How do you explain indirect communication between two processes. explain it with direct communication.?

Answer 1

Guys, remember! when human beings want to communicate each other they must have link to communicate even directly or indirectly. We can't share our feelings if we don't cooperate or communicate each other. In such way , in the computing environment, IPC provides a mechanism to allow processes to communicate and to synchronize their activities. IPC is the best provided by a message system. Message system can be defined in many different ways between the processes. Processes can communicate using the files, through the pipes, and processes could communicate through the variables that are shared between them as well as An IPC facility provides at least the two operations --send (message) and receive (message). If the processes want to communicate they must have a way to refer to each other. They can either directly or indirectly. This kind of communication between the processes is detailed below;

Direct Communication: In the Direct Communication, when two processes want to communicate each other they must know the name explicitly. Otherwise message may not be delivered correctly and the obstruction can create in the communication. The two operations defined in a direct communication system are send (send message to process message) and receive (receive message from process). The links in such kind of environment are established automatically with exactly one pair which exist only one link. The link may be unidirectional or bi-directional.

Indirect Communication: in indirect communication environment the processes can communicate if they have share a mailbox, where the messages are received from mailboxes which is known as ports. Each mailbox has a unique ID. In such kind of communication mechanism the links are established only if two processes share a common mailbox where one process sends message to apposite mailbox and other process picks the messages from the mailbox. The two operations defined in an indirect communication are "send" a message to mailbox and "receive" a message from the mailbox.