Study On Runtime Recovering Techonology In Dalvik Virtual Machine

Because of the outstanding characteristics of open source, good portability andapplication hardware platform independence, Android has quickly become themainstream mobile device operating system. However, due to the constraints of themobile computing and storage capacity, the execution speed of Android applicationcompared with the PC, there is a large gap. In view of cloud computing can providepowerful storage and computing resources, Intel put forward an idea of clone cloud thatmigrate Android applications running on the phone more time-consuming function tothe cloud, thus speeding up the execution speed of Android applications, and providingbetter user experience.In order to achieve the migration of time-consuming function from the phone to thecloud, the thesis proposes a method that is able to reload the implementation of themethod time-consuming function requests from the Android mobile applications in thecloud without application source code. For these four key issues of migration in the faceof cross-process of Android applications, the main content of this thesis is organized asfollows.(1) For the question that which data to migration from the source process, thisthesis has studied the function need to use the data in the analysis execution process,and on this basis, summed up the data required during the migration process, includingthe function parameter data in the Java method stack, Java heap object data associatedwith the function parameters, running shared static data of Dalvik virtual machine, etc.(2) For the question how to store the migrated data from the source process,This thesis has designed a method for storing data. It uses the memory of theoperating system; at the running time the data saved in the memory would be parsed tothe virtual machine memory. The design of the memory has made easy-preservation andparsing the data as the guiding ideology.(3) For the question that how to restore the data in the target process, This thesishas studied the Java memory object model. According to Java’s single inheritance model,the thesis has designed the object recovery method that it would restore their own data and then restore the data of the parent class.(4)For the question that how to make the function migrated from the sourceprocess execute, this thesis has studied Dalvik virtual machine`s Class loadingmechanism, interpreter mechanism and memory management mechanisms. On the basisof the study, this thesis proposes a new method to improve the execution speed of themobile application, that is, Runtime recovering technology in Dalvik virtual machine.Finally, in order to verify the usefulness of the above method，This thesis hasanalyzed the multiple Android application instance. Experimental results show thatRuntime recovering technology in Dalvik virtual machine not only allows Androidapplication migration to high-performance cloud, and the acceleration effect is veryobvious.