mmemalign.c
1.69 KB
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/* Copyright (C) 1991, 1992 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include "mmprivate.h"
PTR
mmemalign (md, alignment, size)
PTR md;
size_t alignment;
size_t size;
{
PTR result;
unsigned long int adj;
struct alignlist *l;
struct mdesc *mdp;
if ((result = mmalloc (md, size + alignment - 1)) != NULL)
{
adj = RESIDUAL (result, alignment);
if (adj != 0)
{
mdp = MD_TO_MDP (md);
for (l = mdp -> aligned_blocks; l != NULL; l = l -> next)
{
if (l -> aligned == NULL)
{
/* This slot is free. Use it. */
break;
}
}
if (l == NULL)
{
l = (struct alignlist *) mmalloc (md, sizeof (struct alignlist));
if (l == NULL)
{
mfree (md, result);
return (NULL);
}
l -> next = mdp -> aligned_blocks;
mdp -> aligned_blocks = l;
}
l -> exact = result;
result = l -> aligned = (char *) result + alignment - adj;
}
}
return (result);
}