Report Implementation of Page Replacement Algorithms FIFO - This algorithm was implemented by using the sample code provided in the lab document. The algorithm checks if the requested page is in the cache and if it is, then it sets the boolean variable foundInCache to true and breaks the for-loop. If the requested page is not found in the cache, then it prints the page at which the fault occurred, replaces the old page that is first in the queue with the new page, increments the page fault counter, and increments the counter variable to keep track of the next page in the queue. Results with accesses.txt and page size of 50: 10000 Total Memory Requests 9515 Total Page Faults Miss Rate = 0.951500 Hit Rate = 0.048500
LRU - This algorithm begins by setting the current item of the outer for-loop to be the oldest item in the queue. If the page is found, page entries that are younger than the current oldest entry have their time variable incremented (because they haven’ t been used), the boolean variable is set to true, and the time variable for the found entry is set to 0 since it was just accessed. The page entries that haven’t been used have time incremented. If the page is not found in the cache, then the oldest page in the queue is found, the page at which the fault occurred is printed, the oldest page in the queue is replaced with the new page and its time variable set to 0, and the fault counter is increased. Results with accesses.txt and page size of 50: 10000 Total Memory Requests 9510 Total Page Faults Miss Rate = 0.951000 Hit Rate = 0.049000
Second chance - This algorithm first searches for the page request and if it is found in the cache, then it sets the flag variable to 1 (to indicate the 2nd chance). f the page request is not found, the fault counter is increased and the algorithm looks for the first page entry that has its flag set to 0 (after its two chances) while keeping track of the last checked page in the queue. When the algorithm finds the next page with flag set to 0, it replaces this page with the new page, sets its flag to 0 (to indicate that it is a fresh entry), and prints the page at which the fault occurred. Results with accesses.txt and page size of 50: 10000 Total Memory Requests 9510 Total Page Faults
