一种Dalvik虚拟机的自适应编译系统  

An Adaptive Compilation System Based on the Dalvik Virtual Machine

作　　者：凌明[1] 武建平[1] 冯克环[1] 

机构地区：[1]东南大学国家专用集成电路系统工程技术研究中心,江苏南京210096

出　　处：《电子学报》2013年第8期1622-1627,共6页Acta Electronica Sinica

基　　金：国家科技重大专项(No.2009ZX01031-001-004-3);青蓝工程资助项目

摘　　要：在深入分析Dalvik虚拟机自适应编译系统的瓶颈之后,针对当阈值计数器自减到零时,系统初始化导致本地代码多次等待的情况,提出一种阈值重置策略;在热点代码密集的应用程序中,针对编译线程因积压大量等待处理任务而导致编译滞后情况,提出一种基于结果反馈的动态自适应阈值改进策略,结合阈值最优化理论,最大限度地挖掘动态编译的性能收益.实验结果显示,基于三星Galaxy S平台,经过阈值重置优化后,Dalvik虚拟机的循环执行效率平均提升7%,分支跳转、派发指令执行效率平均提升5%;采用动态自适应阈值优化后,分支跳转、派发指令执行效率平均提升8%.After the bottle-neck of the adaptive compile system for Dalvik being analyzed,according to the scenery when the threshold counter decrements to zero,a lot of waiting time will be caused by system initialization,the strategy based on threshold reset is introduced.According to some applications centralized with hot-spot codes,which will caused a great deal of compiling work to be suspended,a strategy of dynamic adaptive threshold based on a result feedback mechanism,is implemented.It could maximize the performance enhanced by the dynamic compilation scheme.Compared to the Dalvik before optimization,the experimental result based on the platform of Galaxy S of Samsung Corporation indicates that the execution efficiency of loop operations is improved by 7% on average after optimized by the threshold reset strategy,the execution efficiency of conditional jump operations and instruction dispatch are improved by 5% on average and 8% assisted by the dynamic adaptive threshold scheme.

关 键 词：DALVIK虚拟机 自适应编译系统 阈值重置 动态自适应阈值 

分 类 号：TN302[电子电信—物理电子学]