/*
* add_block - add a block to the list in order of address
*/
static void add_block(void *bp) {
int list = get_list(GET_SIZE(HDRP(bp)));
void *next = free_lists[list];
while (next != LIST_END) {
/* Insert bp in middle of list, or beginning if prev(next) is NULL */
if (next > bp) {
if (GET_PREV_FREE(next) == LIST_END)
free_lists[list] = bp; /* Update list head */
else
SET_NEXT_FREE(GET_PREV_FREE(next), bp);
SET_PREV_FREE(bp, GET_PREV_FREE(next));
SET_PREV_FREE(next, bp);
SET_NEXT_FREE(bp, next);
return;
/* Reached end of list, add bp to the end using saved block */
} else if (GET_NEXT_FREE(next) == LIST_END) {
SET_PREV_FREE(bp, next);
SET_NEXT_FREE(next, bp);
SET_NEXT_FREE(bp, LIST_END);
return;
}
next = GET_NEXT_FREE(next);
}
/* Edge case: list is empty, add bp */
SET_PREV_FREE(bp, LIST_END);
SET_NEXT_FREE(bp, LIST_END);
free_lists[list] = bp;
}
/*
* delete_block - delete a block from the free list
*/
static void delete_block(void *bp) {
void *prev = GET_PREV_FREE(bp);
void *next = GET_NEXT_FREE(bp);
int list = get_list(GET_SIZE(HDRP(bp)));
/* Case 1: bp is the only block in list */
if ((prev == LIST_END) && (next == LIST_END)) {
free_lists[list] = NULL;
return;
/* Case 2: bp is the first block in the list */
} else if (prev == LIST_END) {
SET_PREV_FREE(next, LIST_END);
free_lists[list] = next;
return;
/* Case 3: bp is the last block in the list */
} else if (next == LIST_END) {
SET_NEXT_FREE(prev, LIST_END);
return;
/* Case 4: bp is in the middle of the list */
} else {
SET_NEXT_FREE(prev, next);
SET_PREV_FREE(next, prev);
return;
}
}
/*
* add_block - add a block to the front of the free list
*/
static void add_block(void *bp) {
/* Case 1: Add bp to front of list */
if (free_list != NULL) {
SET_PREV_FREE(free_list, bp);
SET_NEXT_FREE(bp, free_list);
SET_PREV_FREE(bp, LIST_END);
/* Case 2: List is empty, make bp the first block */
} else {
SET_PREV_FREE(bp, LIST_END);
SET_NEXT_FREE(bp, LIST_END);
}
free_list = bp; /* update list root */
}
/*Removes the free block pointer int the free_list*/
static void removeFromFree(void *bp){
if (GET_PREV_FREE(bp))
SET_NEXT_FREE(GET_PREV_FREE(bp), GET_NEXT_FREE(bp));
else
free_listp = GET_NEXT_FREE(bp);
SET_PREV_FREE(GET_NEXT_FREE(bp), GET_PREV_FREE(bp));
}
void addFreeBlock(void *bp) {
void *current = root;
void *temp = current;
void *previous = NULL;
while (current != NULL && bp < current) {
previous = PREV_FREE_BLKP(current);
temp = current;
current = NEXT_FREE_BLKP(current);
}
SET_PREV_FREE(bp, previous);
SET_NEXT_FREE(bp, temp);
if (previous != NULL) {
SET_NEXT_FREE(previous, bp);
} else {
root = bp;
}
if (temp != NULL) {
SET_PREV_FREE(temp, bp);
}
}
void delFreeBlock(void *bp) {
void *next = (void *) NEXT_FREE_BLKP(bp);
void *previous = (void *) PREV_FREE_BLKP(bp);
if (previous == NULL) {
root = next;
} else {
SET_NEXT_FREE(previous, next);
}
if (next != NULL) {
SET_PREV_FREE(next, previous);
}
}
/*Inserts the free block pointer int the free_list*/
static void addToFree(void *bp){
SET_NEXT_FREE(bp, free_listp);
SET_PREV_FREE(free_listp, bp);
SET_PREV_FREE(bp, NULL);
free_listp = bp;
}