//TODO: should return the frame number
public void addPage(PageTableEntry pte, int step)
{
bool pageAdded = false;
int longestDeltaTime = 0;
int longestDeltaTimeIndex = 0;
int index = 0;
//see if there is an empty slot
foreach (PhysicalFrame pf in pfList)
{
int newDelta = step - pf.getStepLastModified();
if (newDelta > longestDeltaTime)
{
longestDeltaTime = newDelta;
longestDeltaTimeIndex = index;
}
if (pf.isEmpty())
{
pf.fillFrame(pte, step);
pageAdded = true;
break;
}
index++;
}
if (pageAdded)
{
return;
}
pfList[longestDeltaTimeIndex].fillFrame(pte, step);
}
//returns the location of a page table entry in the physical mem
public int inFrame(PageTableEntry pte)
{
int retVal = 0;
foreach (PhysicalFrame pf in pfList)
{
if (pf.getEntry() == pte)
{
return(retVal);
}
retVal++;
}
return(-1);
}
public void addPage(PageTableEntry pte, int step)
{
bool pageAdded = false;
int longestDeltaTime = 0;
int longestDeltaTimeIndex = 0;
int index = 0;
pte.setModified(step);
//see if there is an empty slot (LRU algorithm)
foreach (PhysicalFrame pf in pfList)
{
int newDelta = step - pf.getStepLastReferenced();
if (newDelta > longestDeltaTime)
{
longestDeltaTime = newDelta;
longestDeltaTimeIndex = index;
}
if (pf.isEmpty())
{
pageFaultCounter++;
pte.getPageTable().getOwningProcess().incrementPageFaultCounter();
pf.fillFrame(pte);
pageAdded = true;
break;
}
index++;
}
if (pageAdded)
{
return;
}
pageFaultCounter++;
pte.getPageTable().getOwningProcess().incrementPageFaultCounter();
pfList[longestDeltaTimeIndex].fillFrame(pte);
}
//fills the physical memory frame with a page
public void fillFrame(PageTableEntry _pte)
{
pte = _pte;
}
public void addPage(int frameId, int step)
{
bool added = false;
for (int x = 0; x < 16; x++)
{
//an empty valid frame was found in page table
if (entryList[x].isEmpty())
{
entryList[x].setFrame(frameId);
added = true;
pm.addPage(entryList[x], owningProcess.getPid());
break;
}
}
if (added)
{
return;
}
//a valid page wasnt found, make room for the frame in valid page
int leasedUsed = 0;
int leasedUsedIndex = 0;
int index = 0;
foreach (PageTableEntry pte in entryList)
{
//find the page which was lease recently used
int timeDelta = step - pte.getLastModified();
if (timeDelta > leasedUsed)
{
leasedUsed = timeDelta;
leasedUsedIndex = index;
}
index++;
}
//save a copy of the frame being removed in next open space
//TODO: if the frame being removed was in memory, do proper computations
for (int x = 16; x < 64; x++)
{
if (entryList[x].isEmpty())
{
//copy page info to new frame
PageTableEntry pte = entryList[x];
pte.setFrame(entryList[index].getFrame());
pte.setModified(step);
pte.setResident(false);
pte.setValid(false);
break;
}
}
//overwrite the old valid page
PageTableEntry npte = entryList[index];
npte.setFrame(frameId);
npte.setModified(step);
pm.addPage(npte, owningProcess.getPid());
}
void updateGui(int _pid, Process p)
{
DataGridView dgv = this.dgvList[_pid - 1];
List <VirtualFrame> vfl = p.getFrameList();
List <PageTableEntry> ptel = p.getPageTable().getEntryList();
List <PhysicalFrame> pfl = this.pm.getFrameList();
//virtual memory
for (int x = 0; x < LOGICAL_ADDR_SPACE; x++)
{
VirtualFrame vf = vfl[x];
if (vf.isReferenced())
{
dgv.Rows[x].Cells[1].Value = "Yes";
dgv.Rows[x].Cells[1].Style.BackColor = Color.Gray;
}
}
this.pageDataGridView.Rows.Clear();
//page table
int y = 0;
foreach (PageTableEntry pte in ptel)
{
string frame = pte.getFrame().ToString();
string valid = "Y";
string resident = "Y";
string secondary = pte.getSecondary().ToString();
if (pte.getFrame() == -1)
{
frame = "";
}
if (pte.getSecondary() == -1)
{
secondary = "";
}
if (!pte.isValid())
{
valid = "N";
}
if (y < 16)
{
if (!pte.isResident())
{
resident = "N";
}
}
else
{
resident = "-";
}
this.pageDataGridView.Rows.Add(frame, valid, resident, secondary);
y++;
}
this.pageGroupBox.Text = "Page Table (P" + _pid + ")";
//physical memory
for (int x = 0; x < PHY_MEM_SIZE; x++)
{
if (!pfl[x].isEmpty())
{
PageTableEntry pteInMem = pfl[x].getEntry();
int framePID = pteInMem.getOwnerPID();
int pageTableFrame = pteInMem.getFrame();
this.phyDataGridView.Rows[x].Cells[1].Value = "Frame: " + pageTableFrame;
this.phyDataGridView.Rows[x].Cells[1].Style.BackColor = getColorForPID(framePID);
}
}
}
public void fillFrame(PageTableEntry _pte, int _stepLastModified)
{
empty = false;
pte = _pte;
stepLastModified = _stepLastModified;
}
void updateGui(int _pid)
{
this.pageFaultLabel.Text = "Page faults: " + pm.getFaultCounter()
+ " (P1: " + processList[1].getPageFaultCounter() + " |"
+ " P2: " + processList[2].getPageFaultCounter() + " |"
+ " P3: " + processList[3].getPageFaultCounter() + " |"
+ " P4: " + processList[4].getPageFaultCounter() + " |"
+ " P5: " + processList[5].getPageFaultCounter() + ")";
//update the VM data grid views
for (int z = 0; z < PROCESS_NUM; z++)
{
DataGridView dgv = this.dgvList[z];
for (int x = 0; x < LOGICAL_ADDR_SPACE; x++)
{
List <VirtualFrame> vfl = processList[z + 1].getFrameList();
VirtualFrame vf = vfl[x];
if (vf.isReferenced())
{
dgv.Rows[x].Cells[1].Value = "Yes";
dgv.Rows[x].Cells[1].Style.BackColor = Color.Gray;
}
}
}
//update each page table data grid view
int y = 0;
foreach (DataGridView dgv in this.pageDVGList)
{
List <PageTableEntry> ptel = this.processList[y + 1].getPageTable().getEntryList();
int ptIndex = 0;
foreach (PageTableEntry pte in ptel)
{
string frame = pte.getFrame().ToString();
string valid = "Y";
string resident = "Y";
if (pte.getFrame() == -1)
{
frame = "";
valid = "";
resident = "";
}
else
{
if (!pte.isValid())
{
valid = "N";
}
if (!pte.isResident())
{
resident = "N";
}
dgv[0, ptIndex].Value = frame;
dgv[1, ptIndex].Value = valid;
dgv[2, ptIndex].Value = resident;
}
ptIndex++;
}
y++;
}
//update physical memory data grid view
List <PhysicalFrame> pfl = this.pm.getFrameList();
for (int x = 0; x < PHY_MEM_SIZE; x++)
{
if (!pfl[x].isEmpty())
{
PageTableEntry pteInMem = pfl[x].getEntry();
int framePID = pteInMem.getOwnerPID();
int pageTableFrame = pteInMem.getFrame();
this.phyDataGridView.Rows[x].Cells[1].Value = pteInMem.getLastModified().ToString();
this.phyDataGridView.Rows[x].Cells[1].Style.BackColor = getColorForPID(framePID);
}
}
}
public void removePage(PageTableEntry pte)
{
}
