// vm.cpp            Dave Reed         11/20/02
//
// 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);

    int pageNum;
    while (cin >> pageNum) {  // if standard input, hit Ctrl-C to end
        if (PT.GetValid(pageNum)) {
            cout << pageNum << ": found at frame " 
                 << PT.GetFrameNumber(pageNum) << endl;
        }
        else if (PT.FreeRemaining()) {
            int frameNum = PT.GetFree();
            PT.SetFrameNumber(pageNum, frameNum);
            PT.SetValid(pageNum, true);
            cout << pageNum << ": PAGE FAULT -- added at frame " 
                 << frameNum << endl;
        }
        else {
            int oldest = PT.GetOldest();
            int frameNum = PT.GetFrameNumber(oldest);
            PT.SetFrameNumber(pageNum, frameNum);
            PT.SetValid(oldest, false);
            PT.SetValid(pageNum, true);
            cout << pageNum << ": PAGE FAULT -- replaces page " << oldest 
                 << " at frame " << frameNum << endl;
        }
    }

    return 0;
}