1#include <stdlib.h> 2#include <assert.h> 3#include <inttypes.h> 4 5#include "memalign.h" 6 7struct align_footer { 8 unsigned int offset; 9}; 10 11#define PTR_ALIGN(ptr, mask) \ 12 (char *) (((uintptr_t) ((ptr) + (mask)) & ~(mask))) 13 14void *fio_memalign(size_t alignment, size_t size) 15{ 16 struct align_footer *f; 17 void *ptr, *ret = NULL; 18 19 assert(!(alignment & (alignment - 1))); 20 21 ptr = malloc(size + alignment + size + 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 31void fio_memfree(void *ptr, size_t size) 32{ 33 struct align_footer *f = ptr + size; 34 35 free(ptr - f->offset); 36} 37