buf.c

minix3的源码

	assert(data);

	/* Find the acc we need to modify. */
	new_acc= data;
	while(offset >= new_acc->acc_length)
	{
		offset -= new_acc->acc_length;
		new_acc= new_acc->acc_next;
#ifdef BUF_TRACK_ALLOC_FREE
		assert(new_acc || (printf("called from %s, %d\n",
			clnt_file, clnt_line),0));
#else
		assert(new_acc);
#endif
	}

	/* Discard the old acc(s) */
	if (new_acc != data)
	{
		new_acc->acc_linkC++;
		bf_afree(data);
		data= new_acc;
	}

	/* Make sure that acc_linkC == 1 */
	if (data->acc_linkC != 1)
	{
		new_acc= bf_dupacc(data);
		bf_afree(data);
		data= new_acc;
	}

	/* Delete the last bit by modifying acc_offset and acc_length */
	data->acc_offset += offset;
	data->acc_length -= offset;
	return data;
}

/*
bf_append
*/

#ifndef BUF_TRACK_ALLOC_FREE
PUBLIC acc_t *bf_append(data_first, data_second)
#else
PUBLIC acc_t *_bf_append(clnt_file, clnt_line, data_first, data_second)
char *clnt_file;
int clnt_line;
#endif
acc_t *data_first;
acc_t  *data_second;
{
	acc_t *head, *tail, *new_acc, *acc_ptr_new, tmp_acc, *curr;
	char *src_ptr, *dst_ptr;
	size_t size, offset_old, offset_new, block_size_old, block_size;

	if (!data_first)
		return data_second;
	if (!data_second)
		return data_first;

	head= NULL;
	tail= NULL;
	while (data_first)
	{
		if (data_first->acc_linkC == 1)
			curr= data_first;
		else
		{
			curr= bf_dupacc(data_first);
			assert (curr->acc_linkC == 1);
			bf_afree(data_first);
		}
		data_first= curr->acc_next;
		if (!curr->acc_length)
		{
			curr->acc_next= NULL;
			bf_afree(curr);
			continue;
		}
		if (!head)
			head= curr;
		else
			tail->acc_next= curr;
		tail= curr;
	}
	if (!head)
		return data_second;
	tail->acc_next= NULL;

	while (data_second && !data_second->acc_length)
	{
		curr= data_second;
		data_second= data_second->acc_next;
		if (data_second)
			data_second->acc_linkC++;
		bf_afree(curr);
	}
	if (!data_second)
		return head;

	if (tail->acc_length + data_second->acc_length >
		tail->acc_buffer->buf_size)
	{
		tail->acc_next= data_second;
		return head;
	}

	if (tail->acc_buffer->buf_size == bf_buf_gran && 
		tail->acc_buffer->buf_linkC == 1)
	{
		if (tail->acc_offset)
		{
			memmove(tail->acc_buffer->buf_data_p,
				ptr2acc_data(tail), tail->acc_length);
			tail->acc_offset= 0;
		}
		dst_ptr= ptr2acc_data(tail) + tail->acc_length;
		src_ptr= ptr2acc_data(data_second);
		memcpy(dst_ptr, src_ptr, data_second->acc_length);
		tail->acc_length += data_second->acc_length;
		tail->acc_next= data_second->acc_next;
		if (data_second->acc_next)
			data_second->acc_next->acc_linkC++;
		bf_afree(data_second);
		return head;
	}

	new_acc= bf_small_memreq(tail->acc_length+data_second->acc_length);
	acc_ptr_new= new_acc;
	offset_old= 0;
	offset_new= 0;
	size= tail->acc_length;
	while (size)
	{
assert (acc_ptr_new);
		if (offset_new == acc_ptr_new->acc_length)
		{
			offset_new= 0;
			acc_ptr_new= acc_ptr_new->acc_next;
			continue;
		}
assert (offset_new < acc_ptr_new->acc_length);
assert (offset_old < tail->acc_length);
		block_size_old= tail->acc_length - offset_old;
		block_size= acc_ptr_new->acc_length - offset_new;
		if (block_size > block_size_old)
			block_size= block_size_old;
		memcpy(ptr2acc_data(acc_ptr_new)+offset_new,
			ptr2acc_data(tail)+offset_old, block_size);
		offset_new += block_size;
		offset_old += block_size;
		size -= block_size;
	}
	offset_old= 0;
	size= data_second->acc_length;
	while (size)
	{
assert (acc_ptr_new);
		if (offset_new == acc_ptr_new->acc_length)
		{
			offset_new= 0;
			acc_ptr_new= acc_ptr_new->acc_next;
			continue;
		}
assert (offset_new < acc_ptr_new->acc_length);
assert (offset_old < data_second->acc_length);
		block_size_old= data_second->acc_length - offset_old;
		block_size= acc_ptr_new->acc_length - offset_new;
		if (block_size > block_size_old)
			block_size= block_size_old;
		memcpy(ptr2acc_data(acc_ptr_new)+offset_new,
			ptr2acc_data(data_second)+offset_old, block_size);
		offset_new += block_size;
		offset_old += block_size;
		size -= block_size;
	}
	tmp_acc= *tail;
	*tail= *new_acc;
	*new_acc= tmp_acc;

	bf_afree(new_acc);
	while (tail->acc_next)
		tail= tail->acc_next;

	tail->acc_next= data_second->acc_next;
	if (data_second->acc_next)
		data_second->acc_next->acc_linkC++;
	bf_afree(data_second);
	return head;
}

#if BUF512_NR
PRIVATE void bf_512free(acc)
acc_t *acc;
{
#ifdef BUF_CONSISTENCY_CHECK 
	if (inet_buf_debug)
		memset(acc->acc_buffer->buf_data_p, 0xa5, 512);
#endif
	acc->acc_next= buf512_freelist;
	buf512_freelist= acc;
}
#endif
#if BUF2K_NR
PRIVATE void bf_2Kfree(acc)
acc_t *acc;
{
#ifdef BUF_CONSISTENCY_CHECK 
	if (inet_buf_debug)
		memset(acc->acc_buffer->buf_data_p, 0xa5, 2*1024);
#endif
	acc->acc_next= buf2K_freelist;
	buf2K_freelist= acc;
}
#endif
#if BUF32K_NR
PRIVATE void bf_32Kfree(acc)
acc_t *acc;
{
#ifdef BUF_CONSISTENCY_CHECK 
	if (inet_buf_debug)
		memset(acc->acc_buffer->buf_data_p, 0xa5, 32*1024);
#endif
	acc->acc_next= buf32K_freelist;
	buf32K_freelist= acc;
}
#endif

#ifdef BUF_CONSISTENCY_CHECK
PUBLIC int bf_consistency_check()
{
	acc_t *acc;
	int silent;
	int error;
	int i;

	buf_generation++;

	for (i=0; i<CLIENT_NR; i++)
	{
		if (checkreq[i])
			(*checkreq[i])();
	}

	/* Add information about free accessors */
	for(acc= acc_freelist; acc; acc= acc->acc_next)
	{
		if (acc->acc_generation == buf_generation-1)
		{
			acc->acc_generation= buf_generation;
			acc->acc_check_linkC= 0;
		}
		else
		{
			assert(acc->acc_generation == buf_generation &&
				acc->acc_check_linkC > 0);
			acc->acc_check_linkC= -acc->acc_check_linkC;
		}
	}

#if BUF512_NR
	count_free_bufs(buf512_freelist);
#endif
#if BUF2K_NR
	count_free_bufs(buf2K_freelist);
#endif
#if BUF32K_NR
	count_free_bufs(buf32K_freelist);
#endif

	error= 0;

	/* Report about accessors */
	silent= 0;
	for (i=0, acc= accessors; i<ACC_NR; i++, acc++)
	{
		if (acc->acc_generation != buf_generation)
		{
			error++;
			assert(acc->acc_generation == buf_generation-1);
			acc->acc_generation= buf_generation;
			if (!silent)
			{
				printf(
"acc[%d] (%p) has been lost with count %d, last allocated at %s, %d\n",
	i, acc, acc->acc_linkC, acc->acc_alloc_file, acc->acc_alloc_line);
#if 0
				silent= 1;
#endif
			}
			continue;
		}
		if (acc->acc_check_linkC == acc->acc_linkC)
			continue;
		error++;
		if (acc->acc_check_linkC < 0)
		{
			if (!silent)
			{
				printf(
"acc[%d] is freed but still in use, allocated at %s, %d, freed at %s, %d\n",
				i, acc->acc_alloc_file, acc->acc_alloc_line, 
				acc->acc_free_file, acc->acc_free_line);
			}
			acc->acc_check_linkC= -acc->acc_check_linkC;
			if (acc->acc_check_linkC == acc->acc_linkC)
			{
				silent= 1;
				continue;
			}
		}
		if (!silent)
		{
			printf(
"# of tracked links (%d) for acc[%d] don't match with stored link count %d\n",
				acc->acc_check_linkC, i, acc->acc_linkC);
			printf("acc[%d] was allocated at %s, %d\n",
				i, acc->acc_alloc_file, acc->acc_alloc_line);
			silent=1;
		}
	}

	/* Report about buffers */
#if BUF512_NR
	{
		for (i= 0; i<BUF512_NR; i++)
		{
			error |= report_buffer(&buffers512[i].buf_header,
				"512-buffer", i);
		}
	}
#endif
#if BUF2K_NR
	{
		for (i= 0; i<BUF2K_NR; i++)
		{
			error |= report_buffer(&buffers2K[i].buf_header,
				"2K-buffer", i);
		}
	}
#endif
#if BUF32K_NR
	{
		for (i= 0; i<BUF32K_NR; i++)
		{
			error |= report_buffer(&buffers32K[i].buf_header,
				"32K-buffer", i);
		}
	}
#endif

	return !error;
}

PRIVATE void count_free_bufs(list)
acc_t *list;
{
	acc_t *acc;
	buf_t *buf;

	for(acc= list; acc; acc= acc->acc_next)
	{
		if (acc->acc_generation != buf_generation-1)
		{
			assert(acc->acc_generation == buf_generation &&
				acc->acc_check_linkC > 0);
			acc->acc_check_linkC= -acc->acc_check_linkC;
			continue;
		}
		acc->acc_generation= buf_generation;
		acc->acc_check_linkC= 0;

		buf= acc->acc_buffer;
		if (buf->buf_generation == buf_generation-1)
		{
			buf->buf_generation= buf_generation;
			buf->buf_check_linkC= 0;
			continue;
		}
		assert(buf->buf_generation == buf_generation &&
			buf->buf_check_linkC > 0);
		buf->buf_check_linkC= -buf->buf_check_linkC;
	}
}

PRIVATE int report_buffer(buf, label, i)
buf_t *buf;
char *label;
int i;
{
	if (buf->buf_generation != buf_generation)
	{
		assert(buf->buf_generation == buf_generation-1);
		buf->buf_generation= buf_generation;
		printf(
"%s[%d] (%p) has been lost with count %d, last allocated at %s, %d\n",
			label, i, buf,
			buf->buf_linkC, buf->buf_alloc_file,
			buf->buf_alloc_line);
		return 1;
	}
	if (buf->buf_check_linkC == buf->buf_linkC)
		return 0;
	if (buf->buf_check_linkC < 0)
	{
		printf(
"%s[%d] is freed but still in use, allocated at %s, %d, freed at %s, %d\n",
			label, i, buf->buf_alloc_file, buf->buf_alloc_line, 
			buf->buf_free_file, buf->buf_free_line);
		buf->buf_check_linkC= -buf->buf_check_linkC;
		if (buf->buf_check_linkC == buf->buf_linkC)
			return 1;
	}
	printf(
"# of tracked links (%d) for %s[%d] don't match with stored link count %d\n",
			buf->buf_check_linkC, label, i, buf->buf_linkC);
	printf("%s[%d] was allocated at %s, %d\n",
		label, i, buf->buf_alloc_file, buf->buf_alloc_line);
	return 1;
}

PUBLIC void bf_check_acc(acc)
acc_t *acc;
{
	buf_t *buf;

	while(acc != NULL)
	{
		if (acc->acc_generation == buf_generation)
		{
			assert(acc->acc_check_linkC > 0);
			acc->acc_check_linkC++;
			return;
		}
		assert(acc->acc_generation == buf_generation-1);
		acc->acc_generation= buf_generation;
		acc->acc_check_linkC= 1;

		buf= acc->acc_buffer;
		if (buf->buf_generation == buf_generation)
		{
			assert(buf->buf_check_linkC > 0);
			buf->buf_check_linkC++;
		}
		else
		{
			assert(buf->buf_generation == buf_generation-1);
			buf->buf_generation= buf_generation;
			buf->buf_check_linkC= 1;
		}

		acc= acc->acc_next;
	}
}

PUBLIC void _bf_mark_1acc(clnt_file, clnt_line, acc)
char *clnt_file;
int clnt_line;
acc_t *acc;
{
	acc->acc_alloc_file= clnt_file;
	acc->acc_alloc_line= clnt_line;
}

PUBLIC void _bf_mark_acc(clnt_file, clnt_line, acc)
char *clnt_file;
int clnt_line;
acc_t *acc;
{
	buf_t *buf;

	for (; acc; acc= acc->acc_next)
	{
		acc->acc_alloc_file= clnt_file;
		acc->acc_alloc_line= clnt_line;
		buf= acc->acc_buffer;
		buf->buf_alloc_file= clnt_file;
		buf->buf_alloc_line= clnt_line;
	}
}
#endif

PUBLIC int bf_linkcheck(acc)
acc_t *acc;
{
	int i;

	buf_t *buffer;
	for (i= 0; i<ACC_NR && acc; i++, acc= acc->acc_next)
	{
		if (acc->acc_linkC <= 0)
		{
			printf("wrong acc_linkC (%d) for acc %p\n", 
				acc->acc_linkC, acc);
			return 0;
		}
		if (acc->acc_offset < 0)
		{
			printf("wrong acc_offset (%d) for acc %p\n",
				acc->acc_offset, acc);
			return 0;
		}
		if (acc->acc_length < 0)
		{
			printf("wrong acc_length (%d) for acc %p\n",
				acc->acc_length, acc);
			return 0;
		}
		buffer= acc->acc_buffer;
		if (buffer == NULL)
		{
			printf("no buffer for acc %p\n", acc);
			return 0;
		}
		if (buffer->buf_linkC <= 0)
		{
			printf(
			"wrong buf_linkC (%d) for buffer %p, from acc %p\n",
				buffer->buf_linkC, buffer, acc);
			return 0;
		}
		if (acc->acc_offset + acc->acc_length > buffer->buf_size)
		{
			printf("%d + %d > %d for buffer %p, and acc %p\n",
				acc->acc_offset, acc->acc_length, 
				buffer->buf_size, buffer, acc);
			return 0;
		}
	}
	if (acc != NULL)
	{
		printf("loop\n");
		return 0;
	}
	return 1;
}

PRIVATE void free_accs()
{
	int i, j;

	DBLOCK(1, printf("free_accs\n"));

assert(bf_linkcheck(bf_linkcheck_acc));
	for (i=0; !acc_freelist && i<MAX_BUFREQ_PRI; i++)
	{
		for (j=0; j<CLIENT_NR; j++)
		{
			bf_free_bufsize= 0;
			if (freereq[j])
			{
				(*freereq[j])(i);
				assert(bf_linkcheck(bf_linkcheck_acc) ||
					(printf("just called %p\n",
					freereq[i]),0));
			}
		}
	}
#if DEBUG
	printf("last level was level %d\n", i-1);
#endif
}

#ifndef BUF_TRACK_ALLOC_FREE
PUBLIC acc_t *bf_align(acc, size, alignment)
#else
PUBLIC acc_t *_bf_align(clnt_file, clnt_line, acc, size, alignment)
char *clnt_file;
int clnt_line;
#endif
acc_t *acc;
size_t size;
size_t alignment;
{
	char *ptr;
	size_t buf_size;
	acc_t *head, *tail;

	/* Fast check if the buffer is aligned already. */
	if (acc->acc_length >= size)
	{
		ptr= ptr2acc_data(acc);
		if (((unsigned)ptr & (alignment-1)) == 0)
			return acc;
	}
	buf_size= bf_bufsize(acc);
#ifdef bf_align
	assert((size != 0 && buf_size != 0) ||
		(printf("bf_align(..., %d, %d) from %s, %d\n",
			size, alignment, clnt_file, clnt_line),0));
#else
	assert(size != 0 && buf_size != 0);
#endif
	if (buf_size <= size)
	{
		acc= bf_pack(acc);
		return acc;
	}
	head= bf_cut(acc, 0, size);
	tail= bf_cut(acc, size, buf_size-size);
	bf_afree(acc);
	head= bf_pack(head);
	assert(head->acc_next == NULL);
	head->acc_next= tail;
	return head;
}

#if 0
int chk_acc(acc)
acc_t *acc;
{
	int acc_nr;

	if (!acc)
		return 1;
	if (acc < accessors || acc >= &accessors[ACC_NR])
		return 0;
	acc_nr= acc-accessors;
	return acc == &accessors[acc_nr];
}
#endif

/*
 * $PchId: buf.c,v 1.19 2003/09/10 08:54:23 philip Exp $
 */