ft_malloc/src/malloc.c

#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) {
	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;
		}
	}
	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));
		}
		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;
		}
	}
	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));
	}
	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) {
		ptr = malloc_tiny(size);
	} else if (size < g_zones.small_block_max_size) {
		ptr = malloc_small(size);
	} else {
		ptr = malloc_large(size);
	}
	pthread_mutex_unlock(&g_malloc_mutex);
	return ptr;
}