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