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#include <assert.h>
#include <stdlib.h>
#include "memalign.h"
#include "smalloc.h"
#define PTR_ALIGN(ptr, mask) \
(char *)((uintptr_t)((ptr) + (mask)) & ~(mask))
struct align_footer {
unsigned int offset;
};
void *__fio_memalign(size_t alignment, size_t size, malloc_fn fn)
{
struct align_footer *f;
void *ptr, *ret = NULL;
assert(!(alignment & (alignment - 1)));
ptr = fn(size + alignment + sizeof(*f) - 1);
if (ptr) {
ret = PTR_ALIGN(ptr, alignment - 1);
f = ret + size;
f->offset = (uintptr_t) ret - (uintptr_t) ptr;
}
return ret;
}
void __fio_memfree(void *ptr, size_t size, free_fn fn)
{
struct align_footer *f = ptr + size;
fn(ptr - f->offset);
}
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