// **************************************************************************
// **************************************************************************
// output page table entry
void outPTE(char* s, int pte)
{
int pte1, pte2;
char flags[10];
// read pt
pte1 = memory[pte];
pte2 = memory[pte+1];
// look at appropriate flags
strcpy(flags, "-----");
if (DEFINED(pte1)) flags[0] = 'F';
if (DIRTY(pte1)) flags[1] = 'D';
if (REFERENCED(pte1)) flags[2] = 'R';
if (PINNED(pte1)) flags[3] = 'P';
if (PAGED(pte2)) flags[4] = 'S';
// output pte line
if(DEFINED(pte1) || DEFINED(pte2))
printf("\n%s x%04x = %04x %04x %s", s, pte, pte1, pte2, flags);
if (DEFINED(pte1) || DEFINED(pte2)) printf(" Frame=%d", FRAME(pte1));
if (DEFINED(pte2)) printf(" Page=%d", SWAPPAGE(pte2));
return;
} // end outPTE
int getClockFrame(int notme)
{
int frame;
// iterate through rpts (0x2400 - LC3_RPT_END)
int maxWrap = 20;
for (;maxWrap; cBigHand += 2, cLittleHand = 0) {
int i;
int rpte1;
int upta, upte1;
if (cBigHand >= LC3_RPT_END) {
DEBUG_STATEMENT(DEBUG_MMU,"\nClock is wrapping");
cBigHand = LC3_RPT;
maxWrap--;
}
rpte1 = memory[cBigHand];
if (DEFINED(rpte1) && REFERENCED(rpte1)) {
// clear reference
DEBUG_STATEMENT(DEBUG_MMU,"\nclearing ref for rpte");
memory[cBigHand] = rpte1 = CLEAR_REF(rpte1);
} else if (DEFINED(rpte1)) { // if one is non-referenced go to the user page table
// scout out the upt!! note that this has not been referenced
if (DEBUG_MMU) { outPTE("\nRPT entry being checked - ", cBigHand); }
upta = (FRAME(rpte1)<<6);
for (i = cLittleHand % 64; i < 64;i += 2, cLittleHand = i % 64) { // - iterate over userpage table
upte1 = memory[upta + (i)];
if (PINNED(upte1) || FRAME(upte1) == notme) {
DEBUG_STATEMENT(DEBUG_MMU,"\nupte1 frame was the notme frame (%x = %x) or pinned", FRAME(upte1), notme);
if (DEBUG_MMU) { outPTE("UPT entry being checked - ", upta + i); }
continue;
}
if (DEFINED(upte1) && REFERENCED(upte1)) { // - if entry is referenced un-reference and move on
// clear reference
DEBUG_STATEMENT(DEBUG_MMU,"\nclearing ref for upte %d", cLittleHand);
memory[cBigHand] = rpte1 = SET_PINNED(rpte1);
memory[upta + (i)] = upte1 = CLEAR_REF(upte1);
} else if (DEFINED(upte1)) { // - otherwise prep it for being put into swap
// we can use the frame referenced by upte1
if (DEBUG_MMU) { outPTE("UPT entry being checked - ", upta + 1); }
DEBUG_STATEMENT(DEBUG_MMU,"\nUpte1 %x, Upte2 %x", upte1, memory[upta + (i + 1)]);
memory[cBigHand] = rpte1 = SET_DIRTY(rpte1);
frame = FRAME(upte1);
swapOutFrame(upta + i);
cLittleHand += 2;
DEBUG_STATEMENT(DEBUG_MMU,"\nFound a data frame that can be used! (%d, %x)", frame, frame);
return frame;
}
}
cLittleHand = 0;
if (!REFERENCED(rpte1) && !PINNED(rpte1) && FRAME(rpte1) != notme) { // if we only replaced or did nothing to upte entries
// we can use the frame referenced by rpte1
frame = FRAME(rpte1);
DEBUG_STATEMENT(DEBUG_MMU,"\nFound a upt frame that can be used! (%d, %x)", frame, frame);
swapOutFrame(cBigHand);
cBigHand += 2;
return frame;
} else { // otherwise remove the pin flag
memory[cBigHand] = rpte1 = CLEAR_PINNED(rpte1);
}
}
} // when you get the bottom start at the top again
DEBUG_STATEMENT(DEBUG_MMU,"\n No valid frame found notme = %d", notme);
if (DEBUG_MMU) { displayTableHierarchy(); }
return -1;
}
int clockRunner(int notme)
{
//extern int curRPT;
//extern TCB tcb[MAX_TASKS];
int i,j,k;
int rpta, rpte1, rpte2;
int upta, upte1, upte2;
int victimFrame;
int tupta, tupte1;
//printf("\nClock running...%d\n",clockCount++);
//victimEntry = 0;
while (1)
{
//rpta = tcb[curRPT].RPT;
for (i = curRPTE; i < 0x3000; i+=2)
{
//rpte1 = memory[rpta + i];
//rpte2 = memory[rpta + i + 1];
rpte1 = memory[i];
rpte2 = memory[i + 1];
if (DEFINED(rpte1))
{
if (curUPTE == 0)
{
if(PINNED(rpte1))
{
//memory[rpta + i] = rpte1 = CLEAR_PINNED(rpte1);
memory[i] = rpte1 = CLEAR_PINNED(rpte1);
}
}
upta = (FRAME(rpte1)<<6);
for (j = curUPTE; j < 64; j+=2)
{
upte1 = memory[upta + j];
upte2 = memory[upta + j + 1];
if (DEFINED(upte1))
{
//memory[rpta + i] = rpte1 = SET_PINNED(rpte1);
memory[i] = rpte1 = SET_PINNED(rpte1);
if (REFERENCED(upte1))
{
memory[upta + j] = upte1 = CLEAR_REF(upte1);
}
else
{
//victimEntry = upte1;
// if end of UPT, reset upte and move to next UPT
//break; // because this is the victim
// instead of break, do swapping and return victim frame number
// immunity from notme
//if (FRAME(upte1) != notme)
//{
if (DIRTY(upte1))
{
int page;
//stat
pageWrites++;
if(PAGED(upte2))
{
page = accessPage(SWAPPAGE(upte2),FRAME(upte1),PAGE_OLD_WRITE);
}
else
{
page = accessPage(0,FRAME(upte1),PAGE_NEW_WRITE);
}
upte2 = page;
memory[upta + j + 1] = upte2 = SET_PAGED(upte2);
}
// save frame number before obliterating first word
victimFrame = FRAME(upte1);
//memory[upta + j] = upte1 = CLEAR_DEFINED(upte1);
memory[upta + j] = upte1 = 0;
curUPTE = (j + 2) % 64;
//printf("\nChose a UPT victim: %d\n",victimFrame);
return victimFrame;
//}
}
}
}
// immunity from notme
if ((FRAME(rpte1) != notme) && (!PINNED(rpte1)))
{
//victimEntry = rpte1;
// if end of RPT, reset rpte and move to next RPT
//break; // because this is the victim
// instead of break, do swapping and return victim frame number
//victimEntry = FRAME(rpte1);
// sanity check
tupta = (FRAME(rpte1)<<6);
for (k = 0; k < 64; k+=2)
{
tupte1 = memory[tupta + k];
if (DEFINED(tupte1))
printf("\nEvicting a UPT that has defined entries!!!\n");
}
//if (DIRTY(rpte1))
{
int page;
//stat
pageWrites++;
if(PAGED(rpte2))
{
page = accessPage(SWAPPAGE(rpte2),FRAME(rpte1),PAGE_OLD_WRITE);
}
else
{
page = accessPage(0,FRAME(rpte1),PAGE_NEW_WRITE);
}
rpte2 = page;
//memory[rpta + i + 1] = rpte2 = SET_PAGED(rpte2);
memory[i + 1] = rpte2 = SET_PAGED(rpte2);
}
// save frame number before obliterating first word
victimFrame = FRAME(rpte1);
//memory[rpta + i] = rpte1 = CLEAR_DEFINED(rpte1);
//memory[rpta + i] = rpte1 = 0;
memory[i] = rpte1 = 0;
//curRPTE = (i + 2) % 64;
//printf("\nChose a RPT victim: %d\n",victimFrame);
return victimFrame;
}
curUPTE = 0;
}
}
//curRPT = (curRPT + 1) % MAX_TASKS;
curRPTE = 0x2400;
}
}
