Preemptive Multitasking

This paper discusses a special thought which uses the active objects to deal with non-preemptive multitasking and discusses problems about the platform security in Symbian OS that is the current popular operation system in the market of smart phone.

分析了当前流行手机操作系统(Symbian OS)中用活动对象处理非抢占式多任务的独特设计思想,讨论了平台安全性相关问题,并阐述了能力、权限、授权、安全标识符和数据锁定等5个安全因素,剖析了异步函数、活动对象和非抢占式多任务等3个基本概念,重点从安全性的角度对活动对象的实现过程进行了比较分析,有助于解决当前手机操作系统中内存小和安全性两方面问题。