Question 1

What is a Real-Time System?

Accepted Answer

A real time process is a process that must respond to the eventswithin a certain time period A real time operating system is an operating system that can run realtime processes successfully

Question 2

What are the various components of a computer system?

Accepted Answer

1The hardware 2The operating system 3The application programs 4The users

Question 3

What are system calls?

Accepted Answer

System calls provide the interface between a process and the operating system System calls for modern Microsoft windows platforms are part of the win32 API, which is available for all the compilers written for Microsoft windows

Question 4

What are various scheduling queues?

Accepted Answer

Job queue Ready queue Device queue

Question 5

What are java threads?

Accepted Answer

Java is one of the small number of languages that support at the language level for the creation and management of threads However, because threads are managed by the java virtual machine (JVM), not by a user-level library or kernel, it is difficult to classify Java threads as either user- or kernel-level

Question 6

What are types of threads?

Accepted Answer

User thread Kernel thread

Question 7

What is a deadlock?

Accepted Answer

Deadlock is a situation where a group of processes are all blocked and none of them can become unblocked until one of the other becomes unblocked The simplest deadlock is two processes each of which is waiting for a message from the other

Question 8

What is mutex?

Accepted Answer

Mutex is a program object that allows multiple program threads to share the same resource, such as file access, but not simultaneously When a program is started a mutex is created woth a unique name After this stage, any thread that needs the resource must lock the mutex from other threads while it is using the resource the mutex is set to unlock when the data is no longer needed or the routine is finished

Question 9

What is Marshalling?

Accepted Answer

The process of packaging and sending interface method parameters across thread or process boundaries

Question 10

What is dual-mode operation?

Accepted Answer

In order to protect the operating systems and the system programs from the malfunctioning programs the two mode operations were evolved System mode User mode

Question 11

What are the different types of Real-Time Scheduling?

Accepted Answer

Hard real-time systems required to complete a critical task within a guaranteed amount of time Soft real-time computing requires that critical processes receive priority over less fortunate ones

Question 12

What is relative path and absolute path?

Accepted Answer

Absolute path-- Exact path from root directory Relative path-- Relative to the current path

Question 13

What is fragmentation?

Accepted Answer

Fragmentation occurs in a dynamic memory allocation system when many of the free blocks are too small to satisfy any request

Question 14

What is context switching?

Accepted Answer

Transferring the control from one process to other process requires saving the state of the old process and loading the saved state for new process This task is known as context switching

Question 15

What is DRAM? In which form does it store data?

Accepted Answer

DRAM is not the best, but it’s cheap, does the job, and is available almost everywhere you look DRAM data resides in a cell made of a capacitor and a transistor The capacitor tends to lose data unless it’s recharged every couple of milliseconds, and this recharging tends to slow down the performance of DRAM compared to speedier RAM types

Question 16

What is the state of the processor, when a process is waiting for some event to occur?

Accepted Answer

Waiting state

Question 17

What is the difference between Primary storage and secondary storage?

Accepted Answer

Main memory - only large storage media that the CPU can access directly Secondary storage - extension of main memory that provides large nonvolatile storage capacity

Question 18

What is process synchronization?

Accepted Answer

A situation, where several processes access and manipulate the same data concurrently and the outcome of the execution depends on the particular order in which the access takes place, is called race condition To guard against the race condition we need to ensure that only one process at a time can be manipulating the same data The technique we use for this is called process synchronization

Question 19

What is the difference between Compiler and Interpreter?

Accepted Answer

An interpreter reads one instruction at a time and carries out the actions implied by that instruction It does not perform any translation But a compiler translates the entire instructions

Question 20

What are the different functions of Scheduler?

Accepted Answer

Scheduler deals with the problem of deciding which of the process in the ready queue is to be allocated the CPU Short Term Schedulers, Long Term Schedulers

Operating Systems Questions