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| 1 | +/* |
| 2 | +Simulating the physical memory and its paging process |
| 3 | +using the FIFO algorithm and |
| 4 | +counting the page faults |
| 5 | +*/ |
| 6 | + |
| 7 | +#include <stdio.h> |
| 8 | +#include <stdlib.h> |
| 9 | +#include <string.h> |
| 10 | + |
| 11 | + |
| 12 | +int main(int argc, char** argv) { |
| 13 | + |
| 14 | + if (argc != 4) { |
| 15 | + printf("Wrong inputs. should be 3 arguments!"); |
| 16 | + return 0; |
| 17 | + } |
| 18 | + |
| 19 | + unsigned int noPhysPages = atoi(argv[1]); |
| 20 | + unsigned int pageSize = atoi(argv[2]); |
| 21 | + char* fileName = argv[3]; |
| 22 | + unsigned int front = 0, rear = 0, count = 0; |
| 23 | + unsigned int pageFaults = 0; |
| 24 | + unsigned int address, page; |
| 25 | + unsigned int references = 0; |
| 26 | + |
| 27 | + if (noPhysPages == 0 || pageSize == 0) { |
| 28 | + printf("page size or no physical pages cant be 0!"); |
| 29 | + return 0; |
| 30 | + } |
| 31 | + |
| 32 | + printf("No physical pages = %u, page size = %u\n", noPhysPages, pageSize); |
| 33 | + printf("Reading memory trace from %s... \n", fileName); |
| 34 | + |
| 35 | + FILE* fp = fopen(fileName, "r"); |
| 36 | + |
| 37 | + unsigned int* queue = malloc(noPhysPages * sizeof(unsigned int)); |
| 38 | + |
| 39 | + while (fscanf(fp, "%u", &address) != EOF) { |
| 40 | + page = address / pageSize; |
| 41 | + int found = 0; |
| 42 | + |
| 43 | + for (unsigned int i = 0; i < count; i++) { |
| 44 | + unsigned int idx = (front + i) % noPhysPages; |
| 45 | + if (queue[idx] == page) { |
| 46 | + found = 1; |
| 47 | + break; |
| 48 | + } |
| 49 | + } |
| 50 | + |
| 51 | + if (!found) { |
| 52 | + pageFaults++; |
| 53 | + if (count < noPhysPages) { |
| 54 | + // Queue not full, add page at rear |
| 55 | + queue[rear] = page; |
| 56 | + rear = (rear + 1) % noPhysPages; |
| 57 | + count++; |
| 58 | + } else { |
| 59 | + // Queue full, replace the oldest page at front |
| 60 | + queue[front] = page; |
| 61 | + front = (front + 1) % noPhysPages; |
| 62 | + rear = (rear + 1) % noPhysPages; |
| 63 | + } |
| 64 | + } |
| 65 | + references++; |
| 66 | + } |
| 67 | + fclose(fp); |
| 68 | + |
| 69 | + printf("Read %u memory references\n", references); |
| 70 | + printf("Result: %u page faults\n", pageFaults); |
| 71 | + |
| 72 | + free(queue); |
| 73 | + return EXIT_SUCCESS; |
| 74 | +} |
| 75 | + |
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