Lockpick_RCM/source/mem/heap.c
2019-10-25 11:41:30 -06:00

125 lines
2.6 KiB
C

/*
* Copyright (c) 2018 naehrwert
* Copyright (c) 2018 M4xw
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <string.h>
#include "heap.h"
#include "../../common/common_heap.h"
static void _heap_create(heap_t *heap, u32 start)
{
heap->start = start;
heap->first = NULL;
}
static u32 _heap_alloc(heap_t *heap, u32 size, u32 alignment)
{
hnode_t *node, *new;
int search = 1;
size = ALIGN(size, alignment);
if (!heap->first)
{
node = (hnode_t *)heap->start;
node->used = 1;
node->size = size;
node->prev = NULL;
node->next = NULL;
heap->first = node;
return (u32)node + sizeof(hnode_t);
}
node = heap->first;
while (search)
{
if (!node->used && size + sizeof(hnode_t) < node->size)
{
new = (hnode_t *)((u32)node + sizeof(hnode_t) + size);
new->size = node->size - sizeof(hnode_t) - size;
node->size = size;
node->used = 1;
new->used = 0;
new->next = node->next;
new->next->prev = new;
new->prev = node;
node->next = new;
return (u32)node + sizeof(hnode_t);
}
if (node->next)
node = node->next;
else
search = 0;
}
new = (hnode_t *)((u32)node + sizeof(hnode_t) + node->size);
new->used = 1;
new->size = size;
new->prev = node;
new->next = NULL;
node->next = new;
return (u32)new + sizeof(hnode_t);
}
static void _heap_free(heap_t *heap, u32 addr)
{
hnode_t *node = (hnode_t *)(addr - sizeof(hnode_t));
node->used = 0;
node = heap->first;
while (node)
{
if (!node->used)
{
if (node->prev && !node->prev->used)
{
node->prev->size += node->size + sizeof(hnode_t);
node->prev->next = node->next;
if (node->next)
node->next->prev = node->prev;
}
}
node = node->next;
}
}
heap_t _heap;
void heap_init(u32 base)
{
_heap_create(&_heap, base);
}
void *malloc(u32 size)
{
return (void *)_heap_alloc(&_heap, size, sizeof(hnode_t));
}
void *calloc(u32 num, u32 size)
{
void *res = (void *)_heap_alloc(&_heap, num * size, sizeof(hnode_t));
memset(res, 0, num * size);
return res;
}
void free(void *buf)
{
if ((u32)buf >= _heap.start)
_heap_free(&_heap, (u32)buf);
}