Operating Systems Page Replacement Algorithms

FIFO Algorithm

First In First Out page replacement algorithm simulator

Open Simulator

FIFO Simulator Details

  • Implements the First-In-First-Out page replacement algorithm
  • Replaces the oldest page in memory when a page fault occurs
  • Features:
    • Visual representation of memory frames
    • Step-by-step simulation
    • Page fault tracking
    • Performance statistics

LRU Algorithm

Least Recently Used page replacement algorithm simulator

Open Simulator

LRU Simulator Details

  • Implements the Least Recently Used page replacement algorithm
  • Replaces the page that hasn't been used for the longest time
  • Features:
    • Access time tracking for each page
    • Visual timeline of page usage
    • Page fault analysis
    • Performance comparison

LFU Algorithm

Least Frequently Used page replacement algorithm simulator

Open Simulator

LFU Simulator Details

  • Implements the Least Frequently Used page replacement algorithm
  • Replaces the page that has been used least frequently
  • Features:
    • Frequency counter for each page
    • Usage statistics visualization
    • Page fault tracking
    • Performance metrics

MFU Algorithm

Most Frequently Used page replacement algorithm simulator

Open Simulator

MFU Simulator Details

  • Implements the Most Frequently Used page replacement algorithm
  • Replaces the page that has been used most frequently
  • Features:
    • Frequency tracking for each page
    • Usage pattern visualization
    • Page fault analysis
    • Performance statistics

Second Chance

Second Chance page replacement algorithm simulator

Open Simulator

Second Chance Simulator Details

  • Implements the Second Chance page replacement algorithm
  • Gives pages a second chance before replacement
  • Features:
    • Reference bit tracking
    • Circular queue visualization
    • Page fault analysis
    • Performance comparison

Random Replacement

Random page replacement algorithm simulator

Open Simulator

Random Replacement Simulator Details

  • Implements the Random page replacement algorithm
  • Randomly selects a page for replacement
  • Features:
    • Random selection visualization
    • Page fault tracking
    • Performance analysis
    • Statistics comparison

Optimal Algorithm

Optimal page replacement algorithm simulator

Open Simulator

Optimal Simulator Details

  • Implements the Optimal page replacement algorithm
  • Replaces the page that will not be used for the longest time
  • Features:
    • Future reference prediction
    • Optimal replacement visualization
    • Page fault analysis
    • Performance metrics

Page Replacement Algorithms - Theory

Page replacement algorithms are crucial in operating systems to manage memory efficiently. When a page fault occurs and there are no free frames available, the operating system must select a page to replace. Different algorithms use different strategies to make this selection:

Key Algorithms:

Performance Metrics:

How to Use the Simulators:

  1. Click on any simulator button to open the specific algorithm's simulation
  2. Enter the reference string (comma-separated page numbers)
  3. Set the number of frames in memory
  4. Click "Simulate" to see the algorithm in action
  5. Observe the step-by-step execution and results
  6. Compare different algorithms using the same input