race condition while jruby is resolving host files

gistfile1.txt

#!/usr/bin/env ruby

require "resolv"
require 'jruby'


class Resolv
  class Hosts

    def initialize(filename = DefaultFileName)
      @filename = filename
      @mutex = Mutex.new
      @initialized = nil
      @mutex.lock
    end
  end
end

class DnsLookup

  def initialize
    @nameserver = [ "8.8.8.8" ]
    @resolv = ::Resolv.new(resolvers=[::Resolv::Hosts.new, ::Resolv::DNS.new(:nameserver => @nameserver, :search => [], :ndots => 1)])
  end

  def getname(address)
    @resolv.getname(address).force_encoding(Encoding::UTF_8)
  end

end

if __FILE__ == $0

  lookup = DnsLookup.new
  thr = Thread.new(lookup) do  |_lookup|
    raise Exception.new unless _lookup.getname("54.218.47.147") == "ec2-54-218-47-147.us-west-2.compute.amazonaws.com"
  end

  Thread.pass until thr.status == "sleep"
  JRuby.reference(thr).native_thread.interrupt

  thr.join

end