CAJ | 학술논문

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％。
재심입분석Dalvik허의궤자괄응편역계통적병경지후，침대당역치계수기자감도령시，계통초시화도치본지대마다차등대적정황，제출일충역치중치책략；재열점대마밀집적응용정서중，침대편역선정인적압대량등대처리임무이도치편역체후정황，제출일충기우결과반궤적동태자괄응역치개진책략，결합역치최우화이론，최대한도지알굴동태편역적성능수익。실험결과현시，기우삼성Galaxy S평태，경과역치중치우화후，Dalvik허의궤적순배집행효솔평균제승7％，분지도전、파발지령집행효솔평균제승5％；채용동태자괄응역치우화후，분지도전、파발지령집행효솔평균제승8％。
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 re-set 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 .