即时编译器辅助的垃圾收集中的插桩算法研究  

Study on Instrumentation Algorithm for Just-in-time Compiler Assisted Garbage Collection

作　　者：张昱[1,2] 袁丽娜[1,2] 

机构地区：[1]中国科学技术大学计算机科学技术学院,安徽合肥230027 [2]中国科学院计算机系统结构重点实验室,北京100080

出　　处：《小型微型计算机系统》2010年第4期651-656,共6页Journal of Chinese Computer Systems

基　　金：中国科学院计算机系统结构重点实验室开放课题;Intel公司研究基金资助项目;国家自然科学基金项目(60673126)资助.

摘　　要：即时编译器辅助的垃圾收集技术结合显式和自动内存管理的优点,在编译阶段由即时编译器分析应用程序并在其中插桩显式释放内存的指令,以便垃圾收集器及时回收死亡对象所占用的内存空间,从而减轻垃圾收集器的负担.提出一种应用于该项技术的插桩算法,它基于控制流中的支配关系并提供不同的插桩策略,保证插桩的正确性和灵活性;它能够主动获得域引用从而释放对象及其域引用的内存空间.实验表明基于该插桩算法的垃圾收集器能够回收大量的内存空间,提高Java程序的执行效率.Just-in-time compiler assisted garbage collection （JIT-assisted GC） combines the advantages of explicit memory management and automatic memory management.Under the framework of JIT-assisted GC,JIT compiler analyses the applications to find dead objects and their dead points,then instruments the explicit ＂free＂ instructions in compilation time,accordingly garbage collector could reclaim the spaces owned by those dead objects in time and relieves its load on automatic garbage collection.A new algorithm on instrumenting ＂free＂ instructions in JIT-assisted-GC is proposed in this paper.It bases on the domination relations in the control flow and various instrumenting strategies are presented to ensure the validity and flexibility of instrumentation.Moreover,the object fields which refer to dead objects are detected,and instructions for loading those field references are produced and instrumented automatically.Experimental results show that the proposed algorithm for JIT-assisted-GC could reclaim plentiful memory spaces and improve the performance of Java applications efficiently

关 键 词：插桩 即时编译器 垃圾收集器 内存管理 

分 类 号：TP311[自动化与计算机技术—计算机软件与理论]