/* Insert the block before the root */
static inline void insert_first(void *bp) {
size_t asize = GET_SIZE(GET_HEADER(bp));
/* root block adress for class size of asize */
char *bclassp = get_class_ptr_by_bsize(asize);
dbg_printf("bclassp = 0x%lx\n", (size_t)bclassp);
char *rootbp = GET_CLASS_ROOT_BLK(bclassp);
if (rootbp == NULL) {
SET_PRED(bp, NULL);
SET_SUCC(bp, NULL);
}
else {
SET_SUCC(bp, rootbp);
SET_PRED(bp, NULL);
SET_PRED(rootbp, bp);
}
rootbp = bp;
SET_CLASS_ROOT_BLK(bclassp, rootbp);
}
static inline void split_free_block(void *bp, void *nextbp) {
if (!GET_SUCC_BLK(bp)) {
SET_SUCC(nextbp, NULL);
}
else {
SET_SUCC(nextbp, GET_SUCC_BLK(bp));
SET_PRED(GET_SUCC_BLK(bp), nextbp);
}
SET_SUCC(bp, nextbp);
SET_PRED(nextbp, bp);
}
static void remove_block(void *bp, size_t size)
{
//printf ("remove block\n");
REQUIRES ( bp != NULL );
REQUIRES ( (size_t)(bp) % 8 == 0);
int offset = get_offset(size);
void *pred = get_pred(bp);
void *succ = get_succ(bp);
if ( pred == NULL && succ != NULL)
//block to be removed is the first block in the list
{
SET_SUCC(bp) = 0;
SET_PRED(succ) = 0;
SET_ROOT(GET_BUCKET(root, offset)) = (long)succ;
}
else if (pred != NULL && succ == NULL)
//block to be removed is the last block in the list
{
SET_SUCC(pred) = 0;
SET_PRED(bp) = 0;
}
else if (pred != NULL && succ != NULL)
//block to be removed is located somewhere within the list.
{
SET_SUCC(pred) = (int)( (long)succ - BASE);
SET_PRED(succ) = (int)((long)pred - BASE);
SET_PRED(bp) = 0;
SET_SUCC(bp) = 0;
}
else if ( pred == NULL && succ == NULL)
{
//printf("resetting root\n");
SET_ROOT(GET_BUCKET(root, offset)) = 0;
}
print_list();
return;
}
/* Equals to remove a node from linked list */
static inline void remove_free_block(void *bp, int class_idx) {
char *bclassp = GET_CLASS(class_idx);
char *rootbp = GET_CLASS_ROOT_BLK(bclassp);
if (!bp) {
dbg_printf("Trying to remove NULL\n");
exit(1);
}
if (!GET_PRED_BLK(bp) && !GET_SUCC_BLK(bp)) {
rootbp = NULL;
SET_CLASS_ROOT_BLK(bclassp, rootbp);
}
/* has pred, no succ */
if (GET_PRED_BLK(bp) && !GET_SUCC_BLK(bp)) {
SET_SUCC(GET_PRED_BLK(bp), NULL);
}
/* has succ, no pred */
if (!GET_PRED_BLK(bp) && GET_SUCC_BLK(bp)) {
rootbp = GET_SUCC_BLK(bp);
SET_PRED(rootbp, NULL);
SET_CLASS_ROOT_BLK(bclassp, rootbp);
}
if (GET_PRED_BLK(bp) && GET_SUCC_BLK(bp)) {
SET_SUCC(GET_PRED_BLK(bp), GET_SUCC_BLK(bp));
SET_PRED(GET_SUCC_BLK(bp), GET_PRED_BLK(bp));
}
SET_PRED(bp, NULL);
SET_SUCC(bp, NULL);
}
static void add_block(void *bp, size_t size)
{
// printf ("in add block\n");
REQUIRES ( bp != NULL ) ;
REQUIRES ((size_t)(bp) % 8 == 0);
int offset = get_offset(size);
if ( (*(long*)GET_BUCKET(root, offset) != 0))
{
//printf ("replacing root\n");
SET_PRED((void*)(*(long*)GET_BUCKET(root, offset))) =
(int)( (long)bp -BASE );
}
int val = (int)(*(long*)GET_BUCKET(root,offset) - BASE);
//printf ("val = 0x%x \n",val);
SET_SUCC(bp) = val;
SET_PRED(bp) = 0;
SET_ROOT(GET_BUCKET(root, offset)) = (long)bp;
//print_list();
//printf("returned from adding block\n");
return;
}
static void *extend_heap(int words) {
/* last block of heap, size = 0, alloc = 1 */
char *epilogue = (mem_heap_hi() + 1);
char *bp; /* block pointer */
int bsize; /* block size to extend */
size_t flag = 0;
/* Allocate even number of words to maintain alignment */
bsize = (words % 2) ? ((words + 1) * WSIZE) : (words * WSIZE);
dbg_printf("EXTEND_HEAD: words = %d bszie = %d\n", words, bsize);
dbg_printf("!!!!!!!!!!!!!!!!!!!!!!!!Before Extend!!!!\n");
mm_checkheap(CHECK_HEAP);
/* Record if last block is allocated or not */
flag = GET_PREV_ALLOC(GET_HEADER(epilogue)) ? 0x2 : 0x0;
if ((long)(bp = mem_sbrk(bsize)) == -1)
return NULL;
/* Init free block header/footer and the epilogue header */
PUT(GET_HEADER(bp), PACK(bsize, flag));
PUT(GET_FOOTER(bp), PACK(bsize, flag));
/* Set epilogue to be size = 0, alloc = 1 */
PUT(GET_HEADER(NEXT_BLKP(bp)), PACK(0, 1));
SET_PRED(bp, NULL);
SET_SUCC(bp, NULL);
mm_checkheap(CHECK_HEAP);
return coalesce(bp);
}