trying to understand https://github.com/rubygems/rubygems-mirror/blob/master/lib/rubygems/mirror/pool.rb

raggi_queue.txt

# https://github.com/rubygems/rubygems-mirror/blob/master/lib/rubygems/mirror/pool.rb
# also check 
require 'thread'

class MirrorPool
  def initialize(size)
    @size = size
    @queue = Queue.new
  end

  def job(&blk)
    @queue << blk
  end

  def run_til_done
    threads = Array.new(@size) do
      Thread.new {
        while true
          @queue.pop.call
          puts "done"
        end
      }
    end
    puts "queue_empty: #{@queue.empty?} num_waiting: #{@queue.num_waiting} size: #{@size}"
    # what does num_waiting denote. test-case where it grows. 
    until @queue.empty? && @queue.num_waiting == @size
      threads.each { |t| t.join(0.1) }
    end
    puts "queue_empty: #{@queue.empty?} num_waiting: #{@queue.num_waiting} size: #{@size}"
    threads.each { |t| t.kill }
  end
end

queue_size = 5
pool = MirrorPool.new(queue_size)
(1..queue_size).each do |x|
  pool.job { puts x }
end
pool.run_til_done

q = Queue.new
q << Proc.new { puts 1 }
q.instance_eval { puts @que.inspect } #nil - WTF why does it not print the varible. it is initialized to []
q.instance_eval { puts @waiting.inspect } #nil - WTF why does it not print the varible. it is initialized to []

class Foo
  def initialize
    @foo = []
  end
end

Foo.new.instance_eval { puts @foo.inspect } #[]

__END__
1
done
2
done
3
done
4
done
5
done
queue_empty: true num_waiting: 5 size: 5
queue_empty: true num_waiting: 5 size: 5
nil
nil
[]