Unit 2

Seite 1

IPC

Inter process communication (IPC) is a mechanism which allows processes to communicate each other and synchronize their actions.The communication between these processes can be seen as a method of co-operation between them. Processes can communicate with each other using these two ways:

Shared memory and message passing

Message passing:In this method, processes communicate with each other without using any kind of shared memory. If two processes p1 and p2 want to communicate with each other, they proceed as follow:

Establish a communication link (if a link already exists, no need to establish it again.)

Start exchanging messages using basic primitives.

We need at least two primitives: – send(message, destinaion) or send(message) – receive(message, host) or receive(message)

Following are some of the features of a good message passing System.

Simplicity

Uniform semantics

Efficiency

Reliability

Corrections

Flexibility

Security

Portability

Simplicity: A message-passing system should be straightforward, simple, and easy to use. It should also be feasible for a developer to assign various modules of the distributed application and to send and receive the message between them in a way as simple as possible without the need to stress over the system and are network aspects.

Uniform Semantics: In a distributed system the message can be passed in two ways.

Local communication

Remote communication

Whenever we are utilizing the remote procedure call system we ought to utilize 2 semantics one is at:

Client machine

Server machine both the semantics ought to be like get good communication among the process.

Efficiency: Efficiency is a critical task in the distributed message-passing system. If the event that the passing system is inter-process communication. The whole message passing system is collapsed.

Reliability: The message passing system ought to be reliable. This feature can be accomplished when the message passing system is following the right convention. Generally, the communication link failures may interrupt the communication cycle. A reliable IPC protocol can manage failure issues and guarantee of delivery of a message.

Correctness: A message-passing system ought to confirm the clients regardless of whether they are the right clients.If the right client isn’t found delivery of the message will become celled and again send the status to the sender.

Flexibility: The message passing system should be flexible for the different services like general SMS, file transfer, audio, and video sharing, and so on.

Security: A good message passing system must also be capable to provide secure end-to-end communication. to provide the security we ought to utilize the following:

Authentication system

Encryption system

Decryption system

Portability: The message passing system ought to be portable itself.

1. Synchronous Message Passing

Synchronous message passing is a communication mechanism in existing programming where processes or threads change messages in a synchronous manner. The sender blocks until the receiver has received and processed the message, ensuring coordination and predictable execution. This approach is generally enforced through blocking method calls or procedure invocations, where a process or thread blocks until the called system returns a result or completes its prosecution. This blocking behavior ensures that the caller waits until the message is processed before proceeding.