void *rt_malloc(rt_size_t size)
{
void* ptr;
/* try to allocate in system heap */
ptr = rt_memheap_alloc(&_heap, size);
if (ptr == RT_NULL)
{
struct rt_object *object;
struct rt_list_node *node;
struct rt_memheap *heap;
struct rt_object_information *information;
extern struct rt_object_information rt_object_container[];
/* try to allocate on other memory heap */
information = &rt_object_container[RT_Object_Class_MemHeap];
for (node = information->object_list.next;
node != &(information->object_list);
node = node->next)
{
object = rt_list_entry(node, struct rt_object, list);
heap = (struct rt_memheap *)object;
/* not allocate in the default system heap */
if (heap == &_heap)
continue;
ptr = rt_memheap_alloc(heap, size);
if (ptr != RT_NULL)
break;
}
}
return ptr;
}
void *rt_memheap_realloc(struct rt_memheap *heap, void *ptr, rt_size_t newsize)
{
rt_err_t result;
rt_size_t oldsize;
struct rt_memheap_item *header_ptr;
struct rt_memheap_item *new_ptr;
if (newsize == 0)
{
rt_memheap_free(ptr);
return RT_NULL;
}
/* align allocated size */
newsize = RT_ALIGN(newsize, RT_ALIGN_SIZE);
if (newsize < RT_MEMHEAP_MINIALLOC)
newsize = RT_MEMHEAP_MINIALLOC;
if (ptr == RT_NULL)
{
return rt_memheap_alloc(heap, newsize);
}
/* get memory block header and get the size of memory block */
header_ptr = (struct rt_memheap_item *)
((rt_uint8_t *)ptr - RT_MEMHEAP_SIZE);
oldsize = MEMITEM_SIZE(header_ptr);
/* re-allocate memory */
if (newsize > oldsize)
{
void* new_ptr;
struct rt_memheap_item *next_ptr;
/* lock memheap */
result = rt_sem_take(&(heap->lock), RT_WAITING_FOREVER);
if (result != RT_EOK)
{
rt_set_errno(result);
return RT_NULL;
}
next_ptr = header_ptr->next;
/* header_ptr should not be the tail */
RT_ASSERT(next_ptr > header_ptr);
/* check whether the following free space is enough to expand */
if (!RT_MEMHEAP_IS_USED(next_ptr))
{
rt_int32_t nextsize;
nextsize = MEMITEM_SIZE(next_ptr);
RT_ASSERT(next_ptr > 0);
/* Here is the ASCII art of the situation that we can make use of
* the next free node without alloc/memcpy, |*| is the control
* block:
*
* oldsize free node
* |*|-----------|*|----------------------|*|
* newsize >= minialloc
* |*|----------------|*|-----------------|*|
*/
if (nextsize + oldsize > newsize + RT_MEMHEAP_MINIALLOC)
{
/* decrement the entire free size from the available bytes count. */
heap->available_size = heap->available_size - (newsize - oldsize);
if (heap->pool_size - heap->available_size > heap->max_used_size)
heap->max_used_size = heap->pool_size - heap->available_size;
/* remove next_ptr from free list */
RT_DEBUG_LOG(RT_DEBUG_MEMHEAP,
("remove block: block[0x%08x], next_free 0x%08x, prev_free 0x%08x",
next_ptr,
next_ptr->next_free,
next_ptr->prev_free));
next_ptr->next_free->prev_free = next_ptr->prev_free;
next_ptr->prev_free->next_free = next_ptr->next_free;
next_ptr->next->prev = next_ptr->prev;
next_ptr->prev->next = next_ptr->next;
/* build a new one on the right place */
next_ptr = (struct rt_memheap_item*)((char*)ptr + newsize);
RT_DEBUG_LOG(RT_DEBUG_MEMHEAP,
("new free block: block[0x%08x] nextm[0x%08x] prevm[0x%08x]",
next_ptr,
next_ptr->next,
next_ptr->prev));
/* mark the new block as a memory block and freed. */
next_ptr->magic = RT_MEMHEAP_MAGIC;
/* put the pool pointer into the new block. */
next_ptr->pool_ptr = heap;
next_ptr->prev = header_ptr;
next_ptr->next = header_ptr->next;
header_ptr->next->prev = next_ptr;
header_ptr->next = next_ptr;
/* insert next_ptr to free list */
next_ptr->next_free = heap->free_list->next_free;
next_ptr->prev_free = heap->free_list;
heap->free_list->next_free->prev_free = next_ptr;
heap->free_list->next_free = next_ptr;
RT_DEBUG_LOG(RT_DEBUG_MEMHEAP, ("new ptr: next_free 0x%08x, prev_free 0x%08x",
next_ptr->next_free,
next_ptr->prev_free));
/* release lock */
rt_sem_release(&(heap->lock));
return ptr;
}
}
/* release lock */
rt_sem_release(&(heap->lock));
/* re-allocate a memory block */
new_ptr = (void*)rt_memheap_alloc(heap, newsize);
if (new_ptr != RT_NULL)
{
rt_memcpy(new_ptr, ptr, oldsize < newsize ? oldsize : newsize);
rt_memheap_free(ptr);
}
return new_ptr;
}
/* don't split when there is less than one node space left */
if (newsize + RT_MEMHEAP_SIZE + RT_MEMHEAP_MINIALLOC >= oldsize)
return ptr;
/* lock memheap */
result = rt_sem_take(&(heap->lock), RT_WAITING_FOREVER);
if (result != RT_EOK)
{
rt_set_errno(result);
return RT_NULL;
}
/* split the block. */
new_ptr = (struct rt_memheap_item *)
(((rt_uint8_t *)header_ptr) + newsize + RT_MEMHEAP_SIZE);
RT_DEBUG_LOG(RT_DEBUG_MEMHEAP,
("split: block[0x%08x] nextm[0x%08x] prevm[0x%08x] to new[0x%08x]\n",
header_ptr,
header_ptr->next,
header_ptr->prev,
new_ptr));
/* mark the new block as a memory block and freed. */
new_ptr->magic = RT_MEMHEAP_MAGIC;
/* put the pool pointer into the new block. */
new_ptr->pool_ptr = heap;
/* break down the block list */
new_ptr->prev = header_ptr;
new_ptr->next = header_ptr->next;
header_ptr->next->prev = new_ptr;
header_ptr->next = new_ptr;
/* determine if the block can be merged with the next neighbor. */
if (!RT_MEMHEAP_IS_USED(new_ptr->next))
{
struct rt_memheap_item *free_ptr;
/* merge block with next neighbor. */
free_ptr = new_ptr->next;
heap->available_size = heap->available_size - MEMITEM_SIZE(free_ptr);
RT_DEBUG_LOG(RT_DEBUG_MEMHEAP,
("merge: right node 0x%08x, next_free 0x%08x, prev_free 0x%08x\n",
header_ptr, header_ptr->next_free, header_ptr->prev_free));
free_ptr->next->prev = new_ptr;
new_ptr->next = free_ptr->next;
/* remove free ptr from free list */
free_ptr->next_free->prev_free = free_ptr->prev_free;
free_ptr->prev_free->next_free = free_ptr->next_free;
}
/* insert the split block to free list */
new_ptr->next_free = heap->free_list->next_free;
new_ptr->prev_free = heap->free_list;
heap->free_list->next_free->prev_free = new_ptr;
heap->free_list->next_free = new_ptr;
RT_DEBUG_LOG(RT_DEBUG_MEMHEAP, ("new free ptr: next_free 0x%08x, prev_free 0x%08x\n",
new_ptr->next_free,
new_ptr->prev_free));
/* increment the available byte count. */
heap->available_size = heap->available_size + MEMITEM_SIZE(new_ptr);
/* release lock */
rt_sem_release(&(heap->lock));
/* return the old memory block */
return ptr;
}
void *sram_malloc(unsigned long size)
{
return rt_memheap_alloc(&system_heap, size);
}
