cyclic iterator for multithread

SyncCyclicIterator.rb

class SyncCyclicIterator
  def initialize(ary)
    @ary = ary
    @mtx = Mutex.new
    @idx = 0
  end
  
  def next
    ret = nil
    @mtx.synchronize do
      ret = @ary[@idx]
      @idx += 1
      @idx = 0 if @idx == @ary.size
    end
    return ret
  end
end