que0que.c

这是linux下运行的mysql软件包,可用于linux 下安装 php + mysql + apach 的网络配置

		} else if (fork_type == QUE_FORK_RECOVERY) {

			/* Do nothing */
		} else if (fork_type == QUE_FORK_MYSQL_INTERFACE) {

			/* Do nothing */
		} else {
			ut_error;	/* not used in MySQL */
		}
	}

	if (UT_LIST_GET_LEN(trx->signals) > 0 && trx->n_active_thrs == 0) {

	    	/* If the trx is signaled and its query thread count drops to
		zero, then we start processing a signal; from it we may get
		a new query thread to run */

		trx_sig_start_handle(trx, next_thr);
	}

	if (trx->handling_signals && UT_LIST_GET_LEN(trx->signals) == 0) {

		trx_end_signal_handling(trx);
	}

	mutex_exit(&kernel_mutex);
}

/**************************************************************************
Stops a query thread if graph or trx is in a state requiring it. The
conditions are tested in the order (1) graph, (2) trx. The kernel mutex has
to be reserved. */

ibool
que_thr_stop(
/*=========*/
				/* out: TRUE if stopped */
	que_thr_t*	thr)	/* in: query thread */
{
	trx_t*	trx;
	que_t*	graph;
	ibool	ret	= TRUE;

#ifdef UNIV_SYNC_DEBUG
	ut_ad(mutex_own(&kernel_mutex));
#endif /* UNIV_SYNC_DEBUG */
	
	graph = thr->graph;
	trx = graph->trx;

	if (graph->state == QUE_FORK_COMMAND_WAIT) {
		thr->state = QUE_THR_SUSPENDED;

	} else if (trx->que_state == TRX_QUE_LOCK_WAIT) {

		UT_LIST_ADD_FIRST(trx_thrs, trx->wait_thrs, thr);
		thr->state = QUE_THR_LOCK_WAIT;

	} else if (trx->error_state != DB_SUCCESS
			&& trx->error_state != DB_LOCK_WAIT) {

		/* Error handling built for the MySQL interface */
		thr->state = QUE_THR_COMPLETED;

	} else if (UT_LIST_GET_LEN(trx->signals) > 0
				&& graph->fork_type != QUE_FORK_ROLLBACK) {

		thr->state = QUE_THR_SUSPENDED;
	} else {
		ut_ad(graph->state == QUE_FORK_ACTIVE);

		ret = FALSE;
	}		        

	return(ret);
}

/**************************************************************************
A patch for MySQL used to 'stop' a dummy query thread used in MySQL. The
query thread is stopped and made inactive, except in the case where
it was put to the lock wait state in lock0lock.c, but the lock has already
been granted or the transaction chosen as a victim in deadlock resolution. */

void
que_thr_stop_for_mysql(
/*===================*/
	que_thr_t*	thr)	/* in: query thread */
{
	trx_t*	trx;

	trx = thr_get_trx(thr);
	
	mutex_enter(&kernel_mutex);

	if (thr->state == QUE_THR_RUNNING) {

		if (trx->error_state != DB_SUCCESS
			   	&& trx->error_state != DB_LOCK_WAIT) {

			/* Error handling built for the MySQL interface */
			thr->state = QUE_THR_COMPLETED;
		} else {
			/* It must have been a lock wait but the lock was
			already released, or this transaction was chosen
			as a victim in selective deadlock resolution */

			mutex_exit(&kernel_mutex);

			return;
		}
	}
		
	ut_ad(thr->is_active == TRUE);
	ut_ad(trx->n_active_thrs == 1);
	ut_ad(thr->graph->n_active_thrs == 1);

	thr->is_active = FALSE;
	(thr->graph)->n_active_thrs--;

	trx->n_active_thrs--;

	mutex_exit(&kernel_mutex);
}

/**************************************************************************
Moves a thread from another state to the QUE_THR_RUNNING state. Increments
the n_active_thrs counters of the query graph and transaction if thr was
not active. */

void
que_thr_move_to_run_state_for_mysql(
/*================================*/
	que_thr_t*	thr,	/* in: an query thread */
	trx_t*		trx)	/* in: transaction */
{
	if (thr->magic_n != QUE_THR_MAGIC_N) {
		fprintf(stderr,
	"que_thr struct appears corrupt; magic n %lu\n",
			(unsigned long) thr->magic_n);

		mem_analyze_corruption((byte*)thr);

		ut_error;
	}

	if (!thr->is_active) {

		thr->graph->n_active_thrs++;

		trx->n_active_thrs++;

		thr->is_active = TRUE;
	}
	
	thr->state = QUE_THR_RUNNING;
}

/**************************************************************************
A patch for MySQL used to 'stop' a dummy query thread used in MySQL
select, when there is no error or lock wait. */

void
que_thr_stop_for_mysql_no_error(
/*============================*/
	que_thr_t*	thr,	/* in: query thread */
	trx_t*		trx)	/* in: transaction */
{
	ut_ad(thr->state == QUE_THR_RUNNING);
	ut_ad(thr->is_active == TRUE);
	ut_ad(trx->n_active_thrs == 1);
	ut_ad(thr->graph->n_active_thrs == 1);
		
	if (thr->magic_n != QUE_THR_MAGIC_N) {
		fprintf(stderr,
	"que_thr struct appears corrupt; magic n %lu\n",
			(unsigned long) thr->magic_n);

		mem_analyze_corruption((byte*)thr);

		ut_error;
	}

	thr->state = QUE_THR_COMPLETED;

	thr->is_active = FALSE;
	(thr->graph)->n_active_thrs--;

	trx->n_active_thrs--;
}

/**************************************************************************
Prints info of an SQL query graph node. */

void
que_node_print_info(
/*================*/
	que_node_t*	node)	/* in: query graph node */
{
	ulint		type;
	const char*	str;

	type = que_node_get_type(node);

	if (type == QUE_NODE_SELECT) {
		str = "SELECT";
	} else if (type == QUE_NODE_INSERT) {
		str = "INSERT";
	} else if (type == QUE_NODE_UPDATE) {
		str = "UPDATE";
	} else if (type == QUE_NODE_WHILE) {
		str = "WHILE";
	} else if (type == QUE_NODE_ASSIGNMENT) {
		str = "ASSIGNMENT";
	} else if (type == QUE_NODE_IF) {
		str = "IF";
	} else if (type == QUE_NODE_FETCH) {
		str = "FETCH";
	} else if (type == QUE_NODE_OPEN) {
		str = "OPEN";
	} else if (type == QUE_NODE_PROC) {
		str = "STORED PROCEDURE";
	} else if (type == QUE_NODE_FUNC) {
		str = "FUNCTION";
	} else if (type == QUE_NODE_LOCK) {
		str = "LOCK";
	} else if (type == QUE_NODE_THR) {
		str = "QUERY THREAD";
	} else if (type == QUE_NODE_COMMIT) {
		str = "COMMIT";
	} else if (type == QUE_NODE_UNDO) {
		str = "UNDO ROW";
	} else if (type == QUE_NODE_PURGE) {
		str = "PURGE ROW";
	} else if (type == QUE_NODE_ROLLBACK) {
		str = "ROLLBACK";
	} else if (type == QUE_NODE_CREATE_TABLE) {
		str = "CREATE TABLE";
	} else if (type == QUE_NODE_CREATE_INDEX) {
		str = "CREATE INDEX";
	} else if (type == QUE_NODE_FOR) {
		str = "FOR LOOP";
	} else if (type == QUE_NODE_RETURN) {
		str = "RETURN";
	} else {
		str = "UNKNOWN NODE TYPE";
	}

	fprintf(stderr, "Node type %lu: %s, address %p\n", (ulong) type, str, node);
}

/**************************************************************************
Performs an execution step on a query thread. */
UNIV_INLINE
que_thr_t*
que_thr_step(
/*=========*/
				/* out: query thread to run next: it may
				differ from the input parameter if, e.g., a
				subprocedure call is made */ 
	que_thr_t*	thr)	/* in: query thread */
{
	que_node_t*	node;
	que_thr_t*	old_thr;
	trx_t*		trx;
	ulint		type;
	
	ut_ad(thr->state == QUE_THR_RUNNING);

	thr->resource++;
	
	type = que_node_get_type(thr->run_node);
	node = thr->run_node;

	old_thr = thr;
	
#ifdef UNIV_DEBUG
	if (que_trace_on) {
		fputs("To execute: ", stderr);
		que_node_print_info(node);
	}
#endif
	if (type & QUE_NODE_CONTROL_STAT) {
		if ((thr->prev_node != que_node_get_parent(node))
				&& que_node_get_next(thr->prev_node)) {

			/* The control statements, like WHILE, always pass the
			control to the next child statement if there is any
			child left */

			thr->run_node = que_node_get_next(thr->prev_node);

		} else if (type == QUE_NODE_IF) {
			if_step(thr);
		} else if (type == QUE_NODE_FOR) {
			for_step(thr);
		} else if (type == QUE_NODE_PROC) {

			/* We can access trx->undo_no without reserving
			trx->undo_mutex, because there cannot be active query
			threads doing updating or inserting at the moment! */
	
			if (thr->prev_node == que_node_get_parent(node)) {
				trx = thr_get_trx(thr);
				trx->last_sql_stat_start.least_undo_no
							= trx->undo_no;
			}
			
			proc_step(thr);
		} else if (type == QUE_NODE_WHILE) {
			while_step(thr);
		}
	} else if (type == QUE_NODE_ASSIGNMENT) {
		assign_step(thr);
	} else if (type == QUE_NODE_SELECT) {
		thr = row_sel_step(thr);
	} else if (type == QUE_NODE_INSERT) {
		thr = row_ins_step(thr);
	} else if (type == QUE_NODE_UPDATE) {
		thr = row_upd_step(thr);
	} else if (type == QUE_NODE_FETCH) {
		thr = fetch_step(thr);
	} else if (type == QUE_NODE_OPEN) {
		thr = open_step(thr);
	} else if (type == QUE_NODE_FUNC) {
		proc_eval_step(thr);

	} else if (type == QUE_NODE_LOCK) {

		ut_error;
/*
		thr = que_lock_step(thr);
*/
	} else if (type == QUE_NODE_THR) {
		thr = que_thr_node_step(thr);
	} else if (type == QUE_NODE_COMMIT) {
		thr = trx_commit_step(thr);
	} else if (type == QUE_NODE_UNDO) {
		thr = row_undo_step(thr);
	} else if (type == QUE_NODE_PURGE) {
		thr = row_purge_step(thr);
	} else if (type == QUE_NODE_RETURN) {
		thr = return_step(thr);
	} else if (type == QUE_NODE_ROLLBACK) {
		thr = trx_rollback_step(thr);
	} else if (type == QUE_NODE_CREATE_TABLE) {
		thr = dict_create_table_step(thr);
	} else if (type == QUE_NODE_CREATE_INDEX) {
		thr = dict_create_index_step(thr);
	} else if (type == QUE_NODE_ROW_PRINTF) {
		thr = row_printf_step(thr);
	} else {
		ut_error;
	}

	old_thr->prev_node = node;

	return(thr);
}

/**************************************************************************
Runs query threads. Note that the individual query thread which is run
within this function may change if, e.g., the OS thread executing this
function uses a threshold amount of resources. */

void
que_run_threads(
/*============*/
	que_thr_t*	thr)	/* in: query thread which is run initially */
{
	que_thr_t*	next_thr;
	ulint		cumul_resource;	
	ulint		loop_count;
	
	ut_ad(thr->state == QUE_THR_RUNNING);
#ifdef UNIV_SYNC_DEBUG
	ut_ad(!mutex_own(&kernel_mutex));
#endif /* UNIV_SYNC_DEBUG */

	/* cumul_resource counts how much resources the OS thread (NOT the
	query thread) has spent in this function */

	loop_count = QUE_MAX_LOOPS_WITHOUT_CHECK;
	cumul_resource = 0;	
loop:
	/* Check that there is enough space in the log to accommodate
	possible log entries by this query step; if the operation can touch
	more than about 4 pages, checks must be made also within the query
	step! */

	log_free_check();
	
	/* Perform the actual query step: note that the query thread
	may change if, e.g., a subprocedure call is made */

	/*-------------------------*/
	next_thr = que_thr_step(thr);
	/*-------------------------*/

	/* Test the effect on performance of adding extra mutex
	reservations */

/*	if (srv_test_extra_mutexes) {
		mutex_enter(&kernel_mutex);
		mutex_exit(&kernel_mutex);
	}	
*/
	loop_count++;

	if (next_thr != thr) {
		ut_a(next_thr == NULL);
		que_thr_dec_refer_count(thr, &next_thr);

		if (next_thr == NULL) {

			return;
		}

		loop_count = QUE_MAX_LOOPS_WITHOUT_CHECK;

		thr = next_thr;
	}

	goto loop;
}