AISE
/
malloc-lab
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Perf index = 57 (util) + 40 (thru) = 97/100

master
TuDatTr 2021-01-24 20:23:57 +01:00
parent 6d390de8a2
commit b1a5273123
2 changed files with 201 additions and 158 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
Makefile
View File

@ -2,8 +2,8 @@
# Students' Makefile for the Malloc Lab
#
CC = gcc
# CFLAGS = -Wall -O2 -m32 -g03 -pg
CFLAGS = -Wall -O0 -m32 -g03 -pg
CFLAGS = -Wall -O2 -m32
# CFLAGS = -Wall -O0 -m32 -g03 -pg
OBJS = mdriver.o mm.o memlib.o fsecs.o fcyc.o clock.o ftimer.o

355
mm.c
View File

@ -89,6 +89,7 @@ team_t team = {
/* Read and write a word at address p */
#define GET(p) (*(unsigned int *)(p))
#define PUT(p, val) (*(unsigned int *)(p) = (val))
#define PUTT(p, val) (*(unsigned int *)(p) = (val))
/* Read the size and allocated fields from address p */
#define GET_SIZE(p) (GET(p) & ~0x7)
@ -121,9 +122,7 @@ char* seg_list[LISTSIZE];
///////////////////////////////// HELPER PREDEF ////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
/* Page 856-858, Pearson R. Bryant – D. O’Hallaron. Computer Systems: A Programmer’s Perspective.3rd Edition, Pearson, 2003. */
static void place(void *bp, size_t asize);
/* 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);
static void* place(void *bp, size_t asize);
/* Page 833, Pearson R. Bryant – D. O’Hallaron. Computer Systems: A Programmer’s Perspective.3rd Edition, Pearson, 2003. */
static void* coalesce(void *bp);
/* Page 831, Pearson R. Bryant – D. O’Hallaron. Computer Systems: A Programmer’s Perspective.3rd Edition, Pearson, 2003. */
@ -132,152 +131,174 @@ static void add_free(void* bp, size_t asize);
////////////////////////////////////////////////////////////////////////////////
/////////////////////////////// HELPER FUNCTIONS ///////////////////////////////
////////////////////////////////////////////////////////////////////////////////
static int getSzClass(size_t asize) {
for (size_t i = 0; i < LISTSIZE; ++i) {
if (asize == (1 << i)) {
return i;
}
}
return LISTSIZE-1;
}
static void add_free(void* ptr, size_t size)
static void *extend_heap(size_t size)
{
int szClass = getSzClass(size);
void* classPtr = seg_list[szClass];
while(classPtr != NULL)
{
classPtr = NXT_PTR(classPtr);
}
PUT_PTR(NXT_PTR(classPtr), ptr);
PUT_PTR(PRV_PTR(ptr), classPtr);
PUT_PTR(NXT_PTR(ptr), NULL);
}
static void place(void *bp, size_t asize)
{
size_t csize = GET_SIZE(HDRP(bp));
if ((csize - asize) >= (2*DSIZE)) {
PUT(HDRP(bp), PACK(asize, 1));
PUT(FTRP(bp), PACK(asize, 1));
bp = NEXT_BLKP(bp);
PUT(HDRP(bp), PACK(csize-asize, 0));
PUT(FTRP(bp), PACK(csize-asize, 0));
}
else {
PUT(HDRP(bp), PACK(csize, 1));
PUT(FTRP(bp), PACK(csize, 1));
}
}
static void remove_free(void* bp) {
int szClass = getSzClass(GET_SIZE(HDRP(bp)));
if (PRV_BLK(bp) == NULL && NXT_BLK(bp) == NULL) {
seg_list[szClass] = NULL;
} else if (PRV_BLK(bp) != NULL && NXT_BLK(bp) == NULL) {
PUT_PTR(PRV_PTR(PRV_BLK(bp)), NULL);
seg_list[szClass] = PRV_BLK(bp);
} else if (PRV_BLK(bp) == NULL && NXT_BLK(bp) != NULL) {
PUT_PTR(PRV_PTR(NXT_BLK(bp)), NULL);
} if (PRV_BLK(bp) != NULL && NXT_BLK(bp) != NULL) {
PUT_PTR(NXT_PTR(PRV_BLK(bp)), NXT_BLK(bp));
PUT_PTR(PRV_PTR(NXT_BLK(bp)), PRV_BLK(bp));
}
}
static void* best_fit(void* ptr, size_t asize) {
unsigned long left_over = GET_SIZE(ptr) - asize;
void* bestfit = ptr;
unsigned long best_left_over = GET_SIZE(ptr) - asize;
while (NXT_PTR(ptr) != NULL) {
left_over = GET_SIZE(ptr) - asize;
if(left_over<best_left_over){
best_left_over = left_over;
bestfit=ptr;
}
ptr = NXT_BLK(ptr);
}
return bestfit;
}
/* 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)
{
int szClass = getSzClass(asize);
void* classPtr = seg_list[szClass];
if (classPtr == NULL) {
void *ptr;
size_t asize; // Adjusted size
asize = ALIGN(size);
if ((ptr = mem_sbrk(asize)) == (void *)-1)
return NULL;
} else {
if (szClass != LISTSIZE -1) {
while (NXT_PTR(classPtr) != NULL) {
classPtr = NXT_BLK(classPtr);
}
return classPtr;
// Set headers and footer
PUTT(HDRP(ptr), PACK(asize, 0));
PUTT(FTRP(ptr), PACK(asize, 0));
PUTT(HDRP(NEXT_BLKP(ptr)), PACK(0, 1));
add_free(ptr, asize);
return coalesce(ptr);
}
static void add_free(void *ptr, size_t size) {
int list = 0;
void *search_ptr = ptr;
void *insert_ptr = NULL;
// Select segregated list
while ((list < LISTSIZE - 1) && (size > 1)) {
size >>= 1;
list++;
}
// Keep size ascending order and search
search_ptr = seg_list[list];
while ((search_ptr != NULL) && (size > GET_SIZE(HDRP(search_ptr)))) {
insert_ptr = search_ptr;
search_ptr = PRV_BLK(search_ptr);
}
// Set predecessor and successor
if (search_ptr != NULL) {
if (insert_ptr != NULL) {
PUT_PTR(PRV_PTR(ptr), search_ptr);
PUT_PTR(NXT_PTR(search_ptr), ptr);
PUT_PTR(NXT_PTR(ptr), insert_ptr);
PUT_PTR(PRV_PTR(insert_ptr), ptr);
} else {
return best_fit(classPtr, asize);
PUT_PTR(PRV_PTR(ptr), search_ptr);
PUT_PTR(NXT_PTR(search_ptr), ptr);
PUT_PTR(NXT_PTR(ptr), NULL);
seg_list[list] = ptr;
}
} else {
if (insert_ptr != NULL) {
PUT_PTR(PRV_PTR(ptr), NULL);
PUT_PTR(NXT_PTR(ptr), insert_ptr);
PUT_PTR(PRV_PTR(insert_ptr), ptr);
} else {
PUT_PTR(PRV_PTR(ptr), NULL);
PUT_PTR(NXT_PTR(ptr), NULL);
seg_list[list] = ptr;
}
}
return;
}
/* Page 833, Pearson R. Bryant – D. O’Hallaron. Computer Systems: A Programmer’s Perspective.3rd Edition, Pearson, 2003. */
static void *coalesce(void *bp) {
size_t prev_alloc = GET_ALLOC(FTRP(PREV_BLKP(bp)));
size_t next_alloc = GET_ALLOC(HDRP(NEXT_BLKP(bp)));
size_t size = GET_SIZE(HDRP(bp));
if (prev_alloc && next_alloc) { /* Case 1 */
return bp;
} else if (prev_alloc && !next_alloc) { /* Case 2 */
remove_free(bp);
remove_free(NEXT_BLKP(bp));
size += GET_SIZE(HDRP(NEXT_BLKP(bp)));
PUT(HDRP(bp),PACK(size,0));
PUT(FTRP(bp),PACK(size,0));
} else if (!prev_alloc && next_alloc) { /* Case 3 */
remove_free(bp);
remove_free(PREV_BLKP(bp));
size += GET_SIZE(HDRP(PREV_BLKP(bp)));
PUT(FTRP(bp), PACK(size, 0));
PUT(HDRP(PREV_BLKP(bp)), PACK(size, 0));
bp = PREV_BLKP(bp);
} else { /* Case 4 */
remove_free(bp);
remove_free(PREV_BLKP(bp));
remove_free(NEXT_BLKP(bp));
size += GET_SIZE(HDRP(PREV_BLKP(bp))) +
GET_SIZE(FTRP(NEXT_BLKP(bp)));
PUT(HDRP(PREV_BLKP(bp)), PACK(size, 0));
PUT(FTRP(NEXT_BLKP(bp)), PACK(size, 0));
bp = PREV_BLKP(bp);
static void delete_node(void *ptr) {
int list = 0;
size_t size = GET_SIZE(HDRP(ptr));
// Select segregated list
while ((list < LISTSIZE - 1) && (size > 1)) {
size >>= 1;
list++;
}
add_free(bp, size);
return bp;
if (PRV_BLK(ptr) != NULL) {
if (NXT_BLK(ptr) != NULL) {
PUT_PTR(NXT_PTR(PRV_BLK(ptr)), NXT_BLK(ptr));
PUT_PTR(PRV_PTR(NXT_BLK(ptr)), PRV_BLK(ptr));
} else {
PUT_PTR(NXT_PTR(PRV_BLK(ptr)), NULL);
seg_list[list] = PRV_BLK(ptr);
}
} else {
if (NXT_BLK(ptr) != NULL) {
PUT_PTR(PRV_PTR(NXT_BLK(ptr)), NULL);
} else {
seg_list[list] = NULL;
}
}
return;
}
/* Page 831, Pearson R. Bryant – D. O’Hallaron. Computer Systems: A Programmer’s Perspective.3rd Edition, Pearson, 2003. */
static void *extend_heap(size_t words)
static void *coalesce(void *ptr)
{
char *bp;
size_t size;
size_t prev_alloc = GET_ALLOC(HDRP(PREV_BLKP(ptr)));
size_t next_alloc = GET_ALLOC(HDRP(NEXT_BLKP(ptr)));
size_t size = GET_SIZE(HDRP(ptr));
/* Allocate an even number of words to maintain alignment */
size = (words % 2) ? (words+1) * WSIZE : words * WSIZE;
if ((long)(bp = mem_sbrk(size)) == -1)
return NULL;
if (prev_alloc && next_alloc) { // Case 1
return ptr;
}
else if (prev_alloc && !next_alloc) { // Case 2
delete_node(ptr);
delete_node(NEXT_BLKP(ptr));
size += GET_SIZE(HDRP(NEXT_BLKP(ptr)));
PUT(HDRP(ptr), PACK(size, 0));
PUT(FTRP(ptr), PACK(size, 0));
} else if (!prev_alloc && next_alloc) { // Case 3
delete_node(ptr);
delete_node(PREV_BLKP(ptr));
size += GET_SIZE(HDRP(PREV_BLKP(ptr)));
PUT(FTRP(ptr), PACK(size, 0));
PUT(HDRP(PREV_BLKP(ptr)), PACK(size, 0));
ptr = PREV_BLKP(ptr);
} else { // Case 4
delete_node(ptr);
delete_node(PREV_BLKP(ptr));
delete_node(NEXT_BLKP(ptr));
size += GET_SIZE(HDRP(PREV_BLKP(ptr))) + GET_SIZE(HDRP(NEXT_BLKP(ptr)));
PUT(HDRP(PREV_BLKP(ptr)), PACK(size, 0));
PUT(FTRP(NEXT_BLKP(ptr)), PACK(size, 0));
ptr = PREV_BLKP(ptr);
}
add_free(ptr, size);
return ptr;
}
/* Initialize free block header/footer and the epilogue header */
PUT(HDRP(bp), PACK(size,0)); /* Free block header */
PUT(FTRP(bp), PACK(size,0)); /* Free block footer */
PUT(HDRP(NEXT_BLKP(bp)), PACK(0, 1)); /* New epilogue header */
add_free(bp, size);
/* Coalesce if the previous block was free */
return coalesce(bp);
static void *place(void *ptr, size_t asize)
{
size_t ptr_size = GET_SIZE(HDRP(ptr));
size_t remainder = ptr_size - asize;
delete_node(ptr);
if (remainder <= DSIZE * 2) {
// Do not split block
PUT(HDRP(ptr), PACK(ptr_size, 1));
PUT(FTRP(ptr), PACK(ptr_size, 1));
}
else if (asize >= 100) {
// Split block
PUT(HDRP(ptr), PACK(remainder, 0));
PUT(FTRP(ptr), PACK(remainder, 0));
PUTT(HDRP(NEXT_BLKP(ptr)), PACK(asize, 1));
PUTT(FTRP(NEXT_BLKP(ptr)), PACK(asize, 1));
add_free(ptr, remainder);
return NEXT_BLKP(ptr);
}
else {
// Split block
PUT(HDRP(ptr), PACK(asize, 1));
PUT(FTRP(ptr), PACK(asize, 1));
PUTT(HDRP(NEXT_BLKP(ptr)), PACK(remainder, 0));
PUTT(FTRP(NEXT_BLKP(ptr)), PACK(remainder, 0));
add_free(NEXT_BLKP(ptr), remainder);
}
return ptr;
}
////////////////////////////////////////////////////////////////////////////////
@ -316,32 +337,54 @@ int mm_init(void)
*/
void *mm_malloc(size_t size)
{
size_t asize; /* Adjusted block size */
size_t asize; /* Adjusted block size */
size_t extendsize; /* Amount to extend heap if no fit */
char *bp; /* Pointer */
/* Ignore spurious requests */
void *ptr = NULL; /* Pointer */
// Ignore size 0 cases
if (size == 0)
return NULL;
/* Adjust block size to include overhead and alignment reqs. */
if (size <= DSIZE)
asize = 2*DSIZE;
else
// Align block size
if (size <= DSIZE) {
asize = 2 * DSIZE;
} else {
asize = ALIGN(size+DSIZE);
/* Search the free list for a fit */
if ((bp = find_fit(asize)) != NULL) {
place(bp, asize);
return bp;
}
/* No fit found. Get more memory and place the block */
extendsize = MAX(asize,CHUNKSIZE);
if ((bp = extend_heap(extendsize/WSIZE)) == NULL)
return NULL;
place(bp, asize);
return bp;
int list = 0;
size_t searchsize = asize;
// Search for free block in segregated list
while (list < LISTSIZE) {
if ((list == LISTSIZE- 1) || ((searchsize <= 1) && (seg_list[list] != NULL))) {
ptr = seg_list[list];
// Ignore blocks that are too small or marked with the reallocation bit
while ((ptr != NULL) && (asize > GET_SIZE(HDRP(ptr))))
{
ptr = PRV_BLK(ptr);
}
if (ptr != NULL)
break;
}
searchsize >>= 1;
list++;
}
// if free block is not found, extend the heap
if (ptr == NULL) {
extendsize = MAX(asize, CHUNKSIZE);
if ((ptr = extend_heap(extendsize)) == NULL)
return NULL;
}
// Place and divide block
ptr = place(ptr, asize);
// Return pointer to newly allocated block
return ptr;
}
/* Page 833, Pearson R. Bryant – D. O’Hallaron. Computer Systems: A Programmer’s Perspective.3rd Edition, Pearson, 2003. */