42 lines
661 B
C
42 lines
661 B
C
#include <stdlib.h>
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#include <stdint.h>
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#include <unistd.h>
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#include <string.h>
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#include "malloc.h"
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void* realloc(void *ptr, size_t size)
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{
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block_t* h;
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size_t nblocks;
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void* newptr;
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if (size == 0)
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{
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free(ptr);
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return NULL;
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}
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if (!ptr)
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return malloc(size);
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h = BLOCKOF(ptr);
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nblocks = BLOCKCOUNT(size);
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/* Overflow check. */
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if (nblocks < size)
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return NULL;
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/* Shrinking the block? Don't bother doing anything (it's never worth it). */
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if (nblocks <= h->size)
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return ptr;
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/* Allocate and copy. */
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newptr = malloc(size);
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if (!newptr)
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return NULL;
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memcpy(newptr, ptr, h->size * sizeof(block_t));
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free(ptr);
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return newptr;
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}
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