The Research And Implementation Of Mixed Real-Time Message System

The real-time system is a kind of multi-task with time limit property complex controlling system by the computer. It's one of the based requirements that the computer power offered by CPU must satisfy the time limit of all various kinds of complex real-time task to be scheduled. With the development of enterprise information system, the real-time system with complex real-time requirement composed with various tasks is focused on by the researcher in the real-time field, which recently causes to the hot research of mixed real-time message system.The mixed real-time message system in the paper is an important part supported the Grdi-based Collaborative Geographic Information System (CoGIS), which is a sub-project of the National 10th Five-Plan. The system extends the traditional C/S model using the object request agent technology, and builds a stable and flexible 3-hiberarchy architecture with fast response to solve the danger caused by the exposure of inside infrastructure, and realize the remote call from clients. Based on the Java Message Specification (JMS), standardizes the union message format and supports various communication models. By message queue, the system can message with the property of, which realizes the communication among the enterprise applications and inside models in the application.Based on the scheduling model of the mixed real-time message system, the scheduled object is expands to be the pair of task set and server. A scheduling model based on the virtual server preview gained the process time is proposed in the paper to satisfy with the requirement of the real-time cooperative system. The scheduling model is proved to be schedulable. By separating the scheduling mechanism and strategy, realizes the open schedule framework. And uses the multi-thread parallel technology, which makes it sure that several scheduler algorithms work together in a system.Later, in the cooperative marking environment of geography information system, the scheduling effective is acceptable according to the model evaluating and test result. And the mixed real-time message system is valuable for using and researching.