Write a program that implements the fifo and lru page-replacement algorithms learned in class. first, generate a random page reference string where page numbers range from 0 to 9. then, apply the random page-reference string to each algorithm, and record the number of page faults incurred by each algorithm. implement the replacement algorithms so that the number of page frames can vary from 1 to 7. assume demand paging is used.

Code implemented using C++ below

Explanation:

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#include<iostream>

#include<cstdlib>

#define CYCLES 100

using namespace std;

struct page_table_entry {

int page_num;

int last_access_time;

int first_access_time;

};

int num_of_frames;

int sequence;

struct page_table_entry *page_table;

void init() {

page_table = new page_table_entry[num_of_frames];

for (int i = 0; i < num_of_frames; i++) {

page_table[i].page_num = -1;

page_table[i].first_access_time = -1;

page_table[i].last_access_time = -1;

}

sequence = 0;

}

int get_random_page() {

sequence++;

return rand() % 10;

}

int request_frame_LRU() {

for (int i = 0; i < num_of_frames; i++)

if (page_table[i].page_num == -1) {

cout << "Empty frame found at location " << i << endl;

return i;

}

int target = 0;

for (int i = 1; i < num_of_frames; i++)

if (page_table[i].last_access_time < page_table[target].last_access_time)

target = i;

cout << "target frame is " << target << ", containing page " << page_table[target].page_num << endl;

return target;

}

int request_frame_FIFO() {

for (int i = 0; i < num_of_frames; i++)

if (page_table[i].page_num == -1){

cout << "Empty frame found at location " << i << endl;

return i;

}

int target = 0;

for (int i = 1; i < num_of_frames; i++)

if (page_table[i].first_access_time < page_table[target].first_access_time)

target = i;

cout << "target frame is " << target << ", containing page " << page_table[target].page_num << endl;

return target;

}

int search_page(int page) {

for (int i = 0; i < num_of_frames; i++) {

if (page_table[i].page_num == -1)

continue;

if (page_table[i].page_num == page) {

cout << "page " << page << " found at location " << i << endl;

return i;

}

}

cout << "page " << page << " not found" << endl;

return -1;

}

void LRU() {

init();

int miss = 0;

int hit = 0;

for (int i = 0; i < CYCLES; i++) {

int page = get_random_page();

cout << "Requested page is: " << page << endl;

int location = search_page(page);

if (location > 0) {

page_table[location].last_access_time = sequence;

hit ++;

}

else {

location = request_frame_LRU();

page_table[location].page_num = page;

page_table[location].first_access_time = sequence;

page_table[location].last_access_time = sequence;

miss++;

}

cout << endl;

}

double hit_ratio = (double)hit/(hit+miss);

cout << " LRU " << endl;

cout << "hits: " << hit << endl;

cout << "misses: " << miss << endl;

cout << "hit ratio: " << hit_ratio << endl;

cout << "for frame size " << num_of_frames << endl;

cout << "" << endl << endl;

}

void FIFO() {

init();

int miss = 0;

int hit = 0;

for (int i = 0; i < CYCLES; i++) {

int page = get_random_page();

cout << "Requested page is: " << page << endl;

int location = search_page(page);

if (location > 0) {

page_table[location].last_access_time = sequence;

hit ++;

}

else {

location = request_frame_FIFO();

page_table[location].page_num = page;

page_table[location].first_access_time = sequence;

page_table[location].last_access_time = sequence;

miss++;

}

cout << endl;

}

double hit_ratio = (double)hit/(hit+miss);

cout << " FIFO " << endl;

cout << "hits: " << hit << endl;

cout << "misses: " << miss << endl;

cout << "hit ratio: " << hit_ratio << endl;

cout << "for frame size " << num_of_frames << endl;

cout << "" << endl << endl;

}

int main() {

srand(time(NULL));

num_of_frames = rand() % 7 + 1;

LRU();

FIFO();

}

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the correct answer is "part of speech" if the portion used is "verb, noun" there is another question similar to this with the same question but different portion. the other portion is "hand write" and the correct component for that question is "antonym".

hope this . : )