反省的对象中间件——高可伸缩的反省ORB

Reflective Object-Oriented Middleware——High Scalable Reflective ORB

1 引言 以CORBA为代表的对象中间件在企业应用中越来越发挥着重要的作用,但日趋增多的应用领域如:电子商务、多媒体与实时系统、移动计算等,及新CORBA标准都对中间件开发者提出了新的挑战.只有协调好统一的体系结构、广泛而灵活的适应性及优化的性能这三方面问题,产品才能快速适应各种应用领域的需求,同时保持良好的性能.

Today's object-oriented middlewares, especially CORBA.are confronted with challenges from progressive applications. Many black-box based ORBs are not flexible enough to adapt themselves quickly to satisfy lots of new requirements. This paper applies reflective computation technology to the architecture of ORBs,proposing a kind of reflection on message transport protocols ,extending the meta-level functions for object activation,and implementing the structural and behavioral reflection of IDL interfaces with help of the IDL compiler. By introducing 'slots',meta-components can be dynamically selected and loaded into run-time kernel,that improves system's scalability effectively and partly solves problem of inconsistency existing in distributed reflective system. Based on reflection, we implement some critical functions aiming to enterprise applications, including pluggable prototcols framework, integration of message-oriented middleware, and component-based applications. This paper ends with the conclusion that reflection is very useful in building flexible and scalable object-oriented middleware.