DS notes #5

2. Communication

1. Message passing - IPC - share information.
2. Method

1. Message passing Approach.

• Sender and receiver - communicate - send and receive primitives.

2. Shared Memory Approach - info shared memory

1. Message passing approach
2. Shared memory approach

• Advantages

• Message passing - parallel computing

1. Hardware match
2. Functionality - full set of functions
3. Performance

Drawbacks

• Programmer - data distribution scheme - resolve data dependencies - avoid deadlock and race condition.

(10 marks) Desirable features of message passing system.

1. Uniform semantics

• Sender and receiver local and remote process.

2. Efficiency

• System - no.of message exchange.
• Optimization technique

• Avoid setup costs and termination.

3. Reliability

• Guarantee - message delivery
• Handle - lost and duplicate message.
• Timeout mechanism.
• Sequence number.

4. Correctness

• Atomicity
• Ordered delivery.

5. Flexibility
6. Portability
7. Security

• Secure communication
• Steps - authentication - receiver - sender
•                                    - sender - receiver
• encryption