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feat: malloc multi zones and large blocks

This commit is contained in:
gbrochar 2025-07-11 14:21:25 +02:00
parent 8b7d7ca958
commit 912064ae31
5 changed files with 157 additions and 64 deletions
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2
inc/malloc.h
View File

@ -29,7 +29,9 @@ typedef struct s_zones {
size_t pagesize;
size_t max_align;
size_t tiny_block_max_size;
size_t tiny_zone_size;
size_t small_block_max_size;
size_t small_zone_size;
t_zone *tiny_zones;
t_zone *small_zones;
t_block *large_blocks;

19
main.c
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@ -1,16 +1,15 @@
#include <stdlib.h>
#include "inc/malloc.h"
int main(void) {
int *arr = ft_malloc(42);
printf ("addr of arr is : %p\n", arr);
arr = realloc(arr, 42);
int *arr2 = ft_malloc(124);
int *arr3 = ft_malloc(1540);
printf ("addr of arr is : %p\n", arr);
printf ("addr of arr2 is : %p\n", arr2);
printf ("addr of arr3 is : %p\n", arr3);
free(arr);
int main(int argc, char **argv) {
srand(argv[1][0]+argv[1][1]+argv[1][2]);
int *arr;
size_t size;
for (int i = 0; i < atoi(argv[2]); i++) {
size = (rand() & 0x7ff) | 0xf00000;
arr = (int *)ft_malloc(size * sizeof(int));
printf ("arr %d addr: %p arr size: %zu\n", i, arr, size);
}
show_alloc_sizes();
return 0;
}

7
src/init.c
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@ -5,16 +5,18 @@ t_zones g_zones;
void init_tiny_zones(void) {
g_zones.tiny_block_max_size = g_zones.pagesize / 2;
g_zones.tiny_zone_size = g_zones.tiny_block_max_size * 128;
// TODO protect mmap
g_zones.tiny_zones = (t_zone *)mmap(NULL, g_zones.tiny_block_max_size * 128, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
g_zones.tiny_zones = (t_zone *)mmap(NULL, g_zones.tiny_zone_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
g_zones.tiny_zones->head = NULL;
g_zones.tiny_zones->next = NULL;
}
void init_small_zones(void) {
g_zones.small_block_max_size = g_zones.tiny_block_max_size * 128;
g_zones.small_zone_size = g_zones.small_block_max_size * 128;
// TODO protect mmap
g_zones.small_zones = (t_zone *)mmap(NULL, g_zones.small_block_max_size * 128, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
g_zones.small_zones = (t_zone *)mmap(NULL, g_zones.small_zone_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
g_zones.small_zones->head = NULL;
g_zones.small_zones->next = NULL;
}
@ -25,5 +27,6 @@ static void init_malloc(void) {
g_zones.max_align = MAX_ALIGNMENT;
init_tiny_zones();
init_small_zones();
g_zones.large_blocks = NULL;
}

191
src/malloc.c
View File

@ -1,78 +1,167 @@
#include "malloc.h"
t_zone *create_new_tiny_zone(void) {
t_zone *zone;
// TODO protect mmap
zone = (t_zone *)mmap(NULL, g_zones.tiny_zone_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
zone->head = NULL;
zone->next = NULL;
return zone;
}
void *malloc_tiny(size_t size) {
// TODO check if zone still has size and expand zone if needed
t_block **head = &(g_zones.tiny_zones->head);
if (*head == NULL) {
// TODO size_t should be replaced by char * for pointer arithmetic
size_t addr = ((size_t)g_zones.tiny_zones + sizeof(t_zone));
printf("addr %zu\n", addr);
if ((addr + sizeof(t_block)) % 16 != 0) {
addr += 16 - ((addr + sizeof(t_block)) % 16);
t_zone *zone = g_zones.tiny_zones;
while (1) {
t_block *curr = zone->head;
if (curr == NULL) {
// TODO size_t should be replaced by char * for pointer arithmetic
size_t addr = ((size_t)zone + sizeof(t_zone));
if ((addr + sizeof(t_block)) % 16 != 0) {
addr += 16 - ((addr + sizeof(t_block)) % 16);
}
zone->head = (t_block *)addr;
curr = zone->head;
printf("addr of g_zones.tiny_zones : %p\n"
"addr of zone : %p\n"
"addr of *head %p\n"
"sizeof tzone : %zu\n"
"size of tblock %zu\n",
g_zones.tiny_zones,
zone,
curr,
sizeof(t_zone),
sizeof(t_block));
curr->size = size;
curr->free = 0;
curr->next = NULL;
return (void *)((char *)(curr) + sizeof(t_block));
}
else {
while (curr->next) {
// todo check if free and defrag
curr = curr->next;
}
// TODO size_t should be replaced by char * for pointer arithmetic
size_t addr = (size_t)curr + sizeof(t_block) + curr->size;
if ((addr + sizeof(t_block)) % 16 != 0) {
addr += 16 - ((addr + sizeof(t_block)) % 16);
}
if (((size_t)zone + g_zones.tiny_zone_size) - addr >= size + sizeof(t_block) + (16 - sizeof(t_block) % 16))
{
curr->next = (t_block *)addr;
curr = curr->next;
curr->size = size;
curr->free = 0;
curr->next = NULL;
return (void *)((char *)curr + sizeof(t_block));
}
if (zone->next == NULL) {
zone->next = create_new_tiny_zone();
}
zone = zone->next;
}
printf("addr %zu\n", addr);
*head = (t_block *)addr;
printf("addr of g_zones.tiny_zones : %p\n \
addr of *head %p\n \
sizeof tzone : %zu\n \
size of tblock %zu\n",
g_zones.tiny_zones,
*head,
sizeof(t_zone),
sizeof(t_block));
(*head)->size = size;
(*head)->free = 0;
(*head)->next = NULL;
return (void *)((char *)(*head) + sizeof(t_block));
}
else {
t_block *curr = *head;
while (curr->next) {
// todo check if free and defrag
curr = curr->next;
return NULL;
}
t_zone *create_new_small_zone(void) {
t_zone *zone;
// TODO protect mmap
zone = (t_zone *)mmap(NULL, g_zones.small_zone_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
zone->head = NULL;
zone->next = NULL;
return zone;
}
void *malloc_small(size_t size) {
t_zone *zone = g_zones.small_zones;
while (1) {
t_block *curr = zone->head;
if (curr == NULL) {
// TODO size_t should be replaced by char * for pointer arithmetic
size_t addr = ((size_t)zone + sizeof(t_zone));
if ((addr + sizeof(t_block)) % 16 != 0) {
addr += 16 - ((addr + sizeof(t_block)) % 16);
}
zone->head = (t_block *)addr;
curr = zone->head;
printf("addr of g_zones.small_zones : %p\n"
"addr of zone : %p\n"
"addr of *head %p\n"
"sizeof tzone : %zu\n"
"size of tblock %zu\n",
g_zones.small_zones,
zone,
curr,
sizeof(t_zone),
sizeof(t_block));
curr->size = size;
curr->free = 0;
curr->next = NULL;
return (void *)((char *)(curr) + sizeof(t_block));
}
printf("addr of curr %p\n \
curr->size %zu\n", curr, curr->size);
// TODO size_t should be replaced by char * for pointer arithmetic
size_t addr = (size_t)curr + sizeof(t_block) + curr->size;
printf("addr %zu\n", addr);
if ((addr + sizeof(t_block)) % 16 != 0) {
addr += 16 - ((addr + sizeof(t_block)) % 16);
else {
while (curr->next) {
// todo check if free and defrag
curr = curr->next;
}
// TODO size_t should be replaced by char * for pointer arithmetic
size_t addr = (size_t)curr + sizeof(t_block) + curr->size;
if ((addr + sizeof(t_block)) % 16 != 0) {
addr += 16 - ((addr + sizeof(t_block)) % 16);
}
if (((size_t)zone + g_zones.small_zone_size) - addr >= size + sizeof(t_block) + (16 - sizeof(t_block) % 16))
{
curr->next = (t_block *)addr;
curr = curr->next;
curr->size = size;
curr->free = 0;
curr->next = NULL;
return (void *)((char *)curr + sizeof(t_block));
}
if (zone->next == NULL) {
zone->next = create_new_small_zone();
}
zone = zone->next;
}
printf("addr %zu\n", addr);
curr->next = (t_block *)addr;
curr = curr->next;
printf("addr of curr %p\n", curr);
}
return NULL;
}
void *malloc_large(size_t size) {
t_block *curr = g_zones.large_blocks;
if (curr == NULL) {
// TODO protect mmap
curr = (t_block *)((char *)mmap(NULL, size + sizeof(t_block) + (16 - sizeof(t_block) % 16), PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0) + (16 - sizeof(t_block) % 16));
curr->size = size;
curr->free = 0;
curr->next = NULL;
return (void *)((char *)curr + sizeof(t_block));
}
return NULL;
}
void *malloc_small(size_t size) {
(void)size;
return NULL;
}
void *malloc_large(size_t size) {
(void)size;
return NULL;
while (curr->next) {
curr = curr->next;
}
// TODO protect mmap
curr->next = (t_block *)((char *)mmap(NULL, size + sizeof(t_block) + (16 - sizeof(t_block) % 16), PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0) + (16 - sizeof(t_block) % 16));
curr = curr->next;
curr->size = size;
curr->free = 0;
curr->next = NULL;
return (void *)((char *)curr + sizeof(t_block));
}
void *ft_malloc(size_t size) {
pthread_mutex_lock(&g_malloc_mutex);
void *ptr = NULL;
if (size < g_zones.tiny_block_max_size) {
printf("entering malloc_tiny\n");
ptr = malloc_tiny(size);
} else if (size < g_zones.small_block_max_size) {
ptr = malloc_small(size);
} else {
ptr = malloc_large(size);
}
write(1, "42 from malloc\n", 15);
pthread_mutex_unlock(&g_malloc_mutex);
return ptr;
}

2
test.sh
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@ -1,4 +1,4 @@
#!/bin/sh
make
gcc main.c libft_malloc.so -o malloc_test.out
LD_LIBRARY_PATH=. LD_PRELOAD=./libft_malloc.so ./malloc_test.out
LD_LIBRARY_PATH=. LD_PRELOAD=./libft_malloc.so ./malloc_test.out $1 $2