/* 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 */ #include "mysql_priv.h" #include "events.h" #include "event_data_objects.h" #include "event_db_repository.h" #include "event_queue.h" #include "event_scheduler.h" #include "sp_head.h" // for Stored_program_creation_ctx /** @addtogroup Event_Scheduler @{ */ /* TODO list : - CREATE EVENT should not go into binary log! Does it now? The SQL statements issued by the EVENT are replicated. I have an idea how to solve the problem at failover. So the status field will be ENUM('DISABLED', 'ENABLED', 'SLAVESIDE_DISABLED'). In this case when CREATE EVENT is replicated it should go into the binary as SLAVESIDE_DISABLED if it is ENABLED, when it's created as DISABLEd it should be replicated as disabled. If an event is ALTERed as DISABLED the query should go untouched into the binary log, when ALTERed as enable then it should go as SLAVESIDE_DISABLED. This is regarding the SQL interface. TT routines however modify mysql.event internally and this does not go the log so in this case queries has to be injected into the log...somehow... or maybe a solution is RBR for this case, because the event may go only from ENABLED to DISABLED status change and this is safe for replicating. As well an event may be deleted which is also safe for RBR. - Add logging to file */ /* If the user (un)intentionally removes an event directly from mysql.event the following sequence has to be used to be able to remove the in-memory counterpart. 1. CREATE EVENT the_name ON SCHEDULE EVERY 1 SECOND DISABLE DO SELECT 1; 2. DROP EVENT the_name In other words, the first one will create a row in mysql.event . In the second step because there will be a line, disk based drop will pass and the scheduler will remove the memory counterpart. The reason is that in-memory queue does not check whether the event we try to drop from memory is disabled. Disabled events are not kept in-memory because they are not eligible for execution. */ /* Keep the order of the first to as in var_typelib sys_var_event_scheduler::value_ptr() references this array. Keep in mind! */ static const char *opt_event_scheduler_state_names[]= { "OFF", "ON", "0", "1", "DISABLED", NullS }; const TYPELIB Events::opt_typelib= { array_elements(opt_event_scheduler_state_names)-1, "", opt_event_scheduler_state_names, NULL }; /* The order should not be changed. We consider OFF to be equivalent of INT 0 And ON of 1. If OFF & ON are interchanged the logic in sys_var_event_scheduler::update() will be broken! */ static const char *var_event_scheduler_state_names[]= { "OFF", "ON", NullS }; const TYPELIB Events::var_typelib= { array_elements(var_event_scheduler_state_names)-1, "", var_event_scheduler_state_names, NULL }; Event_queue *Events::event_queue; Event_scheduler *Events::scheduler; Event_db_repository *Events::db_repository; enum Events::enum_opt_event_scheduler Events::opt_event_scheduler= Events::EVENTS_OFF; pthread_mutex_t Events::LOCK_event_metadata; bool Events::check_system_tables_error= FALSE; /* Compares 2 LEX strings regarding case. SYNOPSIS sortcmp_lex_string() s First LEX_STRING t Second LEX_STRING cs Charset RETURN VALUE -1 s < t 0 s == t 1 s > t */ int sortcmp_lex_string(LEX_STRING s, LEX_STRING t, CHARSET_INFO *cs) { return cs->coll->strnncollsp(cs, (uchar *) s.str,s.length, (uchar *) t.str,t.length, 0); } /** @brief Initialize the start up option of the Events scheduler. Do not initialize the scheduler subsystem yet - the initialization is split into steps as it has to fit into the common MySQL initialization framework. No locking as this is called only at start up. @param[in,out] argument The value of the argument. If this value is found in the typelib, the argument is updated. @retval TRUE unknown option value @retval FALSE success */ bool Events::set_opt_event_scheduler(char *argument) { if (argument == NULL) opt_event_scheduler= Events::EVENTS_ON; else { int type; /* type= 1 2 3 4 5 (OFF | ON) - (0 | 1) (DISABLE ) */ const static enum enum_opt_event_scheduler type2state[]= { EVENTS_OFF, EVENTS_ON, EVENTS_OFF, EVENTS_ON, EVENTS_DISABLED }; type= find_type(argument, &opt_typelib, 1); DBUG_ASSERT(type >= 0 && type <= 5); /* guaranteed by find_type */ if (type == 0) { fprintf(stderr, "Unknown option to event-scheduler: %s\n", argument); return TRUE; } opt_event_scheduler= type2state[type-1]; } return FALSE; } /** Return a string representation of the current scheduler mode. */ const char * Events::get_opt_event_scheduler_str() { const char *str; pthread_mutex_lock(&LOCK_event_metadata); str= opt_typelib.type_names[(int) opt_event_scheduler]; pthread_mutex_unlock(&LOCK_event_metadata); return str; } /** Push an error into the error stack if the system tables are not up to date. */ bool Events::check_if_system_tables_error() { DBUG_ENTER("Events::check_if_system_tables_error"); if (check_system_tables_error) { my_error(ER_EVENTS_DB_ERROR, MYF(0)); DBUG_RETURN(TRUE); } DBUG_RETURN(FALSE); } /** Reconstructs interval expression from interval type and expression value that is in form of a value of the smalles entity: For YEAR_MONTH - expression is in months DAY_MINUTE - expression is in minutes SYNOPSIS Events::reconstruct_interval_expression() buf Preallocated String buffer to add the value to interval The interval type (for instance YEAR_MONTH) expression The value in the lowest entity RETURN VALUE 0 OK 1 Error */ int Events::reconstruct_interval_expression(String *buf, interval_type interval, longlong expression) { ulonglong expr= expression; char tmp_buff[128], *end; bool close_quote= TRUE; int multipl= 0; char separator=':'; switch (interval) { case INTERVAL_YEAR_MONTH: multipl= 12; separator= '-'; goto common_1_lev_code; case INTERVAL_DAY_HOUR: multipl= 24; separator= ' '; goto common_1_lev_code; case INTERVAL_HOUR_MINUTE: case INTERVAL_MINUTE_SECOND: multipl= 60; common_1_lev_code: buf->append('\''); end= longlong10_to_str(expression/multipl, tmp_buff, 10); buf->append(tmp_buff, (uint) (end- tmp_buff)); expr= expr - (expr/multipl)*multipl; break; case INTERVAL_DAY_MINUTE: { ulonglong tmp_expr= expr; tmp_expr/=(24*60); buf->append('\''); end= longlong10_to_str(tmp_expr, tmp_buff, 10); buf->append(tmp_buff, (uint) (end- tmp_buff));// days buf->append(' '); tmp_expr= expr - tmp_expr*(24*60);//minutes left end= longlong10_to_str(tmp_expr/60, tmp_buff, 10); buf->append(tmp_buff, (uint) (end- tmp_buff));// hours expr= tmp_expr - (tmp_expr/60)*60; /* the code after the switch will finish */ } break; case INTERVAL_HOUR_SECOND: { ulonglong tmp_expr= expr; buf->append('\''); end= longlong10_to_str(tmp_expr/3600, tmp_buff, 10); buf->append(tmp_buff, (uint) (end- tmp_buff));// hours buf->append(':'); tmp_expr= tmp_expr - (tmp_expr/3600)*3600; end= longlong10_to_str(tmp_expr/60, tmp_buff, 10); buf->append(tmp_buff, (uint) (end- tmp_buff));// minutes expr= tmp_expr - (tmp_expr/60)*60; /* the code after the switch will finish */ } break; case INTERVAL_DAY_SECOND: { ulonglong tmp_expr= expr; tmp_expr/=(24*3600); buf->append('\''); end= longlong10_to_str(tmp_expr, tmp_buff, 10); buf->append(tmp_buff, (uint) (end- tmp_buff));// days buf->append(' '); tmp_expr= expr - tmp_expr*(24*3600);//seconds left end= longlong10_to_str(tmp_expr/3600, tmp_buff, 10); buf->append(tmp_buff, (uint) (end- tmp_buff));// hours buf->append(':'); tmp_expr= tmp_expr - (tmp_expr/3600)*3600; end= longlong10_to_str(tmp_expr/60, tmp_buff, 10); buf->append(tmp_buff, (uint) (end- tmp_buff));// minutes expr= tmp_expr - (tmp_expr/60)*60; /* the code after the switch will finish */ } break; case INTERVAL_DAY_MICROSECOND: case INTERVAL_HOUR_MICROSECOND: case INTERVAL_MINUTE_MICROSECOND: case INTERVAL_SECOND_MICROSECOND: case INTERVAL_MICROSECOND: my_error(ER_NOT_SUPPORTED_YET, MYF(0), "MICROSECOND"); return 1; break; case INTERVAL_QUARTER: expr/= 3; close_quote= FALSE; break; case INTERVAL_WEEK: expr/= 7; default: close_quote= FALSE; break; } if (close_quote) buf->append(separator); end= longlong10_to_str(expr, tmp_buff, 10); buf->append(tmp_buff, (uint) (end- tmp_buff)); if (close_quote) buf->append('\''); return 0; } /** Create a new event. @param[in,out] thd THD @param[in] parse_data Event's data from parsing stage @param[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. @sa Events::drop_event for the notes about locking, pre-locking and Events DDL. @retval FALSE OK @retval TRUE Error (reported) */ bool Events::create_event(THD *thd, Event_parse_data *parse_data, bool if_not_exists) { int ret; DBUG_ENTER("Events::create_event"); /* Let's commit the transaction first - MySQL manual specifies that a DDL issues an implicit commit, and it doesn't say "successful DDL", so that an implicit commit is a property of any successfully parsed DDL statement. */ if (end_active_trans(thd)) DBUG_RETURN(TRUE); if (check_if_system_tables_error()) DBUG_RETURN(TRUE); /* Perform semantic checks outside of Event_db_repository: once CREATE EVENT is supported in prepared statements, the checks will be moved to PREPARE phase. */ if (parse_data->check_parse_data(thd)) DBUG_RETURN(TRUE); /* At create, one of them must be set */ DBUG_ASSERT(parse_data->expression || parse_data->execute_at); if (check_access(thd, EVENT_ACL, parse_data->dbname.str, 0, 0, 0, is_schema_db(parse_data->dbname.str))) DBUG_RETURN(TRUE); if (check_db_dir_existence(parse_data->dbname.str)) { my_error(ER_BAD_DB_ERROR, MYF(0), parse_data->dbname.str); DBUG_RETURN(TRUE); } if (parse_data->do_not_create) DBUG_RETURN(FALSE); /* Turn off row binlogging of this statement and use statement-based so that all supporting tables are updated for CREATE EVENT command. */ if (thd->current_stmt_binlog_row_based) thd->clear_current_stmt_binlog_row_based(); pthread_mutex_lock(&LOCK_event_metadata); /* On error conditions my_error() is called so no need to handle here */ if (!(ret= db_repository->create_event(thd, parse_data, if_not_exists))) { Event_queue_element *new_element; if (!(new_element= new Event_queue_element())) ret= TRUE; // OOM else if ((ret= db_repository->load_named_event(thd, parse_data->dbname, parse_data->name, new_element))) { db_repository->drop_event(thd, parse_data->dbname, parse_data->name, TRUE); delete new_element; } else { /* TODO: do not ignore the out parameter and a possible OOM error! */ bool created; if (event_queue) event_queue->create_event(thd, new_element, &created); /* Binlog the create event. */ DBUG_ASSERT(thd->query && thd->query_length); write_bin_log(thd, TRUE, thd->query, thd->query_length); } } pthread_mutex_unlock(&LOCK_event_metadata); DBUG_RETURN(ret); } /** Alter an event. @param[in,out] thd THD @param[in] parse_data Event's data from parsing stage @param[in] new_dbname A new schema name for the event. Set in the case of ALTER EVENT RENAME, otherwise is NULL. @param[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 @sa Events::drop_event for the locking notes. @retval FALSE OK @retval TRUE error (reported) */ bool Events::update_event(THD *thd, Event_parse_data *parse_data, LEX_STRING *new_dbname, LEX_STRING *new_name) { int ret; Event_queue_element *new_element; DBUG_ENTER("Events::update_event"); /* For consistency, implicit COMMIT should be the first thing in the execution chain. */ if (end_active_trans(thd)) DBUG_RETURN(TRUE); if (check_if_system_tables_error()) DBUG_RETURN(TRUE); if (parse_data->check_parse_data(thd) || parse_data->do_not_create) DBUG_RETURN(TRUE); if (check_access(thd, EVENT_ACL, parse_data->dbname.str, 0, 0, 0, is_schema_db(parse_data->dbname.str))) DBUG_RETURN(TRUE); if (new_dbname) /* It's a rename */ { /* Check that the new and the old names differ. */ if ( !sortcmp_lex_string(parse_data->dbname, *new_dbname, system_charset_info) && !sortcmp_lex_string(parse_data->name, *new_name, system_charset_info)) { my_error(ER_EVENT_SAME_NAME, MYF(0), parse_data->name.str); DBUG_RETURN(TRUE); } /* And the user has sufficient privileges to use the target database. Do it before checking whether the database exists: we don't want to tell the user that a database doesn't exist if they can not access it. */ if (check_access(thd, EVENT_ACL, new_dbname->str, 0, 0, 0, is_schema_db(new_dbname->str))) DBUG_RETURN(TRUE); /* Check that the target database exists */ if (check_db_dir_existence(new_dbname->str)) { my_error(ER_BAD_DB_ERROR, MYF(0), new_dbname->str); DBUG_RETURN(TRUE); } } /* Turn off row binlogging of this statement and use statement-based so that all supporting tables are updated for UPDATE EVENT command. */ if (thd->current_stmt_binlog_row_based) thd->clear_current_stmt_binlog_row_based(); pthread_mutex_lock(&LOCK_event_metadata); /* On error conditions my_error() is called so no need to handle here */ if (!(ret= db_repository->update_event(thd, parse_data, new_dbname, new_name))) { LEX_STRING dbname= new_dbname ? *new_dbname : parse_data->dbname; LEX_STRING name= new_name ? *new_name : parse_data->name; if (!(new_element= new Event_queue_element())) ret= TRUE; // OOM else if ((ret= db_repository->load_named_event(thd, dbname, name, new_element))) { DBUG_ASSERT(ret == OP_LOAD_ERROR); delete new_element; } else { /* TODO: check if an update actually has inserted an entry into the queue. If not, and the element is ON COMPLETION NOT PRESERVE, delete it right away. */ if (event_queue) event_queue->update_event(thd, parse_data->dbname, parse_data->name, new_element); /* Binlog the alter event. */ DBUG_ASSERT(thd->query && thd->query_length); write_bin_log(thd, TRUE, thd->query, thd->query_length); } } pthread_mutex_unlock(&LOCK_event_metadata); DBUG_RETURN(ret); } /** Drops an event @param[in,out] thd THD @param[in] dbname Event's schema @param[in] name Event's name @param[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. @retval FALSE OK @retval TRUE Error (reported) */ bool Events::drop_event(THD *thd, LEX_STRING dbname, LEX_STRING name, bool if_exists) { int ret; DBUG_ENTER("Events::drop_event"); /* In MySQL, DDL must always commit: since mysql.* tables are non-transactional, we must modify them outside a transaction to not break atomicity. But the second and more important reason to commit here regardless whether we're actually changing mysql.event table or not is replication: end_active_trans syncs the binary log, and unless we run DDL in it's own transaction it may simply never appear on the slave in case the outside transaction rolls back. */ if (end_active_trans(thd)) DBUG_RETURN(TRUE); if (check_if_system_tables_error()) DBUG_RETURN(TRUE); if (check_access(thd, EVENT_ACL, dbname.str, 0, 0, 0, is_schema_db(dbname.str))) DBUG_RETURN(TRUE); /* Turn off row binlogging of this statement and use statement-based so that all supporting tables are updated for DROP EVENT command. */ if (thd->current_stmt_binlog_row_based) thd->clear_current_stmt_binlog_row_based(); pthread_mutex_lock(&LOCK_event_metadata); /* On error conditions my_error() is called so no need to handle here */ if (!(ret= db_repository->drop_event(thd, dbname, name, if_exists))) { if (event_queue) event_queue->drop_event(thd, dbname, name); /* Binlog the drop event. */ DBUG_ASSERT(thd->query && thd->query_length); write_bin_log(thd, TRUE, thd->query, thd->query_length); } pthread_mutex_unlock(&LOCK_event_metadata); DBUG_RETURN(ret); } /** 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. @param[in,out] thd Thread @param[in] db ASCIIZ schema name */ void Events::drop_schema_events(THD *thd, char *db) { LEX_STRING const db_lex= { db, strlen(db) }; DBUG_ENTER("Events::drop_schema_events"); DBUG_PRINT("enter", ("dropping events from %s", db)); /* sic: no check if the scheduler is disabled or system tables are damaged, as intended. */ pthread_mutex_lock(&LOCK_event_metadata); if (event_queue) event_queue->drop_schema_events(thd, db_lex); db_repository->drop_schema_events(thd, db_lex); pthread_mutex_unlock(&LOCK_event_metadata); DBUG_VOID_RETURN; } /** A helper function to generate SHOW CREATE EVENT output from a named event */ static bool send_show_create_event(THD *thd, Event_timed *et, Protocol *protocol) { char show_str_buf[10 * STRING_BUFFER_USUAL_SIZE]; String show_str(show_str_buf, sizeof(show_str_buf), system_charset_info); List field_list; LEX_STRING sql_mode; const String *tz_name; DBUG_ENTER("send_show_create_event"); show_str.length(0); if (et->get_create_event(thd, &show_str)) DBUG_RETURN(TRUE); field_list.push_back(new Item_empty_string("Event", NAME_CHAR_LEN)); if (sys_var_thd_sql_mode::symbolic_mode_representation(thd, et->sql_mode, &sql_mode)) DBUG_RETURN(TRUE); field_list.push_back(new Item_empty_string("sql_mode", sql_mode.length)); tz_name= et->time_zone->get_name(); field_list.push_back(new Item_empty_string("time_zone", tz_name->length())); field_list.push_back(new Item_empty_string("Create Event", show_str.length())); field_list.push_back( new Item_empty_string("character_set_client", MY_CS_NAME_SIZE)); field_list.push_back( new Item_empty_string("collation_connection", MY_CS_NAME_SIZE)); field_list.push_back( new Item_empty_string("Database Collation", MY_CS_NAME_SIZE)); if (protocol->send_fields(&field_list, Protocol::SEND_NUM_ROWS | Protocol::SEND_EOF)) DBUG_RETURN(TRUE); protocol->prepare_for_resend(); protocol->store(et->name.str, et->name.length, system_charset_info); protocol->store(sql_mode.str, sql_mode.length, system_charset_info); protocol->store(tz_name->ptr(), tz_name->length(), system_charset_info); protocol->store(show_str.c_ptr(), show_str.length(), et->creation_ctx->get_client_cs()); protocol->store(et->creation_ctx->get_client_cs()->csname, strlen(et->creation_ctx->get_client_cs()->csname), system_charset_info); protocol->store(et->creation_ctx->get_connection_cl()->name, strlen(et->creation_ctx->get_connection_cl()->name), system_charset_info); protocol->store(et->creation_ctx->get_db_cl()->name, strlen(et->creation_ctx->get_db_cl()->name), system_charset_info); if (protocol->write()) DBUG_RETURN(TRUE); my_eof(thd); DBUG_RETURN(FALSE); } /** Implement SHOW CREATE EVENT statement thd Thread context spn The name of the event (db, name) @retval FALSE OK @retval TRUE error (reported) */ bool Events::show_create_event(THD *thd, LEX_STRING dbname, LEX_STRING name) { Open_tables_state open_tables_backup; Event_timed et; bool ret; DBUG_ENTER("Events::show_create_event"); DBUG_PRINT("enter", ("name: %s@%s", dbname.str, name.str)); if (check_if_system_tables_error()) DBUG_RETURN(TRUE); if (check_access(thd, EVENT_ACL, dbname.str, 0, 0, 0, is_schema_db(dbname.str))) DBUG_RETURN(TRUE); /* We would like to allow SHOW CREATE EVENT under LOCK TABLES and in pre-locked mode. mysql.event table is marked as a system table. This flag reduces the set of its participation scenarios in LOCK TABLES operation, and therefore an out-of-bound open of this table for reading like the one below (sic, only for reading) is more or less deadlock-free. For additional information about when a deadlock can occur please refer to the description of 'system table' flag. */ thd->reset_n_backup_open_tables_state(&open_tables_backup); ret= db_repository->load_named_event(thd, dbname, name, &et); thd->restore_backup_open_tables_state(&open_tables_backup); if (!ret) ret= send_show_create_event(thd, &et, thd->protocol); DBUG_RETURN(ret); } /** Check access rights and fill INFORMATION_SCHEMA.events table. @param[in,out] thd Thread context @param[in] tables The temporary table to fill. In MySQL INFORMATION_SCHEMA tables are temporary tables that are created and filled on demand. In this function, we fill INFORMATION_SCHEMA.events. It is a callback for I_S module, invoked from sql_show.cc @return Has to be integer, as such is the requirement of the I_S API @retval 0 success @retval 1 an error, pushed into the error stack */ int Events::fill_schema_events(THD *thd, TABLE_LIST *tables, COND * /* cond */) { char *db= NULL; int ret; Open_tables_state open_tables_backup; DBUG_ENTER("Events::fill_schema_events"); if (check_if_system_tables_error()) DBUG_RETURN(1); /* If it's SHOW EVENTS then thd->lex->select_lex.db is guaranteed not to be NULL. Let's do an assert anyway. */ if (thd->lex->sql_command == SQLCOM_SHOW_EVENTS) { DBUG_ASSERT(thd->lex->select_lex.db); if (!is_schema_db(thd->lex->select_lex.db) && // There is no events in I_S check_access(thd, EVENT_ACL, thd->lex->select_lex.db, 0, 0, 0, 0)) DBUG_RETURN(1); db= thd->lex->select_lex.db; } /* Reset and backup of the currently open tables in this thread is a way to allow SELECTs from INFORMATION_SCHEMA.events under LOCK TABLES and in pre-locked mode. See also Events::show_create_event for additional comments. */ thd->reset_n_backup_open_tables_state(&open_tables_backup); ret= db_repository->fill_schema_events(thd, tables, db); thd->restore_backup_open_tables_state(&open_tables_backup); DBUG_RETURN(ret); } /* Inits the scheduler's structures. SYNOPSIS Events::init() NOTES This function is not synchronized. RETURN VALUE FALSE OK TRUE Error in case the scheduler can't start */ bool Events::init(my_bool opt_noacl) { THD *thd; bool res= FALSE; DBUG_ENTER("Events::init"); /* Disable the scheduler if running with --skip-grant-tables */ if (opt_noacl) opt_event_scheduler= EVENTS_DISABLED; /* We need a temporary THD during boot */ if (!(thd= new THD())) { res= TRUE; goto end; } /* The thread stack does not start from this function but we cannot guess the real value. So better some value that doesn't assert than no value. */ thd->thread_stack= (char*) &thd; thd->store_globals(); lex_start(thd); /* We will need Event_db_repository anyway, even if the scheduler is disabled - to perform events DDL. */ if (!(db_repository= new Event_db_repository)) { res= TRUE; /* fatal error: request unireg_abort */ goto end; } /* Since we allow event DDL even if the scheduler is disabled, check the system tables, as we might need them. */ if (Event_db_repository::check_system_tables(thd)) { sql_print_error("Event Scheduler: An error occurred when initializing " "system tables.%s", opt_event_scheduler == EVENTS_DISABLED ? "" : " Disabling the Event Scheduler."); /* Disable the scheduler since the system tables are not up to date */ opt_event_scheduler= EVENTS_DISABLED; check_system_tables_error= TRUE; goto end; } /* Was disabled explicitly from the command line, or because we're running with --skip-grant-tables, or because we have no system tables. */ if (opt_event_scheduler == Events::EVENTS_DISABLED) goto end; DBUG_ASSERT(opt_event_scheduler == Events::EVENTS_ON || opt_event_scheduler == Events::EVENTS_OFF); if (!(event_queue= new Event_queue) || !(scheduler= new Event_scheduler(event_queue))) { res= TRUE; /* fatal error: request unireg_abort */ goto end; } if (event_queue->init_queue(thd) || load_events_from_db(thd) || opt_event_scheduler == EVENTS_ON && scheduler->start()) { sql_print_error("Event Scheduler: Error while loading from disk."); res= TRUE; /* fatal error: request unireg_abort */ goto end; } Event_worker_thread::init(db_repository); end: if (res) { delete db_repository; delete event_queue; delete scheduler; } delete thd; /* Remember that we don't have a THD */ my_pthread_setspecific_ptr(THR_THD, NULL); DBUG_RETURN(res); } /* Cleans up scheduler's resources. Called at server shutdown. SYNOPSIS Events::deinit() NOTES This function is not synchronized. */ void Events::deinit() { DBUG_ENTER("Events::deinit"); if (opt_event_scheduler != EVENTS_DISABLED) { delete scheduler; scheduler= NULL; /* safety */ delete event_queue; event_queue= NULL; /* safety */ } delete db_repository; db_repository= NULL; /* safety */ DBUG_VOID_RETURN; } /** Inits Events mutexes SYNOPSIS Events::init_mutexes() thd Thread */ void Events::init_mutexes() { pthread_mutex_init(&LOCK_event_metadata, MY_MUTEX_INIT_FAST); } /* Destroys Events mutexes SYNOPSIS Events::destroy_mutexes() */ void Events::destroy_mutexes() { pthread_mutex_destroy(&LOCK_event_metadata); } /* Dumps the internal status of the scheduler and the memory cache into a table with two columns - Name & Value. Different properties which could be useful for debugging for instance deadlocks are returned. SYNOPSIS Events::dump_internal_status() */ void Events::dump_internal_status() { DBUG_ENTER("Events::dump_internal_status"); puts("\n\n\nEvents status:"); puts("LLA = Last Locked At LUA = Last Unlocked At"); puts("WOC = Waiting On Condition DL = Data Locked"); pthread_mutex_lock(&LOCK_event_metadata); if (opt_event_scheduler == EVENTS_DISABLED) puts("The Event Scheduler is disabled"); else { scheduler->dump_internal_status(); event_queue->dump_internal_status(); } pthread_mutex_unlock(&LOCK_event_metadata); DBUG_VOID_RETURN; } /** Starts or stops the event scheduler thread. @retval FALSE success @retval TRUE error */ bool Events::switch_event_scheduler_state(enum_opt_event_scheduler new_state) { bool ret= FALSE; DBUG_ENTER("Events::switch_event_scheduler_state"); DBUG_ASSERT(new_state == Events::EVENTS_ON || new_state == Events::EVENTS_OFF); /* If the scheduler was disabled because there are no/bad system tables, produce a more meaningful error message than ER_OPTION_PREVENTS_STATEMENT */ if (check_if_system_tables_error()) DBUG_RETURN(TRUE); pthread_mutex_lock(&LOCK_event_metadata); if (opt_event_scheduler == EVENTS_DISABLED) { my_error(ER_OPTION_PREVENTS_STATEMENT, MYF(0), "--event-scheduler=DISABLED or --skip-grant-tables"); ret= TRUE; goto end; } if (new_state == EVENTS_ON) ret= scheduler->start(); else ret= scheduler->stop(); if (ret) { my_error(ER_EVENT_SET_VAR_ERROR, MYF(0)); goto end; } opt_event_scheduler= new_state; end: pthread_mutex_unlock(&LOCK_event_metadata); DBUG_RETURN(ret); } /** Loads all ENABLED events from mysql.event 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. @param[in,out] thd Thread context. Used for memory allocation in some cases. @retval FALSE success @retval TRUE error, the load is aborted @note Reports the error to the console */ bool Events::load_events_from_db(THD *thd) { TABLE *table; READ_RECORD read_record_info; bool ret= TRUE; uint count= 0; ulong saved_master_access; DBUG_ENTER("Events::load_events_from_db"); DBUG_PRINT("enter", ("thd: 0x%lx", (long) thd)); /* NOTE: even if we run in read-only mode, we should be able to lock the mysql.event table for writing. In order to achieve this, we should call mysql_lock_tables() under the super user. */ saved_master_access= thd->security_ctx->master_access; thd->security_ctx->master_access |= SUPER_ACL; ret= db_repository->open_event_table(thd, TL_WRITE, &table); thd->security_ctx->master_access= saved_master_access; if (ret) { sql_print_error("Event Scheduler: Failed to open table mysql.event"); DBUG_RETURN(TRUE); } init_read_record(&read_record_info, thd, table, NULL, 0, 1, FALSE); while (!(read_record_info.read_record(&read_record_info))) { Event_queue_element *et; bool created; bool drop_on_completion; if (!(et= new Event_queue_element)) goto end; DBUG_PRINT("info", ("Loading event from row.")); if (et->load_from_row(thd, table)) { sql_print_error("Event Scheduler: " "Error while loading events from mysql.event. " "The table probably contains bad data or is corrupted"); delete et; goto end; } drop_on_completion= (et->on_completion == Event_parse_data::ON_COMPLETION_DROP); if (event_queue->create_event(thd, et, &created)) { /* Out of memory */ delete et; goto end; } if (created) count++; else if (drop_on_completion) { /* If not created, a stale event - drop if immediately if ON COMPLETION NOT PRESERVE. XXX: This won't be replicated, thus the drop won't appear in in the slave. When the slave is restarted it will drop events. However, as the slave will be "out of sync", it might happen that an event created on the master, after master restart, won't be replicated to the slave correctly, as the create will fail there. */ int rc= table->file->ha_delete_row(table->record[0]); if (rc) { table->file->print_error(rc, MYF(0)); goto end; } } } sql_print_information("Event Scheduler: Loaded %d event%s", count, (count == 1) ? "" : "s"); ret= FALSE; end: end_read_record(&read_record_info); close_thread_tables(thd); DBUG_RETURN(ret); } /** @} (End of group Event_Scheduler) */