WebSVN - shark - Rev 229 - /shark/branches/xen/ports/didma/didma.c

/*
* Doubly indexed dynamic memory allocator (DIDMA)
* Version 0.61
*
* Written by Miguel Masmano Tello <mmasmano@disca.upv.es>
* Copyright (C) Dec, 2002 OCERA Consortium
* Release under the terms of the GNU General Public License Version 2
* shark porting Trimarchi Michael
*/

#include <kernel/func.h>
#include "didma.h"
#include "queuem.h"
#include "i386/bitops.h"
#include "i386/bits.h"

#ifndef NULL
#define NULL ((void *) 0)
#endif // #ifndef NULL

#define INIT_THREAD_MUTEX()
#define THREAD_LOCK() kern_cli()
#define THREAD_UNLOCK() kern_sti()

// u8, u16, u32 are only defined in kernel headers

#define u8 char
#define u16 unsigned short int
#define u32 unsigned int

#define MAX_SL_LOG2_INDEX 5 // Real value is 2**MAX_SL_INDEX

#define MAX_SL_INDEX (1 << MAX_SL_LOG2_INDEX)

#define F_OK 0
#define F_ERROR -1

#define MIN_LOG2_SIZE 5 // 32 bytes
#define MAX_LOG2_SIZE MAX_FL_INDEX
#define MIN_SIZE (1 << MIN_LOG2_SIZE)
#define MAX_SIZE (1 << MAX_LOG2_SIZE)

#define DIDMA__set_bit(num, mem) mem |= (1 << num)
#define DIDMA__clear_bit(num, mem) mem &= ~(1 << num)

/*
* First, all necessary TADs are defined
*/

/*
* the follow TAD will be a double level indexed array, the most important
* thing is that the time is limited, it is because this dynamic memory manger
* is designed to run with real time programs.
*
* First level Second level
* it is indexed it is indexed by 2**n+(2**n/m*index_number)
* by power of 2
* 0 1 m-1 m
* ----> NULL --> NULL ----> NUL
* | | |
* ------- ---------------------...---------------------
* 2**n | n | -----> |2**n+(2**n/m*0)|...| |...|2**n+(2**n/m*m)|
* |-----| ---------------------...---------------------
* 2**n-1| n-1 | -----> .... |
* |-----| --->NULL
* .....
*/

/* DON'T TOUCH THESE MACROS */
#define MAGIC_NUMBER 0xA5A5
#define MAGIC_NUMBER_NONE 0x0000
#define BLOCK_FREE 0
#define BLOCK_USED 1

struct free_ptr_struct {
struct block_header_struct *prev;
struct block_header_struct *next;
/*
* first_l_index and second_l_index are used to store
* mapping_function results, that's how we get some extra
* nanoseconds
*/
u8 first_l_index;
u8 second_l_index;
};

typedef struct block_header_struct {
/* magic_number is the id of the block */
u16 magic_number;
/* size of the block */
size_t size;
/* state of the block can be free or used */
u8 state;

struct block_header_struct *prev;
struct block_header_struct *next;

union {
struct free_ptr_struct free_ptr;
u8 buffer[sizeof(struct free_ptr_struct)];
} ptr;
} block_header_t;

/* first level index array */
typedef struct fl_array_struct {
/* ptr is pointer to next level */
block_header_t **sl_array;
/* n_blocks is the number of the blocks which they are pointed by sl_array */
u32 bitmapSL;
} fl_array_t;

/*
* fl_array will be our first level array.
*/

static fl_array_t *fl_array;// [MAX_FL_INDEX - MIN_LOG2_SIZE];
u32 bitmapFL;
/*
* first_bh will be our first memory block allocated by MALLOC function
*/
static block_header_t *first_bh, *free_block;

static int all_ok = 0;

/*
* header_overhead has size of blocks_header - 2 * ptr to next free block
*/
static int header_overhead = 0, total_size = 0;

/*
* log2size () returns cell of log2 (len)
* it does a search between MIN_SIZE and MAX_SIZE values
*/
static int log2size(size_t size, size_t *new_size)
{
int i;

if (size <= 0) {
PRINT_MSG ("ERROR: Chunk length must be > 0\n");
return F_ERROR;
}

// MIN_SIZE and MAX_SIZE must be defined

if (size <= MIN_SIZE){
*new_size = MIN_SIZE;
return MIN_LOG2_SIZE;
}

for (i = MIN_LOG2_SIZE;
(i <= MAX_LOG2_SIZE) && (size > (*new_size = (1 << i))) ; i++);

if (i > MAX_LOG2_SIZE) {
PRINT_MSG ("ERROR: Maximum chunk size exceeded\n");
return F_ERROR;
}

return i;
}

/*
* caculate_reserve () returns the size that has to be reservate for
* avoid fragmentation
*/

#define MAX(a, b) (a>b)?a:b

/*
May be calculate_reserve can be improved
*/

static inline int calculate_reserve (int size){
// int internal_frag, dummy;

// header_overhead = (int) first_bh -> ptr.buffer - (int) first_bh;

//internal_frag = (1 << log2size(size, &dummy)) / MAX_SL_INDEX;

//dummy = MAX((header_overhead * size / MAX_SL_INDEX) + internal_frag, size);

return size;//(size + dummy);

}

/*
* mapping_function () returns first and second level index
*
* first level index function is:
* fl = log2 (size)
*
* and second level index function is:
* sl = (size - 2**(log2size (size))) / (log2 (size) - log2 (MAX_SL_INDEX))
*
*/
static int mapping_function (size_t size, int *fl, int *sl){
int aux;
int new_len;

// first level = log2 (size)
*fl = log2size (size, &new_len);

if (new_len == size) {
// if 2**fl == size, second level must be 0
*sl = 0;
} else {
-- *fl;
aux = *fl - MAX_SL_LOG2_INDEX;
*sl = (int)((size - (new_len >> 1)) >> aux);
}

*fl -= MIN_LOG2_SIZE;
return F_OK;
}

/*
* init_TAD () initialize the structure fl_array to NULL
* and free_block with the initial blocks pointed by ptr
*
* its cost is O (n x m)
*/
static int init_TAD (size_t size, u8 *ptr){
int n, aux, dummy;
if (!(size > 0)) {
PRINT_MSG ("ERROR: size must be > 0\n");
return F_ERROR;
}
if (MAX_SL_INDEX > MIN_SIZE) {
PRINT_MSG ("ERROR: MAX_SL_INDEX must be < MIN_SIZE\n");
return F_ERROR;
}

total_size = size;

MAX_FL_INDEX = log2size(size, &dummy);

if (MAX_FL_INDEX < 0) return -1;
fl_array = (fl_array_t *) SYSTEM_MALLOC ((MAX_FL_INDEX - MIN_LOG2_SIZE)
* sizeof(fl_array_t));
if (fl_array == NULL) return -1;
_init_malloc_ (20);
for (n = 0; n < MAX_FL_INDEX - MIN_LOG2_SIZE; n++) {
fl_array [n].bitmapSL = 0;
aux = (1 << (n + MIN_LOG2_SIZE));
fl_array[n].sl_array = NULL;
}
bitmapFL = 0;

header_overhead = (int) first_bh -> ptr.buffer - (int) first_bh;
first_bh = (block_header_t *) ptr;

first_bh -> magic_number = MAGIC_NUMBER;
first_bh -> size = size - header_overhead;
first_bh -> state = BLOCK_FREE;
first_bh -> prev = NULL;
first_bh -> next = NULL;
first_bh -> ptr.free_ptr.prev = NULL;
first_bh -> ptr.free_ptr.next = NULL;

free_block = first_bh;
//mapping_function (first_bh->size,&n, &m);
//fl_array[n].sl_array[m].ptr= first_bh;
//DIDMA__set_bit (m, fl_array[n].bitmapSL);
//DIDMA__set_bit (n, bitmapFL);
all_ok = 1;
return F_OK;
}

/*
* destroy_TAD return a pointer to the initial block
*/
static void *destroy_TAD (void){
all_ok = 0;
_destroy_malloc_();
return (void *) first_bh;
}

/*
* insert_TAD merge a free block pointed by ptr
* with its buddies and then
* insert it into fl_array
*
* The cost of this operation is
* always O (K) = (1)
*/
static int insert_TAD (u8 *ptr){
int fl, sl;
block_header_t *bh = NULL, *bh2;
int for_free_block = 0;

if (!all_ok) return F_ERROR;

bh = (block_header_t *) (ptr - header_overhead);
if (bh -> magic_number != MAGIC_NUMBER)
return F_ERROR;

THREAD_LOCK();
/*
* now bh is a free block
*/
bh -> state = BLOCK_FREE;
bh -> ptr.free_ptr.prev = NULL;
bh -> ptr.free_ptr.next = NULL;

/*
* first bh will be merge with its free buddies and
* then it will be inserted with the free blocks
*/
/*
* it is used to know if bh have to be inserted into free_block or
* into fl_array
*/
if (bh -> next == NULL) for_free_block = 1;

/* is it free the follow block? */
if (bh -> next != NULL) {
bh2 = bh -> next;

if (bh2 -> magic_number == MAGIC_NUMBER &&
bh2 -> state == BLOCK_FREE) {
/* we are lucky, we can merge bh with the next block */

if (bh2 == free_block) for_free_block = 1;
bh2 -> magic_number = MAGIC_NUMBER_NONE;
if (bh2 -> next != NULL)
bh2 -> next -> prev = bh;
if (!for_free_block) {
if (bh2 -> ptr.free_ptr.next != NULL)
bh2 -> ptr.free_ptr.next -> ptr.free_ptr.prev =
bh2 -> ptr.free_ptr.prev;

if (bh2 -> ptr.free_ptr.prev != NULL)
bh2 -> ptr.free_ptr.prev -> ptr.free_ptr.next =
bh2 -> ptr.free_ptr.next;
//mapping_function (bh2 -> size, &fl, &sl);
fl = bh2 -> ptr.free_ptr.first_l_index;
sl = bh2 -> ptr.free_ptr.second_l_index;
/* bh2 must be erased from fl_array */
if (fl_array [fl].sl_array [sl] == bh2)
fl_array [fl].sl_array [sl] = bh2 -> ptr.free_ptr.next;

//fl_array [fl].n_blocks --;
if (fl_array [fl].sl_array [sl] == NULL){
//fl_array[fl].bitmapSL &= ~(1 << sl);
DIDMA__clear_bit (sl, fl_array[fl].bitmapSL);
if (!fl_array[fl].bitmapSL) {
_free_ ((void *) fl_array [fl].sl_array);
DIDMA__clear_bit (fl, bitmapFL);
}
}
}
bh -> size += bh2 -> size + header_overhead;
bh -> next = bh2 -> next;
}
}

/* is it free the previous block? */
if (bh -> prev != NULL) {
bh2 = bh -> prev;
if (bh2 -> magic_number == MAGIC_NUMBER &&
bh2 -> state == BLOCK_FREE) {
bh -> magic_number = MAGIC_NUMBER_NONE;

if (bh -> next != NULL)
bh -> next -> prev = bh2;

if (bh2 -> ptr.free_ptr.next != NULL)
bh2 -> ptr.free_ptr.next -> ptr.free_ptr.prev =
bh2 -> ptr.free_ptr.prev;

if (bh2 -> ptr.free_ptr.prev != NULL)
bh2 -> ptr.free_ptr.prev -> ptr.free_ptr.next =
bh2 -> ptr.free_ptr.next;

//mapping_function (bh2 -> size, &fl, &sl);

fl = bh2 -> ptr.free_ptr.first_l_index;
sl = bh2 -> ptr.free_ptr.second_l_index;
if (fl_array [fl].sl_array [sl] == bh2)
fl_array [fl].sl_array [sl] = bh2 -> ptr.free_ptr.next;

if (fl_array[fl].sl_array[sl] == NULL){
//fl_array[fl].bitmapSL &= ~(1 << sl);
DIDMA__clear_bit (sl, fl_array[fl].bitmapSL);
if (!fl_array[fl].bitmapSL) {
_free_ ((void *) fl_array [fl].sl_array);
DIDMA__clear_bit (fl, bitmapFL);
}
}

bh2 -> size += bh -> size + header_overhead;
bh2 -> next = bh -> next;
bh = bh2;

}
}

/*
* and then we merge the free block with the initial memory
*/
if (for_free_block) {
free_block = bh;
bh -> ptr.free_ptr.next = NULL;
bh -> ptr.free_ptr.prev = NULL;
} else {
/*
* or we insert the free block in the TAD
*/
mapping_function (bh -> size, &fl, &sl);
if (fl_array[fl].bitmapSL == 0)
fl_array[fl].sl_array = (block_header_t **) _malloc_ ();
if (fl_array[fl].sl_array == NULL) {
PRINT_MSG("CRITICAL ERROR: there isn't enought memory for free\n");
THREAD_UNLOCK();
return F_ERROR;
}
bh -> ptr.free_ptr.first_l_index = fl;
bh -> ptr.free_ptr.second_l_index = sl;
bh -> ptr.free_ptr.next = fl_array [fl].sl_array [sl];
bh -> ptr.free_ptr.prev = NULL;
if (fl_array [fl].sl_array [sl] != NULL)
fl_array [fl].sl_array [sl] -> ptr.free_ptr.prev = bh;
fl_array [fl].sl_array [sl] = bh;

DIDMA__set_bit (sl, fl_array[fl].bitmapSL);
DIDMA__set_bit (fl, bitmapFL);

}

THREAD_UNLOCK();
return F_OK;
}

/*
* search_TAD searchs a free block of size 'size'
* then this block will be splitted in two new blocks,
* one of these new blocks will be given to the user and the
* other will be inserted into a free blocks structure
*
* The cost of this operation is
* best case: (K) = (1)
* worst case: (MAX_FL_LOG2_INDEX - MIN_FL_LOG2_INDEX + MAX_SL_INDEX + K)
* = (1)
* where K is an integer constant
*/

static u8 *search_TAD (size_t size) {
int for_free_block = 0;
int fl, sl, n;
int found;
block_header_t *bh = NULL, *bh2;

if (!(size > 0) || size >= MAX_SIZE || !all_ok) return NULL;
THREAD_LOCK();

if (size <= MIN_SIZE) {
size = MIN_SIZE;
fl = 0;
sl = 0;
} else {
mapping_function (size, &fl, &sl);

if (++sl == MAX_SL_INDEX) {
fl ++;
sl = 0;
}
/*
* This is the reason of the internal fragmentation
* The block given is greater that the size demanded
*/
size = (1 << (fl + MIN_LOG2_SIZE));
size = size + ((size >> MAX_SL_LOG2_INDEX) * sl);
}

/* the size given can be bigger than the size demanded */
found = 0;

// we take the first free block from fl_array or a buddy of him

sl = fl_array[fl].bitmapSL & ((~0) << sl);
if (sl != 0) {
sl = DIDMA_fls(sl);
bh = fl_array [fl].sl_array [sl];
fl_array [fl].sl_array [sl] = bh -> ptr.free_ptr.next;
if (fl_array [fl].sl_array [sl] != NULL)
fl_array [fl].sl_array [sl] -> ptr.free_ptr.prev = NULL;
else {
DIDMA__clear_bit (sl, fl_array[fl].bitmapSL);
if (!fl_array[fl].bitmapSL) {
DIDMA__clear_bit (fl, bitmapFL);
_free_ ((void *) fl_array [fl].sl_array);
}
}
found = 1;
goto out;
}
/*
* if fl_array is empty we will take a free block
* from free_block pointer
*/

if (free_block != NULL && free_block -> size >= size) {
bh = free_block;
free_block = NULL;
for_free_block = 1;
found = 1;
goto out;
}

/*
* A free block is searched
*
* Using a bitmap
*/

fl = DIDMA_fls(bitmapFL & ((~0) << (fl + 1)));

if (fl > 0) {
sl = DIDMA_fls(fl_array[fl].bitmapSL);
bh = fl_array [fl].sl_array [sl];
fl_array [fl].sl_array [sl] = bh -> ptr.free_ptr.next;
if (fl_array [fl].sl_array [sl] != NULL){
fl_array [fl].sl_array [sl] -> ptr.free_ptr.prev = NULL;
} else {
DIDMA__clear_bit (sl, fl_array[fl].bitmapSL);
if (!fl_array[fl].bitmapSL) {
_free_ ((void *) fl_array[fl].sl_array);
DIDMA__clear_bit (fl, bitmapFL);
}
}
found = 1;
goto out;
}

out:

/*
* HUGGGG, NOT ENOUGHT MEMORY
* I think that we have done all that we have been able
*/
if (!found) {
PRINT_MSG ("ERROR: Memory pool exhausted!!!\n");
THREAD_UNLOCK();
return NULL;
}

/*
* we can say: YESSSSSSSSSSS, we have enought memory!!!!
*/
bh -> state = BLOCK_USED;

/* can bh be splitted? */
n = (int)(bh -> size - size - header_overhead);
if (n >= (int) MIN_SIZE) {

/*
* Yes, bh will be splitted
*/

bh2 = (block_header_t *) ((u8 *)(bh -> ptr.buffer) + size);
bh2 -> magic_number = MAGIC_NUMBER;
bh2 -> state = BLOCK_FREE;
bh2 -> size = n;
if (bh -> next != NULL)
bh -> next -> prev = bh2;
bh2 -> next = bh -> next;
bh -> next = bh2;
bh2 -> prev = bh;
bh -> size = size;

if (!for_free_block) {
mapping_function (bh2 -> size, &fl, &sl);
if (fl_array[fl].bitmapSL == 0)
fl_array[fl].sl_array = (block_header_t **) _malloc_ ();
if (fl_array[fl].sl_array == NULL) {
PRINT_MSG("CRITICAL ERROR: there isn't enought memory for free\n");
return NULL;
}
bh2 -> ptr.free_ptr.first_l_index = fl;
bh2 -> ptr.free_ptr.second_l_index = sl;
bh2 -> ptr.free_ptr.prev = NULL;
bh2 -> ptr.free_ptr.next = fl_array [fl].sl_array [sl];

if (fl_array [fl].sl_array [sl] != NULL)
fl_array [fl].sl_array [sl] -> ptr.free_ptr.prev = bh2;
fl_array [fl].sl_array [sl] = bh2;
DIDMA__set_bit (sl, fl_array[fl].bitmapSL);
DIDMA__set_bit (fl, bitmapFL);

//fl_array [fl].n_blocks ++;
} else
free_block = bh2;
}
THREAD_UNLOCK();
return (u8 *) bh -> ptr.buffer;
}

int init_memory_pool (int max_size){

u8 *buffer;
int real_max_size = 0;

if (max_size < 0) return -1;

//buffer = (u8 *) SYSTEM_MALLOC (real_max_size * sizeof (u8));
real_max_size = calculate_reserve(max_size);
buffer = (u8 *) SYSTEM_MALLOC (real_max_size * sizeof (u8));
if (buffer == NULL) return F_ERROR;
return init_TAD (real_max_size, buffer);
}

void destroy_memory_pool(void){

SYSTEM_FREE (destroy_TAD ());
}

/* see 'man malloc' */
void *rt_malloc (size_t size){
return (void *) search_TAD (size);
}

/* see 'man free' */
void rt_free (void *ptr){
if (ptr != NULL) insert_TAD ((u8 *) ptr);
}

/* see 'man calloc' */
void *rt_calloc (size_t nelem, size_t elem_size)
{
void *p;

if (!all_ok || nelem <= 0 || elem_size <= 0) return NULL;

if ((p = rt_malloc (nelem * elem_size)) == NULL)
return NULL;

memset (p, 0, nelem * elem_size);

return p;
}

/*
* see man realloc
* be careful, realloc () is an expensive operation because
* it uses malloc () and free ()
*/
void *rt_realloc (void *p, size_t new_len)
{
u8 *aux;
void *addr;
int old_len, min;
block_header_t *b;

if (!all_ok) return NULL;

if (p == NULL)
return rt_malloc (new_len);
else if (new_len == 0) {
rt_free(p);
return NULL;
} else {
/*
* Now we try to achieve old size because
* then we need it to copy all data in the new allocated
* memory
*/
aux = (u8 *) p;
aux -= header_overhead;
b = (block_header_t *) aux;
if (b -> magic_number == MAGIC_NUMBER) {
old_len = b -> size;
} else {
PRINT_MSG ("CRITICAL ERROR: block corrupted\n");
return NULL;
}

addr = rt_malloc (new_len);

if (addr == NULL) return NULL;

min = (old_len > new_len)? new_len : old_len;
memcpy (addr, p, min);
rt_free (p);

return addr;
}
}

#ifdef __DEBUG__

/*
* dump_mem () is a simple operation,
* it only does a dumped of memory
*/

void dump_mem (void){
u8 *aux;
int n;

if (!all_ok) return;

aux = (u8 *) first_bh;

for (n = 0; n < total_size; n++) {
PRINT_DBG_H (aux [n]);
PRINT_DBG_C (" ");
}
PRINT_DBG_C ("\n");
}

/*
* I haven't anything to say about print_block ()
*/
static void print_block (block_header_t *b){
if (b == NULL) return;
PRINT_DBG_C (">>>> MNum 0x");
PRINT_DBG_H (b -> magic_number);
PRINT_DBG_C (" Address 0x");
//PRINT_DBG_H (b);
if (b -> state == BLOCK_FREE)
PRINT_DBG_C (" State FREE");
else
PRINT_DBG_C (" State USED");
PRINT_DBG_C (" Size ");
PRINT_DBG_D (b -> size);
PRINT_DBG_C ("\n---- Prev 0x");
//PRINT_DBG_H (b -> prev);
PRINT_DBG_C (" Next 0x");
//PRINT_DBG_H (b -> next);
if (b -> state == BLOCK_FREE){
PRINT_DBG_C ("\n---- Prev Free 0x");
//PRINT_DBG_H (b -> ptr.free_ptr.prev);
PRINT_DBG_C (" Next Free 0x");
//PRINT_DBG_H (b -> ptr.free_ptr.next);
}
PRINT_DBG_C ("\n");
}

/*
* structure_context () show the content of all blocks
*/
void structure_context (void) {
block_header_t *b;

if (!all_ok) return;

b = first_bh;
PRINT_DBG_C ("\nALL BLOCKS\n");
while (b != NULL) {
print_block (b);
b = b -> next;
}

}

/*
* global_state () returns overhead, free and used space
*/
void global_state (int *free, int *used, int *overhead){
block_header_t *b;

*free = 0;
*used = 0;
*overhead = 0;
if (!all_ok) return;
b = first_bh;
while (b != NULL) {
if (b -> state == BLOCK_USED) {
*used += b -> size;
} else {
*free += b -> size;
}
b = b -> next;
*overhead += header_overhead;
}

}

/*
* free_blocks_context () show the content
* of free blocks
*/
void free_blocks_context (void){
int i, j;
block_header_t *b;

if (!all_ok) return;

PRINT_DBG_C ("\nFREE BLOCKS\n");
PRINT_DBG_C ("MAIN BLOCK\n");
print_block (free_block);
PRINT_DBG_C ("FRAGMENTED BLOCKS\n");
for (i = MAX_FL_INDEX - 1 - MIN_LOG2_SIZE; i >= 0; i--) {
if (fl_array [i].bitmapSL > 0)
for (j = MAX_SL_INDEX - 1; j >= 0; j--) {
if (fl_array [i].sl_array[j] != NULL) {
b = fl_array [i].sl_array [j];
PRINT_DBG_C ("[");
PRINT_DBG_D (i);
PRINT_DBG_C ("] ");
PRINT_DBG_D (1 << (i + MIN_LOG2_SIZE));
PRINT_DBG_C (" bytes -> Free blocks: 0x");
PRINT_DBG_H (fl_array [i].bitmapSL);
PRINT_DBG_C ("\n");

while (b != NULL) {
PRINT_DBG_C (">>>> ");
PRINT_DBG_D ((1 << (i + MIN_LOG2_SIZE)) +
(1<< (i + MIN_LOG2_SIZE)) / MAX_SL_INDEX * j);
PRINT_DBG_C (" bytes\n");
print_block (b);
b = b -> ptr.free_ptr.next;
}
}
}
}
}

/*
* check_mem () checks memory searching
* errors and incoherences
* return :
* 0 if there isn't any error
* or
* -1 in other case
*/
int check_mem (void){
block_header_t *b, *b2;
int i, j, num_blocks;

if (!all_ok) return F_ERROR;

b = first_bh;
num_blocks = 0;
for (i = MAX_FL_INDEX - 1 - MIN_LOG2_SIZE; i >= 0; i--) {
if (fl_array [i].bitmapSL < 0) return F_ERROR;
for (j = MAX_SL_INDEX - 1; j >= 0; j--) {
b2 = fl_array [i].sl_array[j];
while (b2 != NULL) {
b2 = b2 -> ptr.free_ptr.next;
num_blocks ++;
}
}
if (num_blocks != fl_array [i].bitmapSL) return F_ERROR;
num_blocks = 0;
}

while (b != NULL) {
if (b -> magic_number != MAGIC_NUMBER ||
b -> size > MAX_SIZE || b -> size < MIN_SIZE)
return F_ERROR;

if (b -> next != NULL)
if (b -> next < first_bh || b -> next >
(block_header_t *) ((u8 *) (first_bh) + MAX_SIZE))
return F_ERROR;

if (b -> prev != NULL)
if (b -> prev < first_bh || b -> prev >
(block_header_t *) ((u8 *) (first_bh) + MAX_SIZE) )
return F_ERROR;

if (b -> state != BLOCK_FREE && b -> state != BLOCK_USED) return F_ERROR;
if (b -> state == BLOCK_FREE) {
if (b -> ptr.free_ptr.next != NULL)
if (b -> ptr.free_ptr.next < first_bh ||
b -> ptr.free_ptr.next >
(block_header_t *) ((u8 *) (first_bh) + MAX_SIZE))
return F_ERROR;

if (b -> ptr.free_ptr.prev != NULL)
if (b -> ptr.free_ptr.prev < first_bh ||
b -> ptr.free_ptr.prev >
(block_header_t *) ((u8 *) (first_bh) + MAX_SIZE) )
return F_ERROR;
}

b = b -> next;

}
return F_OK;
}
#endif // #ifdef __DEBUG__

Subversion Repositories shark

(root)/shark/branches/xen/ports/didma/didma.c - Rev 229