# File lib/rbot/ircsocket.rb, line 147
    def initialize
      # a MessageQueue is an array of QueueRings
      # rings have decreasing priority, so messages in ring 0
      # are more important than messages in ring 1, and so on
      @rings = Array.new(3) { |i|
        if i > 0
          QueueRing.new
        else
          # ring 0 is special in that if it's not empty, it will
          # be popped. IOW, ring 0 can starve the other rings
          # ring 0 is strictly FIFO and is therefore implemented
          # as an array
          Array.new
        end
      }
      # the other rings are satisfied round-robin
      @last_ring = 0
      self.extend(MonitorMixin)
      @non_empty = self.new_cond
    end