WL#3337 (Event scheduler new architecture)

More small fixes to the API : use LEX_STRING instead of LEX_STRING* and if error
then return bool(true) instead of error code.
Merged functions. Reduced usage of sp_name.
Fixed a lot of function documentation errors.
Added function documentation wherever needed.
Removed some unused defines and error codes.

Next to come is batch rename of Event_scheduler_ng to Event_scheduler.

mysql-test/r/events.result

@@ -111,7 +111,15 @@ a
 800219
 drop event non_qualif_ev;
 drop table non_qualif;
+alter event non_existant rename to non_existant_too;
+ERROR HY000: Unknown event 'non_existant'
 set global event_scheduler = 2;
+create event existant on schedule at now() + interval 1 year do select 12;
+alter event non_existant rename to existant;
+ERROR HY000: Event 'existant' already exists
+alter event existant rename to events_test.existant;
+ERROR HY000: Same old and new event name
+drop event existant;
 create table t_event3 (a int, b float);
 drop event if exists event3;
 Warnings:

mysql-test/r/events_logs_tests.result

-create database if not exists events_test;
-use events_test;
+CREATE DATABASE IF NOT EXISTS events_test;
+USE events_test;
 "We use procedure here because its statements won't be logged into the general log"
 "If we had used normal select that are logged in different ways depending on whether"
 "the test suite is run in normal mode or with --ps-protocol"
@@ -8,18 +8,21 @@ BEGIN
 SELECT user_host, argument FROM mysql.general_log WHERE argument LIKE '%alabala%';
 END|
 "Check General Query Log"
-SET GLOBAL event_scheduler=2;
-create event log_general on schedule every 1 minute do SELect 'alabala', sleep(1) from dual;
-TRUNCATE mysql.general_log;
-"1 row, the current statement!"
-call select_general_log();
+CALL select_general_log();
 user_host	argument
+USER_HOST	CREATE procedure select_general_log()
+BEGIN
+SELECT user_host, argument FROM mysql.general_log WHERE argument LIKE '%alabala%';
+END
 SET GLOBAL event_scheduler=1;
+TRUNCATE mysql.general_log;
+CREATE EVENT log_general ON SCHEDULE EVERY 1 MINUTE DO SELECT 'alabala', SLEEP(1) FROM DUAL;
 "Wait the scheduler to start"
-"Should see 3 rows - the 'SELect' is in the middle. The other two are selects from general_log"
-call select_general_log();
+"Should see 2 rows - the 'SELECT' is in the middle. The other two are selects from general_log"
+CALL select_general_log();
 user_host	argument
-USER_HOST	SELect 'alabala', sleep(1) from dual
+USER_HOST	CREATE EVENT log_general ON SCHEDULE EVERY 1 MINUTE DO SELECT 'alabala', SLEEP(1) FROM DUAL
+USER_HOST	SELECT 'alabala', SLEEP(1) FROM DUAL
 DROP PROCEDURE select_general_log;
 DROP EVENT log_general;
 SET GLOBAL event_scheduler=2;
@@ -90,4 +93,4 @@ TRUNCATE mysql.slow_log;
 DROP TABLE slow_event_test;
 SET GLOBAL  long_query_time =@old_global_long_query_time;
 SET SESSION long_query_time =@old_session_long_query_time;
-drop database events_test;
+DROP DATABASE events_test;

mysql-test/t/events.test

@@ -105,7 +105,18 @@ create event non_qualif_ev on schedule every 10 minute do insert into non_qualif
 select * from non_qualif;
 drop event non_qualif_ev;
 drop table non_qualif;
+
+--error ER_EVENT_DOES_NOT_EXIST
+alter event non_existant rename to non_existant_too;
+
 set global event_scheduler = 2;
+create event existant on schedule at now() + interval 1 year do select 12;
+--error ER_EVENT_ALREADY_EXISTS
+alter event non_existant rename to existant;
+--error ER_EVENT_SAME_NAME
+alter event existant rename to events_test.existant;
+drop event existant;
+
 
 create table t_event3 (a int, b float);
 drop event if exists event3;

mysql-test/t/events_logs_tests.test

 # Can't test with embedded server that doesn't support grants
 -- source include/not_embedded.inc
 
-create database if not exists events_test;
-use events_test;
+CREATE DATABASE IF NOT EXISTS events_test;
+USE events_test;
 --echo "We use procedure here because its statements won't be logged into the general log"
 --echo "If we had used normal select that are logged in different ways depending on whether"
 --echo "the test suite is run in normal mode or with --ps-protocol"
@@ -13,18 +13,16 @@ BEGIN
 END|
 delimiter ;|
 --echo "Check General Query Log"
-SET GLOBAL event_scheduler=2;
-create event log_general on schedule every 1 minute do SELect 'alabala', sleep(1) from dual;
-TRUNCATE mysql.general_log;
---echo "1 row, the current statement!"
 --replace_column 1 USER_HOST
-call select_general_log();
+CALL select_general_log();
 SET GLOBAL event_scheduler=1;
+TRUNCATE mysql.general_log;
+CREATE EVENT log_general ON SCHEDULE EVERY 1 MINUTE DO SELECT 'alabala', SLEEP(1) FROM DUAL;
 --echo "Wait the scheduler to start"
---echo "Should see 3 rows - the 'SELect' is in the middle. The other two are selects from general_log"
---sleep 0.7
+--sleep 1.5
+--echo "Should see 2 rows - the 'SELECT' is in the middle. The other two are selects from general_log"
 --replace_column 1 USER_HOST
-call select_general_log();
+CALL select_general_log();
 DROP PROCEDURE select_general_log;
 DROP EVENT log_general;
 SET GLOBAL event_scheduler=2;
@@ -102,4 +100,4 @@ DROP TABLE slow_event_test;
 SET GLOBAL  long_query_time =@old_global_long_query_time;
 SET SESSION long_query_time =@old_session_long_query_time; 
 
-drop database events_test;
+DROP DATABASE events_test;

sql/event_data_objects.h

@@ -17,45 +17,16 @@
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
 
 
-#define EVEX_OK                  0
-#define EVEX_KEY_NOT_FOUND      -1
-#define EVEX_OPEN_TABLE_FAILED  -2
-#define EVEX_WRITE_ROW_FAILED   -3
-#define EVEX_DELETE_ROW_FAILED  -4
-#define EVEX_GET_FIELD_FAILED   -5
-#define EVEX_PARSE_ERROR        -6
-#define EVEX_INTERNAL_ERROR     -7
-#define EVEX_NO_DB_ERROR        -8
-#define EVEX_COMPILE_ERROR     -19
-#define EVEX_GENERAL_ERROR     -20
-#define EVEX_BAD_IDENTIFIER    -21 
-#define EVEX_BODY_TOO_LONG     -22
-#define EVEX_BAD_PARAMS        -23
-#define EVEX_NOT_RUNNING       -24
-#define EVEX_MICROSECOND_UNSUP -25
-#define EVEX_CANT_KILL         -26
-
-#define EVENT_EXEC_NO_MORE      (1L << 0)
-#define EVENT_NOT_USED          (1L << 1)
-#define EVENT_FREE_WHEN_FINISHED (1L << 2)
-
-
-#define EVENT_EXEC_STARTED      0
-#define EVENT_EXEC_ALREADY_EXEC 1
-#define EVENT_EXEC_CANT_FORK    2
+#define EVEX_GET_FIELD_FAILED   -2
+#define EVEX_COMPILE_ERROR      -3
+#define EVEX_GENERAL_ERROR      -4
+#define EVEX_BAD_PARAMS         -5
+#define EVEX_MICROSECOND_UNSUP  -6
 
 
 class sp_head;
 class Sql_alloc;
-class Event_basic;
 
-/* Compares only the schema part of the identifier */
-bool
-event_basic_db_equal( LEX_STRING *db, Event_basic *et);
-
-/* Compares the whole identifier*/
-bool
-event_basic_identifier_equal(LEX_STRING db, LEX_STRING name, Event_basic *b);
 
 class Event_basic
 {
@@ -206,7 +177,7 @@ public:
   load_from_row(TABLE *table);
 
   int
-  execute(THD *thd, MEM_ROOT *mem_root);
+  execute(THD *thd);
 private:
   int
   get_fake_create_event(THD *thd, String *buf);
@@ -274,7 +245,7 @@ public:
 
 private:
 
-  int
+  void
   init_definer(THD *thd);
 
   void
@@ -303,4 +274,13 @@ private:
 };
 
 
+/* Compares only the schema part of the identifier */
+bool
+event_basic_db_equal(LEX_STRING db, Event_basic *et);
+
+/* Compares the whole identifier*/
+bool
+event_basic_identifier_equal(LEX_STRING db, LEX_STRING name, Event_basic *b);
+
+
 #endif /* _EVENT_DATA_OBJECTS_H_ */

sql/event_db_repository.h

@@ -16,6 +16,8 @@
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
 
+#define EVEX_OPEN_TABLE_FAILED  -1
+
 enum enum_events_table_field
 {
   ET_FIELD_DB = 0,
@@ -60,24 +62,23 @@ public:
   create_event(THD *thd, Event_parse_data *parse_data, my_bool create_if_not,
                uint *rows_affected);
 
-  int
-  update_event(THD *thd, Event_parse_data *parse_data, sp_name *new_name);
+  bool
+  update_event(THD *thd, Event_parse_data *parse_data, LEX_STRING *new_dbname,
+               LEX_STRING *new_name);
 
-  int 
+  bool 
   drop_event(THD *thd, LEX_STRING db, LEX_STRING name, bool drop_if_exists,
              uint *rows_affected);
 
   int
   drop_schema_events(THD *thd, LEX_STRING schema);
 
-  int
-  find_event(THD *thd, LEX_STRING dbname, LEX_STRING name, Event_basic *et);
+  bool
+  find_named_event(THD *thd, LEX_STRING db, LEX_STRING name, TABLE *table);
 
-  int
+  bool
   load_named_event(THD *thd, LEX_STRING dbname, LEX_STRING name, Event_basic *et);
 
-  int
-  find_event_by_name(THD *thd, LEX_STRING db, LEX_STRING name, TABLE *table);
 
   int
   open_event_table(THD *thd, enum thr_lock_type lock_type, TABLE **table);

sql/event_queue.h

@@ -16,7 +16,6 @@
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
 
-class sp_name;
 class Event_basic;
 class Event_db_repository;
 class Event_job_data;
@@ -57,31 +56,28 @@ public:
   void
   drop_schema_events(THD *thd, LEX_STRING schema);
 
-  uint
-  events_count();
-
   static bool
   check_system_tables(THD *thd);
 
   void
   recalculate_activation_times(THD *thd);
 
-  Event_job_data *
-  get_top_for_execution_if_time(THD *thd, time_t now, struct timespec *abstime);
-
+  bool
+  get_top_for_execution_if_time(THD *thd, time_t now, Event_job_data **job_data,
+                                struct timespec *abstime);
   bool
   dump_internal_status(THD *thd);
 
 protected:
   Event_queue_element *
-  find_event(LEX_STRING db, LEX_STRING name, bool remove_from_q);
+  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,
-                       bool (*)(LEX_STRING *, Event_basic *));
+                       bool (*)(LEX_STRING, Event_basic *));
 
   void
   empty_queue();
@@ -93,9 +89,12 @@ protected:
 
   uint mutex_last_locked_at_line;
   uint mutex_last_unlocked_at_line;
+  uint mutex_last_attempted_lock_at_line;
   const char* mutex_last_locked_in_func;
   const char* mutex_last_unlocked_in_func;
+  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

sql/event_scheduler_ng.cc

@@ -176,6 +176,7 @@ deinit_event_thread(THD *thd)
   my_thread_end();
 }
 
+
 /*
   Function that executes the scheduler,
 
@@ -271,7 +272,7 @@ event_worker_ng_thread(void *arg)
 
   thd->enable_slow_log= TRUE;
 
-  ret= event->execute(thd, thd->mem_root);
+  ret= event->execute(thd);
 
   evex_print_warnings(thd, event);
 
@@ -506,8 +507,13 @@ Event_scheduler_ng::run(THD *thd)
   {
     thd->end_time();
     /* Gets a minimized version */
-    job_data= queue->
-            get_top_for_execution_if_time(thd, thd->query_start(), &abstime);
+    if (queue->get_top_for_execution_if_time(thd, thd->query_start(),
+                                                   &job_data, &abstime))
+    {
+      sql_print_information("SCHEDULER: Serious error during getting next"
+                            " event to execute. Stopping.");
+      break;
+    }
 
     DBUG_PRINT("info", ("get_top returned job_data=0x%lx now=%d "
                         "abs_time.tv_sec=%d",

sql/events.cc

@@ -41,10 +41,6 @@
 
  - Add logging to file
 
-Warning:
- - For now parallel execution is not possible because the same sp_head cannot
-   be executed few times!!! There is still no lock attached to particular
-   event.
 */
 
 
@@ -84,18 +80,14 @@ ulong Events::opt_event_scheduler= 2;
 
   SYNOPSIS
     sortcmp_lex_string()
-
-      s - first LEX_STRING
-      t - second LEX_STRING
-      cs - charset
+      s   First LEX_STRING
+      t   Second LEX_STRING
+      cs  Charset
 
   RETURN VALUE
-   -1   - s < t
-    0   - s == t
-    1   - s > t
-
-  Notes
-    TIME.second_part is not considered during comparison
+   -1   s < t
+    0   s == t
+    1   s > t
 */
 
 int sortcmp_lex_string(LEX_STRING s, LEX_STRING t, CHARSET_INFO *cs)
@@ -104,6 +96,7 @@ int sortcmp_lex_string(LEX_STRING s, LEX_STRING t, CHARSET_INFO *cs)
                                   (uchar *) t.str,t.length, 0);
 }
 
+
 /*
   Accessor for the singleton instance.
 
@@ -131,13 +124,13 @@ Events::get_instance()
 
   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
+      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
+    0  OK
+    1  Error
 */
 
 int
@@ -256,7 +249,7 @@ common_1_lev_code:
 
 
 /*
-  Open mysql.event table for read
+  Opens mysql.event table with specified lock
 
   SYNOPSIS
     Events::open_event_table()
@@ -283,11 +276,10 @@ Events::open_event_table(THD *thd, enum thr_lock_type lock_type,
 
   SYNOPSIS
     Events::create_event()
-      thd            THD
-      et             event's data
-      create_options Options specified when in the query. We are
-                     interested whether there is IF NOT EXISTS
-      rows_affected  How many rows were affected
+      thd            [in]  THD
+      et             [in]  Event's data from parsing stage
+      if_not_exists  [in]  Whether IF NOT EXISTS was specified in the DDL
+      rows_affected  [out] How many rows were affected
 
   RETURN VALUE
     0   OK
@@ -328,9 +320,10 @@ Events::create_event(THD *thd, Event_parse_data *parse_data, bool if_not_exists,
 
   SYNOPSIS
     Events::update_event()
-      thd        THD
-      et         Event's data from parsing stage
-      new_name   Set in case of RENAME TO.
+      thd           [in]  THD
+      et            [in]  Event's data from parsing stage
+      rename_to     [in]  Set in case of RENAME TO.
+      rows_affected [out] How many rows were affected.
 
   RETURN VALUE
     0   OK
@@ -338,26 +331,25 @@ Events::create_event(THD *thd, Event_parse_data *parse_data, bool if_not_exists,
 
   NOTES
     et contains data about dbname and event name. 
-    new_name is the new name of the event, if not null (this means
-    that RENAME TO was specified in the query)
+    new_name is the new name of the event, if not null this means
+    that RENAME TO was specified in the query
 */
 
 int
-Events::update_event(THD *thd, Event_parse_data *parse_data, sp_name *new_name,
+Events::update_event(THD *thd, Event_parse_data *parse_data, sp_name *rename_to,
                      uint *rows_affected)
 {
   int ret;
   DBUG_ENTER("Events::update_event");
+  LEX_STRING *new_dbname= rename_to? &rename_to->m_db: NULL;
+  LEX_STRING *new_name= rename_to? &rename_to->m_name: NULL;
 
   pthread_mutex_lock(&LOCK_event_metadata);
   /* On error conditions my_error() is called so no need to handle here */
-  if (!(ret= db_repository->update_event(thd, parse_data, new_name)))
+  if (!(ret= db_repository->update_event(thd, parse_data, new_dbname, new_name)))
   {
-    if ((ret= event_queue->update_event(thd,
-                                        parse_data->dbname,
-                                        parse_data->name,
-                                        new_name? &new_name->m_db: NULL,
-                                        new_name? &new_name->m_name: NULL)))
+    if ((ret= event_queue->update_event(thd, parse_data->dbname,
+                                        parse_data->name, new_dbname, new_name)))
     {
       DBUG_ASSERT(ret == OP_LOAD_ERROR);
       my_error(ER_EVENT_MODIFY_QUEUE_ERROR, MYF(0));
@@ -374,16 +366,16 @@ Events::update_event(THD *thd, Event_parse_data *parse_data, sp_name *new_name,
 
   SYNOPSIS
     Events::drop_event()
-      thd             THD
-      dbname          Event's schema
-      name            Event's name
-      if_exists       When set and the event does not exist => warning onto
-                      the stack
-      rows_affected   Affected number of rows is returned heres
-      only_from_disk  Whether to remove the event from the queue too. In case
-                      of Event_job_data::drop() it's needed to do only disk
-                      drop because Event_queue will handle removal from memory
-                      queue.
+      thd             [in]  THD
+      dbname          [in]  Event's schema
+      name            [in]  Event's name
+      if_exists       [in]  When set and the event does not exist =>
+                            warning onto the stack
+      rows_affected   [out] Affected number of rows is returned here
+      only_from_disk  [in]  Whether to remove the event from the queue too.
+                            In case of Event_job_data::drop() it's needed to
+                            do only disk drop because Event_queue will handle
+                            removal from memory queue.
 
   RETURN VALUE
      0  OK
@@ -429,7 +421,7 @@ Events::drop_schema_events(THD *thd, char *db)
   int ret= 0;
   LEX_STRING db_lex= {db, strlen(db)};
   
-  DBUG_ENTER("evex_drop_db_events");  
+  DBUG_ENTER("Events::drop_schema_events");  
   DBUG_PRINT("enter", ("dropping events from %s", db));
 
   pthread_mutex_lock(&LOCK_event_metadata);
@@ -455,24 +447,22 @@ Events::drop_schema_events(THD *thd, char *db)
 */
 
 int
-Events::show_create_event(THD *thd, sp_name *spn)
+Events::show_create_event(THD *thd, LEX_STRING dbname, LEX_STRING name)
 {
+  CHARSET_INFO *scs= system_charset_info;
   int ret;
   Event_timed *et= new Event_timed();
-  Open_tables_state backup;
 
   DBUG_ENTER("Events::show_create_event");
-  DBUG_PRINT("enter", ("name: %*s", spn->m_name.length, spn->m_name.str));
+  DBUG_PRINT("enter", ("name: %s@%s", dbname.str, name.str));
 
-  thd->reset_n_backup_open_tables_state(&backup);
-  ret= db_repository->find_event(thd, spn->m_db, spn->m_name, et);
-  thd->restore_backup_open_tables_state(&backup);
+  ret= db_repository->load_named_event(thd, dbname, name, et);
 
   if (!ret)
   {
     Protocol *protocol= thd->protocol;
-    char show_str_buf[768];
-    String show_str(show_str_buf, sizeof(show_str_buf), system_charset_info);
+    char show_str_buf[10 * STRING_BUFFER_USUAL_SIZE];
+    String show_str(show_str_buf, sizeof(show_str_buf), scs);
     List<Item> field_list;
     byte *sql_mode_str;
     ulong sql_mode_len=0;
@@ -491,18 +481,19 @@ Events::show_create_event(THD *thd, sp_name *spn)
 
     field_list.push_back(new Item_empty_string("sql_mode", sql_mode_len));
 
-    field_list.push_back(new Item_empty_string("Create Event",
-                                               show_str.length()));
+    field_list.
+        push_back(new Item_empty_string("Create Event", show_str.length()));
+
     if (protocol->send_fields(&field_list, Protocol::SEND_NUM_ROWS |
                                            Protocol::SEND_EOF))
       goto err;
 
     protocol->prepare_for_resend();
-    protocol->store(et->name.str, et->name.length, system_charset_info);
+    protocol->store(et->name.str, et->name.length, scs);
 
-    protocol->store((char*) sql_mode_str, sql_mode_len, system_charset_info);
+    protocol->store((char*) sql_mode_str, sql_mode_len, scs);
 
-    protocol->store(show_str.c_ptr(), show_str.length(), system_charset_info);
+    protocol->store(show_str.c_ptr(), show_str.length(), scs);
     ret= protocol->write();
     send_eof(thd);
   }
@@ -546,7 +537,8 @@ Events::fill_schema_events(THD *thd, TABLE_LIST *tables, COND * /* cond */)
       DBUG_RETURN(1);
     db= thd->lex->select_lex.db;
   }
-  DBUG_RETURN(get_instance()->db_repository->fill_schema_events(thd, tables, db));
+  DBUG_RETURN(get_instance()->db_repository->
+                                      fill_schema_events(thd, tables, db));
 }
 
 
@@ -561,14 +553,12 @@ Events::fill_schema_events(THD *thd, TABLE_LIST *tables, COND * /* cond */)
 
   RETURN VALUE
     0  OK
-    1  Error
+    1  Error in case the scheduler can't start
 */
 
 int
 Events::init()
 {
-  int ret= 0;
-  Event_db_repository *db_repo;
   DBUG_ENTER("Events::init");
   event_queue->init_queue(db_repository, scheduler_ng);
   scheduler_ng->init_scheduler(event_queue);
@@ -653,7 +643,10 @@ Events::destroy_mutexes()
 
 
 /*
-  Proxy for Event_scheduler::dump_internal_status
+  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()

sql/events.h

@@ -81,7 +81,7 @@ public:
                uint *rows_affected);
 
   int
-  update_event(THD *thd, Event_parse_data *parse_data, sp_name *new_name,
+  update_event(THD *thd, Event_parse_data *parse_data, sp_name *rename_to,
                uint *rows_affected);
 
   int
@@ -95,7 +95,7 @@ public:
   open_event_table(THD *thd, enum thr_lock_type lock_type, TABLE **table);
 
   int
-  show_create_event(THD *thd, sp_name *spn);
+  show_create_event(THD *thd, LEX_STRING dbname, LEX_STRING name);
 
   /* Needed for both SHOW CREATE EVENT and INFORMATION_SCHEMA */
   static int

sql/sql_parse.cc

@@ -3926,7 +3926,8 @@ end_with_restore_list:
     }
 
     if (lex->sql_command == SQLCOM_SHOW_CREATE_EVENT)
-      res= Events::get_instance()->show_create_event(thd, lex->spname);
+      res= Events::get_instance()->show_create_event(thd, lex->spname->m_db,
+                                                     lex->spname->m_name);
     else
     {
       uint affected= 1;

sql/sql_yacc.yy

@@ -1447,7 +1447,8 @@ ev_sql_stmt:
             LEX *lex=Lex;
 
             // return back to the original memory root ASAP
-            lex->sphead->init_strings(YYTHD, lex, NULL);
+            lex->sphead->init_strings(YYTHD, lex,
+                                      Lex->event_parse_data->identifier);
             lex->sphead->restore_thd_mem_root(YYTHD);
 
             lex->sp_chistics.suid= SP_IS_SUID;//always the definer!