presumably thread safe ring buffer

ring_buffer.rb

module My
  class RingBuffer
    def initialize(size)
      @size = size
      @pointer = 0
      @buffer = Array.new
      @mutex = Mutex.new
    end

    def push(value)
      @mutex.synchronize do
        @buffer[@pointer%@size] = value
        @pointer+= 1
        value
      end
    end
    alias :<< :push

    def next
      @mutex.synchronize do
        value = @buffer[@pointer % @size]
        @pointer += 1
        value
      end
    end
  end
end


mrb = My::RingBuffer.new(3)
mrb<<1
mrb<<2
mrb<<3
mrb.next # =>1
mrb.next # =>2
mrb.next # =>3
mrb.next # =>1
mrb.next # =>2