💻 Operating Systems
Learn about the fundamental concepts of operating systems, including process management, memory management, file systems, and system architecture.
📚 Core Concepts
Process Management
Managing processes, threads, and CPU scheduling
Memory Management
Managing physical and virtual memory systems
File Systems
Organizing and managing data storage
Inter-Process Communication
Communication mechanisms between processes
Security & Protection
Protecting system resources and user data
⚙️ Process Management
Process vs Thread
| Feature | Process | Thread |
|---|---|---|
| Definition | Program in execution | Lightweight process within a process |
| Memory | Separate memory space | Shared memory space |
| Creation | Expensive (fork) | Inexpensive |
| Communication | IPC mechanisms needed | Direct communication possible |
🔄 CPU Scheduling Algorithms
First Come First Serve (FCFS)
Principle: Processes are executed in order of arrival
Advantages: Simple, fair
Disadvantages: Poor performance, convoy effect
Shortest Job First (SJF)
Principle: Process with shortest burst time executes first
Advantages: Optimal average waiting time
Disadvantages: Starvation, hard to predict burst time
Round Robin (RR)
Principle: Each process gets a fixed time quantum
Advantages: Fair, no starvation
Disadvantages: Overhead, depends on time quantum
🧠 Memory Management
Virtual Memory Concepts
Paging
Memory management scheme that eliminates the need for contiguous allocation of physical memory.
- Physical memory divided into frames
- Logical memory divided into pages
- Page table maps logical to physical addresses
Page Replacement
Algorithm to decide which page to replace when a page fault occurs.
- FIFO: First In First Out
- LRU: Least Recently Used
- Optimal: Replace page not used for longest time
📈 Progress Tracking
Process Management
70% CompleteMemory Management
60% CompleteFile Systems
50% CompleteSecurity & Protection
40% Complete"An operating system is a program that manages the computer hardware. It also provides a basis for application programs and acts as an intermediary between the computer user and the computer hardware." - Abraham Silberschatz