public int createTable() {
int current = machine.memoryManagement.alloc(17);
if (current == 0) return 0;
PagerHeader currentHeader = new PagerHeader(current, 0, 0);
if (first == 0) {
first = last = current;
} else {
PagerHeader ph = getHeader(last);
ph.next = current;
setHeader(ph);
last = current;
}
setHeader(currentHeader);
clearPage(current);
return current;
}
public void freePage(int adr) {
for (int i = 0; i < 16; i++) machine.memoryManagement.free(machine.ram[adr + i]);
PagerHeader ph = getHeader(adr);
PagerHeader next = null;
PagerHeader prev = null;
if (ph.next > 0) next = getHeader(ph.next);
if (ph.prev > 0) prev = getHeader(ph.prev);
if (first == last && first == adr) {
first = last = 0;
} else if (first == adr) {
first = next.adr;
next.prev = 0;
setHeader(next);
} else if (adr == last) {
last = prev.adr;
prev.next = 0;
setHeader(prev);
} else {
prev.next = next.adr;
next.prev = prev.adr;
setHeader(next);
setHeader(prev);
}
machine.memoryManagement.free(adr);
}