/* Copyright (c) 2005, 2024, Oracle and/or its affiliates. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License, version 2.0, as published by the Free Software Foundation. This program is designed to work with certain software (including but not limited to OpenSSL) that is licensed under separate terms, as designated in a particular file or component or in included license documentation. The authors of MySQL hereby grant you an additional permission to link the program and your derivative works with the separately licensed software that they have either included with the program or referenced in the documentation. 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, version 2.0, 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include "sql/events.h" #include #include #include #include #include #include #include #include #include "lex_string.h" #include "m_string.h" #include "my_dbug.h" #include "my_macros.h" #include "my_sys.h" #include "mysql/components/services/bits/psi_bits.h" #include "mysql/components/services/bits/psi_memory_bits.h" #include "mysql/components/services/log_builtins.h" #include "mysql/components/services/log_shared.h" #include "mysql/my_loglevel.h" #include "mysql/psi/mysql_cond.h" #include "mysql/psi/mysql_memory.h" #include "mysql/psi/mysql_mutex.h" #include "mysql/psi/mysql_sp.h" #include "mysql/psi/mysql_stage.h" #include "mysql/psi/mysql_thread.h" #include "mysql/strings/int2str.h" #include "mysql/strings/m_ctype.h" // CHARSET_INFO #include "mysql_com.h" #include "mysqld_error.h" // ER_* #include "sql/auth/auth_acls.h" #include "sql/auth/auth_common.h" // EVENT_ACL #include "sql/dd/cache/dictionary_client.h" #include "sql/dd/dd_schema.h" // dd::Schema_MDL_locker #include "sql/dd/string_type.h" #include "sql/dd/types/event.h" #include "sql/dd/types/schema.h" #include "sql/debug_sync.h" #include "sql/event_data_objects.h" // Event_queue_element #include "sql/event_db_repository.h" // Event_db_repository #include "sql/event_parse_data.h" // Event_parse_data #include "sql/event_queue.h" // Event_queue #include "sql/event_scheduler.h" // Event_scheduler #include "sql/item.h" #include "sql/lock.h" // lock_object_name #include "sql/log.h" #include "sql/mdl.h" #include "sql/mysqld.h" // LOCK_global_system_variables #include "sql/protocol.h" #include "sql/psi_memory_key.h" #include "sql/set_var.h" #include "sql/sp_head.h" // Stored_program_creation_ctx #include "sql/sql_class.h" // THD #include "sql/sql_const.h" #include "sql/sql_lex.h" #include "sql/sql_list.h" #include "sql/sql_show.h" // append_definer #include "sql/sql_table.h" // write_bin_log #include "sql/system_variables.h" #include "sql/table.h" #include "sql/thd_raii.h" #include "sql/transaction.h" #include "sql/tztime.h" // Time_zone #include "sql_string.h" // String #include "string_with_len.h" /** @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 internal table status field will be ENUM('DISABLED', 'ENABLED', 'SLAVESIDE_DISABLED'). In this case when CREATE EVENT is replicated it should go into the binary as DISABLE ON REPLICA 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 DISABLE ON REPLICA. 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. */ Event_queue *Events::event_queue; Event_scheduler *Events::scheduler; ulong Events::opt_event_scheduler = Events::EVENTS_OFF; static bool load_events_from_db(THD *thd, Event_queue *event_queue); /* 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_CSTRING s, LEX_CSTRING t, const CHARSET_INFO *cs) { return cs->coll->strnncollsp(cs, pointer_cast(s.str), s.length, pointer_cast(t.str), t.length); } /* Reconstructs interval expression from interval type and expression value that is in form of a value of the smallest 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; close_quote = false; break; 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 query string for removing executable comments for avoiding leak and keeping consistency of the execution on master and slave. @param[in] thd Thread handler @param[in] buf Query string @return 0 ok 1 error */ static int create_query_string(THD *thd, String *buf) { /* Append the "CREATE" part of the query */ if (buf->append(STRING_WITH_LEN("CREATE "))) return 1; /* Append definer */ append_definer(thd, buf, thd->lex->definer->user, thd->lex->definer->host); /* Append the left part of thd->query after "DEFINER" part */ if (buf->append( thd->lex->stmt_definition_begin, thd->lex->stmt_definition_end - thd->lex->stmt_definition_begin)) return 1; return 0; } /** Create a new event. Atomicity: The operation to create an event is atomic/crash-safe. Changes to the Data-dictionary and writing event to binlog are part of the same transaction. All the changes are done as part of the same transaction or do not have any side effects on the operation failure. Data-dictionary cache and event queues are in sync with operation state. Cache and event queue does not contain any stale/incorrect data in case of failure. In case of crash, there won't be any discrepancy between the data-dictionary table and the binary log. @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) { bool event_already_exists; bool event_added_to_event_queue = false; std::unique_ptr new_element(nullptr); DBUG_TRACE; DBUG_EXECUTE_IF("thd_killed_injection", thd->killed = THD::KILL_QUERY; return false;); /* 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)) return true; /* At create, one of them must be set */ assert(parse_data->expression || parse_data->execute_at); if (check_access(thd, EVENT_ACL, parse_data->dbname.str, nullptr, nullptr, false, false)) return true; // Acquire exclusive MDL lock. if (lock_object_name(thd, MDL_key::EVENT, parse_data->dbname.str, parse_data->name.str)) return true; if (parse_data->do_not_create) return false; /* Turn off row binlogging of this statement and use statement-based so that all supporting tables are updated for CREATE EVENT command. When we are going out of the function scope, the original binary format state will be restored. */ const Save_and_Restore_binlog_format_state binlog_format_state(thd); const dd::cache::Dictionary_client::Auto_releaser releaser(thd->dd_client()); if (Event_db_repository::create_event(thd, parse_data, if_not_exists, &event_already_exists)) { /* On error conditions my_error() is called so no need to handle here */ goto err_with_rollback; } // Create event queue element. if (opt_event_scheduler != Events::EVENTS_DISABLED && !event_already_exists) { new_element.reset(new Event_queue_element()); if (!new_element) { my_error(ER_OUTOFMEMORY, MYF(ME_FATALERROR), sizeof(Event_queue_element)); goto err_with_rollback; } if (Event_db_repository::load_named_event( thd, parse_data->dbname, parse_data->name, new_element.get())) goto err_with_rollback; // Add new event queue element in the events queue. if (event_queue && event_queue->create_event(thd, new_element.get(), &event_added_to_event_queue)) { my_error(ER_OUTOFMEMORY, MYF(ME_FATALERROR), 0); goto err_with_rollback; } // Release new_element ownership if it is added to the event queue. if (event_added_to_event_queue) new_element.release(); } // Binlog the create event. { assert(thd->query().str && thd->query().length); String log_query; if (create_query_string(thd, &log_query)) { LogErr(ERROR_LEVEL, ER_EVENT_ERROR_CREATING_QUERY_TO_WRITE_TO_BINLOG); goto err_with_rollback; } else { thd->add_to_binlog_accessed_dbs(parse_data->dbname.str); /* If the definer is not set or set to CURRENT_USER, the value of CURRENT_USER will be written into the binary log as the definer for the SQL thread. */ if (write_bin_log(thd, true, log_query.c_ptr(), log_query.length(), !event_already_exists)) goto err_with_rollback; } } // Commit changes to the data-dictionary and binary log. if (DBUG_EVALUATE_IF("simulate_create_event_failure", true, false) || trans_commit_stmt(thd) || trans_commit(thd)) goto err_with_rollback; return false; err_with_rollback: DBUG_EXECUTE_IF("simulate_create_event_failure", my_error(ER_UNKNOWN_ERROR, MYF(0));); if (event_added_to_event_queue) { // Event element is dellocated by the drop_event() method. event_queue->drop_event(thd, parse_data->dbname, parse_data->name); } trans_rollback_stmt(thd); /* Full rollback in case we have THD::transaction_rollback_request and to synchronize DD state in cache and on disk (as statement rollback doesn't clear DD cache of modified uncommitted objects). */ trans_rollback(thd); return true; } /** Alter an event. Atomicity: The operation to update an event is atomic/crash-safe. Changes to the Data-dictionary and writing event to binlog are part of the same transaction. All the changes are done as part of the same transaction or do not have any side effects on the operation failure. Data-dictionary cache and event queues are in sync with operation state. Cache and event queue does not contain any stale/incorrect data in case of failure. In case of crash, there won't be any discrepancy between the data-dictionary table and the binary log. @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, const LEX_CSTRING *new_dbname, const LEX_CSTRING *new_name) { std::unique_ptr new_element(nullptr); DBUG_TRACE; if (parse_data->check_parse_data(thd) || parse_data->do_not_create) return true; if (check_access(thd, EVENT_ACL, parse_data->dbname.str, nullptr, nullptr, false, false)) return true; if (lock_object_name(thd, MDL_key::EVENT, parse_data->dbname.str, parse_data->name.str)) return true; if (new_dbname != nullptr) /* 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)); 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, nullptr, nullptr, false, false)) return true; // Acquire mdl exclusive lock on target database name. if (lock_object_name(thd, MDL_key::EVENT, new_dbname->str, new_name->str)) return true; } /* Turn off row binlogging of this statement and use statement-based so that all supporting tables are updated for CREATE EVENT command. When we are going out of the function scope, the original binary format state will be restored. */ const Save_and_Restore_binlog_format_state binlog_format_state(thd); const dd::cache::Dictionary_client::Auto_releaser releaser(thd->dd_client()); if (Event_db_repository::update_event(thd, parse_data, new_dbname, new_name)) { /* On error conditions my_error() is called so no need to handle here */ goto err_with_rollback; } if (opt_event_scheduler != Events::EVENTS_DISABLED) { // Create event queue element. new_element.reset(new Event_queue_element()); if (!new_element) { my_error(ER_OUTOFMEMORY, MYF(ME_FATALERROR), sizeof(Event_queue_element)); goto err_with_rollback; } const LEX_CSTRING dbname = new_dbname ? *new_dbname : parse_data->dbname; const LEX_CSTRING name = new_name ? *new_name : parse_data->name; if (Event_db_repository::load_named_event(thd, dbname, name, new_element.get())) goto err_with_rollback; } /* Binlog the alter event. */ { assert(thd->query().str && thd->query().length); thd->add_to_binlog_accessed_dbs(parse_data->dbname.str); if (new_dbname) thd->add_to_binlog_accessed_dbs(new_dbname->str); if (write_bin_log(thd, true, thd->query().str, thd->query().length, true)) goto err_with_rollback; } // Commit changes to the data-dictionary and binary log. if (DBUG_EVALUATE_IF("simulate_alter_event_failure", true, false) || trans_commit_stmt(thd) || trans_commit(thd)) goto err_with_rollback; if (new_dbname != nullptr) { /* RENAME: Drop the old event instrumentation. */ MYSQL_DROP_SP(to_uint(enum_sp_type::EVENT), parse_data->dbname.str, parse_data->dbname.length, parse_data->name.str, parse_data->name.length); } // Update element in event queue. if (event_queue && new_element != nullptr) { /* 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. */ event_queue->update_event(thd, parse_data->dbname, parse_data->name, new_element.get()); new_element.release(); } return false; err_with_rollback: DBUG_EXECUTE_IF("simulate_alter_event_failure", my_error(ER_UNKNOWN_ERROR, MYF(0));); trans_rollback_stmt(thd); /* Full rollback in case we have THD::transaction_rollback_request and to synchronize DD state in cache and on disk (as statement rollback doesn't clear DD cache of modified uncommitted objects). */ trans_rollback(thd); return true; } /** Drops an event Atomicity: The operation to drop an event is atomic/crash-safe. Changes to the Data-dictionary and writing event to binlog are part of the same transaction. All the changes are done as part of the same transaction or do not have any side effects on the operation failure. Data-dictionary cache and event queues are in sync with operation state. Cache and event queue does not contain any stale/incorrect data in case of failure. In case of crash, there won't be any discrepancy between the data-dictionary table and the binary log. @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_CSTRING dbname, LEX_CSTRING name, bool if_exists) { DBUG_TRACE; if (check_access(thd, EVENT_ACL, dbname.str, nullptr, nullptr, false, false)) return true; // Acquire exclusive MDL lock. if (lock_object_name(thd, MDL_key::EVENT, dbname.str, name.str)) return true; DEBUG_SYNC(thd, "after_acquiring_exclusive_lock_on_the_event"); const dd::cache::Dictionary_client::Auto_releaser releaser(thd->dd_client()); bool event_exists; if (Event_db_repository::drop_event(thd, dbname, name, if_exists, &event_exists)) { /* On error conditions my_error() is called so no need to handle here */ goto err_with_rollback; } // Binlog the drop event. { assert(thd->query().str && thd->query().length); thd->add_to_binlog_accessed_dbs(dbname.str); if (write_bin_log(thd, true, thd->query().str, thd->query().length, event_exists)) goto err_with_rollback; } // Commit changes to the data-dictionary and binary log. if (DBUG_EVALUATE_IF("simulate_drop_event_failure", true, false) || trans_commit_stmt(thd) || trans_commit(thd)) goto err_with_rollback; if (event_queue) event_queue->drop_event(thd, dbname, name); #ifdef HAVE_PSI_SP_INTERFACE /* Drop statistics for this stored program from performance schema. */ MYSQL_DROP_SP(to_uint(enum_sp_type::EVENT), dbname.str, dbname.length, name.str, name.length); #endif return false; err_with_rollback: DBUG_EXECUTE_IF("simulate_drop_event_failure", my_error(ER_UNKNOWN_ERROR, MYF(0));); trans_rollback_stmt(thd); /* Full rollback in case we have THD::transaction_rollback_request and to synchronize DD state in cache and on disk (as statement rollback doesn't clear DD cache of modified uncommitted objects). */ trans_rollback(thd); return true; } /** Take exclusive metadata lock on all events in a schema. @param thd Thread handle. @param schema Schema object. */ bool Events::lock_schema_events(THD *thd, const dd::Schema &schema) { DBUG_TRACE; std::vector event_names; if (thd->dd_client()->fetch_schema_component_names(&schema, &event_names)) return true; /* If lower_case_table_names == 2 then schema names should be lower cased for proper hash key comparisons. */ const char *schema_name = schema.name().c_str(); char schema_name_buf[NAME_LEN + 1]; if (lower_case_table_names == 2) { my_stpcpy(schema_name_buf, schema_name); my_casedn_str(system_charset_info, schema_name_buf); schema_name = schema_name_buf; } /* Ensure that we don't hold memory used by MDL_requests after locks have been acquired. This reduces memory usage in cases when we have DROP DATABASE that needs to drop lots of different objects. */ MEM_ROOT mdl_reqs_root(key_memory_rm_db_mdl_reqs_root, MEM_ROOT_BLOCK_SIZE); MDL_request_list mdl_requests; for (std::vector::const_iterator name = event_names.begin(); name != event_names.end(); ++name) { MDL_key mdl_key; dd::Event::create_mdl_key(dd::String_type(schema_name), *name, &mdl_key); // Add MDL_request for routine to mdl_requests list. MDL_request *mdl_request = new (&mdl_reqs_root) MDL_request; MDL_REQUEST_INIT_BY_KEY(mdl_request, &mdl_key, MDL_EXCLUSIVE, MDL_TRANSACTION); mdl_requests.push_front(mdl_request); } return thd->mdl_context.acquire_locks(&mdl_requests, thd->variables.lock_wait_timeout); } /** 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] thd THD handle. @param[in] schema Schema object. @returns true drop events from database failed. @returns false drop events from database succeeded. */ bool Events::drop_schema_events(THD *thd, const dd::Schema &schema) { LEX_CSTRING db_lex = {schema.name().c_str(), schema.name().length()}; if (event_queue) event_queue->drop_schema_events(db_lex); return Event_db_repository::drop_schema_events(thd, schema); } /** A helper function to generate SHOW CREATE EVENT output from a named event. @param[in] thd THD handle. @param[in] et Pointer to Event_timed object. @param[in] protocol Pointer to Protocol object. */ 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); mem_root_deque field_list(thd->mem_root); LEX_STRING sql_mode; const String *tz_name; DBUG_TRACE; show_str.length(0); if (et->get_create_event(thd, &show_str)) return true; field_list.push_back(new Item_empty_string("Event", NAME_CHAR_LEN)); if (sql_mode_string_representation(thd, et->m_sql_mode, &sql_mode)) return true; field_list.push_back( new Item_empty_string("sql_mode", (uint)sql_mode.length)); tz_name = et->m_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 (thd->send_result_metadata(field_list, Protocol::SEND_NUM_ROWS | Protocol::SEND_EOF)) return true; protocol->start_row(); protocol->store_string(et->m_event_name.str, et->m_event_name.length, system_charset_info); protocol->store_string(sql_mode.str, sql_mode.length, system_charset_info); protocol->store_string(tz_name->ptr(), tz_name->length(), system_charset_info); protocol->store_string(show_str.c_ptr(), show_str.length(), et->m_creation_ctx->get_client_cs()); const char *csname = et->m_creation_ctx->get_client_cs()->csname; protocol->store_string(csname, strlen(csname), system_charset_info); protocol->store_string( et->m_creation_ctx->get_connection_cl()->m_coll_name, strlen(et->m_creation_ctx->get_connection_cl()->m_coll_name), system_charset_info); protocol->store_string(et->m_creation_ctx->get_db_cl()->m_coll_name, strlen(et->m_creation_ctx->get_db_cl()->m_coll_name), system_charset_info); if (protocol->end_row()) return true; my_eof(thd); 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_CSTRING dbname, LEX_CSTRING name) { Event_timed et; bool ret; DBUG_TRACE; DBUG_PRINT("enter", ("name: %s@%s", dbname.str, name.str)); if (check_access(thd, EVENT_ACL, dbname.str, nullptr, nullptr, false, false)) return true; // We must make sure the schema is released and unlocked in the right // order. Fail if we are unable to get a meta data lock on the schema // name. dd::Schema_MDL_locker mdl_handler(thd); if (mdl_handler.ensure_locked(dbname.str)) return true; // Grab MDL lock on object in shared mode. MDL_key mdl_key; dd::Event::create_mdl_key(dbname.str, name.str, &mdl_key); MDL_request event_mdl_request; MDL_REQUEST_INIT_BY_KEY(&event_mdl_request, &mdl_key, MDL_SHARED_HIGH_PRIO, MDL_TRANSACTION); if (thd->mdl_context.acquire_lock(&event_mdl_request, thd->variables.lock_wait_timeout)) return true; DEBUG_SYNC(thd, "after_acquiring_shared_lock_on_the_event"); /* 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. */ ret = Event_db_repository::load_named_event(thd, dbname, name, &et); if (!ret) ret = send_show_create_event(thd, &et, thd->get_protocol()); return ret; } /** Initializes the scheduler's structures. @param opt_noacl_or_bootstrap true if there is --skip-grant-tables or --initialize. In that case we disable the event scheduler. @note This function is not synchronized. @retval false Perhaps there was an error, and the event scheduler is disabled. But the error is not fatal and the server start up can continue. @retval true Fatal error. Startup must terminate (call unireg_abort()). */ bool Events::init(bool opt_noacl_or_bootstrap) { THD *thd; int err_no; bool res = false; DBUG_TRACE; // If event scheduler was explicitly disabled from command-line, do not // initialize it. if (opt_event_scheduler == Events::EVENTS_DISABLED) return res; // If run with --skip-grant-tables or --initialize, disable the event // scheduler and return. if (opt_noacl_or_bootstrap) { opt_event_scheduler = Events::EVENTS_DISABLED; return res; } /* We need a temporary THD during boot Current time is stored in data member start_time of THD class and initialized by THD::set_time() called by ctor->THD::init() Subsequently, this value is used to check whether event was expired when make loading events from storage. Check for event expiration time is done at Event_queue_element::compute_next_execution_time() where event's status set to Event_parse_data::DISABLED and dropped flag set to true if event was expired. */ 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(); 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() || load_events_from_db(thd, event_queue) || (opt_event_scheduler == EVENTS_ON && scheduler->start(&err_no))) { LogErr(ERROR_LEVEL, ER_EVENT_SCHEDULER_ERROR_LOADING_FROM_DB); res = true; /* fatal error: request unireg_abort */ goto end; } end: if (res) { delete event_queue; event_queue = nullptr; delete scheduler; scheduler = nullptr; } delete thd; return res; } /* Cleans up scheduler's resources. Called at server shutdown. SYNOPSIS Events::deinit() NOTES This function is not synchronized. */ void Events::deinit() { DBUG_TRACE; if (opt_event_scheduler != EVENTS_DISABLED) { delete scheduler; scheduler = nullptr; /* safety */ delete event_queue; event_queue = nullptr; /* safety */ } } #ifdef HAVE_PSI_INTERFACE PSI_mutex_key key_LOCK_event_queue, key_event_scheduler_LOCK_scheduler_state; /* clang-format off */ static PSI_mutex_info all_events_mutexes[]= { { &key_LOCK_event_queue, "LOCK_event_queue", PSI_FLAG_SINGLETON, 0, PSI_DOCUMENT_ME}, { &key_event_scheduler_LOCK_scheduler_state, "Event_scheduler::LOCK_scheduler_state", PSI_FLAG_SINGLETON, 0, PSI_DOCUMENT_ME} }; /* clang-format on */ PSI_cond_key key_event_scheduler_COND_state, key_COND_queue_state; static PSI_cond_info all_events_conds[] = { {&key_event_scheduler_COND_state, "Event_scheduler::COND_state", PSI_FLAG_SINGLETON, 0, PSI_DOCUMENT_ME}, {&key_COND_queue_state, "COND_queue_state", PSI_FLAG_SINGLETON, 0, PSI_DOCUMENT_ME}, }; PSI_thread_key key_thread_event_scheduler, key_thread_event_worker; static PSI_thread_info all_events_threads[] = { {&key_thread_event_scheduler, "event_scheduler", "evt_sched", PSI_FLAG_SINGLETON, 0, PSI_DOCUMENT_ME}, {&key_thread_event_worker, "event_worker", "evt_wkr", 0, 0, PSI_DOCUMENT_ME}}; #endif /* HAVE_PSI_INTERFACE */ PSI_stage_info stage_waiting_on_empty_queue = {0, "Waiting on empty queue", 0, PSI_DOCUMENT_ME}; PSI_stage_info stage_waiting_for_next_activation = { 0, "Waiting for next activation", 0, PSI_DOCUMENT_ME}; PSI_stage_info stage_waiting_for_scheduler_to_stop = { 0, "Waiting for the scheduler to stop", 0, PSI_DOCUMENT_ME}; PSI_memory_key key_memory_event_basic_root; #ifdef HAVE_PSI_INTERFACE PSI_stage_info *all_events_stages[] = {&stage_waiting_on_empty_queue, &stage_waiting_for_next_activation, &stage_waiting_for_scheduler_to_stop}; static PSI_memory_info all_events_memory[] = { {&key_memory_event_basic_root, "Event_basic::mem_root", PSI_FLAG_ONLY_GLOBAL_STAT, 0, "Event base class with root used for definiton etc."}}; static void init_events_psi_keys(void) { const char *category = "sql"; int count; count = static_cast(array_elements(all_events_mutexes)); mysql_mutex_register(category, all_events_mutexes, count); count = static_cast(array_elements(all_events_conds)); mysql_cond_register(category, all_events_conds, count); count = static_cast(array_elements(all_events_threads)); mysql_thread_register(category, all_events_threads, count); count = static_cast(array_elements(all_events_stages)); mysql_stage_register(category, all_events_stages, count); count = static_cast(array_elements(all_events_memory)); mysql_memory_register(category, all_events_memory, count); } #endif /* HAVE_PSI_INTERFACE */ /* Inits Events mutexes SYNOPSIS Events::init_mutexes() thd Thread */ void Events::init_mutexes() { #ifdef HAVE_PSI_INTERFACE init_events_psi_keys(); #endif } /* 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_TRACE; puts("\n\n\nEvents status:"); puts("LLA = Last Locked At LUA = Last Unlocked At"); puts("WOC = Waiting On Condition DL = Data Locked"); /* opt_event_scheduler should only be accessed while holding LOCK_global_system_variables. */ mysql_mutex_lock(&LOCK_global_system_variables); if (opt_event_scheduler == EVENTS_DISABLED) puts("The Event Scheduler is disabled"); else { scheduler->dump_internal_status(); event_queue->dump_internal_status(); } mysql_mutex_unlock(&LOCK_global_system_variables); } bool Events::start(int *err_no) { bool ret = false; if (scheduler) ret = scheduler->start(err_no); return ret; } bool Events::stop() { bool ret = false; if (scheduler) ret = scheduler->stop(); return ret; } /** Loads all ENABLED events 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 thd THD context. Used for memory allocation in some cases. @param event_queue Pointer to Event_queue object. @retval false success @retval true error, the load is aborted @note Reports the error to the console */ static bool load_events_from_db(THD *thd, Event_queue *event_queue) { DBUG_TRACE; DBUG_PRINT("enter", ("thd: %p", thd)); const dd::cache::Dictionary_client::Auto_releaser releaser(thd->dd_client()); // Fetch all Schemas std::vector schemas; if (thd->dd_client()->fetch_global_components(&schemas)) return true; std::vector> drop_events_vector; for (const dd::Schema *schema_obj : schemas) { // Fetch all events in a schema std::vector events; if (thd->dd_client()->fetch_schema_components(schema_obj, &events)) return true; const char *converted_schema_name = schema_obj->name().c_str(); char name_buf[NAME_LEN + 1]; if (lower_case_table_names == 2) { // Lower case table names == 2 is tested on OSX. my_stpcpy(name_buf, converted_schema_name); my_casedn_str(&my_charset_utf8mb3_tolower_ci, name_buf); converted_schema_name = name_buf; } for (const dd::Event *ev_obj : events) { std::unique_ptr et(new (std::nothrow) Event_queue_element); if (et == nullptr) { LogErr(ERROR_LEVEL, ER_EVENT_SCHEDULER_ERROR_GETTING_EVENT_OBJECT); return true; } if (et->fill_event_info(thd, *ev_obj, converted_schema_name)) { LogErr(ERROR_LEVEL, ER_EVENT_SCHEDULER_GOT_BAD_DATA_FROM_TABLE); return true; } bool drop_event = et->m_dropped; // create_event may free et. bool created = false; if (event_queue->create_event(thd, et.get(), &created)) { /* Out of memory */ return true; } if (created) et.release(); if (drop_event) { /* 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. */ drop_events_vector.push_back(std::make_pair(schema_obj, ev_obj)); } } } bool error = false; for (auto event_info : drop_events_vector) { if (lock_object_name(thd, MDL_key::EVENT, event_info.first->name().c_str(), event_info.second->name().c_str())) { LogErr(WARNING_LEVEL, ER_EVENT_CANT_GET_LOCK_FOR_DROPPING_EVENT, event_info.second->name().c_str(), event_info.first->name().c_str()); continue; } if (thd->dd_client()->drop(event_info.second)) { error = true; LogErr(WARNING_LEVEL, ER_EVENT_UNABLE_TO_DROP_EVENT, event_info.second->name().c_str(), event_info.first->name().c_str()); break; } } if (error) { trans_rollback_stmt(thd); // Full rollback in case we have THD::transaction_rollback_request. trans_rollback(thd); } else error = trans_commit_stmt(thd) || trans_commit(thd); // Note that locks are released here before the Auto_releaser // goes out of scope. This is safe since no cached objects were // acquired. thd->mdl_context.release_transactional_locks(); return error; } /** @} (End of group Event_Scheduler) */