1 #include <assert.h>
2 #include <stdlib.h>
3
4 #include "memalign.h"
5 #include "smalloc.h"
6
7 #define PTR_ALIGN(ptr, mask) \
8 (char *)((uintptr_t)((ptr) + (mask)) & ~(mask))
9
10 struct align_footer {
11 unsigned int offset;
12 };
13
__fio_memalign(size_t alignment,size_t size,malloc_fn fn)14 void *__fio_memalign(size_t alignment, size_t size, malloc_fn fn)
15 {
16 struct align_footer *f;
17 void *ptr, *ret = NULL;
18
19 assert(!(alignment & (alignment - 1)));
20
21 ptr = fn(size + alignment + sizeof(*f) - 1);
22 if (ptr) {
23 ret = PTR_ALIGN(ptr, alignment - 1);
24 f = ret + size;
25 f->offset = (uintptr_t) ret - (uintptr_t) ptr;
26 }
27
28 return ret;
29 }
30
__fio_memfree(void * ptr,size_t size,free_fn fn)31 void __fio_memfree(void *ptr, size_t size, free_fn fn)
32 {
33 struct align_footer *f = ptr + size;
34
35 fn(ptr - f->offset);
36 }
37