Software Components Implemented with Meta Information of Programs

本研究的目标是应用下一代面向对象技术中的反射技术，开发一种将软件系统分解成模块的新方案。首先，我们对OpenC++进行了扩展，以减轻描述描述模块间关系的元程序的负担，反射的表达能力很强，但现有的反射技术不能将软件系统的某些类分解为模块。这项研究开发了分解这些类别的软件系统所需的基本技术。在本研究中，讨论了以下软件系统：容错系统、操作系统和分布式中间件。容错系统的研究是与法国LAAS合作进行的。在对操作系统进行分解时，我们面临着性能和安全性之间的权衡，因此我们开发了一种方法，使程序员能够控制权衡。由于OpenC++在编译时解释元程序，因此在模块执行期间很难提供模块之间的保护。这意味着在执行期间必须保护的模块在运行时承受着巨大的保护开销。我们开发了一种新的虚拟内存机制，使模块能够得到有效的保护。

The goal of this research is to develop a novel scheme to decompose software systems into modules by applying the reflection technique that is an object-oriented tech no logy of the next generation.In this research, we exploited OpenC++, the language system based on reflection, which has been developed by our research group. First of all, we have extended OpenC++ to mitigate the burden of describing meta-programs that represent the relationship between modules.The expressive power of reflection is high, but the current technology of reflection fails to decompose some classes of software systems into modules. This research developed fundamental technologies required to decompose those classes of software systems. In this research, the following software systems are addressed : fault tolerant systems, operating systems, and distributed middleware. The research on fault tolerant systems is a collaboration with LAAS in France. To decompose operating systems, we confronted the tradeoff between performance and safety, and thus we have developed a method to enable programmers to control the tradeoff.Since OpenC++ interprets meta-programs at compile time, it is difficult to provide protection between modules during the execution of modules. This implies that modules that must be protected during execution suffer huge overhead of protection at runtime. We developed a novel mechanism of virtual memories that enable efficient protection of modules.