Event Scheduler

Collaboration diagram for Event Scheduler:

Files
file	event_data_objects.h
file	event_db_repository.h
	Data Dictionary related operations of Event Scheduler.
file	event_queue.h
	Queue of events awaiting execution.
file	event_scheduler.h
	Declarations of the scheduler thread class and related functionality.
file	events.h
	A public interface of Events_Scheduler module.

Namespaces
namespace	dd
	The version of the current data dictionary table definitions.

Classes
class	Event_creation_ctx
	Event_creation_ctx – creation context of events. More...
class	Event_queue_element_for_exec
class	Event_basic
class	Event_queue_element
class	Event_timed
class	Event_job_data
class	Event_db_repository
struct	Event_queue_less
class	Event_queue
	Queue of active events awaiting execution. More...
struct	scheduler_param
class	Is_worker
	This class implements callback for do_for_all_thd(). More...
class	Event_worker_thread
class	Event_scheduler
class	Events
	A facade to the functionality of the Event Scheduler. More...

Macros
#define	EVENT_QUEUE_INITIAL_SIZE   30
#define	LOCK_QUEUE_DATA()   lock_data(__func__, __LINE__)
#define	UNLOCK_QUEUE_DATA()   unlock_data(__func__, __LINE__)
#define	LOCK_DATA()   lock_data(__func__, __LINE__)
#define	UNLOCK_DATA()   unlock_data(__func__, __LINE__)
#define	COND_STATE_WAIT(mythd, abstime, stage)    cond_wait(mythd, abstime, stage, __func__, __FILE__, __LINE__)

Typedefs
using	sql_mode_t = uint64_t

Functions
void	init_scheduler_psi_keys ()
static LEX_STRING	make_lex_string (MEM_ROOT *mem_root, const dd::String_type &str)
static LEX_CSTRING	make_lex_cstring (MEM_ROOT *mem_root, const dd::String_type &str)
static my_time_t	add_interval (MYSQL_TIME *ltime, const Time_zone *time_zone, interval_type scale, Interval interval)
static bool	get_next_time (const Time_zone *time_zone, my_time_t *next, my_time_t start, my_time_t time_now, int i_value, interval_type i_type)
	Computes the sum of a timestamp plus interval. More...
static void	append_datetime (String *buf, Time_zone *time_zone, my_time_t secs, const char *name, uint len)
bool	construct_drop_event_sql (THD *thd, String *sp_sql, LEX_CSTRING schema_name, LEX_CSTRING event_name)
	Get DROP EVENT statement to binlog the drop of ON COMPLETION NOT PRESERVE event. More...
bool	event_basic_db_equal (LEX_CSTRING db, Event_basic *et)
bool	event_basic_identifier_equal (LEX_CSTRING db, LEX_CSTRING name, Event_basic *b)
bool	post_init_event_thread (THD *thd)
void	deinit_event_thread (THD *thd)
void	pre_init_event_thread (THD *thd)
static void *	event_scheduler_thread (void *arg)
static void *	event_worker_thread (void *arg)
	Function that executes an event in a child thread. More...
static bool	load_events_from_db (THD *thd, Event_queue *event_queue)
	Loads all ENABLED events into a prioritized queue. More...
int	sortcmp_lex_string (LEX_CSTRING s, LEX_CSTRING t, const CHARSET_INFO *cs)
static int	create_query_string (THD *thd, String *buf)
	Create a new query string for removing executable comments for avoiding leak and keeping consistency of the execution on master and slave. More...
static bool	send_show_create_event (THD *thd, Event_timed *et, Protocol *protocol)
	A helper function to generate SHOW CREATE EVENT output from a named event. More...
static void	init_events_psi_keys (void)
static bool	Event_creation_ctx::create_event_creation_ctx (const dd::Event &event_obj, Stored_program_creation_ctx **ctx)
bool	Event_queue_element_for_exec::init (LEX_CSTRING dbname, LEX_CSTRING name)
void	Event_queue_element_for_exec::claim_memory_ownership (bool claim)
	Event_queue_element_for_exec::~Event_queue_element_for_exec ()
	Event_basic::Event_basic ()
virtual	Event_basic::~Event_basic ()
	Event_queue_element::Event_queue_element ()
	Event_queue_element::~Event_queue_element () override
	Event_timed::Event_timed ()
	Event_timed::~Event_timed () override
	Event_job_data::Event_job_data ()
void	Event_timed::init ()
bool	Event_job_data::fill_event_info (THD *thd, const dd::Event &event, const char *schema_name) override
bool	Event_queue_element::fill_event_info (THD *thd, const dd::Event &event, const char *dbname) override
bool	Event_timed::fill_event_info (THD *thd, const dd::Event &event, const char *schema_name) override
bool	Event_queue_element::compute_next_execution_time (THD *thd)
void	Event_queue_element::mark_last_executed (THD *thd)
	Set last execution time. More...
int	Event_timed::get_create_event (const THD *thd, String *buf)
	Get SHOW CREATE EVENT as string. More...
bool	Event_job_data::construct_sp_sql (THD *thd, String *sp_sql)
	Get an artificial stored procedure to parse as an event definition. More...
bool	Event_job_data::execute (THD *thd, bool drop)
	Compiles and executes the event (the underlying sp_head object) More...
static bool	Event_db_repository::create_event (THD *thd, Event_parse_data *parse_data, bool create_if_not, bool *event_already_exists)
	Creates an event object and persist to Data Dictionary. More...
static bool	Event_db_repository::update_event (THD *thd, Event_parse_data *parse_data, const LEX_CSTRING *new_dbname, const LEX_CSTRING *new_name)
	Used to execute ALTER EVENT. More...
static bool	Event_db_repository::drop_event (THD *thd, LEX_CSTRING db, LEX_CSTRING name, bool drop_if_exists, bool *event_exists)
	Delete event. More...
static bool	Event_db_repository::drop_schema_events (THD *thd, const dd::Schema &schema)
	Drops all events in the selected database. More...
static bool	Event_db_repository::load_named_event (THD *thd, LEX_CSTRING dbname, LEX_CSTRING name, Event_basic *et)
	Looks for a named event in the Data Dictionary and load it. More...
static bool	Event_db_repository::update_timing_fields_for_event (THD *thd, LEX_CSTRING event_db_name, LEX_CSTRING event_name, my_time_t last_executed, ulonglong status)
	Update the event in Data Dictionary with changed status and/or last execution time. More...
	Event_queue::Event_queue ()
	Event_queue::~Event_queue ()
bool	Event_queue::init_queue ()
void	Event_queue::deinit_queue ()
bool	Event_queue::create_event (THD *thd, Event_queue_element *new_element, bool *created)
	Adds an event to the queue. More...
void	Event_queue::update_event (THD *thd, LEX_CSTRING dbname, LEX_CSTRING name, Event_queue_element *new_element)
void	Event_queue::drop_event (THD *thd, LEX_CSTRING dbname, LEX_CSTRING name)
void	Event_queue::drop_matching_events (LEX_CSTRING pattern, bool(*)(LEX_CSTRING, Event_basic *))
void	Event_queue::drop_schema_events (LEX_CSTRING schema)
void	Event_queue::find_n_remove_event (LEX_CSTRING db, LEX_CSTRING name)
void	Event_queue::recalculate_activation_times (THD *thd)
void	Event_queue::empty_queue ()
void	Event_queue::dbug_dump_queue (time_t now)
bool	Event_queue::get_top_for_execution_if_time (THD *thd, Event_queue_element_for_exec **event_name)
void	Event_queue::lock_data (const char *func, uint line)
void	Event_queue::unlock_data (const char *func, uint line)
void	Event_queue::cond_wait (THD *thd, struct timespec *abstime, const PSI_stage_info *stage, const char *src_func, const char *src_file, uint src_line)
void	Event_queue::dump_internal_status ()
void	Event_worker_thread::print_warnings (THD *thd, Event_job_data *et)
void	Event_worker_thread::run (THD *thd, Event_queue_element_for_exec *event)
	Function that executes an event in a child thread. More...
	Event_scheduler::Event_scheduler (Event_queue *event_queue_arg)
	Event_scheduler::~Event_scheduler ()
bool	Event_scheduler::start (int *err_no)
	Starts the scheduler (again). More...
bool	Event_scheduler::run (THD *thd)
bool	Event_scheduler::execute_top (Event_queue_element_for_exec *event_name)
bool	Event_scheduler::is_running ()
bool	Event_scheduler::stop ()
	Stops the scheduler (again). More...
int	Event_scheduler::workers_count ()
void	Event_scheduler::lock_data (const char *func, uint line)
void	Event_scheduler::unlock_data (const char *func, uint line)
void	Event_scheduler::cond_wait (THD *thd, struct timespec *abstime, const PSI_stage_info *stage, const char *src_func, const char *src_file, uint src_line)
void	Event_scheduler::dump_internal_status ()
static int	Events::reconstruct_interval_expression (String *buf, interval_type interval, longlong expression)
static bool	Events::create_event (THD *thd, Event_parse_data *parse_data, bool if_exists)
	Create a new event. More...
static bool	Events::update_event (THD *thd, Event_parse_data *parse_data, const LEX_CSTRING *new_dbname, const LEX_CSTRING *new_name)
	Alter an event. More...
static bool	Events::drop_event (THD *thd, LEX_CSTRING dbname, LEX_CSTRING name, bool if_exists)
	Drops an event. More...
static bool	Events::lock_schema_events (THD *thd, const dd::Schema &schema)
	Take exclusive metadata lock on all events in a schema. More...
static bool	Events::drop_schema_events (THD *thd, const dd::Schema &schema)
	Drops all events from a schema. More...
static bool	Events::show_create_event (THD *thd, LEX_CSTRING dbname, LEX_CSTRING name)
	Implement SHOW CREATE EVENT statement. More...
static bool	Events::init (bool opt_noacl)
	Initializes the scheduler's structures. More...
static void	Events::deinit ()
static void	Events::init_mutexes ()
static void	Events::dump_internal_status ()
static bool	Events::start (int *err_no)
static bool	Events::stop ()

Variables
PSI_mutex_key	key_LOCK_event_queue
PSI_cond_key	key_COND_queue_state
my_thread_attr_t	connection_attrib
static const LEX_CSTRING	scheduler_states_names []
PSI_mutex_key	key_LOCK_event_queue
PSI_mutex_key	key_event_scheduler_LOCK_scheduler_state
static PSI_mutex_info	all_events_mutexes []
PSI_cond_key	key_event_scheduler_COND_state
PSI_cond_key	key_COND_queue_state
static PSI_cond_info	all_events_conds []
PSI_thread_key	key_thread_event_scheduler
PSI_thread_key	key_thread_event_worker
static PSI_thread_info	all_events_threads []
PSI_stage_info	stage_waiting_on_empty_queue
PSI_stage_info	stage_waiting_for_next_activation
PSI_stage_info	stage_waiting_for_scheduler_to_stop
PSI_memory_key	key_memory_event_basic_root
PSI_stage_info *	all_events_stages []
static PSI_memory_info	all_events_memory []
PSI_mutex_key	key_event_scheduler_LOCK_scheduler_state
PSI_cond_key	key_event_scheduler_COND_state
PSI_thread_key	key_thread_event_scheduler
PSI_thread_key	key_thread_event_worker
PSI_stage_info	stage_waiting_on_empty_queue
PSI_stage_info	stage_waiting_for_next_activation
PSI_stage_info	stage_waiting_for_scheduler_to_stop
static PSI_statement_info	Event_queue_element_for_exec::psi_info
static Event_queue *	Events::event_queue
static Event_scheduler *	Events::scheduler
static ulong	Events::opt_event_scheduler = Events::EVENTS_OFF

Detailed Description

Macro Definition Documentation

COND_STATE_WAIT

#define COND_STATE_WAIT	(		mythd,
			abstime,
			stage
	)		cond_wait(mythd, abstime, stage, __func__, __FILE__, __LINE__)

EVENT_QUEUE_INITIAL_SIZE

#define EVENT_QUEUE_INITIAL_SIZE   30

LOCK_DATA

#define LOCK_DATA

(

)

lock_data(__func__, __LINE__)

LOCK_QUEUE_DATA

#define LOCK_QUEUE_DATA

(

)

lock_data(__func__, __LINE__)

UNLOCK_DATA

#define UNLOCK_DATA

(

)

unlock_data(__func__, __LINE__)

UNLOCK_QUEUE_DATA

#define UNLOCK_QUEUE_DATA

(

)

unlock_data(__func__, __LINE__)

Typedef Documentation

sql_mode_t

using sql_mode_t = uint64_t

Function Documentation

Event_basic()

Event_basic::Event_basic

(

)

Event_job_data()

Event_job_data::Event_job_data

(

)

Event_queue()

Event_queue::Event_queue

(

)

Event_queue_element()

Event_queue_element::Event_queue_element

(

)

Event_scheduler()

Event_scheduler::Event_scheduler

(

Event_queue *

event_queue_arg

)

Event_timed()

Event_timed::Event_timed

(

)

~Event_basic()

Event_basic::~Event_basic ( )

virtual

~Event_queue()

Event_queue::~Event_queue

(

)

~Event_queue_element()

Event_queue_element::~Event_queue_element ( )

overridedefault

~Event_queue_element_for_exec()

Event_queue_element_for_exec::~Event_queue_element_for_exec

(

)

~Event_scheduler()

Event_scheduler::~Event_scheduler

(

)

~Event_timed()

Event_timed::~Event_timed ( )

overridedefault

add_interval()

static my_time_t add_interval ( MYSQL_TIME *  ltime, const Time_zone *  time_zone, interval_type  scale, Interval  interval  )

static

append_datetime()

static void append_datetime ( String *  buf, Time_zone *  time_zone, my_time_t  secs, const char *  name, uint  len  )

static

claim_memory_ownership()

void Event_queue_element_for_exec::claim_memory_ownership

(

bool

claim

)

compute_next_execution_time()

bool Event_queue_element::compute_next_execution_time

(

THD *

thd

)

cond_wait() [1/2]

void Event_queue::cond_wait ( THD *  thd, struct timespec *  abstime, const PSI_stage_info *  stage, const char *  src_func, const char *  src_file, uint  src_line  )

private

cond_wait() [2/2]

void Event_scheduler::cond_wait ( THD *  thd, struct timespec *  abstime, const PSI_stage_info *  stage, const char *  src_func, const char *  src_file, uint  src_line  )

private

construct_drop_event_sql()

bool construct_drop_event_sql	(	THD *	thd,
		String *	sp_sql,
		LEX_CSTRING	db_name,
		LEX_CSTRING	event_name
	)

Get DROP EVENT statement to binlog the drop of ON COMPLETION NOT PRESERVE event.

Build an SQL drop event string.

Parameters

[in]	thd	Thread handle
[in,out]	sp_sql	Pointer to String object where the SQL query will be stored
[in]	db_name	The schema name
[in]	event_name	The event name

Return values

false	The drop event SQL query is built
true	Otherwise

construct_sp_sql()

bool Event_job_data::construct_sp_sql ( THD *  thd, String *  sp_sql  )

private

Get an artificial stored procedure to parse as an event definition.

create_event() [1/3]

bool Event_db_repository::create_event ( THD *  thd, Event_parse_data *  parse_data, bool  create_if_not, bool *  event_already_exists  )

static

Creates an event object and persist to Data Dictionary.

Precondition

All semantic checks must be performed outside.

Parameters

[in,out]	thd	THD
[in]	parse_data	Parsed event definition
[in]	create_if_not	true if IF NOT EXISTS clause was provided to CREATE EVENT statement
[out]	event_already_exists	When method is completed successfully set to true if event already exists else set to false

Return values

false	Success
true	Error

create_event() [2/3]

bool Events::create_event ( THD *  thd, Event_parse_data *  parse_data, bool  if_not_exists  )

static

Create a new event.

Atomicity: The operation to create an event is atomic/crash-safe. Changes to the Data-dictionary and writing event to binlog are part of the same transaction. All the changes are done as part of the same transaction or do not have any side effects on the operation failure. Data-dictionary cache and event queues are in sync with operation state. Cache and event queue does not contain any stale/incorrect data in case of failure. In case of crash, there won't be any discrepancy between the data-dictionary table and the binary log.

Parameters

[in,out]	thd	THD
[in]	parse_data	Event's data from parsing stage
[in]	if_not_exists	Whether IF NOT EXISTS was specified In case there is an event with the same name (db) and IF NOT EXISTS is specified, an warning is put into the stack.

See also

Events::drop_event for the notes about locking, pre-locking and Events DDL.

Return values

false	OK
true	Error (reported)

create_event() [3/3]

bool Event_queue::create_event	(	THD *	thd,
		Event_queue_element *	new_element,
		bool *	created
	)

Adds an event to the queue.

Compute the next execution time for an event, and if it is still active, add it to the queue. The object is left intact in case of an error. Otherwise the queue container assumes ownership of it.

Parameters

[in]	thd	thread handle
[in]	new_element	a new element to add to the queue
[out]	created	set to true if no error and the element is added to the queue, false otherwise

Return values

true	an error occurred. The value of created is undefined, the element was not deleted.
false	success

create_event_creation_ctx()

bool Event_creation_ctx::create_event_creation_ctx ( const dd::Event &  event_obj, Stored_program_creation_ctx **  ctx  )

static

create_query_string()

static int create_query_string ( THD *  thd, String *  buf  )

static

Create a new query string for removing executable comments for avoiding leak and keeping consistency of the execution on master and slave.

Parameters

[in]	thd	Thread handler
[in]	buf	Query string

Returns

0 ok 1 error

dbug_dump_queue()

void Event_queue::dbug_dump_queue ( time_t  now )

private

deinit()

void Events::deinit ( )

static

deinit_event_thread()

void deinit_event_thread

(

THD *

thd

)

deinit_queue()

void Event_queue::deinit_queue ( )

private

drop_event() [1/3]

bool Event_db_repository::drop_event ( THD *  thd, LEX_CSTRING  db, LEX_CSTRING  name, bool  drop_if_exists, bool *  event_exists  )

static

Delete event.

Parameters

[in]	thd	THD context
[in]	db	Database name
[in]	name	Event name
[in]	drop_if_exists	DROP IF EXISTS clause was specified. If set, and the event does not exist, the error is downgraded to a warning.
[out]	event_exists	Set to true if event exists. Set to false otherwise.

Return values

false	success
true	error (reported)

drop_event() [2/3]

void Event_queue::drop_event	(	THD *	thd,
		LEX_CSTRING	dbname,
		LEX_CSTRING	name
	)

drop_event() [3/3]

bool Events::drop_event ( THD *  thd, LEX_CSTRING  dbname, LEX_CSTRING  name, bool  if_exists  )

static

Drops an event.

Atomicity: The operation to drop an event is atomic/crash-safe. Changes to the Data-dictionary and writing event to binlog are part of the same transaction. All the changes are done as part of the same transaction or do not have any side effects on the operation failure. Data-dictionary cache and event queues are in sync with operation state. Cache and event queue does not contain any stale/incorrect data in case of failure. In case of crash, there won't be any discrepancy between the data-dictionary table and the binary log.

Parameters

[in,out]	thd	THD
[in]	dbname	Event's schema
[in]	name	Event's name
[in]	if_exists	When this is set and the event does not exist a warning is pushed into the warning stack. Otherwise the operation produces an error.

Note

Similarly to DROP PROCEDURE, we do not allow DROP EVENT under LOCK TABLES mode, unless table mysql.event is locked. To ensure that, we do not reset & backup the open tables state in this function - if in LOCK TABLES or pre-locking mode, this will lead to an error 'Table mysql.event is not locked with LOCK TABLES' unless it is locked. In pre-locked mode there is another barrier - DROP EVENT commits the current transaction, and COMMIT/ROLLBACK is not allowed in stored functions and triggers.

Return values

false	OK
true	Error (reported)

drop_matching_events()

void Event_queue::drop_matching_events ( LEX_CSTRING  pattern, bool(*)(LEX_CSTRING, Event_basic *)  comparator  )

private

drop_schema_events() [1/3]

void Event_queue::drop_schema_events

(

LEX_CSTRING

schema

)

drop_schema_events() [2/3]

bool Event_db_repository::drop_schema_events ( THD *  thd, const dd::Schema &  schema  )

static

Drops all events in the selected database.

Parameters

thd	THD context
schema	The database under which events are to be dropped.

Returns

true on error, false on success.

drop_schema_events() [3/3]

bool Events::drop_schema_events ( THD *  thd, const dd::Schema &  schema  )

static

Drops all events from a schema.

Note

We allow to drop all events in a schema even if the scheduler is disabled. This is to not produce any warnings in case of DROP DATABASE and a disabled scheduler.

Parameters

[in]	thd	THD handle.
[in]	schema	Schema object.

Returns

true drop events from database failed.

false drop events from database succeeded.

dump_internal_status() [1/3]

void Event_queue::dump_internal_status

(

)

dump_internal_status() [2/3]

void Event_scheduler::dump_internal_status

(

)

dump_internal_status() [3/3]

void Events::dump_internal_status ( )

static

empty_queue()

void Event_queue::empty_queue ( )

private

event_basic_db_equal()

bool event_basic_db_equal	(	LEX_CSTRING	db,
		Event_basic *	et
	)

event_basic_identifier_equal()

bool event_basic_identifier_equal	(	LEX_CSTRING	db,
		LEX_CSTRING	name,
		Event_basic *	b
	)

event_scheduler_thread()

static void * event_scheduler_thread ( void *  arg )

static

event_worker_thread()

static void * event_worker_thread ( void *  arg )

static

Function that executes an event in a child thread.

Setups the environment for the event execution and cleans after that.

SYNOPSIS event_worker_thread() arg The Event_job_data object to be processed

RETURN VALUE 0 OK

execute()

bool Event_job_data::execute	(	THD *	thd,
		bool	drop
	)

Compiles and executes the event (the underlying sp_head object)

Return values

true	error (reported to the error log)
false	success

execute_top()

bool Event_scheduler::execute_top ( Event_queue_element_for_exec *  event_name )

private

fill_event_info() [1/3]

bool Event_queue_element::fill_event_info ( THD *  thd, const dd::Event &  event, const char *  dbname  )

overridevirtual

Implements Event_basic.

Reimplemented in Event_timed.

fill_event_info() [2/3]

bool Event_timed::fill_event_info ( THD *  thd, const dd::Event &  event, const char *  schema_name  )

overridevirtual

Reimplemented from Event_queue_element.

fill_event_info() [3/3]

bool Event_job_data::fill_event_info ( THD *  thd, const dd::Event &  event, const char *  schema_name  )

overrideprivatevirtual

Implements Event_basic.

find_n_remove_event()

void Event_queue::find_n_remove_event ( LEX_CSTRING  db, LEX_CSTRING  name  )

private

get_create_event()

int Event_timed::get_create_event	(	const THD *	thd,
		String *	buf
	)

Get SHOW CREATE EVENT as string.

Parameters

thd	THD context.
buf	String*, should be already allocated. CREATE EVENT goes inside.

Return values

0

OK

get_next_time()

static bool get_next_time ( const Time_zone *  time_zone, my_time_t *  next, my_time_t  start, my_time_t  time_now, int  i_value, interval_type  i_type  )

static

Computes the sum of a timestamp plus interval.

Parameters

time_zone	event time zone
next	the sum
start	add interval_value to this time
time_now	current time
i_value	quantity of time type interval to add
i_type	type of interval to add (SECOND, MINUTE, HOUR, WEEK ...)

Return values

0	on success
1	on error.

Note

1. If the interval is conversible to SECOND, like MINUTE, HOUR, DAY, WEEK. Then we use TIMEDIFF()'s implementation as underlying and number of seconds as resolution for computation.
2. In all other cases - MONTH, QUARTER, YEAR we use MONTH as resolution and PERIOD_DIFF()'s implementation

get_top_for_execution_if_time()

bool Event_queue::get_top_for_execution_if_time	(	THD *	thd,
		Event_queue_element_for_exec **	event_name
	)

init() [1/3]

void Event_timed::init

(

)

init() [2/3]

bool Events::init ( bool  opt_noacl_or_bootstrap )

static

Initializes the scheduler's structures.

Parameters

opt_noacl_or_bootstrap

true if there is –skip-grant-tables or –initialize. In that case we disable the event scheduler.

Note

This function is not synchronized.

Return values

false	Perhaps there was an error, and the event scheduler is disabled. But the error is not fatal and the server start up can continue.
true	Fatal error. Startup must terminate (call unireg_abort()).

init() [3/3]

bool Event_queue_element_for_exec::init	(	LEX_CSTRING	dbname,
		LEX_CSTRING	name
	)

init_events_psi_keys()

static void init_events_psi_keys ( void  )

static

init_mutexes()

void Events::init_mutexes ( )

static

init_queue()

bool Event_queue::init_queue

(

)

init_scheduler_psi_keys()

void init_scheduler_psi_keys

(

)

is_running()

bool Event_scheduler::is_running

(

)

load_events_from_db()

static bool load_events_from_db ( THD *  thd, Event_queue *  event_queue  )

static

Loads all ENABLED events into a prioritized queue.

This function is called during the server start up. It reads every event, computes the next execution time, and if the event needs execution, adds it to a prioritized queue. Otherwise, if ON COMPLETION DROP is specified, the event is automatically removed from the table.

Parameters

thd	THD context. Used for memory allocation in some cases.
event_queue	Pointer to Event_queue object.

Return values

false	success
true	error, the load is aborted

Note

Reports the error to the console

load_named_event()

bool Event_db_repository::load_named_event ( THD *  thd, LEX_CSTRING  dbname, LEX_CSTRING  name, Event_basic *  etn  )

static

Looks for a named event in the Data Dictionary and load it.

Precondition

The given thread does not have open tables.

Return values

false	success
true	error

lock_data() [1/2]

void Event_queue::lock_data ( const char *  func, uint  line  )

private

lock_data() [2/2]

void Event_scheduler::lock_data ( const char *  func, uint  line  )

private

lock_schema_events()

bool Events::lock_schema_events ( THD *  thd, const dd::Schema &  schema  )

static

Take exclusive metadata lock on all events in a schema.

Parameters

thd	Thread handle.
schema	Schema object.

make_lex_cstring()

static LEX_CSTRING make_lex_cstring ( MEM_ROOT *  mem_root, const dd::String_type &  str  )

inlinestatic

make_lex_string()

static LEX_STRING make_lex_string ( MEM_ROOT *  mem_root, const dd::String_type &  str  )

inlinestatic

mark_last_executed()

void Event_queue_element::mark_last_executed

(

THD *

thd

)

Set last execution time.

Parameters

thd	THD context

post_init_event_thread()

bool post_init_event_thread

(

THD *

thd

)

pre_init_event_thread()

void pre_init_event_thread

(

THD *

thd

)

print_warnings()

void Event_worker_thread::print_warnings ( THD *  thd, Event_job_data *  et  )

private

recalculate_activation_times()

void Event_queue::recalculate_activation_times

(

THD *

thd

)

reconstruct_interval_expression()

int Events::reconstruct_interval_expression ( String *  buf, interval_type  interval, longlong  expression  )

static

run() [1/2]

bool Event_scheduler::run

(

THD *

thd

)

run() [2/2]

void Event_worker_thread::run	(	THD *	thd,
		Event_queue_element_for_exec *	event
	)

Function that executes an event in a child thread.

Setups the environment for the event execution and cleans after that.

SYNOPSIS Event_worker_thread::run() thd Thread context event The Event_queue_element_for_exec object to be processed

send_show_create_event()

static bool send_show_create_event ( THD *  thd, Event_timed *  et, Protocol *  protocol  )

static

A helper function to generate SHOW CREATE EVENT output from a named event.

Parameters

[in]	thd	THD handle.
[in]	et	Pointer to Event_timed object.
[in]	protocol	Pointer to Protocol object.

show_create_event()

bool Events::show_create_event ( THD *  thd, LEX_CSTRING  dbname, LEX_CSTRING  name  )

static

Implement SHOW CREATE EVENT statement.

thd   Thread context
spn   The name of the event (db, name)

Return values

false	OK
true	error (reported)

sortcmp_lex_string()

int sortcmp_lex_string	(	LEX_CSTRING	s,
		LEX_CSTRING	t,
		const CHARSET_INFO *	cs
	)

start() [1/2]

bool Event_scheduler::start

(

int *

err_no

)

Starts the scheduler (again).

Creates a new THD and passes it to a forked thread. Does not wait for acknowledgement from the new thread that it has started. Asynchronous starting. Most of the needed initializations are done in the current thread to minimize the chance of failure in the spawned thread.

Parameters

[out]

err_no

- errno indicating type of error which caused failure to start scheduler thread.

Return values

false	Success.
true	Error.

start() [2/2]

bool Events::start ( int *  err_no )

static

stop() [1/2]

bool Event_scheduler::stop

(

)

Stops the scheduler (again).

Waits for acknowledgement from the scheduler that it has stopped - synchronous stopping.

Already running events will not be stopped. If the user needs them stopped manual intervention is needed.

SYNOPSIS Event_scheduler::stop()

RETURN VALUE false OK true Error (not reported)

stop() [2/2]

bool Events::stop ( )

static

unlock_data() [1/2]

void Event_queue::unlock_data ( const char *  func, uint  line  )

private

unlock_data() [2/2]

void Event_scheduler::unlock_data ( const char *  func, uint  line  )

private

update_event() [1/3]

bool Event_db_repository::update_event ( THD *  thd, Event_parse_data *  parse_data, const LEX_CSTRING *  new_dbname, const LEX_CSTRING *  new_name  )

static

Used to execute ALTER EVENT.

Pendant to Events::update_event().

Parameters

[in]	thd	THD context
[in]	parse_data	parsed event definition
[in]	new_dbname	not NULL if ALTER EVENT RENAME points at a new database name
[in]	new_name	not NULL if ALTER EVENT RENAME points at a new event name

Precondition

All semantic checks are performed outside this function.

Return values

false	Success
true	Error (reported)

update_event() [2/3]

bool Events::update_event ( THD *  thd, Event_parse_data *  parse_data, const LEX_CSTRING *  new_dbname, const LEX_CSTRING *  new_name  )

static

Alter an event.

Atomicity: The operation to update an event is atomic/crash-safe. Changes to the Data-dictionary and writing event to binlog are part of the same transaction. All the changes are done as part of the same transaction or do not have any side effects on the operation failure. Data-dictionary cache and event queues are in sync with operation state. Cache and event queue does not contain any stale/incorrect data in case of failure. In case of crash, there won't be any discrepancy between the data-dictionary table and the binary log.

Parameters

[in,out]	thd	THD
[in]	parse_data	Event's data from parsing stage
[in]	new_dbname	A new schema name for the event. Set in the case of ALTER EVENT RENAME, otherwise is NULL.
[in]	new_name	A new name for the event. Set in the case of ALTER EVENT RENAME

Parameter 'et' contains data about dbname and event name. Parameter 'new_name' is the new name of the event, if not null this means that RENAME TO was specified in the query

See also

Events::drop_event for the locking notes.

Return values

false	OK
true	error (reported)

update_event() [3/3]

void Event_queue::update_event	(	THD *	thd,
		LEX_CSTRING	dbname,
		LEX_CSTRING	name,
		Event_queue_element *	new_element
	)

update_timing_fields_for_event()

bool Event_db_repository::update_timing_fields_for_event ( THD *  thd, LEX_CSTRING  event_db_name, LEX_CSTRING  event_name, my_time_t  last_executed, ulonglong  status  )

static

Update the event in Data Dictionary with changed status and/or last execution time.

workers_count()

int Event_scheduler::workers_count ( )

private

Variable Documentation

all_events_conds

PSI_cond_info all_events_conds[]

static

Initial value:

= {
    {&key_event_scheduler_COND_state, "Event_scheduler::COND_state",
     PSI_FLAG_SINGLETON, 0, PSI_DOCUMENT_ME},
    {&key_COND_queue_state, "COND_queue_state", PSI_FLAG_SINGLETON, 0,
     PSI_DOCUMENT_ME},
}

all_events_memory

PSI_memory_info all_events_memory[]

static

Initial value:

= {
    {&key_memory_event_basic_root, "Event_basic::mem_root",
     PSI_FLAG_ONLY_GLOBAL_STAT, 0,
     "Event base class with root used for definiton etc."}}

all_events_mutexes

PSI_mutex_info all_events_mutexes[]

static

Initial value:

=
{
  { &key_LOCK_event_queue, "LOCK_event_queue", PSI_FLAG_SINGLETON, 0, PSI_DOCUMENT_ME},
  { &key_event_scheduler_LOCK_scheduler_state, "Event_scheduler::LOCK_scheduler_state", PSI_FLAG_SINGLETON, 0, PSI_DOCUMENT_ME}
}

all_events_stages

PSI_stage_info* all_events_stages[]

Initial value:

= {&stage_waiting_on_empty_queue,
                                       &stage_waiting_for_next_activation,
                                       &stage_waiting_for_scheduler_to_stop}

all_events_threads

PSI_thread_info all_events_threads[]

static

Initial value:

= {
    {&key_thread_event_scheduler, "event_scheduler", "evt_sched",
     PSI_FLAG_SINGLETON, 0, PSI_DOCUMENT_ME},
    {&key_thread_event_worker, "event_worker", "evt_wkr", 0, 0,
     PSI_DOCUMENT_ME}}

connection_attrib

my_thread_attr_t connection_attrib

extern

event_queue

Event_queue * Events::event_queue

staticprivate

key_COND_queue_state [1/2]

PSI_cond_key key_COND_queue_state

extern

key_COND_queue_state [2/2]

PSI_cond_key key_COND_queue_state

key_event_scheduler_COND_state [1/2]

PSI_cond_key key_event_scheduler_COND_state

key_event_scheduler_COND_state [2/2]

PSI_cond_key key_event_scheduler_COND_state

extern

key_event_scheduler_LOCK_scheduler_state [1/2]

PSI_mutex_key key_event_scheduler_LOCK_scheduler_state

key_event_scheduler_LOCK_scheduler_state [2/2]

PSI_mutex_key key_event_scheduler_LOCK_scheduler_state

extern

key_LOCK_event_queue [1/2]

PSI_mutex_key key_LOCK_event_queue

extern

key_LOCK_event_queue [2/2]

PSI_mutex_key key_LOCK_event_queue

key_memory_event_basic_root

PSI_memory_key key_memory_event_basic_root

key_thread_event_scheduler [1/2]

PSI_thread_key key_thread_event_scheduler

key_thread_event_scheduler [2/2]

PSI_thread_key key_thread_event_scheduler

extern

key_thread_event_worker [1/2]

PSI_thread_key key_thread_event_worker

key_thread_event_worker [2/2]

PSI_thread_key key_thread_event_worker

opt_event_scheduler

ulong Events::opt_event_scheduler = Events::EVENTS_OFF

static

psi_info

PSI_statement_info Event_queue_element_for_exec::psi_info

static

Initial value:

= {0, "event", 0,
                                                             PSI_DOCUMENT_ME}

scheduler

Event_scheduler * Events::scheduler

staticprivate

scheduler_states_names

const LEX_CSTRING scheduler_states_names[]

static

Initial value:

= {
    {STRING_WITH_LEN("INITIALIZED")},
    {STRING_WITH_LEN("RUNNING")},
    {STRING_WITH_LEN("STOPPING")}}

stage_waiting_for_next_activation [1/2]

PSI_stage_info stage_waiting_for_next_activation

Initial value:

= {
    0, "Waiting for next activation", 0, PSI_DOCUMENT_ME}

stage_waiting_for_next_activation [2/2]

PSI_stage_info stage_waiting_for_next_activation

extern

stage_waiting_for_scheduler_to_stop [1/2]

PSI_stage_info stage_waiting_for_scheduler_to_stop

Initial value:

= {
    0, "Waiting for the scheduler to stop", 0, PSI_DOCUMENT_ME}

stage_waiting_for_scheduler_to_stop [2/2]

PSI_stage_info stage_waiting_for_scheduler_to_stop

extern

stage_waiting_on_empty_queue [1/2]

PSI_stage_info stage_waiting_on_empty_queue

Initial value:

= {0, "Waiting on empty queue", 0,
                                               PSI_DOCUMENT_ME}

stage_waiting_on_empty_queue [2/2]

PSI_stage_info stage_waiting_on_empty_queue

extern