💻 Operating System Concepts

📂 Topics Covered

🎯 Quick Reference

Process vs Thread

| Feature | Process | Thread | |———|———|——–| | Memory | Separate | Shared | | Creation | Heavy | Light | | Communication | IPC needed | Direct | | Crash Effect | Isolated | Affects all threads |

Process States

New → Ready → Running → Terminated
              ↓    ↑
           Waiting

CPU Scheduling Algorithms

| Algorithm | Description | |———–|————-| | FCFS | First Come First Serve | | SJF | Shortest Job First | | Round Robin | Time quantum based | | Priority | Based on priority value |

Memory Management

• Paging - Fixed size blocks
• Segmentation - Variable size blocks
• Virtual Memory - Disk as extended RAM
• Page Replacement - FIFO, LRU, Optimal

Deadlock Conditions (All 4 required)

1. Mutual Exclusion - Resource held exclusively
2. Hold and Wait - Hold one, wait for another
3. No Preemption - Can’t forcibly take resource
4. Circular Wait - Circular chain of waiting

File System

/
├── bin/    # Essential binaries
├── etc/    # Configuration files
├── home/   # User directories
├── var/    # Variable data
└── tmp/    # Temporary files

📚 Resources

• Operating System Concepts (Dinosaur Book)
• MIT OpenCourseWare - OS

Last Updated: March 2026