include » sys

mm.h File Reference

Internal Interface: memory management. More...

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

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Defines

#define MM_FREE   0x0000
 marker: block free
#define MM_RESERVED   0xffff
 marker: block reserved
#define MM_HEADER_SIZE   2
 2 words header: pid, size
#define MM_SPLIT_THRESH   (MM_HEADER_SIZE+8)
 split off if 8+ data bytes
#define MM_BLOCK_FREE(addr)
 memory from addr on can be allocated
#define MM_BLOCK_RESERVED(addr)
 memory from addr on is reserved

Functions

void mm_init ()
 initialize memory management
void mm_reaper ()
 free all blocks allocated by the current process
int mm_free_mem (void)
 how many bytes of memory are free?

Variables

size_t mm_start
 end of kernel code + data
size_t * mm_first_free
 ptr to first free block.

Detailed Description

Internal Interface: memory management.

Author:
Markus L. Noga <markus@noga.de>

Definition in file mm.h.

Define Documentation

#define MM_BLOCK_FREE ( addr   ) 

Value:

next=(size_t*)(addr);                                   \
        *current=((((size_t)next)-(size_t)current)-2)>>1;       \
        *(next++)=MM_FREE;                                      \
        current=next;
memory from addr on can be allocated

Macro for mm_init(). Always alternate MM_BLOCK_FREE and MM_BLOCK_RESERVED.

Definition at line 68 of file mm.h.

#define MM_BLOCK_RESERVED ( addr   ) 

Value:

next=(size_t*)(((size_t)addr)-4);                       \
        *current=((((size_t)next)-(size_t)current)-2)>>1;       \
        *(next++)=MM_RESERVED;                                  \
        current=next;
memory from addr on is reserved

Macro for mm_init(). Always alternate MM_BLOCK_FREE and MM_BLOCK_RESERVED.

Definition at line 79 of file mm.h.

#define MM_FREE   0x0000

marker: block free

Definition at line 47 of file mm.h.

#define MM_HEADER_SIZE   2

2 words header: pid, size

Definition at line 53 of file mm.h.

#define MM_RESERVED   0xffff

marker: block reserved

Definition at line 48 of file mm.h.

#define MM_SPLIT_THRESH   (MM_HEADER_SIZE+8)

split off if 8+ data bytes

Definition at line 54 of file mm.h.

Function Documentation

int mm_free_mem ( void   ) 

how many bytes of memory are free?

void mm_init (  ) 

initialize memory management

Referenced by kmain().

void mm_reaper (  ) 

free all blocks allocated by the current process

Variable Documentation

size_t* mm_first_free

ptr to first free block.

size_t mm_start

end of kernel code + data

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Original code copyright 1998-2005 by the authors.
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