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34 lines
568 B
C
34 lines
568 B
C
/*
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* K&R Malloc
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*
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* System specifc code should implement `more_core'
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*/
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#include "k_r_malloc.h"
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#include <stdlib.h>
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#include <string.h>
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void *
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realloc(void *ptr, size_t size)
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{
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Header *bp;
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void *new_ptr;
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size_t old_size;
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if (ptr == NULL)
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return malloc(size);
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bp = (Header *) ptr - 1; /* point to block header */
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old_size = sizeof(Header) * bp->s.size;
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new_ptr = malloc(size);
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if (new_ptr == NULL) {
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return NULL;
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}
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if (old_size <= size) {
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memcpy(new_ptr, ptr, old_size);
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} else {
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memcpy(new_ptr, ptr, size);
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}
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free(ptr);
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return new_ptr;
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}
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