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implement heap_alloc

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mykola2312 2022-05-24 20:54:19 +03:00
parent b1222ef8df
commit 758409b454
1 changed files with 43 additions and 1 deletions
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44
heap.c
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@ -15,6 +15,7 @@ typedef struct {
#define MBLOCK_ALLOCATED (1<<0)
#define MBLOCK_SIZE(size) ((size) & ~MBLOCK_ALLOCATED)
#define MBLOCK_ALIGN 3
void heap_init(mheap_t* heap, void* start, unsigned int size)
{
@ -50,8 +51,49 @@ void heap_join(mblock_t* block, mblock_t* other)
}
}
mblock_t* heap_alloc(mheap_t* heap, unsigned int _size)
{
unsigned int size = cu_round2_up(_size + sizeof(mblock_t), MBLOCK_ALIGN);
mblock_t* block = (mblock_t*)((uint8_t*)heap->start);
mblock_t* end = (mblock_t*)((uint8_t*)heap->start + heap->size);
while ((block->size & MBLOCK_ALLOCATED) || MBLOCK_SIZE(block->size) < size)
{
block = (mblock_t*)((uint8_t*)block + MBLOCK_SIZE(block->size));
if (block >= end) return NULL;
}
if (block->size > size)
{
heap_split(block, size);
}
block->size |= MBLOCK_ALLOCATED;
return block;
}
static void heap_debug(mheap_t* heap)
{
mblock_t* block = (mblock_t*)((uint8_t*)heap->start);
mblock_t* end = (mblock_t*)((uint8_t*)heap->start + heap->size);
printf("heap\t%p\t%p\n", block, end);
while (block < end && MBLOCK_SIZE(block->size))
{
printf("block\t%p\t%u\n", block, block->size);
block = (mblock_t*)((uint8_t*)block + MBLOCK_SIZE(block->size));
}
}
static uint8_t internal_heap[4096] = {0};
int main()
{
printf("mblock_t\t%u\n", sizeof(mblock_t));
mheap_t heap;
heap_init(&heap, internal_heap, sizeof(internal_heap));
printf("heap_alloc\t%p\n", heap_alloc(&heap, 8));
printf("heap_alloc\t%p\n", heap_alloc(&heap, 8));
heap_debug(&heap);
return 0;
}