/* 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; either version 2 of the License, or (at your option) any later version. 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" /* 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 }; 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 }; TYPELIB Events::var_typelib= { array_elements(var_event_scheduler_state_names)-1, "", var_event_scheduler_state_names, NULL }; static Event_queue events_event_queue; static Event_scheduler events_event_scheduler; static Event_db_repository events_event_db_repository; Events Events::singleton; enum Events::enum_opt_event_scheduler Events::opt_event_scheduler= Events::EVENTS_OFF; /* 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); } /* Accessor for the singleton instance. SYNOPSIS Events::get_instance() RETURN VALUE address */ Events * Events::get_instance() { DBUG_ENTER("Events::get_instance"); DBUG_RETURN(&singleton); } /* 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; } /* Constructor of Events class. It's called when events.o is loaded. Assigning addressed of static variables in this object file. SYNOPSIS Events::Events() */ Events::Events() { scheduler= &events_event_scheduler; event_queue= &events_event_queue; db_repository= &events_event_db_repository; } /* Opens mysql.event table with specified lock SYNOPSIS Events::open_event_table() thd Thread context lock_type How to lock the table table We will store the open table here RETURN VALUE 1 Cannot lock table 2 The table is corrupted - different number of fields 0 OK */ int Events::open_event_table(THD *thd, enum thr_lock_type lock_type, TABLE **table) { return db_repository->open_event_table(thd, lock_type, table); } /* The function exported to the world for creating of events. SYNOPSIS Events::create_event() thd [in] THD parse_data [in] Event's data from parsing stage if_not_exists [in] Whether IF NOT EXISTS was specified in the DDL RETURN VALUE FALSE OK TRUE Error (Reported) NOTES In case there is an event with the same name (db) and IF NOT EXISTS is specified, an warning is put into the stack. */ bool Events::create_event(THD *thd, Event_parse_data *parse_data, bool if_not_exists) { int ret; DBUG_ENTER("Events::create_event"); if (unlikely(check_system_tables_error)) { my_error(ER_EVENTS_DB_ERROR, MYF(0)); DBUG_RETURN(TRUE); } 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))) { if ((ret= event_queue->create_event(thd, parse_data->dbname, parse_data->name))) { DBUG_ASSERT(ret == OP_LOAD_ERROR); my_error(ER_EVENT_MODIFY_QUEUE_ERROR, MYF(0)); } } pthread_mutex_unlock(&LOCK_event_metadata); DBUG_RETURN(ret); } /* The function exported to the world for alteration of events. SYNOPSIS Events::update_event() thd [in] THD parse_data [in] Event's data from parsing stage rename_to [in] Set in case of RENAME TO. RETURN VALUE FALSE OK TRUE Error NOTES et contains data about dbname and event name. new_name is the new name of the event, if not null this means that RENAME TO was specified in the query */ bool Events::update_event(THD *thd, Event_parse_data *parse_data, sp_name *rename_to) { int ret; DBUG_ENTER("Events::update_event"); LEX_STRING *new_dbname= rename_to ? &rename_to->m_db : NULL; LEX_STRING *new_name= rename_to ? &rename_to->m_name : NULL; if (unlikely(check_system_tables_error)) { my_error(ER_EVENTS_DB_ERROR, MYF(0)); DBUG_RETURN(TRUE); } 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))) { if ((ret= event_queue->update_event(thd, parse_data->dbname, parse_data->name, new_dbname, new_name))) { DBUG_ASSERT(ret == OP_LOAD_ERROR); my_error(ER_EVENT_MODIFY_QUEUE_ERROR, MYF(0)); } } pthread_mutex_unlock(&LOCK_event_metadata); DBUG_RETURN(ret); } /* Drops an event SYNOPSIS Events::drop_event() thd [in] THD dbname [in] Event's schema name [in] Event's name if_exists [in] When set and the event does not exist => warning onto the stack only_from_disk [in] Whether to remove the event from the queue too. In case of Event_job_data::drop() it's needed to do only disk drop because Event_queue will handle removal from memory queue. RETURN VALUE FALSE OK TRUE Error (reported) */ bool Events::drop_event(THD *thd, LEX_STRING dbname, LEX_STRING name, bool if_exists, bool only_from_disk) { int ret; DBUG_ENTER("Events::drop_event"); if (unlikely(check_system_tables_error)) { my_error(ER_EVENTS_DB_ERROR, MYF(0)); DBUG_RETURN(TRUE); } 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 (!only_from_disk) event_queue->drop_event(thd, dbname, name); } pthread_mutex_unlock(&LOCK_event_metadata); DBUG_RETURN(ret); } /* Drops all events from a schema SYNOPSIS Events::drop_schema_events() thd Thread 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)); if (unlikely(check_system_tables_error)) { my_error(ER_EVENTS_DB_ERROR, MYF(0)); DBUG_VOID_RETURN; } pthread_mutex_lock(&LOCK_event_metadata); 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; } /* SHOW CREATE EVENT SYNOPSIS Events::show_create_event() thd Thread context spn The name of the event (db, name) RETURN VALUE FALSE OK TRUE Error during writing to the wire */ bool Events::show_create_event(THD *thd, LEX_STRING dbname, LEX_STRING name) { CHARSET_INFO *scs= system_charset_info; int ret; Event_timed *et= new Event_timed(); DBUG_ENTER("Events::show_create_event"); DBUG_PRINT("enter", ("name: %s@%s", dbname.str, name.str)); if (unlikely(check_system_tables_error)) { my_error(ER_EVENTS_DB_ERROR, MYF(0)); DBUG_RETURN(TRUE); } ret= db_repository->load_named_event(thd, dbname, name, et); if (!ret) { Protocol *protocol= thd->protocol; char show_str_buf[10 * STRING_BUFFER_USUAL_SIZE]; String show_str(show_str_buf, sizeof(show_str_buf), scs); List<Item> field_list; byte *sql_mode_str; ulong sql_mode_len=0; show_str.length(0); show_str.set_charset(system_charset_info); if (et->get_create_event(thd, &show_str)) goto err; field_list.push_back(new Item_empty_string("Event", NAME_LEN)); sql_mode_str= sys_var_thd_sql_mode::symbolic_mode_representation(thd, et->sql_mode, &sql_mode_len); field_list.push_back(new Item_empty_string("sql_mode", sql_mode_len)); field_list.push_back(new Item_empty_string("Create Event", show_str.length())); if (protocol->send_fields(&field_list, Protocol::SEND_NUM_ROWS | Protocol::SEND_EOF)) goto err; protocol->prepare_for_resend(); protocol->store(et->name.str, et->name.length, scs); protocol->store((char*) sql_mode_str, sql_mode_len, scs); protocol->store(show_str.c_ptr(), show_str.length(), scs); ret= protocol->write(); send_eof(thd); } delete et; DBUG_RETURN(ret); err: delete et; DBUG_RETURN(TRUE); } /* Proxy for Event_db_repository::fill_schema_events. Callback for I_S from sql_show.cc SYNOPSIS Events::fill_schema_events() thd Thread context tables The schema table cond Unused RETURN VALUE 0 OK !0 Error */ int Events::fill_schema_events(THD *thd, TABLE_LIST *tables, COND * /* cond */) { char *db= NULL; DBUG_ENTER("Events::fill_schema_events"); Events *myself= get_instance(); if (unlikely(myself->check_system_tables_error)) { my_error(ER_EVENTS_DB_ERROR, MYF(0)); DBUG_RETURN(TRUE); } /* 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 (check_access(thd, EVENT_ACL, thd->lex->select_lex.db, 0, 0, 0, is_schema_db(thd->lex->select_lex.db))) DBUG_RETURN(1); db= thd->lex->select_lex.db; } DBUG_RETURN(myself->db_repository->fill_schema_events(thd, tables, db)); } /* 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() { THD *thd; bool res= FALSE; DBUG_ENTER("Events::init"); if (opt_event_scheduler == Events::EVENTS_DISABLED) DBUG_RETURN(FALSE); /* 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(); if (check_system_tables(thd)) { check_system_tables_error= TRUE; sql_print_error("SCHEDULER: The system tables are damaged. " "The scheduler subsystem will be unusable during this run."); goto end; } check_system_tables_error= FALSE; if (event_queue->init_queue(thd, db_repository)) { sql_print_error("SCHEDULER: Error while loading from disk."); goto end; } scheduler->init_scheduler(event_queue); DBUG_ASSERT(opt_event_scheduler == Events::EVENTS_ON || opt_event_scheduler == Events::EVENTS_OFF); if (opt_event_scheduler == Events::EVENTS_ON) res= scheduler->start(); end: 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 (likely(!check_system_tables_error)) { scheduler->stop(); scheduler->deinit_scheduler(); event_queue->deinit_queue(); } 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); event_queue->init_mutexes(); scheduler->init_mutexes(); } /* Destroys Events mutexes SYNOPSIS Events::destroy_mutexes() */ void Events::destroy_mutexes() { event_queue->deinit_mutexes(); scheduler->deinit_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"); scheduler->dump_internal_status(); event_queue->dump_internal_status(); DBUG_VOID_RETURN; } /* Starts execution of events by the scheduler SYNOPSIS Events::start_execution_of_events() RETURN VALUE FALSE OK TRUE Error */ bool Events::start_execution_of_events() { DBUG_ENTER("Events::start_execution_of_events"); if (unlikely(check_system_tables_error)) { my_error(ER_EVENTS_DB_ERROR, MYF(0)); DBUG_RETURN(TRUE); } DBUG_RETURN(scheduler->start()); } /* Stops execution of events by the scheduler. Already running events will not be stopped. If the user needs them stopped manual intervention is needed. SYNOPSIS Events::stop_execution_of_events() RETURN VALUE FALSE OK TRUE Error */ bool Events::stop_execution_of_events() { DBUG_ENTER("Events::stop_execution_of_events"); if (unlikely(check_system_tables_error)) { my_error(ER_EVENTS_DB_ERROR, MYF(0)); DBUG_RETURN(TRUE); } DBUG_RETURN(scheduler->stop()); } /* Checks whether the scheduler is running or not. SYNOPSIS Events::is_started() RETURN VALUE TRUE Yes FALSE No */ bool Events::is_execution_of_events_started() { DBUG_ENTER("Events::is_execution_of_events_started"); if (unlikely(check_system_tables_error)) { my_error(ER_EVENTS_DB_ERROR, MYF(0)); DBUG_RETURN(FALSE); } DBUG_RETURN(scheduler->is_running()); } /* Opens mysql.db and mysql.user and checks whether: 1. mysql.db has column Event_priv at column 20 (0 based); 2. mysql.user has column Event_priv at column 29 (0 based); SYNOPSIS Events::check_system_tables() thd Thread RETURN VALUE FALSE OK TRUE Error */ bool Events::check_system_tables(THD *thd) { TABLE_LIST tables; Open_tables_state backup; bool ret= FALSE; DBUG_ENTER("Events::check_system_tables"); DBUG_PRINT("enter", ("thd=0x%lx", thd)); thd->reset_n_backup_open_tables_state(&backup); bzero((char*) &tables, sizeof(tables)); tables.db= (char*) "mysql"; tables.table_name= tables.alias= (char*) "db"; tables.lock_type= TL_READ; if ((ret= simple_open_n_lock_tables(thd, &tables))) { sql_print_error("SCHEDULER: Cannot open mysql.db"); ret= TRUE; } ret= table_check_intact(tables.table, MYSQL_DB_FIELD_COUNT, mysql_db_table_fields, &mysql_db_table_last_check, ER_CANNOT_LOAD_FROM_TABLE); close_thread_tables(thd); bzero((char*) &tables, sizeof(tables)); tables.db= (char*) "mysql"; tables.table_name= tables.alias= (char*) "user"; tables.lock_type= TL_READ; if (simple_open_n_lock_tables(thd, &tables)) { sql_print_error("SCHEDULER: Cannot open mysql.user"); ret= TRUE; } else { if (tables.table->s->fields < 29 || strncmp(tables.table->field[29]->field_name, STRING_WITH_LEN("Event_priv"))) { sql_print_error("mysql.user has no `Event_priv` column at position %d", 29); ret= TRUE; } close_thread_tables(thd); } thd->restore_backup_open_tables_state(&backup); DBUG_RETURN(ret); }