/*Removing a block from the free list either due to allocation or during coalascing*/
static void remove_list(void *bp){
if (GET_PREVP(bp))
SET_NEXTP(GET_PREVP(bp), GET_NEXTP(bp));
else
list_head = GET_NEXTP(bp);
SET_PREVP(GET_NEXTP(bp), GET_PREVP(bp));
}
/**
* add_free_list_lifo - add the specific block ptr to the free list, making it
* the first element in the list(LIFO).
* @param bp Pointer to the block being added to the list
*/
static void *add_free_list_lifo(void *bp)
{
int list_no ;
/*Coalesce the block*/
bp = coalesce_block(bp);
list_no = get_list_no(GET_SIZE(HDRP(bp)));
if ( GET_SEGI(seg_list,list_no) == NULL) {
SET_PREVP(bp, NULL);
SET_NEXTP(bp, NULL);
} else if ( GET_SEGI(seg_list,list_no) != NULL) {
SET_NEXTP(bp,GET_SEGI(seg_list,list_no));
SET_PREVP(bp,NULL);
SET_PREVP(GET_SEGI(seg_list,list_no),bp);
}
/*Point next of bp to where root node was pointing*/
/*Make root to point to new node*/
SET_SEGI(seg_list, list_no, bp);
return bp;
}
/**
* delete_free_list - Delete a block from the free seg list
* @param bp block to be deleted from free list
*/
static inline void delete_free_list(void *bp)
{
int list_no = get_list_no(GET_SIZE(HDRP(bp)));
temp++;
void *next = GET_NEXTP(bp);
void *prev = GET_PREVP(bp);
/*Handle corner case of deleting head node.*/
if(bp == GET_SEGI(seg_list, list_no) ) {
SET_SEGI(seg_list, list_no, next);
}
if(prev != NULL) {
SET_NEXTP(prev, next);
}
if(next != NULL) {
SET_PREVP(next, prev);
}
/*Clean Up task. Set next/prev pointers of bp to NULL*/
SET_NEXTP(bp,NULL);
SET_PREVP(bp,NULL);
}
/**
* Initialize the memory manager.
* @param - void no parameter passed in
* @return - int 0 for success or -1 for failure
*/
int
mm_init(void)
{
/* Create the initial empty heap. */
if ((heap_listp = mem_sbrk(8*WSIZE)) == (void *)-1)
return -1;
PUT(heap_listp, 0); /* Alignment padding */
PUT(heap_listp + (1 * WSIZE), PACK(DSIZE, 1)); /* Prologue header */
PUT(heap_listp + (2 * WSIZE), PACK(DSIZE, 1)); /* Prologue footer */
PUT(heap_listp + (3 * WSIZE), PACK(0, 1)); /* Epilogue header */
list_head = heap_listp + 3*WSIZE;
SET_NEXTP(list_head, NULL); /*setting next pointer to null*/
/* Extend the empty heap with a free block of minimum possible block size */
if (extend_heap(CHUNKSIZE / WSIZE) == NULL){
return -1;
}
return 0;
}
/*Inserting a free block into the free list*/
static void insert_list(void *bp){
SET_NEXTP(bp, list_head);
SET_PREVP(list_head, bp);
SET_PREVP(bp, NULL);
list_head = bp;
}
