require 'socket'
i = 0
while true
    puts "try #{i += 1}"

    sock = UDPSocket.new
    close_end_notify = Queue.new

    Thread.new do
        while close_end_notify.empty?
            begin
                puts "gets"
                sock.gets
                puts "gets end"
            rescue
                puts "exception #{$!}"
            end
        end
    end

    sleep 2
    puts "close"
    sock.close
    puts "close end"
    close_end_notify << nil

    sleep 2
    puts
end