C++ UT_LIST_GET_LEN函数代码示例

/********************************************************************//**
Prints info of a memory pool. */
UNIV_INTERN
void
mem_pool_print_info(
/*================*/
	FILE*		outfile,/*!< in: output file to write to */
	mem_pool_t*	pool)	/*!< in: memory pool */
{
	ulint		i;

	mem_pool_validate(pool);

	fprintf(outfile, "INFO OF A MEMORY POOL\n");

	mutex_enter(&(pool->mutex));

	for (i = 0; i < 64; i++) {
		if (UT_LIST_GET_LEN(pool->free_list[i]) > 0) {

			fprintf(outfile,
				"Free list length %lu for"
				" blocks of size %lu\n",
				(ulong) UT_LIST_GET_LEN(pool->free_list[i]),
				(ulong) ut_2_exp(i));
		}
	}

	fprintf(outfile, "Pool size %lu, reserved %lu.\n", (ulong) pool->size,
		(ulong) pool->reserved);
	mutex_exit(&(pool->mutex));
}

/***********************************************************************
Initializes the old blocks pointer in the LRU list. This function should be
called when the LRU list grows to BUF_LRU_OLD_MIN_LEN length. */
static
void
buf_LRU_old_init(void)
/*==================*/
{
	buf_block_t*	block;

	ut_ad(mutex_own(&(buf_pool->mutex)));
	ut_a(UT_LIST_GET_LEN(buf_pool->LRU) == BUF_LRU_OLD_MIN_LEN);

	/* We first initialize all blocks in the LRU list as old and then use
	the adjust function to move the LRU_old pointer to the right
	position */

	block = UT_LIST_GET_FIRST(buf_pool->LRU);

	while (block != NULL) {
		ut_a(block->state == BUF_BLOCK_FILE_PAGE);
		ut_a(block->in_LRU_list);
		block->old = TRUE;
		block = UT_LIST_GET_NEXT(LRU, block);
	}

	buf_pool->LRU_old = UT_LIST_GET_FIRST(buf_pool->LRU);
	buf_pool->LRU_old_len = UT_LIST_GET_LEN(buf_pool->LRU);

	buf_LRU_old_adjust_len();
}

/**********************************************************************
Adds a block to the LRU list end. */
UNIV_INLINE
void
buf_LRU_add_block_to_end_low(
/*=========================*/
	buf_block_t*	block)	/* in: control block */
{
	buf_block_t*	last_block;

	ut_ad(buf_pool);
	ut_ad(block);
	ut_ad(mutex_own(&(buf_pool->mutex)));

	ut_a(block->state == BUF_BLOCK_FILE_PAGE);

	block->old = TRUE;

	last_block = UT_LIST_GET_LAST(buf_pool->LRU);

	if (last_block) {
		block->LRU_position = last_block->LRU_position;
	} else {
		block->LRU_position = buf_pool_clock_tic();
	}

	ut_a(!block->in_LRU_list);
	UT_LIST_ADD_LAST(LRU, buf_pool->LRU, block);
	block->in_LRU_list = TRUE;

	if (srv_use_awe && block->frame) {
		/* Add to the list of mapped pages */

		UT_LIST_ADD_LAST(awe_LRU_free_mapped,
				 buf_pool->awe_LRU_free_mapped, block);
	}

	if (UT_LIST_GET_LEN(buf_pool->LRU) >= BUF_LRU_OLD_MIN_LEN) {

		buf_pool->LRU_old_len++;
	}

	if (UT_LIST_GET_LEN(buf_pool->LRU) > BUF_LRU_OLD_MIN_LEN) {

		ut_ad(buf_pool->LRU_old);

		/* Adjust the length of the old block list if necessary */

		buf_LRU_old_adjust_len();

	} else if (UT_LIST_GET_LEN(buf_pool->LRU) == BUF_LRU_OLD_MIN_LEN) {

		/* The LRU list is now long enough for LRU_old to become
		defined: init it */

		buf_LRU_old_init();
	}
}

int
trx_weight_cmp(
/*===========*/
			/* out: <0, 0 or >0; similar to strcmp(3) */
	trx_t*	a,	/* in: the first transaction to be compared */
	trx_t*	b)	/* in: the second transaction to be compared */
{
	ibool	a_notrans_edit;
	ibool	b_notrans_edit;

	/* If mysql_thd is NULL for a transaction we assume that it has
	not edited non-transactional tables. */

	a_notrans_edit = a->mysql_thd != NULL
	    && thd_has_edited_nontrans_tables(a->mysql_thd);

	b_notrans_edit = b->mysql_thd != NULL
	    && thd_has_edited_nontrans_tables(b->mysql_thd);

	if (a_notrans_edit && !b_notrans_edit) {

		return(1);
	}

	if (!a_notrans_edit && b_notrans_edit) {

		return(-1);
	}

	/* Either both had edited non-transactional tables or both had
	not, we fall back to comparing the number of altered/locked
	rows. */

#if 0
	fprintf(stderr,
		"%s TRX_WEIGHT(a): %lld+%lu, TRX_WEIGHT(b): %lld+%lu\n",
		__func__,
		ut_conv_dulint_to_longlong(a->undo_no),
		UT_LIST_GET_LEN(a->trx_locks),
		ut_conv_dulint_to_longlong(b->undo_no),
		UT_LIST_GET_LEN(b->trx_locks));
#endif

#define TRX_WEIGHT(t)	\
	ut_dulint_add((t)->undo_no, UT_LIST_GET_LEN((t)->trx_locks))

	return(ut_dulint_cmp(TRX_WEIGHT(a), TRX_WEIGHT(b)));
}

ulint
buf_LRU_get_recent_limit(void)
/*==========================*/
			/* out: the limit; zero if could not determine it */
{
	buf_block_t*	block;
	ulint		len;
	ulint		limit;

	mutex_enter(&(buf_pool->mutex));

	len = UT_LIST_GET_LEN(buf_pool->LRU);

	if (len < BUF_LRU_OLD_MIN_LEN) {
		/* The LRU list is too short to do read-ahead */

		mutex_exit(&(buf_pool->mutex));

		return(0);
	}

	block = UT_LIST_GET_FIRST(buf_pool->LRU);

	limit = block->LRU_position - len / BUF_LRU_INITIAL_RATIO;

	mutex_exit(&(buf_pool->mutex));

	return(limit);
}

/******************************************************************//**
Assigns a rollback segment to a transaction in a round-robin fashion.
Skips the SYSTEM rollback segment if another is available.
@return	assigned rollback segment id */
UNIV_INLINE
ulint
trx_assign_rseg(void)
/*=================*/
{
	trx_rseg_t*	rseg	= trx_sys->latest_rseg;

	ut_ad(mutex_own(&kernel_mutex));
loop:
	/* Get next rseg in a round-robin fashion */

	rseg = UT_LIST_GET_NEXT(rseg_list, rseg);

	if (rseg == NULL) {
		rseg = UT_LIST_GET_FIRST(trx_sys->rseg_list);
	}

	/* If it is the SYSTEM rollback segment, and there exist others, skip
	it */

	if ((rseg->id == TRX_SYS_SYSTEM_RSEG_ID)
	    && (UT_LIST_GET_LEN(trx_sys->rseg_list) > 1)) {
		goto loop;
	}

	trx_sys->latest_rseg = rseg;

	return(rseg->id);
}

/**********************************************************************
Removes a block from the LRU list. */
UNIV_INLINE
void
buf_LRU_remove_block(
/*=================*/
	buf_block_t*	block)	/* in: control block */
{
	ut_ad(buf_pool);
	ut_ad(block);
	ut_ad(mutex_own(&(buf_pool->mutex)));

	ut_a(block->state == BUF_BLOCK_FILE_PAGE);
	ut_a(block->in_LRU_list);

	/* If the LRU_old pointer is defined and points to just this block,
	move it backward one step */

	if (block == buf_pool->LRU_old) {

		/* Below: the previous block is guaranteed to exist, because
		the LRU_old pointer is only allowed to differ by the
		tolerance value from strict 3/8 of the LRU list length. */

		buf_pool->LRU_old = UT_LIST_GET_PREV(LRU, block);
		(buf_pool->LRU_old)->old = TRUE;

		buf_pool->LRU_old_len++;
		ut_a(buf_pool->LRU_old);
	}

	/* Remove the block from the LRU list */
	UT_LIST_REMOVE(LRU, buf_pool->LRU, block);
	block->in_LRU_list = FALSE;

	if (srv_use_awe && block->frame) {
		/* Remove from the list of mapped pages */

		UT_LIST_REMOVE(awe_LRU_free_mapped,
			       buf_pool->awe_LRU_free_mapped, block);
	}

	/* If the LRU list is so short that LRU_old not defined, return */
	if (UT_LIST_GET_LEN(buf_pool->LRU) < BUF_LRU_OLD_MIN_LEN) {

		buf_pool->LRU_old = NULL;

		return;
	}

	ut_ad(buf_pool->LRU_old);

	/* Update the LRU_old_len field if necessary */
	if (block->old) {

		buf_pool->LRU_old_len--;
	}

	/* Adjust the length of the old block list if necessary */
	buf_LRU_old_adjust_len();
}

/*************************************************************//**
Prints info of a hash table. */
UNIV_INTERN
void
ha_print_info(
/*==========*/
	FILE*		file,	/*!< in: file where to print */
	hash_table_t*	table)	/*!< in: hash table */
{
#ifdef UNIV_DEBUG
/* Some of the code here is disabled for performance reasons in production
builds, see http://bugs.mysql.com/36941 */
#define PRINT_USED_CELLS
#endif /* UNIV_DEBUG */

#ifdef PRINT_USED_CELLS
	hash_cell_t*	cell;
	ulint		cells	= 0;
	ulint		i;
#endif /* PRINT_USED_CELLS */
	ulint		n_bufs;

	ut_ad(table);
	ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
#ifdef PRINT_USED_CELLS
	for (i = 0; i < hash_get_n_cells(table); i++) {

		cell = hash_get_nth_cell(table, i);

		if (cell->node) {

			cells++;
		}
	}
#endif /* PRINT_USED_CELLS */

	fprintf(file, "Hash table size %lu",
		(ulong) hash_get_n_cells(table));

#ifdef PRINT_USED_CELLS
	fprintf(file, ", used cells %lu", (ulong) cells);
#endif /* PRINT_USED_CELLS */

	if (table->heaps == NULL && table->heap != NULL) {

		/* This calculation is intended for the adaptive hash
		index: how many buffer frames we have reserved? */

		n_bufs = UT_LIST_GET_LEN(table->heap->base) - 1;

		if (table->heap->free_block) {
			n_bufs++;
		}

		fprintf(file, ", node heap has %lu buffer(s)\n",
			(ulong) n_bufs);
	}
}

/***********************************************************************//**
Free's an instance of the rollback segment in memory. */
UNIV_INTERN
void
trx_rseg_mem_free(
/*==============*/
	trx_rseg_t*	rseg)	/* in, own: instance to free */
{
	trx_undo_t*	undo;

	mutex_free(&rseg->mutex);

	if (!srv_apply_log_only) {
	/* There can't be any active transactions. */
	ut_a(UT_LIST_GET_LEN(rseg->update_undo_list) == 0);
	ut_a(UT_LIST_GET_LEN(rseg->insert_undo_list) == 0);
	}

	undo = UT_LIST_GET_FIRST(rseg->update_undo_cached);

	while (undo != NULL) {
		trx_undo_t*	prev_undo = undo;

		undo = UT_LIST_GET_NEXT(undo_list, undo);
		UT_LIST_REMOVE(undo_list, rseg->update_undo_cached, prev_undo);

		trx_undo_mem_free(prev_undo);
	}

	undo = UT_LIST_GET_FIRST(rseg->insert_undo_cached);

	while (undo != NULL) {
		trx_undo_t*	prev_undo = undo;

		undo = UT_LIST_GET_NEXT(undo_list, undo);
		UT_LIST_REMOVE(undo_list, rseg->insert_undo_cached, prev_undo);

		trx_undo_mem_free(prev_undo);
	}

	trx_sys_set_nth_rseg(trx_sys, rseg->id, NULL);

	mem_free(rseg);
}

ibool
buf_LRU_buf_pool_running_out(void)
/*==============================*/
				/* out: TRUE if less than 25 % of buffer pool
				left */
{
	ibool	ret	= FALSE;

	mutex_enter(&(buf_pool->mutex));

	if (!recv_recovery_on && UT_LIST_GET_LEN(buf_pool->free)
	    + UT_LIST_GET_LEN(buf_pool->LRU) < buf_pool->max_size / 4) {

		ret = TRUE;
	}

	mutex_exit(&(buf_pool->mutex));

	return(ret);
}

/******************************************************************//**
Calling this function is obligatory only if the memory buffer containing
the mutex is freed. Removes a mutex object from the mutex list. The mutex
is checked to be in the reset state. */
UNIV_INTERN
void
mutex_free(
/*=======*/
	mutex_t*	mutex)	/*!< in: mutex */
{
	ut_ad(mutex_validate(mutex));
	ut_a(mutex_get_lock_word(mutex) == 0);
	ut_a(mutex_get_waiters(mutex) == 0);

#ifdef UNIV_MEM_DEBUG
	if (mutex == &mem_hash_mutex) {
		ut_ad(UT_LIST_GET_LEN(mutex_list) == 1);
		ut_ad(UT_LIST_GET_FIRST(mutex_list) == &mem_hash_mutex);
		UT_LIST_REMOVE(list, mutex_list, mutex);
		goto func_exit;
	}
#endif /* UNIV_MEM_DEBUG */

	if (mutex != &mutex_list_mutex
#ifdef UNIV_SYNC_DEBUG
	    && mutex != &sync_thread_mutex
#endif /* UNIV_SYNC_DEBUG */
	    ) {

		mutex_enter(&mutex_list_mutex);

		ut_ad(!UT_LIST_GET_PREV(list, mutex)
		      || UT_LIST_GET_PREV(list, mutex)->magic_n
		      == MUTEX_MAGIC_N);
		ut_ad(!UT_LIST_GET_NEXT(list, mutex)
		      || UT_LIST_GET_NEXT(list, mutex)->magic_n
		      == MUTEX_MAGIC_N);

		UT_LIST_REMOVE(list, mutex_list, mutex);

		mutex_exit(&mutex_list_mutex);
	}

	os_event_free(mutex->event);
#ifdef UNIV_MEM_DEBUG
func_exit:
#endif /* UNIV_MEM_DEBUG */
#if !defined(HAVE_ATOMIC_BUILTINS)
	os_fast_mutex_free(&(mutex->os_fast_mutex));
#endif
	/* If we free the mutex protecting the mutex list (freeing is
	not necessary), we have to reset the magic number AFTER removing
	it from the list. */
#ifdef UNIV_DEBUG
	mutex->magic_n = 0;
#endif /* UNIV_DEBUG */
}

/*******************************************************************//**
Frees a single savepoint struct. */
UNIV_INTERN
void
trx_roll_savepoint_free(
/*=====================*/
	trx_t*			trx,	/*!< in: transaction handle */
	trx_named_savept_t*	savep)	/*!< in: savepoint to free */
{
	ut_a(savep != NULL);
	ut_a(UT_LIST_GET_LEN(trx->trx_savepoints) > 0);

	UT_LIST_REMOVE(trx_savepoints, trx->trx_savepoints, savep);
	mem_free(savep->name);
	mem_free(savep);
}

/***************************************************************//**
Builds an index definition row to insert.
@return	DB_SUCCESS or error code */
static
ulint
dict_build_index_def_step(
    /*======================*/
    que_thr_t*	thr,	/*!< in: query thread */
    ind_node_t*	node)	/*!< in: index create node */
{
    dict_table_t*	table;
    dict_index_t*	index;
    dtuple_t*	row;
    trx_t*		trx;

    ut_ad(mutex_own(&(dict_sys->mutex)));

    trx = thr_get_trx(thr);

    index = node->index;

    table = dict_table_get_low(index->table_name);

    if (table == NULL) {
        return(DB_TABLE_NOT_FOUND);
    }

    trx->table_id = table->id;

    node->table = table;

    ut_ad((UT_LIST_GET_LEN(table->indexes) > 0)
          || dict_index_is_clust(index));

    dict_hdr_get_new_id(NULL, &index->id, NULL);

    /* Inherit the space id from the table; we store all indexes of a
    table in the same tablespace */

    index->space = table->space;
    node->page_no = FIL_NULL;
    row = dict_create_sys_indexes_tuple(index, node->heap);
    node->ind_row = row;

    ins_node_set_new_row(node->ind_def, row);

    /* Note that the index was created by this transaction. */
    index->trx_id = trx->id;

    return(DB_SUCCESS);
}

ibool
sess_try_close(
/*===========*/
			/* out: TRUE if closed */
	sess_t*	sess)	/* in, own: session object */
{
#ifdef UNIV_SYNC_DEBUG
	ut_ad(mutex_own(&kernel_mutex));
#endif /* UNIV_SYNC_DEBUG */
	if (UT_LIST_GET_LEN(sess->graphs) == 0) {
		sess_close(sess);

		return(TRUE);
	}

	return(FALSE);
}

/*******************************************************************
Builds an index definition row to insert. */
static
ulint
dict_build_index_def_step(
/*======================*/
				/* out: DB_SUCCESS or error code */
	que_thr_t*	thr,	/* in: query thread */
	ind_node_t*	node)	/* in: index create node */
{
	dict_table_t*	table;
	dict_index_t*	index;
	dtuple_t*	row;
	trx_t*		trx;

	ut_ad(mutex_own(&(dict_sys->mutex)));

	trx = thr_get_trx(thr);

	index = node->index;

	table = dict_table_get_low(index->table_name);

	if (table == NULL) {
		return(DB_TABLE_NOT_FOUND);
	}

	trx->table_id = table->id;

	node->table = table;

	ut_ad((UT_LIST_GET_LEN(table->indexes) > 0)
	      || (index->type & DICT_CLUSTERED));

	index->id = dict_hdr_get_new_id(DICT_HDR_INDEX_ID);

	/* Inherit the space id from the table; we store all indexes of a
	table in the same tablespace */

	index->space = table->space;
	node->page_no = FIL_NULL;
	row = dict_create_sys_indexes_tuple(index, node->heap);
	node->ind_row = row;

	ins_node_set_new_row(node->ind_def, row);

	return(DB_SUCCESS);
}