require "sys"

exit_loop = false

sys.taskInit( function()

                        while true do

                            print("this is a test")

                            sys.wait(100)            --sleep 100ms

                            if exit_loop == true then break end            --检查变量，如果是true，则break，退出循环；

                                                                                              --while循环停止，该任务停止

                        end

                    end

)

sys.timerStart(function() exit_loop = true, 15000)        --15秒后，更改变量值