Interview Questions on OS - Process

1. What is a Process ?

A program under execution is process

2. What are the process states?

New: The process is being created.
Running: Instructions are being executed.
Waiting: The process is waiting for some event to occur (such as an I/O completion or reception of a signal).
Ready: The process is waiting to be assigned to a processor.
Terminated: The process has finished execution.

3. What is fork() ?

Fork() is a system call which is used to create a separate, duplicate process.

4. What is exex() ?

exex () is a system call which id used to replace the entire process.

5. What is Process Control Block?

Each process is represented in the operating system by a process control block. It contains many pieces of information associated with a specific process, including these:
1. Process state
2. Program counter
3. CPU registers
4. Memory-management information.

6. What is Context switch?

Switching the CPU to another process requires performing a state save of the current process and a state restore of a different process. This task is known as a context switch.

7. What do you know about Inter process Communication

interprocess communication (IPC) mechanism that will allow them to exchange data and information.
There are two fundamental models of interprocess communication:
1. shared memory
2. message passing

8. What is Socket?

A socket is defined as an endpoint for communication. A socket is identified by an IP address concatenated with a port number.

9. What is Remote Procedure calls?

This mechanism provides Communication of the system over the network.

10. What is Remote Method Invocation?

It is java feature to provide similar to RPC.

11. What is Critical Section problem?

Each process has a segment of code, called a critical section, in which the process may be changing common variables, updating a table, writing a file, and so on. The important feature of the system is that, when one process is executing in its critical section, no other process is to be allowed to execute in its critical section.

12. What is semaphore?

It is a flag variable which is used whether process is executing in critical section or not.

13 . What is synchronization?

Process of controlling multiple access to one resource is called synchronization.