库实现之分配内存对齐的程序aligned_malloc和aligned_free函数

分配内存管理对齐的程序

void *aligned_malloc(int size, int alignment)

{

void *ptr = (void*)malloc(size + alignment);

if (ptr)

{

void * aligned =(void *)(((long)ptr + alignment) & (~(alignment-1)));

(void **)aligned[-1] = ptr;

return aligned;

}

return NULL;

}

释放函数aligned_free

void *aligned_free(void *paligned)

{

free(paligned);

}

关键是利用分配的内存首地址的前一地址记录内存真正分配的起始地址