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implement heap_realloc

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mykola2312 2022-05-24 21:36:52 +03:00
parent 67446040c8
commit c33f72b6af
1 changed files with 34 additions and 1 deletions
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35
heap.c
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@ -1,5 +1,6 @@
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#define cu_round2_up(val,bit) (((val>>bit) + !!(val&((1<<bit)-1)) ) << bit)
@ -82,6 +83,31 @@ void heap_free(mblock_t* block)
heap_join(block, next);
}
mblock_t* heap_realloc(mheap_t* heap, mblock_t* block, unsigned int _size)
{
block->size &= ~MBLOCK_ALLOCATED;
unsigned int size = cu_round2_up(_size, MBLOCK_ALIGN);
mblock_t* next = (mblock_t*)((uint8_t*)block + block->size);
mblock_t* new;
if (!(next->size & MBLOCK_ALLOCATED) && next->size >= size)
{
new = block;
heap_join(new, next);
heap_split(new, size);
new->size |= MBLOCK_ALLOCATED;
}
else
{
heap_free(block);
new = heap_alloc(heap, size);
if (new)
{
memcpy((uint8_t*)new + sizeof(mblock_t),
(uint8_t*)block + sizeof(mblock_t), size - sizeof(mblock_t));
}
}
return new;
}
static void heap_debug(mheap_t* heap)
{
@ -108,7 +134,14 @@ int main()
printf("heap_alloc\t%p\n", m3);
printf("heap_alloc\t%p\n", heap_alloc(&heap, 8));
heap_free(m3);
printf("heap_alloc\t%p\n", heap_alloc(&heap, 8));
m3 = heap_alloc(&heap, 8);
printf("heap_alloc\t%p\n", m3);
m3 = heap_realloc(&heap, m3, 12);
printf("heap_realloc\t%p\n", m3);
m3 = heap_realloc(&heap, m3, 8);
printf("heap_realloc\t%p\n", m3);
m3 = heap_realloc(&heap, m3, 32);
printf("heap_realloc\t%p\n", m3);
heap_debug(&heap);
return 0;