mm.h

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/*
 *  The contents of this file are subject to the Mozilla Public License
 *  Version 1.0 (the "License"); you may not use this file except in
 *  compliance with the License. You may obtain a copy of the License
 *  at http://www.mozilla.org/MPL/
 *
 *  Software distributed under the License is distributed on an "AS IS"
 *  basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 *  the License for the specific language governing rights and
 *  limitations under the License.
 *
 *  The Original Code is legOS code, released October 17, 1999.
 *
 *  The Initial Developer of the Original Code is Markus L. Noga.
 *  Portions created by Markus L. Noga are Copyright (C) 1999
 *  Markus L. Noga. All Rights Reserved.
 *
 *  Contributor(s): Markus L. Noga <markus@noga.de>
 */

#ifndef __sys_mm_h__
#define __sys_mm_h__

#ifdef  __cplusplus
extern "C" {
#endif

#include <config.h>

#ifdef CONF_MM

#include <mem.h>
#include <stdlib.h>


//
// Definitions
//

#define MM_FREE         0x0000                  
#define MM_RESERVED     0xffff                  

// as data generally nees to be word aligned, 1 unit ^= 2 bytes
//

#define MM_HEADER_SIZE  2                       
#define MM_SPLIT_THRESH (MM_HEADER_SIZE+8)      

extern size_t mm_start;                         

extern size_t* mm_first_free;                   

// Macros for mm_init()
// Always alternate FREE and RESERVED.
//


#define MM_BLOCK_FREE(addr)                                     \
        next=(size_t*)(addr);                                   \
        *current=((((size_t)next)-(size_t)current)-2)>>1;       \
        *(next++)=MM_FREE;                                      \
        current=next;



#define MM_BLOCK_RESERVED(addr)                                 \
        next=(size_t*)(((size_t)addr)-4);                       \
        *current=((((size_t)next)-(size_t)current)-2)>>1;       \
        *(next++)=MM_RESERVED;                                  \
        current=next;


//
// Functions
//

extern void mm_init();

extern void mm_reaper();

extern int mm_free_mem(void);

#endif  // CONF_MM

#ifdef  __cplusplus
}
#endif

#endif  // __sys_mm_h__

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