Merge ahristov@bk-internal.mysql.com:/home/bk/mysql-5.1-new (79298b3e) · Commits · Software / OSDI20 Artifacts / mariadb

mysql-test/r/events.result

+48 −0

Original line number	Diff line number	Diff line
		@@ -37,6 +37,54 @@ alter event event3 rename to event2;
		drop event event2;
		create event event2 on schedule every 2 second starts now() ends date_add(now(), interval 5 hour) comment "some" DO begin end;
		drop event event2;
		CREATE EVENT event_starts_test ON SCHEDULE EVERY 10 SECOND COMMENT "" DO SELECT 1;
		SHOW EVENTS;
		Db Name Definer Type Execute at Interval value Interval field Starts Ends Status
		events_test event_starts_test root@localhost RECURRING NULL 10 SECOND # # ENABLED
		SELECT starts IS NULL, ends IS NULL, comment FROM mysql.event WHERE db='events_test' AND name='event_starts_test';
		starts IS NULL ends IS NULL comment
		0 1
		ALTER EVENT event_starts_test ON SCHEDULE AT '2020-02-02 20:00:02';
		SHOW EVENTS;
		Db Name Definer Type Execute at Interval value Interval field Starts Ends Status
		events_test event_starts_test root@localhost ONE TIME 2020-02-02 17:00:02 NULL NULL # # ENABLED
		SELECT starts IS NULL, ends IS NULL, comment FROM mysql.event WHERE db='events_test' AND name='event_starts_test';
		starts IS NULL ends IS NULL comment
		1 1
		ALTER EVENT event_starts_test COMMENT "non-empty comment";
		SHOW EVENTS;
		Db Name Definer Type Execute at Interval value Interval field Starts Ends Status
		events_test event_starts_test root@localhost ONE TIME 2020-02-02 17:00:02 NULL NULL # # ENABLED
		SELECT starts IS NULL, ends IS NULL, comment FROM mysql.event WHERE db='events_test' AND name='event_starts_test';
		starts IS NULL ends IS NULL comment
		1 1 non-empty comment
		ALTER EVENT event_starts_test COMMENT "";
		SHOW EVENTS;
		Db Name Definer Type Execute at Interval value Interval field Starts Ends Status
		events_test event_starts_test root@localhost ONE TIME 2020-02-02 17:00:02 NULL NULL # # ENABLED
		SELECT starts IS NULL, ends IS NULL, comment FROM mysql.event WHERE db='events_test' AND name='event_starts_test';
		starts IS NULL ends IS NULL comment
		1 1
		DROP EVENT event_starts_test;
		CREATE EVENT event_starts_test ON SCHEDULE EVERY 20 SECOND STARTS '2020-02-02 20:00:02' ENDS '2022-02-02 20:00:02' DO SELECT 2;
		SHOW EVENTS;
		Db Name Definer Type Execute at Interval value Interval field Starts Ends Status
		events_test event_starts_test root@localhost RECURRING NULL 20 SECOND # # ENABLED
		SELECT starts IS NULL, ends IS NULL, comment FROM mysql.event WHERE db='events_test' AND name='event_starts_test';
		starts IS NULL ends IS NULL comment
		0 0
		ALTER EVENT event_starts_test COMMENT "non-empty comment";
		SHOW EVENTS;
		Db Name Definer Type Execute at Interval value Interval field Starts Ends Status
		events_test event_starts_test root@localhost RECURRING NULL 20 SECOND # # ENABLED
		SELECT starts IS NULL, ends IS NULL, comment FROM mysql.event WHERE db='events_test' AND name='event_starts_test';
		starts IS NULL ends IS NULL comment
		0 0 non-empty comment
		ALTER EVENT event_starts_test COMMENT "";
		SHOW EVENTS;
		Db Name Definer Type Execute at Interval value Interval field Starts Ends Status
		events_test event_starts_test root@localhost RECURRING NULL 20 SECOND # # ENABLED
		DROP EVENT event_starts_test;
		create event e_43 on schedule every 1 second do set @a = 5;
		set global event_scheduler = 1;
		alter event e_43 do alter event e_43 do set @a = 4;

mysql-test/t/events.test

+32 −0

Original line number	Diff line number	Diff line
		@@ -48,6 +48,38 @@ drop event event2;
		create event event2 on schedule every 2 second starts now() ends date_add(now(), interval 5 hour) comment "some" DO begin end;
		drop event event2;

		# BUG #16537 (Events: mysql.event.starts is null)
		CREATE EVENT event_starts_test ON SCHEDULE EVERY 10 SECOND COMMENT "" DO SELECT 1;
		--replace_column 8 # 9 #
		SHOW EVENTS;
		SELECT starts IS NULL, ends IS NULL, comment FROM mysql.event WHERE db='events_test' AND name='event_starts_test';
		ALTER EVENT event_starts_test ON SCHEDULE AT '2020-02-02 20:00:02';
		--replace_column 8 # 9 #
		SHOW EVENTS;
		SELECT starts IS NULL, ends IS NULL, comment FROM mysql.event WHERE db='events_test' AND name='event_starts_test';
		ALTER EVENT event_starts_test COMMENT "non-empty comment";
		--replace_column 8 # 9 #
		SHOW EVENTS;
		SELECT starts IS NULL, ends IS NULL, comment FROM mysql.event WHERE db='events_test' AND name='event_starts_test';
		ALTER EVENT event_starts_test COMMENT "";
		--replace_column 8 # 9 #
		SHOW EVENTS;
		SELECT starts IS NULL, ends IS NULL, comment FROM mysql.event WHERE db='events_test' AND name='event_starts_test';
		DROP EVENT event_starts_test;
		CREATE EVENT event_starts_test ON SCHEDULE EVERY 20 SECOND STARTS '2020-02-02 20:00:02' ENDS '2022-02-02 20:00:02' DO SELECT 2;
		--replace_column 8 # 9 #
		SHOW EVENTS;
		SELECT starts IS NULL, ends IS NULL, comment FROM mysql.event WHERE db='events_test' AND name='event_starts_test';
		ALTER EVENT event_starts_test COMMENT "non-empty comment";
		--replace_column 8 # 9 #
		SHOW EVENTS;
		SELECT starts IS NULL, ends IS NULL, comment FROM mysql.event WHERE db='events_test' AND name='event_starts_test';
		ALTER EVENT event_starts_test COMMENT "";
		--replace_column 8 # 9 #
		SHOW EVENTS;
		DROP EVENT event_starts_test;
		#
		#
		create event e_43 on schedule every 1 second do set @a = 5;
		set global event_scheduler = 1;
		--sleep 2

sql/event.cc

+122 −120

Original line number	Diff line number	Diff line
		@@ -120,6 +120,7 @@ static TABLE_FIELD_W_TYPE event_table_fields[EVEX_FIELD_COUNT] = {
		{
		{(char *) STRING_WITH_LEN("last_executed")},
		{(char *) STRING_WITH_LEN("datetime")},
		{NULL, 0}
		},
		{
		{(char *) STRING_WITH_LEN("starts")},
		@@ -343,8 +344,6 @@ event_timed_compare_q(void vptr, byte a, byte *b)
		RETURNS
		0 - OK
		1 - Error


		*/

		int
		@@ -619,7 +618,7 @@ evex_fill_row(THD thd, TABLE table, event_timed *et, my_bool is_update)
		store(et->name.str, et->name.length, system_charset_info))
		goto trunc_err;

		// both ON_COMPLETION and STATUS are NOT NULL thus not calling set_notnull()
		/* both ON_COMPLETION and STATUS are NOT NULL thus not calling set_notnull() */
		table->field[EVEX_FIELD_ON_COMPLETION]->store((longlong)et->on_completion);

		table->field[EVEX_FIELD_STATUS]->store((longlong)et->status);
		@@ -637,20 +636,6 @@ evex_fill_row(THD thd, TABLE table, event_timed *et, my_bool is_update)
		goto trunc_err;
		}

		if (et->starts.year)
		{
		table->field[EVEX_FIELD_STARTS]->set_notnull();// set NULL flag to OFF
		table->field[EVEX_FIELD_STARTS]->
		store_time(&et->starts, MYSQL_TIMESTAMP_DATETIME);
		}

		if (et->ends.year)
		{
		table->field[EVEX_FIELD_ENDS]->set_notnull();
		table->field[EVEX_FIELD_ENDS]->
		store_time(&et->ends, MYSQL_TIMESTAMP_DATETIME);
		}

		if (et->expression)
		{
		table->field[EVEX_FIELD_INTERVAL_EXPR]->set_notnull();
		@@ -664,36 +649,54 @@ evex_fill_row(THD thd, TABLE table, event_timed *et, my_bool is_update)
		table->field[EVEX_FIELD_TRANSIENT_INTERVAL]->store((longlong)et->interval+1);

		table->field[EVEX_FIELD_EXECUTE_AT]->set_null();

		if (!et->starts_null)
		{
		table->field[EVEX_FIELD_STARTS]->set_notnull();
		table->field[EVEX_FIELD_STARTS]->
		store_time(&et->starts, MYSQL_TIMESTAMP_DATETIME);
		}

		if (!et->ends_null)
		{
		table->field[EVEX_FIELD_ENDS]->set_notnull();
		table->field[EVEX_FIELD_ENDS]->
		store_time(&et->ends, MYSQL_TIMESTAMP_DATETIME);
		}
		}
		else if (et->execute_at.year)
		{
		// fix_fields already called in init_execute_at
		table->field[EVEX_FIELD_INTERVAL_EXPR]->set_null();
		table->field[EVEX_FIELD_TRANSIENT_INTERVAL]->set_null();
		table->field[EVEX_FIELD_STARTS]->set_null();
		table->field[EVEX_FIELD_ENDS]->set_null();

		table->field[EVEX_FIELD_EXECUTE_AT]->set_notnull();
		table->field[EVEX_FIELD_EXECUTE_AT]->store_time(&et->execute_at,
		MYSQL_TIMESTAMP_DATETIME);

		table->field[EVEX_FIELD_TRANSIENT_INTERVAL]->set_null();
		}
		else
		{
		DBUG_ASSERT(is_update);
		// it is normal to be here when the action is update
		// this is an error if the action is create. something is borked
		/*
		it is normal to be here when the action is update
		this is an error if the action is create. something is borked
		*/
		}

		((Field_timestamp *)table->field[EVEX_FIELD_MODIFIED])->set_time();

		if (et->comment.length)
		if (table->field[field_num= EVEX_FIELD_COMMENT]->
		store(et->comment.str, et->comment.length, system_charset_info))
		if (et->comment.str)
		{
		if (table->field[field_num= EVEX_FIELD_COMMENT]->store(et->comment.str,
		et->comment.length,
		system_charset_info))
		goto trunc_err;
		}

		DBUG_RETURN(0);
		trunc_err:
		my_error(ER_EVENT_DATA_TOO_LONG, MYF(0));
		my_error(ER_EVENT_DATA_TOO_LONG, MYF(0), table->field[field_num]->field_name);
		DBUG_RETURN(EVEX_GENERAL_ERROR);
		}

		@@ -797,7 +800,10 @@ db_create_event(THD thd, event_timed et, my_bool create_if_not,

		((Field_timestamp *)table->field[EVEX_FIELD_CREATED])->set_time();

		// evex_fill_row() calls my_error() in case of error so no need to handle it here
		/*
		evex_fill_row() calls my_error() in case of error so no need to
		handle it here
		*/
		if ((ret= evex_fill_row(thd, table, et, false)))
		goto err;

		@@ -807,6 +813,7 @@ db_create_event(THD thd, event_timed et, my_bool create_if_not,
		goto err;
		}

		#ifdef USE_THIS_CODE_AS_TEMPLATE_WHEN_EVENT_REPLICATION_IS_AGREED
		if (mysql_bin_log.is_open())
		{
		thd->clear_error();
		@@ -814,6 +821,7 @@ db_create_event(THD thd, event_timed et, my_bool create_if_not,
		thd->binlog_query(THD::MYSQL_QUERY_TYPE,
		thd->query, thd->query_length, FALSE, FALSE);
		}
		#endif

		*rows_affected= 1;
		ok:
		@@ -865,7 +873,7 @@ db_update_event(THD thd, event_timed et, sp_name *new_name)
		goto err;
		}

		// first look whether we overwrite
		/* first look whether we overwrite */
		if (new_name)
		{
		if (!sortcmp_lex_string(et->name, new_name->m_name, system_charset_info) &&
		@@ -894,13 +902,12 @@ db_update_event(THD thd, event_timed et, sp_name *new_name)
		goto err;
		}


		store_record(table,record[1]);

		// Don't update create on row update.
		/* Don't update create on row update. */
		table->timestamp_field_type= TIMESTAMP_NO_AUTO_SET;

		// evex_fill_row() calls my_error() in case of error so no need to handle it here
		/* evex_fill_row() calls my_error() in case of error so no need to handle it here */
		if ((ret= evex_fill_row(thd, table, et, true)))
		goto err;

		@@ -918,7 +925,7 @@ db_update_event(THD thd, event_timed et, sp_name *new_name)
		goto err;
		}

		// close mysql.event or we crash later when loading the event from disk
		/* close mysql.event or we crash later when loading the event from disk */
		close_thread_tables(thd);
		DBUG_RETURN(0);

		@@ -995,7 +1002,7 @@ db_find_event(THD thd, sp_name name, LEX_STRING definer, event_timed *ett,
		delete et;
		et= 0;
		}
		// don't close the table if we haven't opened it ourselves
		/* don't close the table if we haven't opened it ourselves */
		if (!tbl && table)
		close_thread_tables(thd);
		*ett= et;
		@@ -1017,7 +1024,6 @@ db_find_event(THD thd, sp_name name, LEX_STRING definer, event_timed *ett,
		RETURN VALUE
		0 - OK
		< 0 - error (in this case underlying functions call my_error()).

		*/

		static int
		@@ -1036,7 +1042,7 @@ evex_load_and_compile_event(THD * thd, sp_name *spn, LEX_STRING definer,
		thd->mem_root= &evex_mem_root;

		thd->reset_n_backup_open_tables_state(&backup);
		// no need to use my_error() here because db_find_event() has done it
		/* no need to use my_error() here because db_find_event() has done it */
		ret= db_find_event(thd, spn, &definer, &ett, NULL, NULL);
		thd->restore_backup_open_tables_state(&backup);
		if (ret)
		@@ -1088,7 +1094,7 @@ evex_load_and_compile_event(THD * thd, sp_name *spn, LEX_STRING definer,
		ALTER EVENT.

		RETURNS
		0 - OK (always)
		0 OK (always)
		*/

		static int
		@@ -1131,7 +1137,7 @@ evex_remove_from_cache(LEX_STRING db, LEX_STRING name, bool use_lock,
		}
		DBUG_PRINT("evex_remove_from_cache", ("delete from queue"));
		evex_queue_delete_element(&EVEX_EQ_NAME, i);
		// ok, we have cleaned
		/* ok, we have cleaned */
		ret= 0;
		goto done;
		}
		@@ -1185,7 +1191,7 @@ evex_create_event(THD thd, event_timed et, uint create_options,
		VOID(pthread_mutex_unlock(&LOCK_evex_running));

		done:
		// No need to close the table, it will be closed in sql_parse::do_command
		/* No need to close the table, it will be closed in sql_parse::do_command */

		DBUG_RETURN(ret);
		}
		@@ -1259,7 +1265,6 @@ evex_update_event(THD thd, event_timed et, sp_name *new_name,
		et event's name
		drop_if_exists if set and the event not existing => warning onto the stack
		rows_affected affected number of rows is returned heres

		*/

		int db_drop_event(THD thd, event_timed et, bool drop_if_exists,
		@@ -1362,7 +1367,6 @@ evex_drop_event(THD thd, event_timed et, bool drop_if_exists,
		RETURNS
		0 - OK
		1 - Error during writing to the wire

		*/

		int
		@@ -1413,7 +1417,6 @@ evex_show_create_event(THD thd, sp_name spn, LEX_STRING definer)

		protocol->store((char*) sql_mode_str, sql_mode_len, system_charset_info);


		protocol->store(show_str.c_ptr(), show_str.length(), system_charset_info);
		ret= protocol->write();
		send_eof(thd);
		@@ -1449,7 +1452,6 @@ evex_show_create_event(THD thd, sp_name spn, LEX_STRING definer)
		spawned and can_spawn() is the right method.
		- event_timed::can_spawn() returns false -> being runned ATM
		just set the flags so it should drop itself.

		*/

		int
		@@ -1521,7 +1523,7 @@ evex_drop_db_events(THD thd, char db)
		}
		DBUG_PRINT("info",("%d elements in the queue",
		evex_queue_num_elements(EVEX_EQ_NAME)));
		evex_queue_delete_element(&EVEX_EQ_NAME, i);// 1 is top
		evex_queue_delete_element(&EVEX_EQ_NAME, i);// 0 is top
		DBUG_PRINT("info",("%d elements in the queue",
		evex_queue_num_elements(EVEX_EQ_NAME)));
		/*
		@@ -1598,7 +1600,7 @@ evex_drop_db_events(THD thd, char db)
		VOID(pthread_mutex_unlock(&LOCK_event_arrays));
		end_read_record(&read_record_info);

		thd->version--; // Force close to free memory
		thd->version--; /* Force close to free memory */

		close_thread_tables(thd);

sql/event.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -103,6 +103,9 @@ class event_timed
		TIME starts;
		TIME ends;
		TIME execute_at;
		my_bool starts_null;
		my_bool ends_null;
		my_bool execute_at_null;

		longlong expression;
		interval_type interval;

sql/event_executor.cc

+66 −63

Original line number	Diff line number	Diff line
		@@ -135,7 +135,7 @@ evex_check_system_tables()
		bool not_used;
		Open_tables_state backup;

		// thd is 0x0 during boot of the server. Later it's !=0x0
		/* thd is 0x0 during boot of the server. Later it's !=0x0 */
		if (!thd)
		return;

		@@ -206,7 +206,7 @@ init_events()
		if (event_executor_running_global_var)
		{
		#ifndef DBUG_FAULTY_THR
		//TODO Andrey: Change the error code returned!
		/* TODO Andrey: Change the error code returned! */
		if (pthread_create(&th, &connection_attrib, event_executor_main,(void*)NULL))
		DBUG_RETURN(ER_SLAVE_THREAD);
		#else
		@@ -339,14 +339,14 @@ executor_wait_till_next_event_exec(THD *thd)
		if (et->dropped)
		et->drop(thd);
		delete et;
		evex_queue_delete_element(&EVEX_EQ_NAME, 1);// 1 is top
		evex_queue_delete_element(&EVEX_EQ_NAME, 0);// 0 is top, internally 1
		VOID(pthread_mutex_unlock(&LOCK_event_arrays));
		sql_print_information("Event found disabled, dropping.");
		DBUG_RETURN(1);
		}

		DBUG_PRINT("evex main thread",("computing time to sleep till next exec"));
		// set the internal clock of thd
		/* set the internal clock of thd */
		thd->end_time();
		my_tz_UTC->gmt_sec_to_TIME(&time_now, thd->query_start());
		t2sleep= evex_time_diff(&et->execute_at, &time_now);
		@@ -387,7 +387,7 @@ executor_wait_till_next_event_exec(THD *thd)

		SYNOPSIS
		event_executor_main()
		arg - unused
		arg unused

		NOTES
		1. The host of the thead is my_localhost
		@@ -407,11 +407,10 @@ event_executor_main(void *arg)
		DBUG_PRINT("event_executor_main", ("EVEX thread started"));


		// init memory root
		/* init memory root */
		init_alloc_root(&evex_mem_root, MEM_ROOT_BLOCK_SIZE, MEM_ROOT_PREALLOC);


		// needs to call my_thread_init(), otherwise we get a coredump in DBUG_ stuff
		/* needs to call my_thread_init(), otherwise we get a coredump in DBUG_ stuff*/
		my_thread_init();

		if (sizeof(my_time_t) != sizeof(time_t))
		@@ -422,8 +421,8 @@ event_executor_main(void *arg)
		goto err_no_thd;
		}

		//TODO Andrey: Check for NULL
		if (!(thd = new THD)) // note that contructor of THD uses DBUG_ !
		/* note that contructor of THD uses DBUG_ ! */
		if (!(thd = new THD))
		{
		sql_print_error("SCHEDULER: Cannot create THD for the main thread.");
		goto err_no_thd;
		@@ -523,8 +522,7 @@ event_executor_main(void *arg)
		et= evex_queue_first_element(&EVEX_EQ_NAME, event_timed*);
		DBUG_PRINT("evex main thread",("got event from the queue"));

		if (et->execute_at.year > 1969 &&
		my_time_compare(&time_now, &et->execute_at) == -1)
		if (!et->execute_at_null && my_time_compare(&time_now,&et->execute_at) == -1)
		{
		DBUG_PRINT("evex main thread",("still not the time for execution"));
		VOID(pthread_mutex_unlock(&LOCK_event_arrays));
		@@ -571,8 +569,11 @@ event_executor_main(void *arg)
		#else
		event_executor_worker((void *) et);
		#endif
		if ((et->execute_at.year && !et->expression) \|\|
		TIME_to_ulonglong_datetime(&et->execute_at) == 0)
		/*
		1. For one-time event : year is > 0 and expression is 0
		2. For recurring, expression is != -=> check execute_at_null in this case
		*/
		if ((et->execute_at.year && !et->expression) \|\| et->execute_at_null)
		et->flags \|= EVENT_EXEC_NO_MORE;

		if ((et->flags & EVENT_EXEC_NO_MORE) \|\| et->status == MYSQL_EVENT_DISABLED)
		@@ -582,10 +583,10 @@ event_executor_main(void *arg)
		}
		DBUG_PRINT("evex main thread",("unlocking"));
		VOID(pthread_mutex_unlock(&LOCK_event_arrays));
		}// while
		}/* while */
		finish:

		// First manifest that this thread does not work and then destroy
		/* First manifest that this thread does not work and then destroy */
		VOID(pthread_mutex_lock(&LOCK_evex_running));
		evex_is_running= false;
		evex_main_thread_id= 0;
		@@ -625,7 +626,7 @@ event_executor_main(void *arg)
		delete et;
		}
		VOID(pthread_mutex_unlock(&LOCK_event_arrays));
		// ... then we can thrash the whole queue at once
		/* ... then we can thrash the whole queue at once */
		evex_queue_destroy(&EVEX_EQ_NAME);

		thd->proc_info = "Clearing";
		@@ -665,7 +666,7 @@ event_executor_main(void *arg)

		SYNOPSIS
		event_executor_worker()
		arg - the event_timed object to be processed
		arg The event_timed object to be processed
		*/

		pthread_handler_t
		@@ -682,7 +683,7 @@ event_executor_worker(void *event_void)
		#ifndef DBUG_FAULTY_THR
		my_thread_init();

		if (!(thd = new THD)) // note that contructor of THD uses DBUG_ !
		if (!(thd = new THD)) /* note that contructor of THD uses DBUG_ ! */
		{
		sql_print_error("SCHEDULER: Cannot create a THD structure in an worker.");
		goto err_no_thd;
		@@ -697,7 +698,7 @@ event_executor_worker(void *event_void)

		thd->init_for_queries();

		// make this thread visible it has no vio -> show processlist needs this flag
		/* make this thread visible it has no vio -> show processlist needs this flag */
		thd->system_thread= 1;

		VOID(pthread_mutex_lock(&LOCK_thread_count));
		@@ -778,8 +779,8 @@ event_executor_worker(void *event_void)
		thd - Thread context. Used for memory allocation in some cases.

		RETURNS
		0 - OK
		!0 - Error
		0 OK
		!0 Error

		NOTES
		Reports the error to the console
		@@ -845,7 +846,7 @@ evex_load_events_from_db(THD *thd)
		break;
		}

		// let's find when to be executed
		/* let's find when to be executed */
		if (et->compute_next_execution_time())
		{
		sql_print_error("SCHEDULER: Error while computing execution time of %s.%s."
		@@ -867,7 +868,8 @@ evex_load_events_from_db(THD *thd)
		VOID(pthread_mutex_unlock(&LOCK_event_arrays));
		end_read_record(&read_record_info);

		thd->version--; // Force close to free memory
		/* Force close to free memory */
		thd->version--;

		close_thread_tables(thd);
		if (!ret)
		@@ -889,13 +891,13 @@ evex_load_events_from_db(THD *thd)
		car - the new value

		Returns
		0 - OK (always)
		0 OK (always)
		*/

		bool
		sys_var_event_executor::update(THD thd, set_var var)
		{
		// here start the thread if not running.
		/* here start the thread if not running. */
		DBUG_ENTER("sys_var_event_executor::update");
		VOID(pthread_mutex_lock(&LOCK_evex_running));
		*value= var->save_result.ulong_value;
		@@ -952,7 +954,8 @@ evex_print_warnings(THD thd, event_timed et)
		while ((err= it++))
		{
		String err_msg(msg_buf, sizeof(msg_buf), system_charset_info);
		err_msg.length(0);// set it to 0 or we start adding at the end
		/* set it to 0 or we start adding at the end. That's the trick ;) */
		err_msg.length(0);
		if (!prefix.length())
		{
		prefix.append("SCHEDULER: [");