2. Some application modes for message exchange

2.1 Simple transfer or datagram

A datagram message is like a letter in the post. No response is necessarily expected from the application receiving the message. The sending application is therefore not waiting to receive the reply message from the recipient. This is the most common and appropriate use of a message handler: the exchange is completely asynchronous, as shown in figure 2 , in which the queue is symbolized by a vase containing stacked messages.

An application for displaying...