mariadb/sql/event_scheduler.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

144 lines
2.9 KiB
C++

#ifndef _EVENT_SCHEDULER_H_
#define _EVENT_SCHEDULER_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 */
/**
@file
This file is internal to Events module. Please do not include it directly.
All public declarations of Events module are in events.h and
event_data_objects.h.
*/
class Event_queue;
class Event_job_data;
class Event_db_repository;
class Events;
void
pre_init_event_thread(THD* thd);
bool
post_init_event_thread(THD* thd);
void
deinit_event_thread(THD *thd);
class Event_worker_thread
{
public:
static void
init(Event_db_repository *db_repository_arg)
{
db_repository= db_repository_arg;
}
void
run(THD *thd, Event_queue_element_for_exec *event);
private:
void
print_warnings(THD *thd, Event_job_data *et);
static Event_db_repository *db_repository;
};
class Event_scheduler
{
public:
Event_scheduler(Event_queue *event_queue_arg);
~Event_scheduler();
/* State changing methods follow */
bool
start();
bool
stop();
/*
Need to be public because has to be called from the function
passed to pthread_create.
*/
bool
run(THD *thd);
/* Information retrieving methods follow */
bool
is_running();
void
dump_internal_status();
private:
uint
workers_count();
/* helper functions */
bool
execute_top(Event_queue_element_for_exec *event_name);
/* 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);
pthread_mutex_t LOCK_scheduler_state;
enum enum_state
{
UNINITIALIZED = 0,
INITIALIZED,
RUNNING,
STOPPING
};
/* This is the current status of the life-cycle of the scheduler. */
enum enum_state state;
THD *scheduler_thd;
pthread_cond_t COND_state;
Event_queue *queue;
uint mutex_last_locked_at_line;
uint mutex_last_unlocked_at_line;
const char* mutex_last_locked_in_func;
const char* mutex_last_unlocked_in_func;
bool mutex_scheduler_data_locked;
bool waiting_on_cond;
ulonglong started_events;
private:
/* Prevent use of these */
Event_scheduler(const Event_scheduler &);
void operator=(Event_scheduler &);
};
#endif /* _EVENT_SCHEDULER_H_ */