void BufferManager::start() {
// Clear variables
for (int i = 0; i < 2; i++) {
pages[i] = Page();
pageNums[i] = 0;
dirtied[i] = 0;
pinned[i] = 0;
}
// Load pages from disk
pageIn(0, 1);
pageIn(1, 2);
}
void simulate(mmu *m){
inst *elt, *tmp;
while (instList != NULL){
tmp = instList;
elt = popInst(tmp);
if (elt == NULL){ continue; } //invalid instruction
m->insts_N +=1;
int rw = elt->rw;
int page = elt->page;
int instN = elt->instN;
free(elt); elt =NULL; tmp = NULL;
if (algo==3){
m->mmucounter +=1;
m->cT64[page] = m->mmucounter;
//printf("==> %llu %lu\n", m->cT64[page],m->mmucounter);
}
if (isPresent(m->pageT[page])){
if (rw ==1){
modified(&(m->pageT[page]));
}
referenced(&(m->pageT[page]));
continue;
} //page present
int victim, nextFID;
if (m->frameN < numFrames){
victim = page;
nextFID = m->frameN;
}
else {
updateMMU(m, page);
victim = nextFrame(m);
nextFID = unmap(m,victim,instN);
}
pageIn(m, page, rw, instN, nextFID);
map(m, page, nextFID, instN); /* MAP */
} //while instList NOT NULL
return;
}
int BufferManager::findKey(int key) {
int checked[4] = {0, 0, 0, 0};
// Look for key in pages in memory
for (int i = 0; i < 2; i++) {
int pageNum = pageNums[i];
checked[pageNum - 1] = 1;
if (pages[i].findKey(key) != -1) { return i; }
}
// Look for key in pages on disk
for (int i = 0; i < 4; i++) {
if (checked[i] == 0) {
int pageNum = i + 1;
int index = selectVictim();
pageOut(index);
pageIn(index, pageNum);
if (pages[index].findKey(key) != -1) { return index; }
}
}
return -1;
}
