static void
check_n_pages(void)
{
struct Page* pp, *pp0;
char* addr;
int i;
pp = pp0 = 0;
// Allocate two single pages
pp = page_alloc(0);
pp0 = page_alloc(0);
assert(pp != 0);
assert(pp0 != 0);
assert(pp != pp0);
//cprintf("1");
// Free pp and assign four continuous pages
page_free(pp);
pp = page_alloc_npages(0, 4);
//cprintf("1");
assert(check_continuous(pp, 4));
//
//pps = page_realloc_npages(pps, 4, 6);
//assert(check_continuous(pps, 6));
//cprintf("s");
// Free four continuous pages
//
assert(!page_free_npages(pp, 4));
//cprintf("1");
//
//assert(!page_free_npages(pps, 6));
//cprintf("s");
// Free pp and assign eight continuous pages
pp = page_alloc_npages(0, 8);
//cprintf("1");
assert(check_continuous(pp, 8));
//cprintf("1");
// Free four continuous pages
assert(!page_free_npages(pp, 8));
//cprintf("1");
// Free pp0 and assign four continuous zero pages
page_free(pp0);
//cprintf("1");
pp0 = page_alloc_npages(ALLOC_ZERO, 4);
//cprintf("1");
addr = (char*)page2kva(pp0);
//cprintf("1");
// Check Zero
for( i = 0; i < 4 * PGSIZE; i++ ){
assert(addr[i] == 0);
}
//cprintf("1");
// Free pages
assert(!page_free_npages(pp0, 4));
cprintf("check_n_pages() succeeded!\n");
/*stone: if you want to test page_realloc_pages() function, please use this*/
//check_realloc();
}
static void
check_n_pages(void)
{
struct Page* pp, *pp0;
char* addr;
int i;
pp = pp0 = 0;
// Allocate two single pages
pp = page_alloc(0);
pp0 = page_alloc(0);
assert(pp != 0);
assert(pp0 != 0);
assert(pp != pp0);
// Free pp and assign four continuous pages
page_free(pp);
pp = page_alloc_npages(0, 4);
assert(check_continuous(pp, 4));
// Free four continuous pages
assert(!page_free_npages(pp, 4));
// Free pp and assign eight continuous pages
pp = page_alloc_npages(0, 8);
assert(check_continuous(pp, 8));
// Free four continuous pages
assert(!page_free_npages(pp, 8));
// Free pp0 and assign four continuous zero pages
page_free(pp0);
pp0 = page_alloc_npages(ALLOC_ZERO, 4);
addr = (char*)page2kva(pp0);
// Check Zero
for( i = 0; i < 4 * PGSIZE; i++ ){
assert(addr[i] == 0);
}
// Free pages
assert(!page_free_npages(pp0, 4));
cprintf("check_n_pages() succeeded!\n");
}
//
// Return new_n continuous pages based on the allocated old_n pages.
// You can man realloc for better understanding.
// (Try to reuse the allocated pages as many as possible.)
//
struct Page *
page_realloc_npages(struct Page *pp, int old_n, int new_n)
{
if (old_n == new_n)
return pp;
if (old_n > new_n)
{
page_free_npages(pp+new_n,old_n-new_n);
pp[new_n-1].pp_link = NULL;
return pp;
}
int i;
bool p = 1;
for (i = old_n; i < new_n; i++)
{
if (pp[i].pp_ref != 0)
{
p = 0;
break;
}
}
if (p == 0)
{
struct Page *newpp = page_alloc_npages(ALLOC_ZERO,new_n);
memmove(page2kva(newpp),page2kva(pp),old_n*PGSIZE);
page_free_npages(pp,old_n);
pp = newpp;
}else
{
pp[old_n-1].pp_link = pp+old_n;
struct Page *iter = page_free_list;
struct Page *lst = iter;
while (iter != NULL)
{
if (iter >= pp+old_n && iter <= pp+new_n)
{
if (iter == page_free_list)
page_free_list = iter->pp_link;
else{
lst->pp_link = iter->pp_link;
}
}else{
lst = iter;
}
iter = iter->pp_link;
}
for (i = old_n; i < new_n; i++)
{
pp[i].pp_link = pp+i+1;
}
memset(page2kva(pp+old_n),0,(new_n-old_n)*PGSIZE);
}
return pp;
}
/*stone's check-test for lab2*/
static void
check_realloc(void)
{
struct Page* pps;
pps = page_alloc_npages(0, 12);
assert(check_continuous(pps, 12));
pps = page_realloc_npages(pps, 12, 16);
assert(check_continuous(pps, 16));
assert(!page_free_npages(pps, 16));
pps = page_alloc_npages(0, 12);
pps = page_realloc_npages(pps, 12, 4);
assert(check_continuous(pps, 4));
assert(!page_free_npages(pps, 4));
pps = page_alloc_npages(0, 12);
pps = page_realloc_npages(pps, 12, 12);
assert(check_continuous(pps, 12));
assert(!page_free_npages(pps, 12));
cprintf("check_realloc() succeed!");
}
struct Page *
page_realloc_npages(struct Page *pp, int old_n, int new_n)
{
// Fill this function
//stone's solution for lab2
if (new_n <= 0) return NULL;
if (old_n <= 0) return NULL;
if (check_continuous(pp, old_n) == 0) return NULL;
if (new_n == old_n) return pp;
if (new_n < old_n){
page_free_npages(pp+new_n, old_n-new_n);
return pp;
}
//stone: when new_n > old_n ,if the tail pages is continuous, then link them directly, o.w alloc new pages.
struct Page* tmp = pp + old_n;
size_t i;
int flag = 0;
for (i = 0; i < new_n - old_n; i++){
if (tmp->pp_ref != 0){
flag = 1;
break;
}
else tmp++;
}
struct Page* result;
if (flag == 0){
result = pp + old_n - 1;
for (i = 0; i < new_n - old_n; i++){
result->pp_link = result + 1;
result++;
}
return pp;
}
else{
result = page_alloc_npages(ALLOC_ZERO, new_n);
memmove(page2kva(result), page2kva(pp), old_n*PGSIZE);
page_free_npages(pp, old_n);
pp = result;
return pp;
}
//return NULL;
}
static void
check_realloc_npages(void)
{
struct Page* pp, *pp0;
char* addr;
int i;
pp = pp0 = 0;
// Allocate two single pages
pp = page_alloc(0);
pp0 = page_alloc(0);
assert(pp != 0);
assert(pp0 != 0);
assert(pp != pp0);
// Free pp and pp0
page_free(pp);
page_free(pp0);
// Assign eight continuous pages
pp = page_alloc_npages(0, 8);
assert(check_continuous(pp, 8));
// Realloc to 4 pages
pp0 = page_realloc_npages(pp, 8, 4);
assert(pp0 == pp);
assert(check_continuous(pp, 4));
// Realloc to 6 pages
pp = page_realloc_npages(pp, 4, 6);
assert(pp0 == pp);
assert(check_continuous(pp, 6));
// Realloc to 12 pages
pp0 = page_realloc_npages(pp, 6, 12);
assert(check_continuous(pp0, 12));
// Free 12 continuous pages
assert(!page_free_npages(pp0, 12));
cprintf("check_realloc_npages() succeeded!\n");
}
//
// Return new_n continuous pages based on the allocated old_n pages.
// You can man realloc for better understanding.
// (Try to reuse the allocated pages as many as possible.)
//
struct Page *
page_realloc_npages(struct Page *pp, int old_n, int new_n)
{
// Fill this function
if (new_n == 0) {
page_free_npages(pp, old_n);
return NULL;
}
// assume pp_ref will be added by caller
// need more physical pages
if (old_n < new_n) {
uint32_t more_n = new_n - old_n;
uint32_t can_add_flag = 1;
uint32_t i = 0;
// if can add to tail?
for (i = old_n; i < new_n; i++){
// empty and not over limit
if ((pp+i)->pp_ref == 0 && pp+i < pages+npages ) {
can_add_flag = 0;
break;
}
}
// if can't add to tail, free and alloc
if (can_add_flag == 0){
struct Page* new_alloc;
new_alloc = page_alloc_npages(ALLOC_ZERO, new_n);
memmove(page2kva(new_alloc), page2kva(pp), old_n*PGSIZE);
page_free_npages(pp, old_n);
return new_alloc;
}
// if can add
// first, remove those from page_free_list
struct Page* find_pp;
while(page_free_list > pp && page_free_list <= pp+more_n) {
page_free_list = page_free_list->pp_link;
}
find_pp = page_free_list;
while(find_pp != NULL && find_pp->pp_link != NULL) {
if (find_pp->pp_link > pp && find_pp->pp_link <= pp+more_n) {
find_pp->pp_link = find_pp->pp_link->pp_link;
}
find_pp = find_pp->pp_link;
}
// second, add to old alloc page list
for (i = 0; i < more_n; i++) {
(pp+i)->pp_link = pp+i+1;
}
(pp+more_n)->pp_link = NULL;
// third, init new memory
memset(page2kva(pp+1), 0, more_n*PGSIZE);
// fourth, return pp
return pp;
} else if (old_n > new_n) {
// free last pages
page_free_npages(pp+new_n, old_n-new_n);
(pp+new_n-1)->pp_link = NULL;
return pp;
} else {
// old_n == new_n, do nothing
return pp;
}
return NULL;
}
//
// Return new_n continuous pages based on the allocated old_n pages.
// You can man realloc for better understanding.
// (Try to reuse the allocated pages as many as possible.)
//
struct Page *
page_realloc_npages(struct Page *pp, int old_n, int new_n)
{
// Fill this function
if(old_n==new_n)
return pp;
if(new_n<old_n)
{
struct Page* skip=pp;
int i;
for(i=0;i<new_n;i++)
skip=skip->pp_link;
struct Page* temp;
for(i=new_n;i<old_n;i++)
{
temp=skip;
skip=skip->pp_link;
page_free(temp);
}
return pp;
}
if(new_n>old_n)
{
struct Page* tail=pp;
int i=0;
for(i=0;i<old_n-1;i++)
tail=tail->pp_link;
struct Page* skip=page_free_list;
int found=0;int following=0;
while(skip)
{
if(page2pa(skip)-page2pa(tail)==PGSIZE)
{
found=1;
break;
}
skip=skip->pp_link;
}
if(found==1)
{
if(check_continuous(skip,new_n-old_n)==1)
following=1;
}
if(following==1)
{
struct Page* prev;
struct Page* after;
if(skip==page_free_list)
{
after=skip;
for(i=0;i<new_n-old_n;i++)
{
tail->pp_link=after;
tail=after;
after=after->pp_link;
}
tail->pp_link=NULL;
page_free_list=after;
}
else
{
prev=page_free_list;
while(prev->pp_link!=skip)
prev=prev->pp_link;
after=skip;
for(i=0;i<new_n-old_n;i++)
{
tail->pp_link=after;
tail=after;
after=after->pp_link;
}
tail->pp_link=NULL;
prev->pp_link=after;
}
return pp;
}
else
{
struct Page* allocPage=page_alloc_npages(1,new_n);
if(allocPage==NULL)
return NULL;
memmove(page2kva(allocPage),page2kva(pp),old_n*PGSIZE);
page_free_npages(pp,old_n);
return allocPage;
}
}
return NULL;
}