WL #3337 (Events new architecture)

Final stroke, events should be loaded from disk on server startup.
Also check the validity of their bodies if possible during loading.


sql/event_data_objects.cc:
  Remove Event_job_data::free_sp(), move the code to the destructor
  Change the way we change the security context
  Steal some code from sql_parse.cc
sql/event_data_objects.h:
  Remove free_sp()
  Make compile() public, to be used when booting for verifying the integrity of mysql.event
sql/event_queue.cc:
  Make the queue load events from disk on server boot.
  Compile and thus check for integrity the events.
sql/event_queue.h:
  shift methods around. add queue_loaded boolean.
sql/event_scheduler.cc:
  Rename init_event_thread() to pre_init_event_thread()
  and make it more generic.
  Add post_init_event_thread()
  Export these two as well as deinit_event_thread().
  Now it is quite easy to write code to spawn a new event thread
  whenever needed.
sql/event_scheduler.h:
  export pre_init_event_thread(), post_init_event_thread() and deinit_event_thread()
  to simplify writing of thread functions.
sql/events.cc:
  Events::init() returns only one error code, then make it bool
sql/events.h:
  Events::init() returns only one error code, then make it bool
sql/mysqld.cc:
  Check the return code of Events::init()
sql/sp_head.cc:
  Add trace info
sql/sql_class.cc:
  Reorganize thd::change_security_context() to load main_security_ctx
sql/sql_class.h:
  Reorganize thd::change_security_context() to load main_security_ctx
sql/sql_lex.cc:
  Initialize lex->spname
sql/sql_yacc.yy:
  Add a comment

22 files changed, 315 insertions, 161 deletions

diff --git a/mysql-test/r/events_restart_phase1.result b/mysql-test/r/events_restart_phase1.result
new file mode 100644
index 00000000000..cf0a24c267d
--- /dev/null
+++ b/mysql-test/r/events_restart_phase1.result
@@ -0,0 +1,10 @@
+create database if not exists mysqltest_events_test;
+use mysqltest_events_test;
+set global event_scheduler=2;
+create table execution_log(name char(10));
+create event abc1 on schedule every 1 second do insert into execution_log value('abc1');
+create event abc2 on schedule every 1 second do insert into execution_log value('abc2');
+create event abc3 on schedule every 1 second do insert into execution_log value('abc3');
+insert into mysql.event values ('db1','bad','select 42','root@localhost',NULL,1000,'MICROSECOND','2006-05-05 17:39:11','2006-05-05 17:39:20','2016-05-05 15:39:24','2016-05-05 15:39:11',NULL,'ENABLED','DROP','','comment1');
+insert into mysql.event values ('db1','bad2','sect','root@localhost',NULL,1000,'SECOND','2006-05-05 17:39:11','2006-05-05 17:39:20','2016-05-05 15:39:24','2016-05-05 15:39:11',NULL,'ENABLED','DROP','','comment2');
+"Now we restart the server"
diff --git a/mysql-test/r/events_restart_phase2.result b/mysql-test/r/events_restart_phase2.result
new file mode 100644
index 00000000000..703cb92324f
--- /dev/null
+++ b/mysql-test/r/events_restart_phase2.result
@@ -0,0 +1,6 @@
+use mysqltest_events_test;
+"Should get 0 rows because the queue aborted run
+select distinct name from execution_log order by name;
+name
+delete from mysql.event where name like 'bad%';
+"Now restart the server again"
diff --git a/mysql-test/r/events_restart_phase3.result b/mysql-test/r/events_restart_phase3.result
new file mode 100644
index 00000000000..398a9d06546
--- /dev/null
+++ b/mysql-test/r/events_restart_phase3.result
@@ -0,0 +1,9 @@
+use mysqltest_events_test;
+"Should get 3 rows : abc1, abc2, abc3
+select distinct name from execution_log order by name;
+name
+drop event abc1;
+drop event abc2;
+drop event abc3;
+drop table execution_log;
+drop database mysqltest_events_test;
diff --git a/mysql-test/t/events_restart_phase1.test b/mysql-test/t/events_restart_phase1.test
new file mode 100644
index 00000000000..879591e6141
--- /dev/null
+++ b/mysql-test/t/events_restart_phase1.test
@@ -0,0 +1,17 @@
+# Can't test with embedded server that doesn't support grants
+-- source include/not_embedded.inc
+
+--disable_warnings
+create database if not exists mysqltest_events_test;
+--enable_warnings
+
+use mysqltest_events_test;
+set global event_scheduler=2;
+create table execution_log(name char(10));
+create event abc1 on schedule every 1 second do insert into execution_log value('abc1');
+create event abc2 on schedule every 1 second do insert into execution_log value('abc2');
+create event abc3 on schedule every 1 second do insert into execution_log value('abc3');
+
+insert into mysql.event values ('db1','bad','select 42','root@localhost',NULL,1000,'MICROSECOND','2006-05-05 17:39:11','2006-05-05 17:39:20','2016-05-05 15:39:24','2016-05-05 15:39:11',NULL,'ENABLED','DROP','','comment1');
+insert into mysql.event values ('db1','bad2','sect','root@localhost',NULL,1000,'SECOND','2006-05-05 17:39:11','2006-05-05 17:39:20','2016-05-05 15:39:24','2016-05-05 15:39:11',NULL,'ENABLED','DROP','','comment2');
+--echo "Now we restart the server"
diff --git a/mysql-test/t/events_restart_phase2-master.opt b/mysql-test/t/events_restart_phase2-master.opt
new file mode 100644
index 00000000000..656b9e1b017
--- /dev/null
+++ b/mysql-test/t/events_restart_phase2-master.opt
@@ -0,0 +1 @@
+--event-scheduler=1
diff --git a/mysql-test/t/events_restart_phase2.test b/mysql-test/t/events_restart_phase2.test
new file mode 100644
index 00000000000..845472377ba
--- /dev/null
+++ b/mysql-test/t/events_restart_phase2.test
@@ -0,0 +1,9 @@
+# Can't test with embedded server that doesn't support grants
+-- source include/not_embedded.inc
+
+use mysqltest_events_test;
+--sleep 1.5
+--echo "Should get 0 rows because the queue aborted run
+select distinct name from execution_log order by name;
+delete from mysql.event where name like 'bad%';
+--echo "Now restart the server again"
diff --git a/mysql-test/t/events_restart_phase3-master.opt b/mysql-test/t/events_restart_phase3-master.opt
new file mode 100644
index 00000000000..656b9e1b017
--- /dev/null
+++ b/mysql-test/t/events_restart_phase3-master.opt
@@ -0,0 +1 @@
+--event-scheduler=1
diff --git a/mysql-test/t/events_restart_phase3.test b/mysql-test/t/events_restart_phase3.test
new file mode 100644
index 00000000000..76cd9d22752
--- /dev/null
+++ b/mysql-test/t/events_restart_phase3.test
@@ -0,0 +1,14 @@
+# Can't test with embedded server that doesn't support grants
+-- source include/not_embedded.inc
+
+use mysqltest_events_test;
+--sleep 2
+--echo "Should get 3 rows : abc1, abc2, abc3
+select distinct name from execution_log order by name;
+
+drop event abc1;
+drop event abc2;
+drop event abc3;
+drop table execution_log;
+
+drop database mysqltest_events_test;
diff --git a/sql/event_data_objects.cc b/sql/event_data_objects.cc
index 8f67754a5b2..a367e058f0e 100644
--- a/sql/event_data_objects.cc
+++ b/sql/event_data_objects.cc
@@ -731,7 +731,7 @@ Event_timed::~Event_timed()
 */
 
 Event_job_data::Event_job_data():
-  thd(NULL), sphead(0), sql_mode(0)
+  thd(NULL), sphead(NULL), sql_mode(0)
 {
 }
 
@@ -745,7 +745,10 @@ Event_job_data::Event_job_data():
 
 Event_job_data::~Event_job_data()
 {
-  free_sp();
+  DBUG_ENTER("Event_job_data::~Event_job_data");
+  delete sphead;
+  sphead= NULL;
+  DBUG_VOID_RETURN;
 }
 
 
@@ -1606,20 +1609,6 @@ Event_job_data::get_fake_create_event(THD *thd, String *buf)
 
 
 /*
-  Frees the memory of the sp_head object we hold
-  SYNOPSIS
-    Event_job_data::free_sp()
-*/
-
-void
-Event_job_data::free_sp()
-{
-  delete sphead;
-  sphead= NULL;
-}
-
-
-/*
   Compiles an event before it's execution. Compiles the anonymous
   sp_head object held by the event
 
@@ -1651,9 +1640,7 @@ Event_job_data::compile(THD *thd, MEM_ROOT *mem_root)
   CHARSET_INFO *old_character_set_client,
                *old_collation_connection,
                *old_character_set_results;
-  Security_context *save_ctx;
-  /* this one is local and not needed after exec */
-  Security_context security_ctx;
+  Security_context save_ctx;
 
   DBUG_ENTER("Event_job_data::compile");
 
@@ -1699,10 +1686,9 @@ Event_job_data::compile(THD *thd, MEM_ROOT *mem_root)
   thd->query_length= show_create.length();
   DBUG_PRINT("info", ("query:%s",thd->query));
 
-  thd->change_security_context(definer_user, definer_host, dbname,
-                               &security_ctx, &save_ctx);
+  thd->change_security_context(definer_user, definer_host, dbname, &save_ctx);
   thd->lex= &lex;
-  lex_start(thd, (uchar*)thd->query, thd->query_length);
+  mysql_init_query(thd, (uchar*) thd->query, thd->query_length);
   if (MYSQLparse((void *)thd) || thd->is_fatal_error)
   {
     DBUG_PRINT("error", ("error during compile or thd->is_fatal_error=%d",
@@ -1713,13 +1699,10 @@ Event_job_data::compile(THD *thd, MEM_ROOT *mem_root)
     */
     sql_print_error("error during compile of %s.%s or thd->is_fatal_error=%d",
                     dbname.str, name.str, thd->is_fatal_error);
-    if (lex.sphead)
-    {
-      if (&lex != thd->lex)
-        thd->lex->sphead->restore_lex(thd);
-      delete lex.sphead;
-      lex.sphead= 0;
-    }
+
+    lex.unit.cleanup();
+    delete lex.sphead;
+    sphead= lex.sphead= NULL;
     ret= EVEX_COMPILE_ERROR;
     goto done;
   }
@@ -1734,7 +1717,7 @@ Event_job_data::compile(THD *thd, MEM_ROOT *mem_root)
 done:
 
   lex_end(&lex);
-  thd->restore_security_context(save_ctx);
+  thd->restore_security_context(&save_ctx);
   DBUG_PRINT("note", ("return old data on its place. set back NAMES"));
 
   thd->lex= old_lex;
@@ -1772,20 +1755,17 @@ done:
 int
 Event_job_data::execute(THD *thd)
 {
-  Security_context *save_ctx;
+  Security_context save_ctx;
   /* this one is local and not needed after exec */
-  Security_context security_ctx;
   int ret= 0;
 
   DBUG_ENTER("Event_job_data::execute");
   DBUG_PRINT("info", ("EXECUTING %s.%s", dbname.str, name.str));
 
-
   if ((ret= compile(thd, NULL)))
     goto done;
 
-  thd->change_security_context(definer_user, definer_host, dbname,
-                               &security_ctx, &save_ctx);
+  thd->change_security_context(definer_user, definer_host, dbname, &save_ctx);
   /*
     THD::~THD will clean this or if there is DROP DATABASE in the SP then
     it will be free there. It should not point to our buffer which is allocated
@@ -1810,9 +1790,10 @@ Event_job_data::execute(THD *thd)
     ret= -99;
   }
 
-  thd->restore_security_context(save_ctx);
+  thd->restore_security_context(&save_ctx);
 done:
-  free_sp();
+  thd->end_statement();
+  thd->cleanup_after_query();
 
   DBUG_PRINT("info", ("EXECUTED %s.%s ret=%d", dbname.str, name.str, ret));
 
diff --git a/sql/event_data_objects.h b/sql/event_data_objects.h
index e20d698161e..cf1bd5e390a 100644
--- a/sql/event_data_objects.h
+++ b/sql/event_data_objects.h
@@ -178,15 +178,12 @@ public:
 
   int
   execute(THD *thd);
-private:
-  int
-  get_fake_create_event(THD *thd, String *buf);
 
   int
   compile(THD *thd, MEM_ROOT *mem_root);
-
-  void
-  free_sp();
+private:
+  int
+  get_fake_create_event(THD *thd, String *buf);
 
   Event_job_data(const Event_job_data &);	/* Prevent use of these */
   void operator=(Event_job_data &);
diff --git a/sql/event_queue.cc b/sql/event_queue.cc
index 12eceee8cfb..69114c53118 100644
--- a/sql/event_queue.cc
+++ b/sql/event_queue.cc
@@ -35,6 +35,14 @@
 #define LOCK_QUEUE_DATA()   lock_data(SCHED_FUNC, __LINE__)
 #define UNLOCK_QUEUE_DATA() unlock_data(SCHED_FUNC, __LINE__)
 
+struct event_queue_param
+{
+  THD *thd;
+  Event_queue *queue;
+  pthread_mutex_t LOCK_loaded;
+  pthread_cond_t COND_loaded;
+};
+
 
 /*
   Compares the execute_at members of two Event_queue_element instances.
@@ -64,6 +72,31 @@ event_queue_element_compare_q(void *vptr, byte* a, byte *b)
 }
 
 
+pthread_handler_t
+event_queue_loader_thread(void *arg)
+{
+  /* needs to be first for thread_stack */
+  THD *thd= (THD *)((struct event_queue_param *) arg)->thd;
+  struct event_queue_param *param= (struct event_queue_param *) arg;
+  thd->thread_stack= (char *) &thd;
+
+  if (post_init_event_thread(thd))
+    goto end;
+
+  DBUG_ENTER("event_queue_loader_thread");
+
+  pthread_mutex_lock(&param->LOCK_loaded);
+  param->queue->load_events_from_db(thd);
+  pthread_cond_signal(&param->COND_loaded);
+  pthread_mutex_unlock(&param->LOCK_loaded);
+
+end:
+  deinit_event_thread(thd);
+
+  DBUG_RETURN(0);                               // Against gcc warnings
+}
+
+
 /*
   Constructor of class Event_queue.
 
@@ -80,6 +113,8 @@ Event_queue::Event_queue()
     mutex_last_attempted_lock_in_func= "";
 
   mutex_queue_data_locked= mutex_queue_data_attempting_lock= FALSE;
+
+  queue_loaded= FALSE;
 }
 
 
@@ -125,8 +160,11 @@ Event_queue::deinit_mutexes()
 bool
 Event_queue::init_queue(Event_db_repository *db_repo, Event_scheduler *sched)
 {
-  int i= 0;
-  bool ret= FALSE;
+  THD *new_thd;
+  pthread_t th;
+  bool res;
+  struct event_queue_param *event_queue_param_value= NULL;
+
   DBUG_ENTER("Event_queue::init_queue");
   DBUG_PRINT("enter", ("this=0x%lx", this));
 
@@ -139,8 +177,7 @@ Event_queue::init_queue(Event_db_repository *db_repo, Event_scheduler *sched)
                     NULL, EVENT_QUEUE_EXTENT))
   {
     sql_print_error("SCHEDULER: Can't initialize the execution queue");
-    ret= TRUE;
-    goto end;
+    goto err;
   }
 
   if (sizeof(my_time_t) != sizeof(time_t))
@@ -148,13 +185,43 @@ Event_queue::init_queue(Event_db_repository *db_repo, Event_scheduler *sched)
     sql_print_error("SCHEDULER: sizeof(my_time_t) != sizeof(time_t) ."
                     "The scheduler may not work correctly. Stopping.");
     DBUG_ASSERT(0);
-    ret= TRUE;
-    goto end;
+    goto err;
   }
 
-end:
+  if (!(new_thd= new THD))
+    goto err;
+
+  pre_init_event_thread(new_thd);
+
+  event_queue_param_value= (struct event_queue_param *)
+                          my_malloc(sizeof(struct event_queue_param), MYF(0));
+  event_queue_param_value->thd= new_thd;
+  event_queue_param_value->queue= this;
+  pthread_mutex_init(&event_queue_param_value->LOCK_loaded, MY_MUTEX_INIT_FAST);
+  pthread_cond_init(&event_queue_param_value->COND_loaded, NULL);
+
+  pthread_mutex_lock(&event_queue_param_value->LOCK_loaded);
+  DBUG_PRINT("info", ("Forking new thread for scheduduler. THD=0x%lx", new_thd));
+  if (!(res= pthread_create(&th, &connection_attrib, event_queue_loader_thread,
+                            (void*)event_queue_param_value)))
+  {
+    do {
+      pthread_cond_wait(&event_queue_param_value->COND_loaded,
+                      &event_queue_param_value->LOCK_loaded);
+    } while (queue_loaded == FALSE);
+  }
+
+  pthread_mutex_unlock(&event_queue_param_value->LOCK_loaded);
+  pthread_mutex_destroy(&event_queue_param_value->LOCK_loaded);
+  pthread_cond_destroy(&event_queue_param_value->COND_loaded);
+  my_free((char *)event_queue_param_value, MYF(0));
+
   UNLOCK_QUEUE_DATA();
-  DBUG_RETURN(ret);
+  DBUG_RETURN(res);
+
+err:
+  UNLOCK_QUEUE_DATA();
+  DBUG_RETURN(TRUE);
 }
 
 
@@ -498,7 +565,7 @@ Event_queue::load_events_from_db(THD *thd)
   READ_RECORD read_record_info;
   int ret= -1;
   uint count= 0;
-  bool clean_the_queue= FALSE;
+  bool clean_the_queue= TRUE;
   /* Compile the events on this root but only for syntax check, then discard */
   MEM_ROOT boot_root;
 
@@ -518,14 +585,12 @@ Event_queue::load_events_from_db(THD *thd)
     if (!(et= new Event_queue_element))
     {
       DBUG_PRINT("info", ("Out of memory"));
-      clean_the_queue= TRUE;
       break;
     }
     DBUG_PRINT("info", ("Loading event from row."));
 
     if ((ret= et->load_from_row(table)))
     {
-      clean_the_queue= TRUE;
       sql_print_error("SCHEDULER: Error while loading from mysql.event. "
                       "Table probably corrupted");
       break;
@@ -536,27 +601,6 @@ Event_queue::load_events_from_db(THD *thd)
       delete et;
       continue;
     }
-#if 0
-    init_alloc_root(&boot_root, MEM_ROOT_BLOCK_SIZE, MEM_ROOT_PREALLOC);
-    DBUG_PRINT("info", ("Event %s loaded from row. ", et->name.str));
-
-    /* We load only on scheduler root just to check whether the body compiles */
-    switch (ret= et->compile(thd, &boot_root)) {
-    case EVEX_MICROSECOND_UNSUP:
-      et->free_sp();
-      sql_print_error("SCHEDULER: mysql.event is tampered. MICROSECOND is not "
-                      "supported but found in mysql.event");
-      goto end;
-    case EVEX_COMPILE_ERROR:
-      sql_print_error("SCHEDULER: Error while compiling %s.%s. Aborting load.",
-                      et->dbname.str, et->name.str);
-      goto end;
-    default:
-      /* Free it, it will be compiled again on the worker thread */
-      et->free_sp();
-      break;
-    }
-    free_root(&boot_root, MYF(0));
 
     /* let's find when to be executed */
     if (et->compute_next_execution_time())
@@ -565,11 +609,40 @@ Event_queue::load_events_from_db(THD *thd)
                       " Skipping", et->dbname.str, et->name.str);
       continue;
     }
-#endif
+
+    {
+      Event_job_data temp_job_data;
+      DBUG_PRINT("info", ("Event %s loaded from row. ", et->name.str));
+
+      temp_job_data.load_from_row(table);
+
+      /* We load only on scheduler root just to check whether the body compiles */
+      switch (ret= temp_job_data.compile(thd, thd->mem_root)) {
+      case EVEX_MICROSECOND_UNSUP:
+        sql_print_error("SCHEDULER: mysql.event is tampered. MICROSECOND is not "
+                        "supported but found in mysql.event");
+        break;
+      case EVEX_COMPILE_ERROR:
+        sql_print_error("SCHEDULER: Error while compiling %s.%s. Aborting load.",
+                        et->dbname.str, et->name.str);
+        break;
+      default:
+        break;
+      }
+      thd->end_statement();
+      thd->cleanup_after_query();
+    }
+    if (ret)
+    {
+      delete et;
+      goto end;
+    }
+
     DBUG_PRINT("load_events_from_db", ("Adding 0x%lx to the exec list."));
     queue_insert_safe(&queue,  (byte *) et);
     count++;
   }
+  clean_the_queue= FALSE;
 end:
   end_read_record(&read_record_info);
 
@@ -585,10 +658,12 @@ end:
   }
 
   /* Force close to free memory */
-  thd->version--;  
+  thd->version--;
 
   close_thread_tables(thd);
 
+  queue_loaded= TRUE;
+
   DBUG_PRINT("info", ("Status code %d. Loaded %d event(s)", ret, count));
   DBUG_RETURN(ret);
 }
@@ -713,6 +788,7 @@ Event_queue::empty_queue()
   uint i;
   DBUG_ENTER("Event_queue::empty_queue");
   DBUG_PRINT("enter", ("Purging the queue. %d element(s)", queue.elements));
+  sql_print_information("SCHEDULER: Purging queue. %u events", queue.elements);
   /* empty the queue */
   for (i= 0; i < queue.elements; ++i)
   {
diff --git a/sql/event_queue.h b/sql/event_queue.h
index b7962d14a89..3270938e881 100644
--- a/sql/event_queue.h
+++ b/sql/event_queue.h
@@ -68,12 +68,13 @@ public:
   bool
   dump_internal_status(THD *thd);
 
+  int
+  load_events_from_db(THD *thd);
+
 protected:
   Event_queue_element *
   find_n_remove_event(LEX_STRING db, LEX_STRING name);
 
-  int
-  load_events_from_db(THD *thd);
 
   void
   drop_matching_events(THD *thd, LEX_STRING pattern,
@@ -82,11 +83,24 @@ protected:
   void
   empty_queue();
 
+  void
+  notify_observers();
+
+  void
+  dbug_dump_queue(time_t now);
+
   /* LOCK_event_queue is the mutex which protects the access to the queue. */
   pthread_mutex_t LOCK_event_queue;
 
   Event_db_repository *db_repository;
 
+  Event_scheduler *scheduler;
+
+  /* The sorted queue with the Event_job_data objects */
+  QUEUE queue;
+
+  bool queue_loaded;
+
   uint mutex_last_locked_at_line;
   uint mutex_last_unlocked_at_line;
   uint mutex_last_attempted_lock_at_line;
@@ -95,24 +109,13 @@ protected:
   const char* mutex_last_attempted_lock_in_func;
   bool mutex_queue_data_locked;
   bool mutex_queue_data_attempting_lock;
-
+  
   /* helper functions for working with mutexes & conditionals */
   void
   lock_data(const char *func, uint line);
 
   void
   unlock_data(const char *func, uint line);
-
-  void
-  notify_observers();
-
-  void
-  dbug_dump_queue(time_t now);
-
-  Event_scheduler *scheduler;
-
-  /* The sorted queue with the Event_job_data objects */
-  QUEUE queue;
 };
 
 #endif /* _EVENT_QUEUE_H_ */
diff --git a/sql/event_scheduler.cc b/sql/event_scheduler.cc
index 85d357ec11e..5e6ffb090cb 100644
--- a/sql/event_scheduler.cc
+++ b/sql/event_scheduler.cc
@@ -40,9 +40,6 @@ struct scheduler_param
   Event_scheduler *scheduler;
 };
 
-struct scheduler_param scheduler_param_value;
-
-
 
 static
 LEX_STRING scheduler_states_names[] =
@@ -103,25 +100,23 @@ evex_print_warnings(THD *thd, Event_job_data *et)
 
 
 /*
-  Inits an scheduler thread handler, both the main and a worker
+  Performs pre- pthread_create() initialisation of THD. Do this
+  in the thread that will pass THD to the child thread. In the
+  child thread call post_init_event_thread().
 
   SYNOPSIS
-    init_event_thread()
-      thd - the THD of the thread. Has to be allocated by the caller.
+    pre_init_event_thread()
+      thd  The THD of the thread. Has to be allocated by the caller.
 
   NOTES
     1. The host of the thead is my_localhost
     2. thd->net is initted with NULL - no communication.
-
-  RETURN VALUE
-    0  OK
-   -1  Error
 */
 
-static int
-init_scheduler_thread(THD* thd)
+void
+pre_init_event_thread(THD* thd)
 {
-  DBUG_ENTER("init_event_thread");
+  DBUG_ENTER("pre_init_event_thread");
   thd->client_capabilities= 0;
   thd->security_ctx->master_access= 0;
   thd->security_ctx->db_access= 0;
@@ -148,7 +143,36 @@ init_scheduler_thread(THD* thd)
   thd->version= refresh_version;
   thd->set_time();
 
-  DBUG_RETURN(0);
+  DBUG_VOID_RETURN;
+}
+
+
+/*
+  Performs post initialization of structures in a new thread.
+
+  SYNOPSIS
+    post_init_event_thread()
+      thd  Thread
+*/
+
+bool
+post_init_event_thread(THD *thd)
+{
+  my_thread_init();
+  pthread_detach_this_thread();
+  thd->real_id= pthread_self();
+  if (init_thr_lock() || thd->store_globals())
+  {
+    thd->cleanup();
+    return TRUE;
+  }
+
+#if !defined(__WIN__) && !defined(OS2) && !defined(__NETWARE__)
+  sigset_t set;
+    VOID(sigemptyset(&set));                    // Get mask in use
+  VOID(pthread_sigmask(SIG_UNBLOCK,&set,&thd->block_signals));
+#endif
+  return FALSE;
 }
 
 
@@ -160,7 +184,7 @@ init_scheduler_thread(THD* thd)
       thd  Thread
 */
 
-static void
+void
 deinit_event_thread(THD *thd)
 {
   thd->proc_info= "Clearing";
@@ -192,29 +216,18 @@ pthread_handler_t
 event_scheduler_thread(void *arg)
 {
   /* needs to be first for thread_stack */
-  THD *thd= (THD *)(*(struct scheduler_param *) arg).thd;
+  THD *thd= (THD *)((struct scheduler_param *) arg)->thd;
+  Event_scheduler *scheduler= ((struct scheduler_param *) arg)->scheduler;
 
-  thd->thread_stack= (char *)&thd;              // remember where our stack is
-  DBUG_ENTER("event_scheduler_thread");
+  my_free((char*)arg, MYF(0));
 
-  my_thread_init();
-  pthread_detach_this_thread();
-  thd->real_id=pthread_self();
-  if (init_thr_lock() || thd->store_globals())
-  {
-    thd->cleanup();
-    goto end;
-  }
+  thd->thread_stack= (char *)&thd;              // remember where our stack is
 
-#if !defined(__WIN__) && !defined(OS2) && !defined(__NETWARE__)
-  sigset_t set;
-    VOID(sigemptyset(&set));                    // Get mask in use
-  VOID(pthread_sigmask(SIG_UNBLOCK,&set,&thd->block_signals));
-#endif
+  DBUG_ENTER("event_scheduler_thread");
 
-  ((struct scheduler_param *) arg)->scheduler->run(thd);
+  if (!post_init_event_thread(thd))
+    scheduler->run(thd);
 
-end:
   deinit_event_thread(thd);
 
   DBUG_RETURN(0);                               // Against gcc warnings
@@ -242,27 +255,13 @@ event_worker_thread(void *arg)
   int ret;
 
   thd= event->thd;
-  thd->thread_stack= (char *) &thd;
 
+  thd->thread_stack= (char *) &thd;             // remember where our stack is
+  DBUG_ENTER("event_worker_thread");
 
-  my_thread_init();
-  pthread_detach_this_thread();
-  thd->real_id=pthread_self();
-  if (init_thr_lock() || thd->store_globals())
-  {
-    thd->cleanup();
+  if (post_init_event_thread(thd))
     goto end;
-  }
-
 
-#if !defined(__WIN__) && !defined(OS2) && !defined(__NETWARE__)
-  sigset_t set;
-  VOID(sigemptyset(&set));                      // Get mask in use
-  VOID(pthread_sigmask(SIG_UNBLOCK, &set, &thd->block_signals));
-#endif
-  thd->init_for_queries();
-
-  DBUG_ENTER("event_worker_thread");
   DBUG_PRINT("info", ("Baikonur, time is %d, BURAN reporting and operational."
              "THD=0x%lx", time(NULL), thd));
 
@@ -375,6 +374,7 @@ Event_scheduler::start()
   THD *new_thd= NULL;
   bool ret= FALSE;
   pthread_t th;
+  struct scheduler_param *scheduler_param_value;
   DBUG_ENTER("Event_scheduler::start");
 
   LOCK_SCHEDULER_DATA();
@@ -382,21 +382,24 @@ Event_scheduler::start()
   if (state > INITIALIZED)
     goto end;
 
-  if (!(new_thd= new THD) || init_scheduler_thread(new_thd))
+  if (!(new_thd= new THD))
   {
     sql_print_error("SCHEDULER: Cannot init manager event thread.");
     ret= TRUE;
     goto end;
   }
+  pre_init_event_thread(new_thd);
   new_thd->system_thread= SYSTEM_THREAD_EVENT_SCHEDULER;
   new_thd->command= COM_DAEMON;
 
-  scheduler_param_value.thd= new_thd;
-  scheduler_param_value.scheduler= this;
+  scheduler_param_value=
+    (struct scheduler_param *)my_malloc(sizeof(struct scheduler_param), MYF(0));
+  scheduler_param_value->thd= new_thd;
+  scheduler_param_value->scheduler= this;
 
   DBUG_PRINT("info", ("Forking new thread for scheduduler. THD=0x%lx", new_thd));
   if (pthread_create(&th, &connection_attrib, event_scheduler_thread,
-                    (void*)&scheduler_param_value))
+                    (void*)scheduler_param_value))
   {
     DBUG_PRINT("error", ("cannot create a new thread"));
     state= INITIALIZED;
@@ -588,9 +591,10 @@ Event_scheduler::execute_top(THD *thd, Event_job_data *job_data)
   pthread_t th;
   int res= 0;
   DBUG_ENTER("Event_scheduler::execute_top");
-  if (!(new_thd= new THD) || init_scheduler_thread(new_thd))
+  if (!(new_thd= new THD))
     goto error;
 
+  pre_init_event_thread(new_thd);
   new_thd->system_thread= SYSTEM_THREAD_EVENT_WORKER;
   job_data->thd= new_thd;
   DBUG_PRINT("info", ("BURAN %s@%s ready for start t-3..2..1..0..ignition",
diff --git a/sql/event_scheduler.h b/sql/event_scheduler.h
index bf3e8e63e11..8e00b7b767f 100644
--- a/sql/event_scheduler.h
+++ b/sql/event_scheduler.h
@@ -19,6 +19,15 @@
 class Event_queue;
 class Event_job_data;
 
+void
+pre_init_event_thread(THD* thd);
+
+bool
+post_init_event_thread(THD* thd);
+
+void
+deinit_event_thread(THD *thd);
+
 class Event_scheduler
 {
 public:
diff --git a/sql/events.cc b/sql/events.cc
index 2a4ccbaf5ef..94ef8faa83d 100644
--- a/sql/events.cc
+++ b/sql/events.cc
@@ -556,11 +556,16 @@ Events::fill_schema_events(THD *thd, TABLE_LIST *tables, COND * /* cond */)
     1  Error in case the scheduler can't start
 */
 
-int
+bool
 Events::init()
 {
+  int res;
   DBUG_ENTER("Events::init");
-  event_queue->init_queue(db_repository, scheduler);
+  if (event_queue->init_queue(db_repository, scheduler))
+  {
+    sql_print_information("SCHEDULER: Error while loading from disk.");
+    DBUG_RETURN(TRUE);
+  }
   scheduler->init_scheduler(event_queue);
 
   /* it should be an assignment! */
@@ -571,7 +576,7 @@ Events::init()
       DBUG_RETURN(scheduler->start());
   }
 
-  DBUG_RETURN(0);
+  DBUG_RETURN(FALSE);
 }
 
 
diff --git a/sql/events.h b/sql/events.h
index 5f46c7bb7c5..f14aed0fbd1 100644
--- a/sql/events.h
+++ b/sql/events.h
@@ -52,7 +52,7 @@ public:
   static ulong opt_event_scheduler;
   static TYPELIB opt_typelib;
 
-  int
+  bool
   init();
   
   void
diff --git a/sql/mysqld.cc b/sql/mysqld.cc
index 8fc6155087e..1cc52a204eb 100644
--- a/sql/mysqld.cc
+++ b/sql/mysqld.cc
@@ -3675,7 +3675,8 @@ we force server id to 2, but this MySQL server will not act as a slave.");
 
   if (!opt_noacl)
   {
-    Events::get_instance()->init();
+    if (Events::get_instance()->init())
+      unireg_abort(1);
   }
 #if defined(__NT__) || defined(HAVE_SMEM)
   handle_connections_methods();
diff --git a/sql/sp_head.cc b/sql/sp_head.cc
index 81f5d502ec9..d8995da7c16 100644
--- a/sql/sp_head.cc
+++ b/sql/sp_head.cc
@@ -640,10 +640,12 @@ sp_head::create(THD *thd)
 
 sp_head::~sp_head()
 {
+  DBUG_ENTER("sp_head::~sp_head");
   destroy();
   delete m_next_cached_sp;
   if (m_thd)
     restore_thd_mem_root(m_thd);
+  DBUG_VOID_RETURN;
 }
 
 void
diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index 47381c6aecb..6ce5a8fa01d 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -2085,21 +2085,20 @@ bool Security_context::set_user(char *user_arg)
 
 bool
 THD::change_security_context(LEX_STRING user, LEX_STRING host,
-                             LEX_STRING db, Security_context *s_ctx,
-                             Security_context **backup)
+                             LEX_STRING db, Security_context *backup)
 {
   DBUG_ENTER("change_security_context");
   DBUG_PRINT("info",("%s@%s@%s", user.str, host.str, db.str));
 #ifndef NO_EMBEDDED_ACCESS_CHECKS
-  s_ctx->init();
-  *backup= 0;
-  if (acl_getroot_no_password(s_ctx, user.str, host.str, host.str, db.str))
+
+  *backup= main_security_ctx;
+  if (acl_getroot_no_password(&main_security_ctx, user.str, host.str, host.str,
+                              db.str))
   {
     my_error(ER_NO_SUCH_USER, MYF(0), user.str, host.str);
     DBUG_RETURN(TRUE);
   }
-  *backup= security_ctx;
-  security_ctx= s_ctx;
+  security_ctx= &main_security_ctx;
 #endif
   DBUG_RETURN(FALSE);
 }
@@ -2119,7 +2118,10 @@ THD::restore_security_context(Security_context *backup)
   DBUG_ENTER("restore_security_context");
 #ifndef NO_EMBEDDED_ACCESS_CHECKS
   if (backup)
-    security_ctx= backup;
+  {
+    main_security_ctx= *backup;
+    security_ctx= &main_security_ctx;
+  }
 #endif
   DBUG_VOID_RETURN;
 }
diff --git a/sql/sql_class.h b/sql/sql_class.h
index 18cc53daf6d..1283f55cea6 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -871,8 +871,7 @@ public:
   
   bool
   change_security_context(LEX_STRING user, LEX_STRING host,
-                          LEX_STRING db, Security_context *s_ctx,
-                          Security_context **backup);  
+                          LEX_STRING db, Security_context *backup);  
 
   void
   restore_security_context(Security_context *backup);
diff --git a/sql/sql_lex.cc b/sql/sql_lex.cc
index 386dece8813..1be70ea61d6 100644
--- a/sql/sql_lex.cc
+++ b/sql/sql_lex.cc
@@ -171,6 +171,7 @@ void lex_start(THD *thd, const uchar *buf, uint length)
   lex->sql_command= SQLCOM_END;
   lex->duplicates= DUP_ERROR;
   lex->ignore= 0;
+  lex->spname= NULL;
   lex->sphead= NULL;
   lex->spcont= NULL;
   lex->proc_list.first= 0;
diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy
index 0dd87fbfac6..a29c5f3ee16 100644
--- a/sql/sql_yacc.yy
+++ b/sql/sql_yacc.yy
@@ -4652,6 +4652,13 @@ alter:
              YYTHD->client_capabilities is set back to original value
           */
           {
+            /* 
+               It is safe to use Lex->spname because
+               ALTER EVENT xxx RENATE TO yyy DO ALTER EVENT RENAME TO
+               is not allowed. Lex->spname is used in the case of RENAME TO
+               If it had to be supported spname had to be added to
+               Event_parse_data.
+            */
             Lex->spname= NULL;
 
             if (!(Lex->event_parse_data= Event_parse_data::new_instance(YYTHD)))