/****************************************************************************
*
*                            Open Watcom Project
*
*    Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
*
*  ========================================================================
*
*    This file contains Original Code and/or Modifications of Original
*    Code as defined in and that are subject to the Sybase Open Watcom
*    Public License version 1.0 (the 'License'). You may not use this file
*    except in compliance with the License. BY USING THIS FILE YOU AGREE TO
*    ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is
*    provided with the Original Code and Modifications, and is also
*    available at www.sybase.com/developer/opensource.
*
*    The Original Code and all software distributed under the License are
*    distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
*    EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM
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*    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR
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*  ========================================================================
*
* Description:  WHEN YOU FIGURE OUT WHAT THIS FILE DOES, PLEASE
*               DESCRIBE IT HERE!
*
****************************************************************************/


#include "dll.h"        // needs to be first
#include "variety.h"
#include <stddef.h>
#include <malloc.h>
#include "heap.h"
#include "heapacc.h"


/* Return the amount of memory available in the near heap. */
/* Best done at start of program and after _nheapgrow() has been called. */

_WCRTLINK size_t _memavl( void )
    {
        size_t length;
        frlptr pnext;
        mheapptr mhp;

        length = 0;
        _AccessNHeap();
        for( mhp = __nheapbeg; mhp != NULL; mhp = mhp->next ) {
            pnext = mhp->freehead.next;
            while( pnext != (frlptr) &mhp->freehead ) {
                length += ( (pnext->len - TAG_SIZE) & ~ROUND_SIZE );
                pnext = pnext->next;
            }
        }
        _ReleaseNHeap();
        return( length );
    }
