// vm.cpp            Dave Reed         11/10/03
//
// Virtual Memory Simulator: currently uses FCFS page replacement
//////////////////////////////////////////////////////////////////

#include <iostream>
#include "PageTable.h"
using namespace std;

int main()
{
    int logSize;
    cout << "Enter number of pages in logical memory: " << endl;
    cin >> logSize;

    int physSize;
    cout << "Enter number of frames in physical memory: " << endl;
    cin >> physSize;

    PageTable PT(logSize, physSize);            // CREATE THE PAGE TABLE

    int pageNum;
    while (cin >> pageNum) {                    // REPEAT UNTIL END OF INPUT
        if (PT.AccessPage(pageNum)) {           // ATTEMPT PAGE ACCESS,
            cout << pageNum << ": found at frame "  // IF IN MEMORY, DONE
                 << PT.LocatePage(pageNum) << endl;
        }
        else if (PT.FreeFramesRemaining()) {    // ELSE IF A FRAME IS FREE
            PT.StorePage(pageNum);                  // STORE THE PAGE
            cout << pageNum << ": PAGE FAULT -- added at frame " 
                 << PT.LocatePage(pageNum)  << endl;
        }
        else {                                  // ELSE SELECT A PAGE AND
            int selected = PT.SelectSwapPage();     //  SWAP WITH THE NEW PAGE
            PT.ReplacePage(pageNum, selected);
            cout << pageNum << ": PAGE FAULT -- replaces page " << selected 
                 << " at frame " << PT.LocatePage(pageNum)  << endl;
        }
    }

    return 0;
}