Process

Question 1

Process

Answer 1

A process is basically a program in execution

Question 2

Stack

Answer 2

Stack contains the temporary data such as method/function parameters, return address and local variables

Question 3

Heap

Answer 3

This is dynamically allocated memory to a process during its run time

Question 4

Text

Answer 4

This includes the current activity represented by the value of Program Counter and the contents of the processor’s registers

Question 5

Data

Answer 5

This section contains the global and static variables

Question 6

Process States

Answer 6

• New- The process is in new state when it has just been created.<.li>
• Ready - The process is waiting to be assigned the processor by the short term scheduler.<.li>
• Running - The process instructions are being executed by the processor.<.li>
• Waiting - The process is waiting for some event such as I/O to occur.<.li>
• Terminated - The process has completed its execution.<.li>

Question 7

Process Control Block

Answer 7

A process control block is associated with each of the processes.
* Process State - This specifies the process state i.e. new, ready, running, waiting or terminated.
* Process Number - This shows the number of the particular process.
* Program Counter - This contains the address of the next instruction that needs to be executed in the process.
* Registers - This specifies the registers that are used by the process. They may include accumulators, index registers, stack pointers, general purpose registers etc.
* List of files - These are the different files that are associated with the process.

Question 8

Long Term Scheduler

Answer 8

The job scheduler or long term scheduler selects processes from the storage pool and loads them into memory for execution.

Question 9

Short Term Scheduler

Answer 9

The short term scheduler selects one of the processes from the ready queue and schedules them for execution

Question 10

Medium Term Scheduler

Answer 10

The medium term scheduler swaps out a process from main memory

Question 11

Context Switching

Answer 11

Removing a process from a CPU and scheduling another process requires saving the state of the old process and loading the state of the new process. This is known as context switching

Question 12

1. First-come, first-served (FCFS)

Answer 12

where the process is executed on a first-come, first-served basis

Question 13

Preemptive scheduling

Answer 13

when a process transitions from a running state to a ready state or from a waiting state to a ready state.

Question 14

2. Shortest Job First (SJF

Answer 14

SJF is a proactive scheduling algorithm that selects the process with the shortest burst time.

Question 14

Non-preemptive scheduling

Answer 14

Is employed when a process terminates or transitions from running to waiting state

Question 15

3. Round Robin (RR)

Answer 15

RR is a proactive scheduling algorithm that reserves a fixed amount of time in a round for each process. If a process does not complete its execution within the specified time, it is blocked and added to the end of the queue

Question 16

4. Priority Scheduling

Answer 16

This scheduling algorithm assigns priority to each process and the process with the high priority is executed firstest

Question 17

System Calls

Answer 17

System call provides an interface between user program and operating system

Question 17

Multilevel queue

Answer 17

This scheduling algorithm divides the ready queue into several separate queues, each queue having a different priority

Question 18

Process management system calls in Linux.

Answer 18

• fork − For creating a duplicate process from the parent process.
• wait − Processes are supposed to wait for other processes to complete their work
• exec − Loads the selected program into the memory.
• exit − Terminates the process.