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Added core for segregated list

master
TuDatTr 2021-01-24 16:35:51 +01:00
parent 7a20a7dd86
commit 2a4dd8d48d
1 changed files with 53 additions and 17 deletions
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70
mm.c
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@ -34,6 +34,7 @@ team_t team = {
/* Second member's email address (leave blank if none) */
"tuan-dat.tran@stud.uni-due.de"
};
////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////// STRUCTURE //////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
@ -43,7 +44,7 @@ team_t team = {
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// HEADER | SIZE | A|
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// BODY | ALLOCED MEMORY |
// BP-> | ALLOCED MEMORY |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// FOOTER | SIZE | A|
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
@ -53,11 +54,11 @@ team_t team = {
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// HEADER | SIZE | A|
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | PTR TO PREV FREE BLK |
// BP-> | PTR TO PREV FREE BLK |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | PTR TO NEXT FREE BLK |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// BODY | UNALLOC MEMORY |
// | UNALLOC MEMORY |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// FOOTER | SIZE | A|
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
@ -80,6 +81,7 @@ team_t team = {
#define CHUNKSIZE (1<<12) /* Extend heap by this amount (bytes) */
#define MAX(x, y) ((x) > (y)? (x) : (y))
#define MIN(x, y) ((x) < (y)? (x) : (y))
/* Pack a size and allocated bit into a word */
#define PACK(size, alloc) ((size) | (alloc))
@ -100,12 +102,17 @@ team_t team = {
#define NEXT_BLKP(bp) ((char *)(bp) + GET_SIZE(((char *)(bp) - WSIZE)))
#define PREV_BLKP(bp) ((char *)(bp) - GET_SIZE(((char *)(bp) - DSIZE)))
#define PUT_PTR(p, ptr) (*(unsigned int *)(p) = (unsigned int)(ptr))
#define PRV_FREE(bp) ((char *)(bp))
#define NXT_FREE(bp) ((char *)(bp) + WSIZE)
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////// STATIC VARS /////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
const size_t LIST_SIZE = 100;
const size_t LISTSIZE = 11;
static char* heap_listp;
static char* seg_list[LIST_SIZE];
char* seg_list[LISTSIZE];
////////////////////////////////////////////////////////////////////////////////
///////////////////////////////// HELPER PREDEF ////////////////////////////////
@ -138,23 +145,42 @@ static void place(void *bp, size_t asize)
PUT(FTRP(bp), PACK(csize, 1));
}
}
static void* first_fit(size_t asize) {
/* First fit search */
void *bp;
for (bp = heap_listp; GET_SIZE(HDRP(bp)) > 0; bp = NEXT_BLKP(bp)) {
if (!GET_ALLOC(HDRP(bp)) && (asize <= GET_SIZE(HDRP(bp)))) {
return bp;
static int getSzClass(size_t asize) {
for (size_t i = 0; i < LISTSIZE; ++i) {
if (asize == (1 << i)) {
return i;
}
}
return NULL; /* No fit */
return LISTSIZE;
}
static void* best_fit(void* ptr, size_t asize) {
unsigned long left_over = GET_SIZE(ptr) - asize;
int c = 0;
while (NXT_FREE(ptr) != NULL) {
left_over = (MIN(left_over, GET_SIZE(ptr) - asize));
ptr = NXT_FREE(ptr);
}
return NULL;
}
/* Page 856, Pearson R. Bryant – D. O’Hallaron. Computer Systems: A Programmer’s Perspective.3rd Edition, Pearson, 2003. */
static void* find_fit(size_t asize)
{
return first_fit(asize);
int szClass = getSzClass(asize);
void* classPtr = seg_list[szClass];
if (classPtr == NULL) {
return NULL;
} else {
if (szClass != LISTSIZE -1) {
while (NXT_FREE(classPtr) != NULL) {
classPtr = NXT_FREE(classPtr);
}
return classPtr;
} else {
return best_fit(classPtr, asize);
}
}
}
/* Page 833, Pearson R. Bryant – D. O’Hallaron. Computer Systems: A Programmer’s Perspective.3rd Edition, Pearson, 2003. */
@ -190,6 +216,10 @@ static void *extend_heap(size_t words)
char *bp;
size_t size;
if (words == 0) {
return NULL;
}
/* Allocate an even number of words to maintain alignment */
size = (words % 2) ? (words+1) * WSIZE : words * WSIZE;
if ((long)(bp = mem_sbrk(size)) == -1)
@ -200,6 +230,9 @@ static void *extend_heap(size_t words)
PUT(FTRP(bp), PACK(size,0)); /* Free block footer */
PUT(HDRP(NEXT_BLKP(bp)), PACK(0, 1)); /* New epilogue header */
PUT_PTR(PRV_FREE(bp), 0);
PUT_PTR(NXT_FREE(bp), 0);
/* Coalesce if the previous block was free */
return coalesce(bp);
}
@ -213,9 +246,11 @@ static void *extend_heap(size_t words)
*/
int mm_init(void)
{
for (size_t i = 0; i < LIST_SIZE; ++i) {
// init seg_list
for (size_t i = 0; i < LISTSIZE; ++i) {
seg_list[i] = NULL;
}
/* Create the initial empty heap */
if ((heap_listp = mem_sbrk(4*WSIZE)) == (void *)-1)
return -1;
@ -250,7 +285,7 @@ void *mm_malloc(size_t size)
if (size <= DSIZE)
asize = 2*DSIZE;
else
asize = DSIZE * ((size + (DSIZE) + (DSIZE-1)) / DSIZE);
asize = ALIGN(size+DSIZE);
/* Search the free list for a fit */
if ((bp = find_fit(asize)) != NULL) {
@ -272,9 +307,10 @@ void *mm_malloc(size_t size)
*/
void mm_free(void *ptr)
{
size_t size= GET_SIZE(HDRP(ptr));
size_t size = GET_SIZE(HDRP(ptr));
PUT(HDRP(ptr), PACK(size, 0));
PUT(FTRP(ptr), PACK(size, 0));
coalesce(ptr);
}