summaryrefslogtreecommitdiffstats
path: root/sql/events.cc
diff options
context:
space:
mode:
Diffstat (limited to 'sql/events.cc')
-rw-r--r--sql/events.cc1327
1 files changed, 1327 insertions, 0 deletions
diff --git a/sql/events.cc b/sql/events.cc
new file mode 100644
index 00000000..64ff2642
--- /dev/null
+++ b/sql/events.cc
@@ -0,0 +1,1327 @@
+/*
+ Copyright (c) 2005, 2013, Oracle and/or its affiliates.
+ Copyright (c) 2017, 2020, MariaDB Corporation.
+
+ 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */
+
+#include "mariadb.h"
+#include "sql_priv.h"
+#include "unireg.h"
+#include "sql_parse.h" // check_access
+#include "sql_base.h" // close_mysql_tables
+#include "sql_show.h" // append_definer
+#include "events.h"
+#include "sql_db.h" // check_db_dir_existence
+#include "sql_table.h" // write_bin_log
+#include "tztime.h" // struct Time_zone
+#include "sql_acl.h" // EVENT_ACL
+#include "records.h" // init_read_record, end_read_record
+#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
+#include "set_var.h"
+#include "lock.h" // lock_object_name
+#include "mysql/psi/mysql_sp.h"
+#include "wsrep_mysqld.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 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.
+*/
+
+Event_queue *Events::event_queue;
+Event_scheduler *Events::scheduler;
+Event_db_repository *Events::db_repository;
+ulong Events::opt_event_scheduler= Events::EVENTS_OFF;
+ulong Events::startup_state= Events::EVENTS_OFF;
+ulong Events::inited;
+
+
+/*
+ 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(const LEX_CSTRING *s, const LEX_CSTRING *t,
+ const CHARSET_INFO *cs)
+{
+ return cs->strnncollsp(s->str, s->length,
+ t->str, t->length);
+}
+
+
+/**
+ 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 (!inited)
+ {
+ 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 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;
+ 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)
+{
+ buf->length(0);
+ /* Append the "CREATE" part of the query */
+ if (thd->lex->create_info.or_replace())
+ {
+ if (buf->append(STRING_WITH_LEN("CREATE OR REPLACE ")))
+ return 1;
+ }
+ else 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.
+
+ @param[in,out] thd THD
+ @param[in] parse_data Event's data from parsing stage
+
+ 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 ret;
+ bool event_already_exists;
+ enum_binlog_format save_binlog_format;
+ DBUG_ENTER("Events::create_event");
+
+ if (unlikely(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, NULL, NULL, 0, 0))
+ DBUG_RETURN(TRUE);
+ WSREP_TO_ISOLATION_BEGIN(WSREP_MYSQL_DB, NULL, NULL);
+
+ if (lock_object_name(thd, MDL_key::EVENT,
+ parse_data->dbname.str, parse_data->name.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.
+ */
+ save_binlog_format= thd->set_current_stmt_binlog_format_stmt();
+
+ if (thd->lex->create_info.or_replace() && event_queue)
+ event_queue->drop_event(thd, &parse_data->dbname, &parse_data->name);
+
+ /* On error conditions my_error() is called so no need to handle here */
+ if (!(ret= db_repository->create_event(thd, parse_data,
+ &event_already_exists)))
+ {
+ Event_queue_element *new_element;
+ bool dropped= 0;
+
+ if (!event_already_exists)
+ {
+ 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)))
+ {
+ if (!db_repository->drop_event(thd, &parse_data->dbname,
+ &parse_data->name, TRUE))
+ dropped= 1;
+ 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 unless it's been successfully dropped
+ */
+ if (!dropped)
+ {
+ /* Binlog the create event. */
+ DBUG_ASSERT(thd->query() && thd->query_length());
+ char buffer[1024];
+ String log_query(buffer, sizeof(buffer), &my_charset_bin);
+ if (create_query_string(thd, &log_query))
+ {
+ my_message_sql(ER_STARTUP,
+ "Event Error: An error occurred while creating query "
+ "string, before writing it into binary log.",
+ MYF(ME_ERROR_LOG));
+ ret= true;
+ }
+ else
+ {
+ /*
+ 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.
+ */
+ ret= write_bin_log(thd, TRUE, log_query.ptr(), log_query.length());
+ }
+ }
+ }
+
+ thd->restore_stmt_binlog_format(save_binlog_format);
+
+ if (!ret && Events::opt_event_scheduler == Events::EVENTS_OFF)
+ {
+ push_warning(thd, Sql_condition::WARN_LEVEL_WARN, ER_UNKNOWN_ERROR,
+ "Event scheduler is switched off, use SET GLOBAL event_scheduler=ON to enable it.");
+ }
+
+ DBUG_RETURN(ret);
+#ifdef WITH_WSREP
+wsrep_error_label:
+ DBUG_RETURN(true);
+#endif
+}
+
+
+/**
+ 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_CSTRING *new_dbname, LEX_CSTRING *new_name)
+{
+ int ret;
+ enum_binlog_format save_binlog_format;
+ Event_queue_element *new_element;
+
+ DBUG_ENTER("Events::update_event");
+
+ if (unlikely(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, NULL, NULL, 0, 0))
+ DBUG_RETURN(TRUE);
+
+ WSREP_TO_ISOLATION_BEGIN(WSREP_MYSQL_DB, NULL, NULL);
+
+ if (lock_object_name(thd, MDL_key::EVENT,
+ parse_data->dbname.str, parse_data->name.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 (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));
+ 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, NULL, NULL, 0, 0))
+ DBUG_RETURN(TRUE);
+
+ /*
+ Acquire mdl exclusive lock on target database name.
+ */
+ if (lock_object_name(thd, MDL_key::EVENT,
+ new_dbname->str, new_name->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.
+ */
+ save_binlog_format= thd->set_current_stmt_binlog_format_stmt();
+
+ /* 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_CSTRING dbname= new_dbname ? *new_dbname : parse_data->dbname;
+ LEX_CSTRING 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)))
+ 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());
+ ret= write_bin_log(thd, TRUE, thd->query(), thd->query_length());
+ }
+ }
+
+ thd->restore_stmt_binlog_format(save_binlog_format);
+ DBUG_RETURN(ret);
+#ifdef WITH_WSREP
+wsrep_error_label:
+ DBUG_RETURN(true);
+#endif
+}
+
+
+/**
+ 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, const LEX_CSTRING *dbname,
+ const LEX_CSTRING *name, bool if_exists)
+{
+ int ret;
+ enum_binlog_format save_binlog_format;
+ DBUG_ENTER("Events::drop_event");
+
+ if (unlikely(check_if_system_tables_error()))
+ DBUG_RETURN(TRUE);
+
+ if (check_access(thd, EVENT_ACL, dbname->str, NULL, NULL, 0, 0))
+ DBUG_RETURN(TRUE);
+
+ WSREP_TO_ISOLATION_BEGIN(WSREP_MYSQL_DB, NULL, NULL);
+
+ /*
+ Turn off row binlogging of this statement and use statement-based so
+ that all supporting tables are updated for DROP EVENT command.
+ */
+ save_binlog_format= thd->set_current_stmt_binlog_format_stmt();
+
+ if (lock_object_name(thd, MDL_key::EVENT,
+ dbname->str, name->str))
+ DBUG_RETURN(TRUE);
+ /* 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());
+ ret= write_bin_log(thd, TRUE, thd->query(), thd->query_length());
+ /* Drop statistics for this stored program from performance schema. */
+ MYSQL_DROP_SP(SP_TYPE_EVENT,
+ dbname->str, static_cast<uint>(dbname->length), name->str, static_cast<uint>(name->length));
+ }
+
+ thd->restore_stmt_binlog_format(save_binlog_format);
+ DBUG_RETURN(ret);
+#ifdef WITH_WSREP
+wsrep_error_label:
+ DBUG_RETURN(true);
+#endif
+}
+
+
+/**
+ 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, const char *db)
+{
+ const LEX_CSTRING db_lex= { db, strlen(db) };
+
+ DBUG_ENTER("Events::drop_schema_events");
+ DBUG_PRINT("enter", ("dropping events from %s", db));
+
+ DBUG_SLOW_ASSERT(ok_for_lower_case_names(db));
+
+ /*
+ Sic: no check if the scheduler is disabled or system tables
+ are damaged, as intended.
+ */
+ if (event_queue)
+ event_queue->drop_schema_events(thd, &db_lex);
+ if (db_repository)
+ db_repository->drop_schema_events(thd, &db_lex);
+ else
+ {
+ if ((db_repository= new Event_db_repository))
+ {
+ db_repository->drop_schema_events(thd, &db_lex);
+ delete db_repository;
+ db_repository= 0;
+ }
+ }
+ 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<Item> field_list;
+ LEX_CSTRING sql_mode;
+ const String *tz_name;
+ MEM_ROOT *mem_root= thd->mem_root;
+ 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 (mem_root)
+ Item_empty_string(thd, "Event", NAME_CHAR_LEN),
+ mem_root);
+
+ if (sql_mode_string_representation(thd, et->sql_mode, &sql_mode))
+ DBUG_RETURN(TRUE);
+
+ field_list.push_back(new (mem_root)
+ Item_empty_string(thd, "sql_mode",
+ (uint) sql_mode.length), mem_root);
+
+ tz_name= et->time_zone->get_name();
+
+ field_list.push_back(new (mem_root)
+ Item_empty_string(thd, "time_zone", tz_name->length()),
+ mem_root);
+
+ field_list.push_back(new (mem_root)
+ Item_empty_string(thd, "Create Event",
+ show_str.length()), mem_root);
+
+ field_list.push_back(new (mem_root)
+ Item_empty_string(thd, "character_set_client",
+ MY_CS_CHARACTER_SET_NAME_SIZE),
+ mem_root);
+
+ field_list.push_back(new (mem_root)
+ Item_empty_string(thd, "collation_connection",
+ MY_CS_COLLATION_NAME_SIZE), mem_root);
+
+ field_list.push_back(new (mem_root)
+ Item_empty_string(thd, "Database Collation",
+ MY_CS_COLLATION_NAME_SIZE), mem_root);
+
+ if (protocol->send_result_set_metadata(&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.ptr(), show_str.length(),
+ et->creation_ctx->get_client_cs());
+ protocol->store(&et->creation_ctx->get_client_cs()->cs_name,
+ system_charset_info);
+ protocol->store(&et->creation_ctx->get_connection_cl()->coll_name,
+ system_charset_info);
+ protocol->store(&et->creation_ctx->get_db_cl()->coll_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, const LEX_CSTRING *dbname,
+ const LEX_CSTRING *name)
+{
+ Event_timed et;
+ bool ret;
+
+ DBUG_ENTER("Events::show_create_event");
+ DBUG_PRINT("enter", ("name: %s@%s", dbname->str, name->str));
+
+ if (unlikely(check_if_system_tables_error()))
+ DBUG_RETURN(TRUE);
+
+ if (check_access(thd, EVENT_ACL, dbname->str, NULL, NULL, 0, 0))
+ 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.
+ */
+ ret= db_repository->load_named_event(thd, dbname, name, &et);
+
+ 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 */)
+{
+ const char *db= NULL;
+ int ret;
+ char db_tmp[SAFE_NAME_LEN];
+ DBUG_ENTER("Events::fill_schema_events");
+
+ /*
+ If we didn't start events because of --skip-grant-tables, return an
+ empty set
+ */
+ if (opt_noacl)
+ DBUG_RETURN(0);
+
+ if (unlikely(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)
+ {
+ LEX_CSTRING *lexdb= &thd->lex->first_select_lex()->db;
+ DBUG_ASSERT(lexdb);
+ if (!is_infoschema_db(lexdb) && !is_perfschema_db(lexdb) &&
+ check_access(thd, EVENT_ACL, lexdb->str, NULL, NULL, 0, 0))
+ DBUG_RETURN(1);
+ db= normalize_db_name(lexdb->str, db_tmp, sizeof(db_tmp));
+ }
+ ret= db_repository->fill_schema_events(thd, tables, db);
+
+ DBUG_RETURN(ret);
+}
+
+
+/**
+ Initializes the scheduler's structures.
+
+ @param THD or null (if called by init)
+ @param opt_noacl_or_bootstrap
+ TRUE if there is --skip-grant-tables or --bootstrap
+ option. 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(THD *thd, bool opt_noacl_or_bootstrap)
+{
+ int err_no;
+ bool res= FALSE;
+ bool had_thd= thd != 0;
+ DBUG_ENTER("Events::init");
+
+ DBUG_ASSERT(inited == 0);
+
+ /*
+ Was disabled explicitly from the command line
+ */
+ if (opt_event_scheduler == Events::EVENTS_DISABLED ||
+ opt_noacl_or_bootstrap)
+ DBUG_RETURN(FALSE);
+
+ /* We need a temporary THD during boot */
+ if (!thd)
+ {
+
+ if (!(thd= new THD(0)))
+ {
+ 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();
+ /*
+ Set current time for the thread that handles events.
+ Current time is stored in data member start_time of THD class.
+ 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.
+ */
+ thd->set_time();
+ }
+
+ /*
+ We will need Event_db_repository anyway, even if the scheduler is
+ disabled - to perform events DDL.
+ */
+ DBUG_ASSERT(db_repository == 0);
+
+ 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 run with --skip-grant-tables or --bootstrap, don't try to do the
+ check of system tables and don't complain: in these modes the tables
+ are most likely not there and we're going to disable the event
+ scheduler anyway.
+ */
+ if (Event_db_repository::check_system_tables(thd))
+ {
+ delete db_repository;
+ db_repository= 0;
+ my_message(ER_STARTUP,
+ "Event Scheduler: An error occurred when initializing "
+ "system tables. Disabling the Event Scheduler.",
+ MYF(ME_ERROR_LOG));
+ /* Disable the scheduler since the system tables are not up to date */
+ opt_event_scheduler= EVENTS_OFF;
+ 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(&err_no)))
+ {
+ my_message_sql(ER_STARTUP,
+ "Event Scheduler: Error while loading from mysql.event table.",
+ MYF(ME_ERROR_LOG));
+ res= TRUE; /* fatal error: request unireg_abort */
+ goto end;
+ }
+ Event_worker_thread::init(db_repository);
+ inited= 1;
+
+end:
+ if (res)
+ deinit();
+ if (!had_thd)
+ delete thd;
+
+ 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");
+
+ delete scheduler;
+ scheduler= NULL; /* For restart */
+ delete event_queue;
+ event_queue= NULL; /* For restart */
+ delete db_repository;
+ db_repository= NULL; /* For restart */
+
+ inited= 0;
+ DBUG_VOID_RETURN;
+}
+
+#ifdef HAVE_PSI_INTERFACE
+PSI_mutex_key key_LOCK_event_queue,
+ key_event_scheduler_LOCK_scheduler_state;
+
+static PSI_mutex_info all_events_mutexes[]=
+{
+ { &key_LOCK_event_queue, "LOCK_event_queue", PSI_FLAG_GLOBAL},
+ { &key_event_scheduler_LOCK_scheduler_state, "Event_scheduler::LOCK_scheduler_state", PSI_FLAG_GLOBAL}
+};
+
+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_GLOBAL},
+ { &key_COND_queue_state, "COND_queue_state", PSI_FLAG_GLOBAL},
+};
+
+PSI_thread_key key_thread_event_scheduler, key_thread_event_worker;
+
+static PSI_thread_info all_events_threads[]=
+{
+ { &key_thread_event_scheduler, "event_scheduler", PSI_FLAG_GLOBAL},
+ { &key_thread_event_worker, "event_worker", 0}
+};
+#endif /* HAVE_PSI_INTERFACE */
+
+PSI_stage_info stage_waiting_on_empty_queue= { 0, "Waiting on empty queue", 0};
+PSI_stage_info stage_waiting_for_next_activation= { 0, "Waiting for next activation", 0};
+PSI_stage_info stage_waiting_for_scheduler_to_stop= { 0, "Waiting for the scheduler to stop", 0};
+
+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_GLOBAL}
+};
+
+static void init_events_psi_keys(void)
+{
+ const char* category= "sql";
+ int count;
+
+ count= array_elements(all_events_mutexes);
+ mysql_mutex_register(category, all_events_mutexes, count);
+
+ count= array_elements(all_events_conds);
+ mysql_cond_register(category, all_events_conds, count);
+
+ count= array_elements(all_events_threads);
+ mysql_thread_register(category, all_events_threads, count);
+
+ count= array_elements(all_events_stages);
+ mysql_stage_register(category, all_events_stages, count);
+
+ count= array_elements(all_events_memory);
+ mysql_memory_register(category, all_events_memory, count);
+
+ init_scheduler_psi_keys();
+}
+#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_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");
+
+ /*
+ opt_event_scheduler should only be accessed while
+ holding LOCK_global_system_variables.
+ */
+ mysql_mutex_lock(&LOCK_global_system_variables);
+ if (!inited)
+ puts("The Event Scheduler is disabled");
+ else
+ {
+ scheduler->dump_internal_status();
+ event_queue->dump_internal_status();
+ }
+
+ mysql_mutex_unlock(&LOCK_global_system_variables);
+ DBUG_VOID_RETURN;
+}
+
+bool Events::start(int *err_no)
+{
+ DBUG_ASSERT(inited);
+ return scheduler->start(err_no);
+}
+
+bool Events::stop()
+{
+ DBUG_ASSERT(inited);
+ return scheduler->stop();
+}
+
+/**
+ 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;
+ DBUG_ENTER("Events::load_events_from_db");
+ DBUG_PRINT("enter", ("thd: %p", 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.
+
+ Same goes for transaction access mode.
+ Temporarily reset it to read-write.
+ */
+
+ privilege_t saved_master_access(thd->security_ctx->master_access);
+ thd->security_ctx->master_access |= PRIV_IGNORE_READ_ONLY;
+ bool save_tx_read_only= thd->tx_read_only;
+ thd->tx_read_only= false;
+
+ ret= db_repository->open_event_table(thd, TL_WRITE, &table);
+
+ thd->tx_read_only= save_tx_read_only;
+ thd->security_ctx->master_access= saved_master_access;
+
+ if (ret)
+ {
+ my_message_sql(ER_STARTUP,
+ "Event Scheduler: Failed to open table mysql.event",
+ MYF(ME_ERROR_LOG));
+ DBUG_RETURN(TRUE);
+ }
+
+ if (init_read_record(&read_record_info, thd, table, NULL, NULL, 0, 1, FALSE))
+ {
+ close_thread_tables(thd);
+ DBUG_RETURN(TRUE);
+ }
+
+ while (!(read_record_info.read_record()))
+ {
+ Event_queue_element *et;
+ bool created, dropped;
+
+ if (!(et= new Event_queue_element))
+ goto end;
+
+ DBUG_PRINT("info", ("Loading event from row."));
+
+ if (et->load_from_row(thd, table))
+ {
+ my_message(ER_STARTUP,
+ "Event Scheduler: "
+ "Error while loading events from mysql.event. "
+ "The table probably contains bad data or is corrupted",
+ MYF(ME_ERROR_LOG));
+ delete et;
+ goto end;
+ }
+
+#ifdef WITH_WSREP
+ /**
+ If SST is done from a galera node that is also acting as MASTER
+ newly synced node in galera eco-system will also copy-over the
+ event state enabling duplicate event in galera eco-system.
+ DISABLE such events if the current node is not event orginator.
+ (Also, make sure you skip disabling it if is already disabled to avoid
+ creation of redundant action)
+ NOTE:
+ This complete system relies on server-id. Ideally server-id should be
+ same for all nodes of galera eco-system but they aren't same.
+ Infact, based on galera use-case it seems like it recommends to have each
+ node with different server-id.
+ */
+ if (WSREP(thd) && et->originator != thd->variables.server_id)
+ {
+ if (et->status == Event_parse_data::SLAVESIDE_DISABLED)
+ continue;
+
+ store_record(table, record[1]);
+ table->field[ET_FIELD_STATUS]->
+ store((longlong) Event_parse_data::SLAVESIDE_DISABLED,
+ TRUE);
+
+ /* All the dmls to mysql.events tables are stmt bin-logged. */
+ table->file->row_logging= 0;
+ (void) table->file->ha_update_row(table->record[1], table->record[0]);
+
+ delete et;
+ continue;
+ }
+#endif /* WITH_WSREP */
+
+ /**
+ Since the Event_queue_element object could be deleted inside
+ Event_queue::create_event we should save the value of dropped flag
+ into the temporary variable.
+ */
+ dropped= et->dropped;
+ if (event_queue->create_event(thd, et, &created))
+ {
+ /* Out of memory */
+ delete et;
+ goto end;
+ }
+ if (created)
+ count++;
+ else if (dropped)
+ {
+ /*
+ 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;
+ }
+ }
+ }
+ my_printf_error(ER_STARTUP,
+ "Event Scheduler: Loaded %d event%s",
+ MYF(ME_ERROR_LOG |
+ (global_system_variables.log_warnings) ?
+ ME_NOTE: 0),
+ count, (count == 1) ? "" : "s");
+ ret= FALSE;
+
+end:
+ end_read_record(&read_record_info);
+
+ close_mysql_tables(thd);
+ DBUG_RETURN(ret);
+}
+
+#ifdef WITH_WSREP
+int wsrep_create_event_query(THD *thd, uchar** buf, size_t* buf_len)
+{
+ char buffer[1024];
+ String log_query(buffer, sizeof(buffer), &my_charset_bin);
+
+ if (create_query_string(thd, &log_query))
+ {
+ WSREP_WARN("events create string failed: schema: %s, query: %s",
+ thd->get_db(), thd->query());
+ return 1;
+ }
+ return wsrep_to_buf_helper(thd, log_query.ptr(), log_query.length(), buf, buf_len);
+}
+#endif /* WITH_WSREP */
+/**
+ @} (End of group Event_Scheduler)
+*/