Dalvik 在CAR 构件运行时中的应用研究.docVIP

Dalvik在CAR构件运行时中的应用研究 陈卫伍，王建民，陈榕 （同济大学基础软件工程中心，上海，200092） 摘要：CAR是一种二进制构件技术，Elastos是CAR技术的软件生态环境，是CAR构件的运行时环境。Elastos的表现形式是操作系统或中间件，它简化了在高度分布式环境中的应用程序开发。Java程序依赖Java虚拟机解释执行，在性能上不如可以编译执行的本地代码，软件尺寸、功耗等表现也不如本地代码。本文在基于Google的开源工程Dalvik基础上，结合CAR和Java虚拟机技术，在Elastos平台上提出了一种Java和CAR混合编程的技术，旨在达到让Java虚拟机上运行CAR构件目的的同时，利用CAR构件提高Java程序的运行速度而不破坏Java的编程模型，从而起到优化JAVA运行时的目的。 关键词：Java；Java虚拟机；CAR构件；Elastos；Dalvik The Research of Dalvik Working with CAR Runtime Environment CHEN Weiwu, WANG Jianmin,CHEN Rong (System Software Engineering Centre,Tongji University,Shanghai 200092,China) Abstract: CAR is a binary component technology, and Elastos is a software environment based on CAR technology, the running enviroment of CAR Component. Elastos represents as operating system or middleware, and treats the net as computing and storing resources. This make the application development easily in distributed network enviroment. Java is a cross-platform language, this feature depends on the Java virtual machine to satisfy The Java Virtual Machine Specification on the specific platform. Java program have to be interpreted before being executed on Java virtual machine, then its performance, power and size can hardly be accomplished with native code. This paper presents a technology called JavaCAR mixed programming model, which is base on dalvik, the Google’s open-source project, simultaneously take CAR and Java virtual machine technology into consideration. The JavaCAR let CAR cooperate with Java virtual machine, this will make the Java program work more effectively but needn’t change the Java programming model. Key Words: Java; Java Virtual Machine; CAR Component; Elastos; Dalvik 1 CAR构件及其运行时环境 CAR，即Component? ?Assembly??Runtime。Component，有“零件”的意思；Assembly，有“部件”、“组装”的意思，所以从字面上理解，CAR就是在运行时对软件构件进行组装并最终完成预计功能的一种软件技术[1]。 机械行业有“零部件”的说法，零件和部件都是工厂生产线上的安装单元。零件是最基本的安装单元，部件是由零件组成的半成品安装单元。最终产品一般是由某种部件加上外壳而成[6]。 在Elastos中，Component? ?Assembly?也包含了这两层含义：（1）软件零件，特指“目标代码单元”。在CAR编程规范中就是DLL，也可以是JAVA或C#中的目标代码文件；（2）