1 #ifndef _EVENT_H_
2 #define _EVENT_H_
3 /* Copyright (c) 2004, 2013, Oracle and/or its affiliates. All rights reserved.
4 
5    This program is free software; you can redistribute it and/or modify
6    it under the terms of the GNU General Public License, version 2.0,
7    as published by the Free Software Foundation.
8 
9    This program is also distributed with certain software (including
10    but not limited to OpenSSL) that is licensed under separate terms,
11    as designated in a particular file or component or in included license
12    documentation.  The authors of MySQL hereby grant you an additional
13    permission to link the program and your derivative works with the
14    separately licensed software that they have included with MySQL.
15 
16    This program is distributed in the hope that it will be useful,
17    but WITHOUT ANY WARRANTY; without even the implied warranty of
18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19    GNU General Public License, version 2.0, for more details.
20 
21    You should have received a copy of the GNU General Public License
22    along with this program; if not, write to the Free Software
23    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
24 
25 /**
26   @defgroup Event_Scheduler Event Scheduler
27   @ingroup Runtime_Environment
28   @{
29 
30   @file events.h
31 
32   A public interface of Events_Scheduler module.
33 */
34 
35 #ifdef HAVE_PSI_INTERFACE
36 extern PSI_mutex_key key_event_scheduler_LOCK_scheduler_state;
37 extern PSI_cond_key key_event_scheduler_COND_state;
38 extern PSI_thread_key key_thread_event_scheduler, key_thread_event_worker;
39 #endif /* HAVE_PSI_INTERFACE */
40 
41 /* Always defined, for SHOW PROCESSLIST. */
42 extern PSI_stage_info stage_waiting_on_empty_queue;
43 extern PSI_stage_info stage_waiting_for_next_activation;
44 extern PSI_stage_info stage_waiting_for_scheduler_to_stop;
45 
46 #include "sql_string.h"                         /* LEX_STRING */
47 #include "my_time.h"                            /* interval_type */
48 
49 class Event_db_repository;
50 class Event_parse_data;
51 class Event_queue;
52 class Event_scheduler;
53 struct TABLE_LIST;
54 class THD;
55 typedef struct charset_info_st CHARSET_INFO;
56 
57 int
58 sortcmp_lex_string(LEX_STRING s, LEX_STRING t, CHARSET_INFO *cs);
59 
60 /**
61   @brief A facade to the functionality of the Event Scheduler.
62 
63   Every public operation against the scheduler has to be executed via the
64   interface provided by a static method of this class. No instance of this
65   class is ever created and it has no non-static data members.
66 
67   The life cycle of the Events module is the following:
68 
69   At server start up:
70      init_mutexes() -> init()
71   When the server is running:
72      create_event(), drop_event(), start_or_stop_event_scheduler(), etc
73   At shutdown:
74      deinit(), destroy_mutexes().
75 
76   The peculiar initialization and shutdown cycle is an adaptation to the
77   outside server startup/shutdown framework and mimics the rest of MySQL
78   subsystems (ACL, time zone tables, etc).
79 */
80 
81 class Events
82 {
83 public:
84   /*
85     the following block is to support --event-scheduler command line option
86     and the @@global.event_scheduler SQL variable.
87     See sys_var.cc
88   */
89   enum enum_opt_event_scheduler { EVENTS_OFF, EVENTS_ON, EVENTS_DISABLED };
90   /* Protected using LOCK_global_system_variables only. */
91   static ulong opt_event_scheduler;
92   static bool check_if_system_tables_error();
93   static bool start(int *err_no);
94   static bool stop();
95 
96 public:
97   /* A hack needed for Event_queue_element */
98   static Event_db_repository *
get_db_repository()99   get_db_repository() { return db_repository; }
100 
101   static bool
102   init(my_bool opt_noacl);
103 
104   static void
105   deinit();
106 
107   static void
108   init_mutexes();
109 
110   static void
111   destroy_mutexes();
112 
113   static bool
114   create_event(THD *thd, Event_parse_data *parse_data, bool if_exists);
115 
116   static bool
117   update_event(THD *thd, Event_parse_data *parse_data,
118                LEX_STRING *new_dbname, LEX_STRING *new_name);
119 
120   static bool
121   drop_event(THD *thd, LEX_STRING dbname, LEX_STRING name, bool if_exists);
122 
123   static void
124   drop_schema_events(THD *thd, char *db);
125 
126   static bool
127   show_create_event(THD *thd, LEX_STRING dbname, LEX_STRING name);
128 
129   /* Needed for both SHOW CREATE EVENT and INFORMATION_SCHEMA */
130   static int
131   reconstruct_interval_expression(String *buf, interval_type interval,
132                                   longlong expression);
133 
134   static int
135   fill_schema_events(THD *thd, TABLE_LIST *tables, Item * /* cond */);
136 
137   static void
138   dump_internal_status();
139 
140 private:
141 
142   static bool
143   load_events_from_db(THD *thd);
144 
145 private:
146   static Event_queue         *event_queue;
147   static Event_scheduler     *scheduler;
148   static Event_db_repository *db_repository;
149   /* Set to TRUE if an error at start up */
150   static bool check_system_tables_error;
151 
152 private:
153   /* Prevent use of these */
154   Events(const Events &);
155   void operator=(Events &);
156 };
157 
158 /**
159   @} (end of group Event Scheduler)
160 */
161 
162 #endif /* _EVENT_H_ */
163