README.md

Smart Memory Manager for Browser Tabs

Operating Systems Project | Page Replacement Simulation

---

Languages & Tools

---

Project Analysis

This project simulates browser tab memory behavior using classic page replacement algorithms from Operating Systems.

At a high level, it has three layers:

1. Input and scenario setup
2. Replacement algorithm execution
3. Reporting and metrics visualization

Execution flow:

1. The program reads total references, reference string, and frame count.
2. You choose an algorithm from the menu: FIFO, LRU, or Optimal.
3. The selected algorithm processes references step-by-step.
4. The console prints tab openings/replacements and current memory frames.
5. A summary reports total evictions and retention efficiency.

---

What It Does

• Simulates tab replacement in constrained memory
• Supports FIFO, LRU, and Optimal algorithms
• Prints frame-by-frame state transitions
• Reports total tab evictions (page faults)
• Calculates tab retention efficiency
• Uses browser-tab names for human-friendly output

---

Features

• Interactive menu-driven terminal program
• Clean modular structure (src/ + include/)
• Browser-style page naming (Gmail, YouTube, StackOverflow, etc.)
• Reusable utility helpers for output and metrics
• Cross-platform Makefile with Windows/Linux handling
• Sample demonstration cases in data/

---

Project Structure

smart-memory-manager/
├── Makefile
├── README.md
├── data/
│   └── sample_demonstration.txt
├── docs/
│   ├── references.txt
│   ├── Smart Memory Manager for Browser Tabs.pdf
│   └── SMART MEMORY MANAGER.pdf
├── include/
│   ├── fifo.h
│   ├── lru.h
│   ├── optimal.h
│   └── utils.h
└── src/
    ├── fifo.c
    ├── lru.c
    ├── main.c
    ├── optimal.c
    └── utils.c

---

Requirements

• C compiler (gcc recommended)
• Make utility (make, mingw32-make, or equivalent)
• Git
• Terminal (PowerShell, Bash, or Zsh)

Optional tools

• Visual Studio Code for editing and debugging
• WSL/MSYS2 on Windows for smoother GNU toolchain setup

---

Clone the Repository

git clone https://github.com/Code-Crew-Nexus/smart-memory-manager.git
cd smart-memory-manager

---

Compile

Option A: GNU Make (Linux/macOS, or Windows with make installed)

make clean
make

Option B: Windows with MSYS2/MinGW (mingw32-make)

mingw32-make clean
mingw32-make

Option C: Manual compile without Makefile

gcc -Wall -Iinclude -o memory_manager src/main.c src/fifo.c src/lru.c src/optimal.c src/utils.c

On Windows, the output executable is usually memory_manager.exe.

---

Run

Windows PowerShell

.\memory_manager.exe

Linux/macOS

./memory_manager

---

Input Format

The program asks for:

1. Number of tabs in reference string (n)
2. n space-separated integers as references
3. Number of frames (tabs allowed in memory)
4. Menu choice:
   • 1 FIFO
   • 2 LRU
   • 3 Optimal
   • 4 Exit

Example input:

7
0 1 2 0 3 0 4
3
1
4

---

Page (Tab) Mapping

• 0 -> Gmail
• 1 -> YouTube
• 2 -> StackOverflow
• 3 -> Twitter
• 4 -> LinkedIn
• 5 -> GeeksforGeeks
• 6 -> Reddit
• 7 -> WhatsApp Web

Any value outside this range maps to Unknown Tab.

---

Source File Responsibilities

src/main.c

• CLI entry point
• Reads input and handles algorithm menu loop

src/fifo.c

• Implements FIFO replacement using cyclic pointer

src/lru.c

• Implements LRU replacement using last-used index tracking

src/optimal.c

• Implements Optimal replacement by checking farthest future use

src/utils.c

• Maps page numbers to tab names
• Prints frame state after each reference
• Computes/display metrics

---

Algorithm Explanation

All algorithms process the same reference stream with limited frame capacity.

FIFO

• Rule: evict the oldest loaded tab
• Complexity per reference: $O(f)$ for frame search

LRU

• Rule: evict the least recently used tab
• Tracks recency index for each frame
• Complexity per reference: $O(f)$

Optimal

• Rule: evict the tab used farthest in the future (or never used again)
• Theoretical lower bound for evictions
• Complexity per reference can be up to $O(f \cdot n)$ due to look-ahead scans

---

Output Metrics

At the end of each algorithm run:

• Total Tab Evictions (page faults)
• Tab Retention Efficiency

Formula used:

((totalPages - pageFaults) / totalPages) * 100

---

Makefile Notes

The Makefile includes optional redirection targets (fifo, lru, optimal) that refer to:

• data/ref_string1.txt
• results/ output files

If you want to use those targets, create these resources first. Otherwise use interactive mode.

---

Troubleshooting

• make not recognized on Windows

  • Use mingw32-make or install GNU Make.

• gcc not recognized

  • Install a GCC toolchain and restart terminal.

• Executable not launching in PowerShell

  • Run with ./ prefix equivalent: .\memory_manager.exe.

• Unexpected tab labels

  • Use references mainly in 0-7; others are shown as Unknown Tab.

---

Future Improvements

• Add batch input mode from file
• Add side-by-side algorithm comparison report
• Add automatic result export to results/
• Add unit tests for replacement behavior
• Add runtime complexity benchmark section

---

Contributors

This project was developed as part of the PBL initiative under Code-Crew-Nexus.

• M. Sai Krishna
• MD. Abdul Rayain
• Rishit Ghosh
• Yaram Karthik

Future contributors are welcome through issues and pull requests.