# File lib/em/pure_ruby.rb, line 360
    def crank_selectables
      #$stderr.write 'R'

      readers = @selectables.values.select {|io| io.select_for_reading?}
      writers = @selectables.values.select {|io| io.select_for_writing?}

      s = select( readers, writers, nil, @timer_quantum)

      s and s[1] and s[1].each {|w| w.eventable_write }
      s and s[0] and s[0].each {|r| r.eventable_read }

      @selectables.delete_if {|k,io|
        if io.close_scheduled?
          io.close
          true
        end
      }
    end