Wide-Area Distributed Computing Based on a Mobile Object Computing Approach

移动对象是在对计算资源的严格访问控制下本身可以包括程序代码、数据和计算状态(所谓的线程)的迁移对象。我们正在开发Planet移动对象系统，使其能够在开放的广域网络环境(如互联网)中进行移动对象计算，而不需要固定编程语言和虚拟机的设计。在本研究项目中，我们进行了以下研究：首先，设计了一种实现异种对象迁移的方案，并对其进行了实现和评估；其次，将该方案应用到Web环境中，在不固定编程语言或虚拟机设计的情况下，获得了一个Applet系统；第三，应用Planet的移动对象技术，对TCL现有的脚本语言解释器进行了动员；第四，以可移植的方式，为Java语言系统开发了一个包含迁移线程的移动对象实现方案。它使用源代码翻译技术。最后，利用分布于筑波大学、东京大学、京都大学和电工实验室的实验平台进行了广域分布式计算实验。

A mobile object is a migratory object that may include program code, data, and computational state (so-called thread) in itself under rigorous access control to computational resource. We are developing the Planet mobile object system that enables mobile object computing in an open wide-area network environment such as the Internet without fixing designs of programming languages and virtual machines. In this research project we conducted the following studies.First, we designed a scheme to achieve heterogeneous object mobility, and we implemented and evaluated it.Second, we applied the scheme to the Web environment, then we obtained an applet system without fixing the designs of programing languages or virtual machines.Third, we applied the mobile object technology of the Planet to mobilizing an existing scripting language interpreter of Tcl.Fourth, we developed an implementation scheme of mobile objects for the Java language system including migratory threads in a portable way. It uses a source-code translation technique. Furthermore, we extended the scheme to safely execute mobile objects under a rigorous CPU-consumption control.Lastly, we conducted experiments of wide-area distributed computing by using the experiment platform spreading over the University of Tsukuba, the University of Tokyo, the Kyoto University, and the Electrotechnical Laboratory.