WL#1034

updated sources


sql/event.cc:
  update
  put some error calls to the places they occur
sql/event.h:
  - change the default (does not work in STRICT mode)
sql/event_executor.cc:
  move mutex initialization to evex_init_mutexes so init_events() can be reused when the
  main thread does not work and set global event_scheduler=1; (this will start the thread)
  The main thread is now visible with show processlist and can be killed.
sql/event_priv.h:
  don't use anymore SP for opening table
sql/event_timed.cc:
  don't use anymore SP routines for opening mysql.event
sql/mysqld.cc:
  shutdown_events() should be maximal at the end of the server because
  it destroys mutexes of EVEX. The call should not be in the main thread.
sql/set_var.cc:
  make sys_var_event_executor subclass sys_var_bool_ptr
  to overload ::update() method - needed to start a
  killed (non-running) evex main thread
sql/set_var.h:
  declare class sys_var_event_executor
sql/share/errmsg.txt:
  2 new messages

sql/event.cc

@@ -21,6 +21,8 @@
 
 /*
  TODO list :
+ - The default value of created/modified should not be 0000-00-00 because of
+   STRICT mode restricions.
  - Remove m_ prefixes of member variables.
 
  - Use timestamps instead of datetime.
@@ -150,6 +152,93 @@ event_timed_compare(event_timed **a, event_timed **b)
 }
 
 
+
+/*
+  Open mysql.event table for read
+
+  SYNOPSIS
+    evex_open_event_table_for_read()
+      thd         Thread context
+      lock_type   How to lock the table
+  RETURN
+    0	Error
+    #	Pointer to TABLE object
+*/
+
+TABLE *evex_open_event_table(THD *thd, enum thr_lock_type lock_type)
+{
+  TABLE_LIST tables;
+  bool not_used;
+  DBUG_ENTER("open_proc_table");
+
+  /*
+    Speed up things if the table doesn't exists. *table_exists
+    is set when we create or read stored procedure or on flush privileges.
+  */
+  if (!mysql_event_table_exists)
+    DBUG_RETURN(0);
+
+  bzero((char*) &tables, sizeof(tables));
+  tables.db= (char*) "mysql";
+  tables.table_name= tables.alias= (char*) "event";
+  tables.lock_type= lock_type;
+
+  if (simple_open_n_lock_tables(thd, &tables))
+  {
+    mysql_event_table_exists= 0;
+    DBUG_RETURN(0);
+  }
+
+  DBUG_RETURN(tables.table);
+}
+
+
+/*
+  Find row in open mysql.event table representing event
+
+  SYNOPSIS
+    evex_db_find_routine_aux()
+      thd    Thread context
+      dbname Name of event's database
+      rname  Name of the event inside the db  
+      table  TABLE object for open mysql.event table.
+
+  RETURN VALUE
+    SP_OK           - Routine found
+    SP_KEY_NOT_FOUND- No routine with given name
+*/
+
+static int
+evex_db_find_routine_aux(THD *thd, const LEX_STRING dbname,
+                       const LEX_STRING rname, TABLE *table)
+{
+  byte key[MAX_KEY_LENGTH];	// db, name, optional key length type
+  DBUG_ENTER("evex_db_find_routine_aux");
+  DBUG_PRINT("enter", ("name: %.*s", rname.length, rname.str));
+
+  /*
+    Create key to find row. We have to use field->store() to be able to
+    handle VARCHAR and CHAR fields.
+    Assumption here is that the two first fields in the table are
+    'db' and 'name' and the first key is the primary key over the
+    same fields.
+  */
+  if (rname.length > table->field[1]->field_length)
+    DBUG_RETURN(SP_KEY_NOT_FOUND);
+  table->field[0]->store(dbname.str, dbname.length, &my_charset_bin);
+  table->field[1]->store(rname.str, rname.length, &my_charset_bin);
+  key_copy(key, table->record[0], table->key_info, table->key_info->key_length);
+
+  if (table->file->index_read_idx(table->record[0], 0,
+				  key, table->key_info->key_length,
+				  HA_READ_KEY_EXACT))
+    DBUG_RETURN(SP_KEY_NOT_FOUND);
+
+  DBUG_RETURN(0);
+}
+
+
+
 /*
    Puts some data common to CREATE and ALTER EVENT into a row.
 
@@ -164,13 +253,13 @@ event_timed_compare(event_timed **a, event_timed **b)
 */
 
 static int
-evex_fill_row(THD *thd, TABLE *table, event_timed *et)
+evex_fill_row(THD *thd, TABLE *table, event_timed *et, my_bool is_update)
 {
   DBUG_ENTER("evex_fill_row");
   int ret=0;
 
   if (table->s->fields != EVEX_FIELD_COUNT)
-    goto get_field_failed;
+    DBUG_RETURN(EVEX_GET_FIELD_FAILED);
 
   DBUG_PRINT("info", ("m_db.len=%d",et->m_db.length));  
   DBUG_PRINT("info", ("m_name.len=%d",et->m_name.length));  
@@ -195,13 +284,13 @@ evex_fill_row(THD *thd, TABLE *table, event_timed *et)
   if (et->m_starts.year)
   {
     table->field[EVEX_FIELD_STARTS]->set_notnull();// set NULL flag to OFF
-    table->field[EVEX_FIELD_STARTS]->store_time(&et->m_starts,MYSQL_TIMESTAMP_DATETIME);    
+    table->field[EVEX_FIELD_STARTS]->store_time(&et->m_starts,MYSQL_TIMESTAMP_DATETIME);
   }	   
 
   if (et->m_ends.year)
   {
     table->field[EVEX_FIELD_ENDS]->set_notnull();
-    table->field[EVEX_FIELD_ENDS]->store_time(&et->m_ends, MYSQL_TIMESTAMP_DATETIME);    
+    table->field[EVEX_FIELD_ENDS]->store_time(&et->m_ends, MYSQL_TIMESTAMP_DATETIME);
   }
    
   if (et->m_expr)
@@ -220,13 +309,15 @@ evex_fill_row(THD *thd, TABLE *table, event_timed *et)
   {
     // fix_fields already called in init_execute_at
     table->field[EVEX_FIELD_EXECUTE_AT]->set_notnull();
-    table->field[EVEX_FIELD_EXECUTE_AT]->store_time(&et->m_execute_at, MYSQL_TIMESTAMP_DATETIME);    
+    table->field[EVEX_FIELD_EXECUTE_AT]->store_time(&et->m_execute_at,
+                                                    MYSQL_TIMESTAMP_DATETIME);    
     
 	//this will make it NULL because we don't call set_notnull
     table->field[EVEX_FIELD_TRANSIENT_INTERVAL]->store((longlong) 0);  
   }
   else
   {
+    DBUG_ASSERT(is_update);
     // it is normal to be here when the action is update
     // this is an error if the action is create. something is borked
   }
@@ -238,8 +329,6 @@ evex_fill_row(THD *thd, TABLE *table, event_timed *et)
 	store((et->m_comment).str, (et->m_comment).length, system_charset_info);
 
   DBUG_RETURN(0);  
-get_field_failed:
-  DBUG_RETURN(EVEX_GET_FIELD_FAILED);
 }
 
 
@@ -259,34 +348,38 @@ evex_fill_row(THD *thd, TABLE *table, event_timed *et)
 static int
 db_create_event(THD *thd, event_timed *et)
 {
-  int ret;
+  int ret= EVEX_OK;
   TABLE *table;
-  TABLE_LIST tables;
   char definer[HOSTNAME_LENGTH+USERNAME_LENGTH+2];
   char olddb[128];
-  bool dbchanged;
+  bool dbchanged= false;
   DBUG_ENTER("db_create_event");
   DBUG_PRINT("enter", ("name: %.*s", et->m_name.length, et->m_name.str));
 
-  dbchanged= false;
-  if ((ret= sp_use_new_db(thd, et->m_db.str, olddb, sizeof(olddb),
-			  0, &dbchanged)))
+
+  DBUG_PRINT("info", ("open mysql.event for update"));
+  if (!(table= evex_open_event_table(thd, TL_WRITE)))
   {
-    DBUG_PRINT("info", ("cannot use_new_db. code=%d", ret));
-    DBUG_RETURN(EVEX_NO_DB_ERROR);
+    my_error(ER_EVENT_OPEN_TABLE_FAILED, MYF(0));
+    goto done;
   }
 
-  bzero(&tables, sizeof(tables));
-  tables.db= (char*)"mysql";
-  tables.table_name= tables.alias= (char*)"event";
-
-  if (!(table= EVEX_OPEN_TABLE_FOR_UPDATE()))
+  DBUG_PRINT("info", ("check existance of an event with the same name"));
+  if (!evex_db_find_routine_aux(thd, et->m_db, et->m_name, table))
   {
-    if (dbchanged)
-      (void)mysql_change_db(thd, olddb, 1);
-    DBUG_RETURN(SP_OPEN_TABLE_FAILED);
+    my_error(ER_EVENT_ALREADY_EXISTS, MYF(0), et->m_name.str);
+    goto done;    
   }
 
+  DBUG_PRINT("info", ("non-existant, go forward"));
+  if ((ret= sp_use_new_db(thd, et->m_db.str, olddb, sizeof(olddb),
+			  0, &dbchanged)))
+  {
+    DBUG_PRINT("info", ("cannot use_new_db. code=%d", ret));
+    my_error(ER_BAD_DB_ERROR, MYF(0));
+    DBUG_RETURN(0);
+  }
+  
   restore_record(table, s->default_values); // Get default values for fields
   strxmov(definer, et->m_definer_user.str, "@", et->m_definer_host.str, NullS);
 
@@ -305,25 +398,25 @@ db_create_event(THD *thd, event_timed *et)
 */
   if (!(et->m_expr) && !(et->m_execute_at.year))
   {
-    DBUG_PRINT("error", ("neither m_expr nor m_execute_as is set!"));
-    ret= EVEX_WRITE_ROW_FAILED;
+    DBUG_PRINT("error", ("neither m_expr nor m_execute_as are set!"));
+    my_error(ER_EVENT_NEITHER_M_EXPR_NOR_M_AT, MYF(0));
     goto done;
   }
-  ret= table->field[EVEX_FIELD_DEFINER]->
-       store(definer, (uint)strlen(definer), system_charset_info);
-  if (ret)
+
+  if (table->field[EVEX_FIELD_DEFINER]->
+       store(definer, (uint)strlen(definer), system_charset_info))
   {
-    ret= EVEX_PARSE_ERROR;
+    my_error(ER_EVENT_STORE_FAILED, MYF(0), et->m_name.str);
     goto done;
   }
-    
+
   ((Field_timestamp *)table->field[EVEX_FIELD_CREATED])->set_time();
-  if ((ret= evex_fill_row(thd, table, et)))
+  if ((ret= evex_fill_row(thd, table, et, false)))
     goto done; 
 
   ret= EVEX_OK;
   if (table->file->write_row(table->record[0]))
-    ret= EVEX_WRITE_ROW_FAILED;
+    my_error(ER_EVENT_STORE_FAILED, MYF(0), et->m_name.str);
   else if (mysql_bin_log.is_open())
   {
     thd->clear_error();
@@ -333,9 +426,10 @@ db_create_event(THD *thd, event_timed *et)
   }
 
 done:
-  close_thread_tables(thd);
+  // No need to close the table, it will be closed in sql_parse::do_command
+
   if (dbchanged)
-    (void)mysql_change_db(thd, olddb, 1);
+    (void) mysql_change_db(thd, olddb, 1);
   DBUG_RETURN(ret);
 }
 
@@ -365,34 +459,43 @@ db_update_event(THD *thd, sp_name *name, event_timed *et)
     DBUG_PRINT("enter", ("rename to: %.*s", name->m_name.length, name->m_name.str));
 
   // Todo: Handle in sql_prepare.cc SP_OPEN_TABLE_FAILED
-  if (!(table= EVEX_OPEN_TABLE_FOR_UPDATE()))
-    DBUG_RETURN(SP_OPEN_TABLE_FAILED);
+  if (!(table= evex_open_event_table(thd, TL_WRITE)))
+  {
+    my_error(ER_EVENT_OPEN_TABLE_FAILED, MYF(0));
+    goto done;
+  }
 
-  ret= sp_db_find_routine_aux(thd, 0/*notype*/, et->m_db, et->m_name, table);
-  if (ret == EVEX_OK)
+  if (evex_db_find_routine_aux(thd, et->m_db, et->m_name, table) == SP_KEY_NOT_FOUND)
   {
-    store_record(table,record[1]);
-    table->timestamp_field_type= TIMESTAMP_NO_AUTO_SET; // Don't update create on row update.
-    ret= evex_fill_row(thd, table, et);
-    if (ret)
-      goto done;
-    
-    if (name)
-    {    
-      table->field[EVEX_FIELD_DB]->
-        store(name->m_db.str, name->m_db.length, system_charset_info);
-      table->field[EVEX_FIELD_NAME]->
-        store(name->m_name.str, name->m_name.length, system_charset_info);
-    }
+    my_error(ER_EVENT_DOES_NOT_EXIST, MYF(0), et->m_name.str);
+    goto done;    
+  }
+  
+  store_record(table,record[1]);
+  
+  table->timestamp_field_type= TIMESTAMP_NO_AUTO_SET; // Don't update create on row update.
+  if ((ret= evex_fill_row(thd, table, et, true)))
+    goto done;
+   
+  if (name)
+  {    
+    table->field[EVEX_FIELD_DB]->
+      store(name->m_db.str, name->m_db.length, system_charset_info);
+    table->field[EVEX_FIELD_NAME]->
+      store(name->m_name.str, name->m_name.length, system_charset_info);
+  }
 
-    if ((table->file->update_row(table->record[1],table->record[0])))
-      ret= EVEX_WRITE_ROW_FAILED;
+  if ((ret= table->file->update_row(table->record[1],table->record[0])))
+  {
+    my_error(ER_EVENT_STORE_FAILED, MYF(0), et->m_name.str);
+    goto done;
   }
 done:
   close_thread_tables(thd);
   DBUG_RETURN(ret);
 }
 
+
 /*
     Use sp_name for look up, return in **ett if found
 */
@@ -404,18 +507,18 @@ db_find_event(THD *thd, sp_name *name, event_timed **ett)
   const char *definer;
   char *ptr;
   event_timed *et;  
-  Open_tables_state open_tables_state_backup;
   DBUG_ENTER("db_find_event");
   DBUG_PRINT("enter", ("name: %*s",
 		       name->m_name.length, name->m_name.str));
 
 
-  if (!(table= open_proc_type_table_for_read(thd, &open_tables_state_backup,
-                                             "event", &mysql_event_table_exists)))
-    DBUG_RETURN(SP_OPEN_TABLE_FAILED);
+  if (!(table= evex_open_event_table(thd, TL_READ)))
+  {
+    my_error(ER_EVENT_OPEN_TABLE_FAILED, MYF(0));
+    goto done;
+  }
 
-  if ((ret= sp_db_find_routine_aux(thd, 0/*notype*/, name->m_db, name->m_name,
-                                   table)) != SP_OK)
+  if ((ret= evex_db_find_routine_aux(thd, name->m_db, name->m_name, table)))
     goto done;
 
   et= new event_timed;
@@ -434,7 +537,6 @@ db_find_event(THD *thd, sp_name *name, event_timed **ett)
     et= 0;
   }
   close_thread_tables(thd);
-  thd->restore_backup_open_tables_state(&open_tables_state_backup);
   *ett= et;
   DBUG_RETURN(ret);
 }
@@ -503,8 +605,6 @@ evex_load_and_compile_event(THD * thd, sp_name *spn, bool use_lock)
   if (thd->mem_root != tmp_mem_root)
     thd->mem_root= tmp_mem_root;  
 
-  if (spn) 
-    delete spn;
   DBUG_RETURN(ret);
 }
 
@@ -619,19 +719,19 @@ int
 evex_create_event(THD *thd, event_timed *et, uint create_options)
 {
   int ret = 0;
-  sp_name *spn= 0;
 
   DBUG_ENTER("evex_create_event");
   DBUG_PRINT("enter", ("name: %*s options:%d", et->m_name.length,
                 et->m_name.str, create_options));
 
+/*
   VOID(pthread_mutex_lock(&LOCK_evex_running));
   if (!evex_is_running)
   // TODO: put an warning to the user here.
   //       Is it needed? (Andrey, 051129)
   {}  
   VOID(pthread_mutex_unlock(&LOCK_evex_running));
-
+*/
 
   if ((ret = db_create_event(thd, et)) == EVEX_WRITE_ROW_FAILED && 
         (create_options & HA_LEX_CREATE_IF_NOT_EXISTS))
@@ -652,24 +752,16 @@ evex_create_event(THD *thd, event_timed *et, uint create_options)
     goto done;
 
   VOID(pthread_mutex_lock(&LOCK_evex_running));
-  if (!evex_is_running)
+  if (evex_is_running && et->m_status == MYSQL_EVENT_ENABLED)
   {
-    VOID(pthread_mutex_unlock(&LOCK_evex_running));
-    goto done;
-  }  
-  VOID(pthread_mutex_unlock(&LOCK_evex_running));
-  
-  //cache only if the event is ENABLED
-  if (et->m_status == MYSQL_EVENT_ENABLED)
-  {
-    spn= new sp_name(et->m_db, et->m_name);
-    if ((ret= evex_load_and_compile_event(thd, spn, true)))
-      goto done;
+    sp_name spn(et->m_db, et->m_name);
+    ret= evex_load_and_compile_event(thd, &spn, true);
   }
+  VOID(pthread_mutex_unlock(&LOCK_evex_running));
 
 done:
-  if (spn) 
-    delete spn;
+  // No need to close the table, it will be closed in sql_parse::do_command
+
   DBUG_RETURN(ret);
 }
 
@@ -685,7 +777,7 @@ evex_create_event(THD *thd, event_timed *et, uint create_options)
           
    NOTES
      et contains data about dbname and event name. 
-     name is the new name of the event. if not null this means
+     name is the new name of the event, if not null this means
      that RENAME TO was specified in the query.
    TODO
      - Add code for in-memory structures - caching & uncaching.
@@ -701,19 +793,24 @@ evex_update_event(THD *thd, sp_name *name, event_timed *et)
   DBUG_ENTER("evex_update_event");
   DBUG_PRINT("enter", ("name: %*s", et->m_name.length, et->m_name.str));
 
+/*
   VOID(pthread_mutex_lock(&LOCK_evex_running));
   if (!evex_is_running)
   // put an warning to the user here
   {}  
   VOID(pthread_mutex_unlock(&LOCK_evex_running));
-  
+*/
+
   if ((ret= db_update_event(thd, name, et)))
     goto done_no_evex;
 
   VOID(pthread_mutex_lock(&LOCK_evex_running));
   if (!evex_is_running)
-  // not running - therefore no memory structures
+  {
+    // not running - therefore no memory structures
+    VOID(pthread_mutex_unlock(&LOCK_evex_running));
     goto done_no_evex;
+  }
   VOID(pthread_mutex_unlock(&LOCK_evex_running));
 
   /*
@@ -721,31 +818,23 @@ evex_update_event(THD *thd, sp_name *name, event_timed *et)
     The reason is that DISABLED events are not cached.
   */
   VOID(pthread_mutex_lock(&LOCK_event_arrays));
-  if (name)
-  {
-    evex_remove_from_cache(&name->m_db, &name->m_name, false);
-    if (et->m_status == MYSQL_EVENT_ENABLED &&
-        (ret= evex_load_and_compile_event(thd, name, false))
-       )
-      goto done;
-  }
-  else
-  {
-    evex_remove_from_cache(&et->m_db, &et->m_name, false);
-    spn= new sp_name(et->m_db, et->m_name);
-    if (et->m_status == MYSQL_EVENT_ENABLED &&
-        (ret= evex_load_and_compile_event(thd, spn, false))
-        )
+  evex_remove_from_cache(&et->m_db, &et->m_name, false);
+  if (et->m_status == MYSQL_EVENT_ENABLED)
+    if (name)
+      ret= evex_load_and_compile_event(thd, name, false);
+    else
     {
+      spn= new sp_name(et->m_db, et->m_name);
+      ret= evex_load_and_compile_event(thd, spn, false);
       delete spn;
-      goto done;
-    } 
-  }
+    }
 
 done:
   VOID(pthread_mutex_unlock(&LOCK_event_arrays));
 
 done_no_evex:
+  // No need to close the table, it will be closed in sql_parse::do_command
+
   DBUG_RETURN(ret);
 }
 
@@ -771,13 +860,15 @@ evex_drop_event(THD *thd, event_timed *et, bool drop_if_exists)
   bool opened;
   DBUG_ENTER("evex_drop_event");
 
+/*
   VOID(pthread_mutex_lock(&LOCK_evex_running));
   if (!evex_is_running)
   // put an warning to the user here
   {}  
   VOID(pthread_mutex_unlock(&LOCK_evex_running));
-
-  if (!(table= EVEX_OPEN_TABLE_FOR_UPDATE()))
+*/
+////
+  if (!(table= evex_open_event_table(thd, TL_WRITE)))
     DBUG_RETURN(SP_OPEN_TABLE_FAILED);
 
   ret= sp_db_find_routine_aux(thd, 0/*notype*/, et->m_db, et->m_name, table);
@@ -806,14 +897,8 @@ evex_drop_event(THD *thd, event_timed *et, bool drop_if_exists)
   VOID(pthread_mutex_unlock(&LOCK_evex_running));
 
 done:  
-  /* 
-    "opened" is switched to TRUE when we open mysql.event for checking.
-    In this case we have to close the table after finishing working with it.
-  */
-  close_thread_tables(thd);
+  // No need to close the table, it will be closed in sql_parse::do_command
 
   DBUG_RETURN(ret);
 }
 
-
-

sql/event.h

@@ -214,8 +214,8 @@ CREATE TABLE `event` (
   `execute_at` datetime default NULL,
   `transient_expression` int(11) default NULL,
   `interval_type` enum('YEAR','QUARTER','MONTH','DAY','HOUR','MINUTE','WEEK','SECOND','MICROSECOND','YEAR_MONTH','DAY_HOUR','DAY_MINUTE','DAY_SECOND','HOUR_MINUTE','HOUR_SECOND','MINUTE_SECOND','DAY_MICROSECOND','HOUR_MICROSECOND','MINUTE_MICROSECOND','SECOND_MICROSECOND') default NULL,
-  `created` timestamp NOT NULL default '0000-00-00 00:00:00',
-  `modified` timestamp NOT NULL default '0000-00-00 00:00:00',
+  `created` timestamp NOT NULL,
+  `modified` timestamp NOT NULL,
   `last_executed` datetime default NULL,
   `starts` datetime default NULL,
   `ends` datetime default NULL,

sql/event_executor.cc

@@ -36,6 +36,7 @@ my_bool event_executor_running_global_var= false;
 
 extern ulong thread_created;
 
+static my_bool evex_mutexes_initted= false;
 
 static int
 evex_load_events_from_db(THD *thd);
@@ -50,6 +51,19 @@ evex_load_events_from_db(THD *thd);
 pthread_handler_t event_executor_worker(void *arg);
 pthread_handler_t event_executor_main(void *arg);
 
+static
+void evex_init_mutexes()
+{
+  if (evex_mutexes_initted)
+  {
+    evex_mutexes_initted= true;
+    return;
+  }
+  pthread_mutex_init(&LOCK_event_arrays, MY_MUTEX_INIT_FAST);
+  pthread_mutex_init(&LOCK_workers_count, MY_MUTEX_INIT_FAST);
+  pthread_mutex_init(&LOCK_evex_running, MY_MUTEX_INIT_FAST);
+}
+
 int
 init_events()
 {
@@ -59,15 +73,15 @@ init_events()
 
   DBUG_PRINT("info",("Starting events main thread"));
 
-  pthread_mutex_init(&LOCK_event_arrays, MY_MUTEX_INIT_FAST);
-  pthread_mutex_init(&LOCK_workers_count, MY_MUTEX_INIT_FAST);
-  pthread_mutex_init(&LOCK_evex_running, MY_MUTEX_INIT_FAST);
-
+  evex_init_mutexes();
+  
   VOID(pthread_mutex_lock(&LOCK_evex_running));
   evex_is_running= false;  
   event_executor_running_global_var= false;
   VOID(pthread_mutex_unlock(&LOCK_evex_running));
 
+  DBUG_RETURN(0);
+/*
 #ifndef DBUG_FAULTY_THR
   //TODO Andrey: Change the error code returned!
   if (pthread_create(&th, NULL, event_executor_main, (void*)NULL))
@@ -77,6 +91,7 @@ init_events()
 #endif
 
   DBUG_RETURN(0);
+*/
 }
 
 
@@ -94,6 +109,7 @@ shutdown_events()
   DBUG_VOID_RETURN;
 }
 
+#ifdef ANDREY_0
 
 static int
 init_event_thread(THD* thd)
@@ -165,7 +181,7 @@ pthread_handler_t event_executor_main(void *arg)
     goto err;
 
   // make this thread invisible it has no vio -> show processlist won't see
-  thd->system_thread= 0;
+  thd->system_thread= 1;
 
   VOID(pthread_mutex_lock(&LOCK_thread_count));
   threads.append(thd);
@@ -350,7 +366,7 @@ pthread_handler_t event_executor_main(void *arg)
   free_root(&evex_mem_root, MYF(0));
   sql_print_information("Event executor stopped");
 
-  shutdown_events();
+//  shutdown_events();
 
   my_thread_end();
   pthread_exit(0);
@@ -391,7 +407,7 @@ pthread_handler_t event_executor_worker(void *event_void)
   thd->init_for_queries();
 
   // make this thread visible it has no vio -> show processlist needs this flag
-  thd->system_thread= 0;
+  thd->system_thread= 1;
 
   VOID(pthread_mutex_lock(&LOCK_thread_count));
   threads.append(thd);
@@ -531,3 +547,20 @@ evex_load_events_from_db(THD *thd)
                     ("Events loaded from DB. Status code %d", ret));
   DBUG_RETURN(ret);
 }
+
+#endif
+
+bool sys_var_event_executor::update(THD *thd, set_var *var)
+{
+#ifdef ANDREY_0
+  // here start the thread if not running.
+  VOID(pthread_mutex_lock(&LOCK_evex_running));
+  if ((my_bool) var->save_result.ulong_value && !evex_is_running) {
+    VOID(pthread_mutex_unlock(&LOCK_evex_running));
+    init_events();
+  } else 
+    VOID(pthread_mutex_unlock(&LOCK_evex_running));
+#endif  
+  return sys_var_bool_ptr::update(thd, var);
+}
+

sql/event_priv.h

@@ -17,9 +17,6 @@
 #ifndef _EVENT_PRIV_H_
 #define _EVENT_PRIV_H_
 
-#define EVEX_OPEN_TABLE_FOR_UPDATE() \
-       open_proc_type_table_for_update(thd, "event", &mysql_event_table_exists)
-
 
 enum
 {
@@ -53,5 +50,7 @@ extern pthread_mutex_t LOCK_event_arrays,
 
 int
 my_time_compare(TIME *a, TIME *b);
-                
+
+
+TABLE *evex_open_event_table(THD *thd, enum thr_lock_type lock_type);             
 #endif /* _EVENT_PRIV_H_ */

sql/event_timed.cc

@@ -719,7 +719,7 @@ event_timed::update_fields(THD *thd)
   if (!(m_status_changed || m_last_executed_changed))
     goto done;
   
-  if (!(table= EVEX_OPEN_TABLE_FOR_UPDATE()))
+  if (!(table= evex_open_event_table(thd, TL_WRITE)))
     DBUG_RETURN(SP_OPEN_TABLE_FAILED);
 
   if ((ret= sp_db_find_routine_aux(thd, 0/*notype*/, m_db, m_name, table)))

sql/mysqld.cc

@@ -3568,6 +3568,7 @@ we force server id to 2, but this MySQL server will not act as a slave.");
   clean_up(1);
   wait_for_signal_thread_to_end();
   clean_up_mutexes();
+  shutdown_events();
   my_end(opt_endinfo ? MY_CHECK_ERROR | MY_GIVE_INFO : 0);
  
   exit(0);

sql/set_var.cc

@@ -207,7 +207,7 @@ sys_var_long_ptr	sys_delayed_insert_timeout("delayed_insert_timeout",
 						   &delayed_insert_timeout);
 sys_var_long_ptr	sys_delayed_queue_size("delayed_queue_size",
 					       &delayed_queue_size);
-sys_var_bool_ptr        sys_event_executor("event_scheduler",
+sys_var_event_executor        sys_event_executor("event_scheduler",
                                                &event_executor_running_global_var);
 sys_var_long_ptr	sys_expire_logs_days("expire_logs_days",
 					     &expire_logs_days);
@@ -3364,6 +3364,7 @@ bool sys_var_trust_routine_creators::update(THD *thd, set_var *var)
   return sys_var_bool_ptr::update(thd, var);
 }
 
+
 /****************************************************************************
   Used templates
 ****************************************************************************/

sql/set_var.h

@@ -782,6 +782,17 @@ class sys_var_trust_routine_creators :public sys_var_bool_ptr
   bool update(THD *thd, set_var *var);
 };
 
+
+class sys_var_event_executor :public sys_var_bool_ptr
+{
+  /* We need a derived class only to have a warn_deprecated() */
+public:
+  sys_var_event_executor(const char *name_arg, my_bool *value_arg) :
+    sys_var_bool_ptr(name_arg, value_arg) {};
+  bool update(THD *thd, set_var *var);
+};
+
+
 /****************************************************************************
   Classes for parsing of the SET command
 ****************************************************************************/

sql/share/errmsg.txt

@@ -5737,3 +5737,7 @@ ER_EVENT_ENDS_BEFORE_STARTS
         eng "ENDS must be after STARTS"
 ER_EVENT_EXEC_TIME_IN_THE_PAST
         eng "Activation (AT) time is in the past"
+ER_EVENT_OPEN_TABLE_FAILED
+        eng "Failed to open mysql.event"
+ER_EVENT_NEITHER_M_EXPR_NOR_M_AT
+        eng "No datetime expression provided"