Support Environment for Active Software

新的信息系统功能更高，规模更大，但需要更短的实施时间。针对这些趋势，我们的目标是建立一种新的大型安全软件系统的设计方法，并为其开发合适的环境。（1）设计适合于软件安全性和适应需求变化的算法我们不仅引入了前置条件和后置条件来保证软件安全运行满足规范要求，而且还引入了前置检查和后置检查来提供不可预测的状态。它们由附加在每个激活条件上的激活函数构成。（2）主动软件的设计与分析语言及其语言处理器首先对软件的行为进行分析，并将分析结果用状态转移图或π-表达式表示。然后由第一级翻译器得到包含活动函数的程序框架，手工添加每个函数的详细内容，由第二级翻译器得到C或C++语言的程序文本。所得到的程序具有事件驱动激活的特点，易于修改。第二翻译器能够显示调用函数和被调用函数之间的关系，并使程序能够跟踪运行时的真实的调用。（3）主动软件的可重配置硬件结构在主动软件上，将事件检测为每个主动功能的激活条件的方法影响性能。我们提出了一种新的事件驱动计算机体系结构，它具有可重构部件和处理器阵列，处理器之间的连线可以改变，并对它们的设计结果进行了评价，根据这些结果，我们计划在三年内继续研究灵活、安全的软件、新的编程环境和适合它们的计算机体系结构。

New information system becomes higher in function and larger in size, but it requires shorter implementation time. For these trends, we aim to establish a new design method of large and safe software system and to develop appropriate environment for it.Through the research in 3 years, we gained one basis as follows.(1)Design algorithms suitable to safe and adaptive software for the change of requirementsWe introduced not only per-condition and post-condition to assure safe operation satisfying the specification, but also pre-check and post-check to provide for unpredictable states. They are formed with active functions attached each activation condition.(2)Language to design and analysis active software, and its language processorAt first we analyze the behavior of the software and express the result in state transition diagrams or π-expressions. Then we get the framework of the program with active functions by 1st-translator, append the detail contents of each function by hand, and gain the program text in C or C++ by 2nd-translator. The obtained program has the feature of event driven activation and is easy to change. The 2nd-translator is able to show the relation of calling and called functions, and also to make the program traceable the real calls at running time.(3)Re-configurable hardware architecture for active softwareOn active software the performance is affected by the method to detect events as activation condition of each active function. We proposed new architecture of event driven computer with re-configurable part and array of processors with changeable wire connection between processors, and evaluated the designed results of them.With these results through 3 years, we have some plans to continue the research about flexible and safe software, new programming environment, and suitable computer architecture for them.