mariadb/sql/event_queue.h
kostja@vajra.(none) 98db230086 A set of changes aiming to make the Event Scheduler more user-friendly
when there are no up-to-date system tables to support it:
 - initialize the scheduler before reporting "Ready for connections".
   This ensures that warnings, if any, are printed before "Ready for
   connections", and this message is not mangled.
 - do not abort the scheduler if there are no system tables
 - check the tables once at start up, remember the status and disable
   the scheduler if the tables are not up to date.
   If one attempts to use the scheduler with bad tables,
   issue an error message.
 - clean up the behaviour of the module under LOCK TABLES and pre-locking
   mode
 - make sure implicit commit of Events DDL works as expected.
 - add more tests


Collateral clean ups in the events code.

This patch fixes Bug#23631 Events: SHOW VARIABLES doesn't work 
when mysql.event is damaged
2007-04-05 15:24:34 +04:00

110 lines
2.7 KiB
C++

#ifndef _EVENT_QUEUE_H_
#define _EVENT_QUEUE_H_
/* Copyright (C) 2004-2006 MySQL AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
class Event_basic;
class Event_queue_element;
class Event_queue_element_for_exec;
class THD;
class Event_queue
{
public:
Event_queue();
~Event_queue();
bool
init_queue(THD *thd);
/* Methods for queue management follow */
bool
create_event(THD *thd, Event_queue_element *new_element,
bool *created);
void
update_event(THD *thd, LEX_STRING dbname, LEX_STRING name,
Event_queue_element *new_element);
void
drop_event(THD *thd, LEX_STRING dbname, LEX_STRING name);
void
drop_schema_events(THD *thd, LEX_STRING schema);
void
recalculate_activation_times(THD *thd);
bool
get_top_for_execution_if_time(THD *thd,
Event_queue_element_for_exec **event_name);
void
dump_internal_status();
private:
void
empty_queue();
void
deinit_queue();
/* helper functions for working with mutexes & conditionals */
void
lock_data(const char *func, uint line);
void
unlock_data(const char *func, uint line);
void
cond_wait(THD *thd, struct timespec *abstime, const char* msg,
const char *func, uint line);
void
find_n_remove_event(LEX_STRING db, LEX_STRING name);
void
drop_matching_events(THD *thd, LEX_STRING pattern,
bool (*)(LEX_STRING, Event_basic *));
void
dbug_dump_queue(time_t now);
/* LOCK_event_queue is the mutex which protects the access to the queue. */
pthread_mutex_t LOCK_event_queue;
pthread_cond_t COND_queue_state;
/* The sorted queue with the Event_queue_element objects */
QUEUE queue;
my_time_t next_activation_at;
uint mutex_last_locked_at_line;
uint mutex_last_unlocked_at_line;
uint mutex_last_attempted_lock_at_line;
const char* mutex_last_locked_in_func;
const char* mutex_last_unlocked_in_func;
const char* mutex_last_attempted_lock_in_func;
bool mutex_queue_data_locked;
bool mutex_queue_data_attempting_lock;
bool waiting_on_cond;
};
#endif /* _EVENT_QUEUE_H_ */