Write short notes on: (a) Concurrent Programming (b) Virus (c) Remote Procedure Call (RPC) (d) Time Sharing

(a) Concurrent Programming:

Concurrent programming involves the simultaneous execution of multiple tasks or processes within a single program. It enables efficient utilization of resources and improved performance by allowing tasks to be executed concurrently rather than sequentially.

Key Concepts:

• Concurrency: The ability of multiple tasks to execute simultaneously.
• Synchronization: The coordination of tasks to ensure correct and consistent execution.
• Mutual Exclusion: Ensuring that only one task accesses a shared resource at a time.
• Deadlock: A state where tasks wait indefinitely for each other to release resources.

Approaches to Concurrent Programming:

• Multithreading: Creating and managing multiple threads of execution within a single program.
• Multiprocessing: Utilizing multiple processors or cores to execute different tasks in parallel.
• Message Passing: Communicating between processes through the exchange of messages.

Benefits of Concurrent Programming:

• Improved Performance: Concurrent programs can leverage multiple cores and resources, resulting in faster execution times.
• Scalability: Concurrent programs can be easily scaled to handle larger workloads by adding more processors or resources.
• Responsiveness: Concurrent programs can handle multiple tasks concurrently, making them more responsive to user input or changes.

(b) Virus:

A virus is a type of malicious software program that can replicate itself and spread from one computer to another. It often attaches itself to legitimate files or programs and executes its malicious code when the host file or program is run.

Characteristics of Viruses:

• Replication: Viruses can create copies of themselves and infect other files or computers.
• 传播: Viruses can spread through various means, including email attachments, infected websites, USB drives, or malicious downloads.
• Payload: Viruses often carry a payload, which can perform various malicious activities such as stealing data, corrupting files, or disrupting system operations.