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/*
* Project: S.Ha.R.K.
*
* Coordinators:
* Giorgio Buttazzo <giorgio@sssup.it>
* Paolo Gai <pj@gandalf.sssup.it>
*
* Authors :
* Paolo Gai <pj@gandalf.sssup.it>
* (see the web pages for full authors list)
*
* ReTiS Lab (Scuola Superiore S.Anna - Pisa - Italy)
*
* http://www.sssup.it
* http://retis.sssup.it
* http://shark.sssup.it
*/
/**
------------
CVS : $Id: free.c,v 1.1.1.1 2002-03-29 14:12:52 pj Exp $
File: $File$
Revision: $Revision: 1.1.1.1 $
Last update: $Date: 2002-03-29 14:12:52 $
------------
this code is from:
List-based Memory Management, from OsKit.
**/
/*
* Copyright (C) 2000 Paolo Gai
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
/*
* Copyright (c) 1995, 1998-1999 University of Utah and the Flux Group.
* All rights reserved.
*
* This file is part of the Flux OSKit. The OSKit is free software, also known
* as "open source;" you can redistribute it and/or modify it under the terms
* of the GNU General Public License (GPL), version 2, as published by the Free
* Software Foundation (FSF). To explore alternate licensing terms, contact
* the University of Utah at csl-dist@cs.utah.edu or +1-801-585-3271.
*
* The OSKit 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 GPL for more details. You should have
* received a copy of the GPL along with the OSKit; see the file COPYING. If
* not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
*/
#include <kernel/lmm.h>
#define assert(test) assertk(test)
void lmm_free
(lmm_t
*lmm
, void *block
, size_t size
)
{
struct lmm_region
*reg
;
struct lmm_node
*node
= (struct lmm_node
*)
((DWORD
)block
& ~ALIGN_MASK
);
struct lmm_node
*prevnode
, *nextnode
;
assert(lmm
!= 0);
assert(block
!= 0);
assert(size
> 0);
size
= (((DWORD
)block
& ALIGN_MASK
) + size
+ ALIGN_MASK
)
& ~ALIGN_MASK
;
/* First find the region to add this block to. */
for (reg
= lmm
->regions
; ; reg
= reg
->next
)
{
assert(reg
!= 0);
CHECKREGPTR
(reg
);
if (((DWORD
)node
>= reg
->min
)
&& ((DWORD
)node
< reg
->max
))
break;
}
/* Record the newly freed space in the region's free space counter. */
reg
->free += size
;
assert(reg
->free <= reg
->max
- reg
->min
);
/* Now find the location in that region's free list
at which to add the node. */
for (prevnode
= 0, nextnode
= reg
->nodes
;
(nextnode
!= 0) && (nextnode
< node
);
prevnode
= nextnode
, nextnode
= nextnode
->next
);
/* Coalesce the new free chunk into the previous chunk if possible. */
if ((prevnode
) &&
((DWORD
)prevnode
+ prevnode
->size
>= (DWORD
)node
))
{
assert((DWORD
)prevnode
+ prevnode
->size
== (DWORD
)node
);
/* Coalesce prevnode with nextnode if possible. */
if (((DWORD
)nextnode
)
&& ((DWORD
)node
+ size
>= (DWORD
)nextnode
))
{
assert((DWORD
)node
+ size
== (DWORD
)nextnode
);
prevnode
->size
+= size
+ nextnode
->size
;
prevnode
->next
= nextnode
->next
;
}
else
{
/* Not possible -
just grow prevnode around newly freed memory. */
prevnode
->size
+= size
;
}
}
else
{
/* Insert the new node into the free list. */
if (prevnode
)
prevnode
->next
= node
;
else
reg
->nodes
= node
;
/* Try coalescing the new node with the nextnode. */
if ((nextnode
) &&
(DWORD
)node
+ size
>= (DWORD
)nextnode
)
{
node
->size
= size
+ nextnode
->size
;
node
->next
= nextnode
->next
;
}
else
{
node
->size
= size
;
node
->next
= nextnode
;
}
}
}