Operating Systems Key Concepts: Process States, PCB, Semaphores & Memory
Operating Systems Key Concepts: Process States, PCB, Semaphores & Memory
4. Process State & Process Control Block (PCB)
- Process States: A process cycles through: New (created) → Ready (waiting in memory) → Running (executing instructions) → Waiting/Blocked (waiting for an event/IO) → Terminated (finished execution).
- PCB Definition: A dedicated kernel data structure containing all information about a specific process.
- 5 Essential PCB Fields:
- Process State: Current condition (Ready, Running,
DBMS Fundamentals: Architecture, Data Models, and SQL Languages
1. DBMS – Introduction
Data
Data means raw facts and figures.
Example: 101, Vikas, CSE, 1st Year
Database
A database is an organized collection of related data that can be easily accessed, managed, and updated.
DBMS
DBMS (Database Management System) is software used to create, store, retrieve, update, and manage data in a database.
Examples: MySQL, Oracle, PostgreSQL, SQL Server.
Functions of DBMS
- Data storage
- Data retrieval
- Data insertion and updating
- Data security
- Backup and recovery
- Concurrency control
- Integrity
Data Link Layer: Framing, ARQ, HDLC, PPP, Channel Access and Ethernet Explained
Unit 2: Data Link Layer, Complete Notes with Solved PYQs
Your exam is today, so the ★ boxes (exam-ready answers) and the PYQ solutions come first in priority. Read the basics only if you have time.
One correction to the earlier numbers: the 1 Mbps / 20 ms question has two valid answers. The textbook method (Forouzan, which the paper’s wording follows) gives 5% and 75%. The formula Tₜ/(Tₜ+RTT) gives 4.76% and 71.4%. Write the textbook method in the exam and add the formula as a one-line remark.
Read MoreComplete JavaScript Roadmap and Topic-Wise Tutorial
JavaScript Complete Topic-Wise Explanation
1. JavaScript kya hai?
JavaScript ek programming language hai jo website ko interactive aur dynamic banati hai.
Simple example:
- HTML → Website ka structure
- CSS → Website ka design
- JavaScript → Website ka behavior/functionality
Example: Button click karne par text change karna.
Click Me
Hello
2. JavaScript ko HTML me add karna
Internal JavaScript
External JavaScript
HTML:
script.js:
console.log("Hello JavaScript");External JS real projects me commonly use hoti
Read MoreC++ Algorithms for Binary Search and Prefix Sums
C++ Competitive Programming Solutions
This document contains several C++ solutions for common algorithmic problems involving prefix sums, binary search, and matrix manipulation.
1. Prefix Sum and Lower Bound Algorithm
#include <bits/stdc++.h>
using namespace std;
int main() {
int n;
long long k;
cin >> n >> k;
vector<long long> pref(n + 1, 0);
for (int i = 1; i <= n; i++) {
long long x;
cin >> x;
pref[i] = pref[i - 1] C++ Algorithms and Binary Search Implementation Codes
C++ Binary Search and Algorithms Collection
1. Binary Search Implementation
#include <iostream>
using namespace std;
int main(){
int n;
cin >> n;
int a[100000];
for (int i = 0; i < n; i++)
cin >> a[i];
int x;
cin >> x;
int l = 0, r = n - 1;
while (l <= r) {
int m = (l + r) / 2;
if (a[m] == x) {
cout << "Yes";
return 0;
}
if (a[m] < x)
l = m + 1;