AN EVENT DRIVEN MESSAGE PASS MODEL FOR A METACOMPUTING ENVIRONMENT

The data exchange between heterogeneous nodes of a metasystem can be implemented by different methods. A traditional method is layered calling. A message passing must be fulfilled without interruption, i. e. , the next message passing can only be started after completion of the current message passing. When the message is transmitted below the application layer, the application layer must wait, wasting the CPU time and reducing the system efficiency. In order to overcome the disadvantage of the layered model, the layered communication model of a metacomputing system prototype WADE is discussed, an event-driven communication model is proposed, and its performance is also illustrated in this paper. In this model a message passing is considered as an event. When an event occurs, a corresponding program is executed. The sequence of an event execution is controlled by its priority. The event queue is flushed by a flushing function. By using the event-driven model, the process of messages passing is pipelined, increasing efficiency of the application layer communication and therefore of the entire system.