机构地区: 广东工业大学计算机学院
出 处: 《计算机工程与应用》 2005年第28期41-43,64,共4页
摘 要: 通常的最坏执行时间分析方法的结果过于悲观(overpessimistic),根据这种结果进行调度将导致资源的极大浪费。面向对象的编程语言由于具有封装、继承、多态的特点,使得按照通常的方法获得的最坏执行时间更加悲观。解决这个问题的一个办法就是限制面向对象语言这些特点的使用,但这又导致最终的实时系统不够灵活,失去了面向对象语言的优点。文章以实时JAVA系统为例,介绍了将运行中赚取时间(gaintime)的回收与最坏执行时间分析相结合的方法,这种方法既提高了资源的使用率,又保证了系统的灵活性和性能。 The results of most WCET analysis tools are over pessimistic,and cause great waste of resources if scheduling is based on such results.Object-oriented programming languages,because of their major features:encapsulation,inheritance and polymorphism,produce more pessimistic results if they are analyzed by ordinary WCET analysis tools.One solution is to prohibit the use of these dynamic features,but this results in a system which is not flexible enough.This paper introduces a marvelous way to integrate gain time reclaiming and WCET analysis,which not only improve the efficience of the system,but also ensure the flexibility.