42-archive/malloc/src/malloc.c

81 lines
2.4 KiB
C

/* ************************************************************************** */
/* */
/* ::: :::::::: */
/* malloc.c :+: :+: :+: */
/* +:+ +:+ +:+ */
/* By: jhalford <jack@crans.org> +#+ +:+ +#+ */
/* +#+#+#+#+#+ +#+ */
/* Created: 2017/02/17 12:28:02 by jhalford #+# #+# */
/* Updated: 2017/02/17 13:18:34 by jhalford ### ########.fr */
/* */
/* ************************************************************************** */
#include "malloc.h"
t_node *tiny_zone = NULL;
t_node *small_zone = NULL;
t_node *large_zone = NULL;
t_node *tiny_alloc = NULL;
t_node *small_alloc = NULL;
t_node *large_alloc = NULL;
t_node **find_node(t_node **node, size_t size)
{
while (*node && (size_t)(*node)->size < size + HEADER_SIZE)
node = &(*node)->next;
return (node);
}
void add_chunk(t_node **node_ref, size_t size)
{
size_t chunk_size;
while (*node_ref)
node_ref = &(*node_ref)->next;
if (LARGE(size))
chunk_size = size + HEADER_SIZE;
else
chunk_size = TINY(size) ? malloc_N : malloc_M;
*node_ref = mmap(NULL, chunk_size, PROT_READ|PROT_WRITE,
MAP_ANON|MAP_PRIVATE, -1, 0);
(*node_ref)->size = chunk_size;
(*node_ref)->next = NULL;
}
void *split_node(t_node **free, t_node **alloc, size_t size)
{
t_node *new_alloc;
int free_size;
free_size = (*free)->size;
new_alloc = *free;
*(void**)free += (size + HEADER_SIZE);
(*free)->size = free_size - (size + HEADER_SIZE);
new_alloc->size = size;
insert_node(alloc, new_alloc);
return ((void*)new_alloc + HEADER_SIZE);
}
void *malloc(size_t size)
{
t_node **zone_ref;
t_node **alloc_ref;
t_node **node_ref;
void *ptr;
printf("malloc(%zu) was called\n", size);
if (LARGE(size))
{
zone_ref = &large_zone;
alloc_ref = &large_alloc;
}
else
{
zone_ref = TINY(size) ? &tiny_zone : &small_zone;
alloc_ref = TINY(size) ? &tiny_alloc : &small_alloc;
}
while (!*(node_ref = find_node(zone_ref, size)))
add_chunk(node_ref, size);
ptr = split_node(node_ref, alloc_ref, size);
return (ptr);
}