Research Of Embedded Middleware Based On CORBA/e

In an embedded system with distributed architecture, the embedded devices communicate with each other to accomplish a complicated computing task together in a collaborative way. However, the differences between the embedded system platforms become an obstacle to the communications of embedded devices. If using traditional software development method to solve the problem, some other problems will arise. One is that specific code was needed for different embedded devices and this will lead to poor reusability, scalability, and portability of the code. Meanwhile, different embedded software development involves some common code that manage resource in low level, such as thead scheduling, network connection, and memory management, etc. The repeating development of these code will lead to high cost and reduce the reliability of embedded software. To solve above problems, traditional middleware idea was introduced into embedded system.In 2006 years, the CORBA/e specification for embedded middleware was made by OMG combining the static part of CORBA industrial standard with the basic part of Real-Time CORBA. CORBA/e is based on distributed object technology and this enable embedded software with distributed architecture to communicate with each other in object level. The CORBA/e specification specified the standard interface for embedded middleware, and the concrete implementation of it was left to the people who want to construct it.There are many ways to implement the CORBA/e middleware. In this thesis, the basic structure and the implementation strategies of the embedded middleware were studied considering the special requirements of embedded system combined with CORBA/e specification.First, The CORBA/e architecture was analyzed including the structure of ORB core and Portable Object Adapter, realtime part of CORBA/e, and CORBA/e services. And then, the implementation strategies of embedded middleware were considered through the end-to-end path of request processing. In the ORB core, the characteristics of concurrent tasks were analyzed and an appropriate thread pool and a multiple connection model was selected. For the POA, the existing servant operation locating method was studied and modified according to the characteristics of CORBA/e to make it more appropriate to embedded system. For the memory management, traditional classic memory pool was improved and separated into different sections according to the granularities of memory allocation which can satisfy the need of dynamic change of the size of memory allocation.