From: Robert Klemme <bob.news@...>
Date: 2005-01-24T19:15:55+09:00
Subject: Re: nuby threading on threads


"Assaph Mehr" <assaph@gmail.com> schrieb im Newsbeitrag
news:1106529293.644704.189240@c13g2000cwb.googlegroups.com...
> Sounds like you need an implementation of thread-pool.
> Read http://www.rubygarden.org/ruby?ObjectPoolingAndThreading - it
> might help.

Definitely.  A common pattern is this

require 'thread'
PARALLEL = 10
TERMINATOR = Object.new

# setup
threads = []
queue = Queue.new

PARALLEL.times do
  threads << Thread.new(queue) do |q|
    until ( TERMINATOR == ( obj = q.deq ) )
      # do something with obj
      puts "#{Thread.current.inspect}: #{obj.inspect}"
      # or maybe deal with arbitrary code
      begin
        obj.call if obj.respond_to? :call
      rescue Exception => e
        $stderr.puts e
      end
    end
  end
end

# add tasks to queue
20.times {|i| queue.enq "Task 1.#{i}"}
queue.enq lambda { puts "some arbitrary task"; sleep 2 }
queue.enq lambda { puts "another task"; sleep 2 }
queue.enq lambda { raise "Deadly!" }
5.times {|i| queue.enq "Task 2.#{i}"}

# temination
threads.each { queue.enq TERMINATOR }
threads.each { |t| t.join }

# end

Kind regards

    robert