Page Replacement Algorithms

When a new page is loaded into memory, and no free page frame left:

page replacement algorithm has to be used to select a page frame
write that selected page to the disk if the page is dirty and update any necessary tables
Read the requested page from the disk

Three page replacement algorithms are simulated here:

FIFO - First In First Out
Replace the page that has been in memory the longest
The Principle of Optimality
Replace the page that will not be used again the farthest time in the future.
LRU - Least Recently Used
Replace the page that is used least often