s, "-o", "pcpu,size"
 sleep(1)
end

Kind regards

robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/