WL#3337 (Event scheduler new architecture)

Cleaned up the code a bit. Fixed few leaks.
This code still does not load events on server startup
from disk. The problem is that there is a need for a THD instance, which
does not exist during server boot. This will be solved soon.
Still Event_timed is used both for the memory queue and for exectution.
This will be changed according to WL#3337 probably in the next commit.


sql/event_data_objects.cc:
  Strip unneeded stuff from class Event_timed
  Event_timed is still used for the queue and execution.
  That will be changed in the next commit.
sql/event_data_objects.h:
  Strip unneeded stuff from class Event_timed
  Event_timed is still used for the queue and execution.
  That will be changed in the next commit.
sql/event_db_repository.cc:
  Cosmetics.
  Add a new method load_named_event_job, to be made complete in the 
  next commit. It will load from disk an instance of Event_job_data to
  be used during execution.
sql/event_db_repository.h:
  find_event does not need MEM_ROOT anymore
  because the memory is allocated on Event's own root.
sql/event_queue.cc:
  Remove dead code.
  Move dumping of the queue to separate method.
  Make critical sections in create_event & update_event
  as small as possible - load the new event outside of the section
  and free the object also outside of it.
sql/event_queue.h:
  init -> init_queue -> easier for ctags
  deinit -> deinit_queue -> easier for ctags
sql/event_scheduler.cc:
  empty this file
sql/event_scheduler.h:
  empty this file
sql/event_scheduler_ng.cc:
  add back DBUG_RETURN(0) in thread handlers.
  We don't stop running events when stopping the scheduler. Therefore
  remove this method now. If it is needed later it can be added back.
sql/event_scheduler_ng.h:
  Remove stop_all_running_threads()
  init -> init_scheduler
  deinit -> deinit_scheduler
  easier for ctags
sql/events.cc:
  Cosmetics
sql/events.h:
  Cosmetics
sql/set_var.cc:
  Remove references to dead code
sql/sql_parse.cc:
  Reorganize a bit.

sql/event_data_objects.cc

@@ -530,18 +530,14 @@ Event_parse_data::init_ends(THD *thd, Item *new_ends)
     Event_timed::Event_timed()
 */
 
-Event_timed::Event_timed():in_spawned_thread(0),locked_by_thread_id(0),
-                           running(0), thread_id(0), status_changed(false),
+Event_timed::Event_timed():status_changed(false),
                            last_executed_changed(false), expression(0),
                            created(0), modified(0),
                            on_completion(Event_timed::ON_COMPLETION_DROP),
                            status(Event_timed::ENABLED), sphead(0),
-                           sql_mode(0), dropped(false),
-                           free_sphead_on_delete(true), flags(0)
+                           sql_mode(0), dropped(false), flags(0)
                 
 {
-  pthread_mutex_init(&this->LOCK_running, MY_MUTEX_INIT_FAST);
-  pthread_cond_init(&this->COND_finished, NULL);
   init();
 }
 
@@ -555,46 +551,8 @@ Event_timed::Event_timed():in_spawned_thread(0),locked_by_thread_id(0),
 
 Event_timed::~Event_timed()
 {    
-  deinit_mutexes();
   free_root(&mem_root, MYF(0));
-
-  if (free_sphead_on_delete)
-    free_sp();
-}
-
-
-/*
-  Destructor
-
-  SYNOPSIS
-    Event_timed::deinit_mutexes()
-*/
-
-void
-Event_timed::deinit_mutexes()
-{
-  pthread_mutex_destroy(&this->LOCK_running);
-  pthread_cond_destroy(&this->COND_finished);
-}
-
-
-/*
-  Checks whether the event is running
-
-  SYNOPSIS
-    Event_timed::is_running()
-*/
-
-bool
-Event_timed::is_running()
-{
-  bool ret;
-
-  VOID(pthread_mutex_lock(&this->LOCK_running));
-  ret= running;
-  VOID(pthread_mutex_unlock(&this->LOCK_running));
-
-  return ret;
+  free_sp();
 }
 
 
@@ -1253,7 +1211,7 @@ Event_timed::update_fields(THD *thd)
   Open_tables_state backup;
   int ret;
 
-  DBUG_ENTER("Event_timed::update_time_fields");
+  DBUG_ENTER("Event_timed::update_fields");
 
   DBUG_PRINT("enter", ("name: %*s", name.length, name.str));
 
@@ -1382,7 +1340,7 @@ Event_timed::get_create_event(THD *thd, String *buf)
   Executes the event (the underlying sp_head object);
 
   SYNOPSIS
-    evex_fill_row()
+    Event_timed::execute()
       thd       THD
       mem_root  If != NULL use it to compile the event on it
 
@@ -1607,149 +1565,6 @@ Event_timed::compile(THD *thd, MEM_ROOT *mem_root)
 }
 
 
-extern pthread_attr_t connection_attrib;
-
-/*
-  Checks whether is possible and forks a thread. Passes self as argument.
-
-  RETURN VALUE
-    EVENT_EXEC_STARTED       OK
-    EVENT_EXEC_ALREADY_EXEC  Thread not forked, already working
-    EVENT_EXEC_CANT_FORK     Unable to spawn thread (error)
-*/
-
-int
-Event_timed::spawn_now(void * (*thread_func)(void*), void *arg)
-{
-  THD *thd= current_thd;
-  int ret= EVENT_EXEC_STARTED;
-  DBUG_ENTER("Event_timed::spawn_now");
-  DBUG_PRINT("info", ("[%s.%s]", dbname.str, name.str));
-
-  VOID(pthread_mutex_lock(&this->LOCK_running));
-
-  DBUG_PRINT("info", ("SCHEDULER: execute_at of %s is %lld", name.str,
-             TIME_to_ulonglong_datetime(&execute_at)));
-  mark_last_executed(thd);
-  if (compute_next_execution_time())
-  {
-    sql_print_error("SCHEDULER: Error while computing time of %s.%s . "
-                    "Disabling after execution.", dbname.str, name.str);
-    status= DISABLED;
-  }
-  DBUG_PRINT("evex manager", ("[%10s] next exec at [%llu]", name.str,
-             TIME_to_ulonglong_datetime(&execute_at)));
-   /*
-    1. For one-time event : year is > 0 and expression is 0
-    2. For recurring, expression is != -=> check execute_at_null in this case
-  */
-  if ((execute_at.year && !expression) || execute_at_null)
-  {
-    sql_print_information("SCHEDULER: [%s.%s of %s] no more executions "
-                          "after this one", dbname.str, name.str,
-                          definer.str);
-    flags |= EVENT_EXEC_NO_MORE | EVENT_FREE_WHEN_FINISHED;
-  }
-
-  update_fields(thd);
-
-  if (!in_spawned_thread)
-  {
-    pthread_t th;
-    in_spawned_thread= true;
-
-    if (pthread_create(&th, &connection_attrib, thread_func, arg))
-    {
-      DBUG_PRINT("info", ("problem while spawning thread"));
-      ret= EVENT_EXEC_CANT_FORK;
-      in_spawned_thread= false;
-    }
-  }
-  else
-  {
-    DBUG_PRINT("info", ("already in spawned thread. skipping"));
-    ret= EVENT_EXEC_ALREADY_EXEC;
-  }
-  VOID(pthread_mutex_unlock(&this->LOCK_running));
-
-  DBUG_RETURN(ret);  
-}
-
-
-bool
-Event_timed::spawn_thread_finish(THD *thd)
-{
-  bool should_free;
-  DBUG_ENTER("Event_timed::spawn_thread_finish");
-  VOID(pthread_mutex_lock(&LOCK_running));
-  in_spawned_thread= false;
-  DBUG_PRINT("info", ("Sending COND_finished for thread %d", thread_id));
-  thread_id= 0;
-  if (dropped)
-    drop(thd);
-  pthread_cond_broadcast(&COND_finished);
-  should_free= flags & EVENT_FREE_WHEN_FINISHED;
-  VOID(pthread_mutex_unlock(&LOCK_running));
-  DBUG_RETURN(should_free);
-}
-
-
-/*
-  Kills a running event
-  SYNOPSIS
-    Event_timed::kill_thread()
-    
-  RETURN VALUE 
-     0    OK
-    -1    EVEX_CANT_KILL
-    !0   Error 
-*/
-
-int
-Event_timed::kill_thread(THD *thd)
-{
-  int ret= 0;
-  DBUG_ENTER("Event_timed::kill_thread");
-  pthread_mutex_lock(&LOCK_running);
-  DBUG_PRINT("info", ("thread_id=%lu", thread_id));
-
-  if (thread_id == thd->thread_id)
-  {
-    /*
-      We don't kill ourselves in cases like :
-      alter event e_43 do alter event e_43 do set @a = 4 because
-      we will never receive COND_finished.
-    */
-    DBUG_PRINT("info", ("It's not safe to kill ourselves in self altering queries"));
-    ret= EVEX_CANT_KILL;
-  }
-  else if (thread_id && !(ret= kill_one_thread(thd, thread_id, false)))
-  {
-    thd->enter_cond(&COND_finished, &LOCK_running, "Waiting for finished");
-    DBUG_PRINT("info", ("Waiting for COND_finished from thread %d", thread_id));
-    while (thread_id)
-      pthread_cond_wait(&COND_finished, &LOCK_running);
-
-    DBUG_PRINT("info", ("Got COND_finished"));
-    /* This will implicitly unlock LOCK_running. Hence we return before that */
-    thd->exit_cond("");
-
-    DBUG_RETURN(0);
-  }
-  else if (!thread_id && in_spawned_thread)
-  {
-    /*
-      Because the manager thread waits for the forked thread to update thread_id
-      this situation is impossible.
-    */
-    DBUG_ASSERT(0);
-  }
-  pthread_mutex_unlock(&LOCK_running);
-  DBUG_PRINT("exit", ("%d", ret));
-  DBUG_RETURN(ret);
-}
-
-
 /*
   Checks whether two events have the same name
 

sql/event_data_objects.h

@@ -63,12 +63,6 @@ class Event_timed
 {
   Event_timed(const Event_timed &);	/* Prevent use of these */
   void operator=(Event_timed &);
-  my_bool in_spawned_thread;
-  ulong locked_by_thread_id;
-  my_bool running;
-  ulong thread_id;
-  pthread_mutex_t LOCK_running;
-  pthread_cond_t COND_finished;
 
   bool status_changed;
   bool last_executed_changed;
@@ -118,7 +112,6 @@ class Event_timed
   ulong sql_mode;
 
   bool dropped;
-  bool free_sphead_on_delete;
   uint flags;//all kind of purposes
 
   static void *operator new(size_t size)
@@ -146,9 +139,6 @@ class Event_timed
   void
   init();
 
-  void
-  deinit_mutexes();
-
   int
   load_from_row(TABLE *table);
 
@@ -172,24 +162,9 @@ class Event_timed
 
   int
   compile(THD *thd, MEM_ROOT *mem_root);
-
-  bool
-  is_running();
-
-  int
-  spawn_now(void * (*thread_func)(void*), void *arg);
-  
-  bool
-  spawn_thread_finish(THD *thd);
   
   void
   free_sp();
-
-  int
-  kill_thread(THD *thd);
-
-  void
-  set_thread_id(ulong tid) { thread_id= tid; }
 };
 
 

sql/event_db_repository.cc

@@ -207,7 +207,7 @@ evex_fill_row(THD *thd, TABLE *table, Event_parse_data *et, my_bool is_update)
       table->field[ET_FIELD_STARTS]->set_notnull();
       table->field[ET_FIELD_STARTS]->
                             store_time(&et->starts, MYSQL_TIMESTAMP_DATETIME);
-    }	   
+    }
 
     if (!et->ends_null)
     {
@@ -374,8 +374,7 @@ Event_db_repository::table_scan_all_for_i_s(THD *thd, TABLE *schema_table,
     ret= read_record_info.read_record(&read_record_info);
     if (ret == 0)
       ret= copy_event_to_schema_table(thd, schema_table, event_table);
-  }
-  while (ret == 0);
+  } while (ret == 0);
 
   DBUG_PRINT("info", ("Scan finished. ret=%d", ret));
   end_read_record(&read_record_info);
@@ -464,8 +463,7 @@ Event_db_repository::fill_schema_events(THD *thd, TABLE_LIST *tables, char *db)
 
 int
 Event_db_repository::find_event(THD *thd, LEX_STRING dbname, LEX_STRING name,
-                                Event_timed **ett,
-                                TABLE *tbl, MEM_ROOT *root)
+                                Event_timed **ett, TABLE *tbl)
 {
   TABLE *table;
   int ret;
@@ -505,7 +503,7 @@ Event_db_repository::find_event(THD *thd, LEX_STRING dbname, LEX_STRING name,
   if (ret)
   {
     delete et;
-    et= 0;
+    et= NULL;
   }
   /* don't close the table if we haven't opened it ourselves */
   if (!tbl && table)
@@ -518,7 +516,6 @@ Event_db_repository::find_event(THD *thd, LEX_STRING dbname, LEX_STRING name,
 int
 Event_db_repository::init_repository()
 {
-  init_alloc_root(&repo_root, MEM_ROOT_BLOCK_SIZE, MEM_ROOT_PREALLOC);
   return 0;
 }
 
@@ -526,7 +523,6 @@ Event_db_repository::init_repository()
 void
 Event_db_repository::deinit_repository()
 {
-  free_root(&repo_root, MYF(0));
 }
 
 
@@ -731,7 +727,8 @@ Event_db_repository::create_event(THD *thd, Event_parse_data *parse_data,
              parse_data->name.str));
 
   DBUG_PRINT("info", ("check existance of an event with the same name"));
-  if (!evex_db_find_event_by_name(thd, parse_data->dbname, parse_data->name, table))
+  if (!evex_db_find_event_by_name(thd, parse_data->dbname,
+                                  parse_data->name, table))
   {
     if (create_if_not)
     {
@@ -1026,14 +1023,12 @@ Event_db_repository::find_event_by_name(THD *thd, LEX_STRING db,
   */
   if (db.length > table->field[ET_FIELD_DB]->field_length ||
       name.length > table->field[ET_FIELD_NAME]->field_length)
-      
     DBUG_RETURN(EVEX_KEY_NOT_FOUND);
 
   table->field[ET_FIELD_DB]->store(db.str, db.length, &my_charset_bin);
   table->field[ET_FIELD_NAME]->store(name.str, name.length, &my_charset_bin);
 
-  key_copy(key, table->record[0], table->key_info,
-           table->key_info->key_length);
+  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,
@@ -1125,7 +1120,7 @@ Event_db_repository::drop_events_by_field(THD *thd,
   the table, compiles and inserts it into the cache.
 
   SYNOPSIS
-    Event_scheduler::load_named_event()
+    Event_db_repository::load_named_event_timed()
       thd      THD
       etn      The name of the event to load and compile on scheduler's root
       etn_new  The loaded event
@@ -1136,20 +1131,21 @@ Event_db_repository::drop_events_by_field(THD *thd,
 */
 
 int
-Event_db_repository::load_named_event(THD *thd, LEX_STRING dbname, LEX_STRING name,
-                                      Event_timed **etn_new)
+Event_db_repository::load_named_event_timed(THD *thd, LEX_STRING dbname,
+                                            LEX_STRING name,
+                                            Event_timed **etn_new)
 {
   int ret= 0;
   MEM_ROOT *tmp_mem_root;
   Event_timed *et_loaded= NULL;
   Open_tables_state backup;
 
-  DBUG_ENTER("Event_db_repository::load_named_event");
+  DBUG_ENTER("Event_db_repository::load_named_event_timed");
   DBUG_PRINT("enter",("thd=%p name:%*s",thd, name.length, name.str));
 
   thd->reset_n_backup_open_tables_state(&backup);
   /* No need to use my_error() here because db_find_event() has done it */
-  ret= find_event(thd, dbname, name, &et_loaded, NULL, &repo_root);
+  ret= find_event(thd, dbname, name, &et_loaded, NULL);
   thd->restore_backup_open_tables_state(&backup);
   /* In this case no memory was allocated so we don't need to clean */
   if (ret)
@@ -1171,3 +1167,57 @@ Event_db_repository::load_named_event(THD *thd, LEX_STRING dbname, LEX_STRING na
 
   DBUG_RETURN(OP_OK);
 }
+
+
+/*
+  Looks for a named event in mysql.event and then loads it from
+  the table, compiles and inserts it into the cache.
+
+  SYNOPSIS
+    Event_db_repository::load_named_event_job()
+      thd      THD
+      etn      The name of the event to load and compile on scheduler's root
+      etn_new  The loaded event
+
+  RETURN VALUE
+    NULL       Error during compile or the event is non-enabled.
+    otherwise  Address
+*/
+
+int
+Event_db_repository::load_named_event_job(THD *thd, LEX_STRING dbname,
+                                          LEX_STRING name,
+                                          Event_job_data **etn_new)
+{
+  int ret= 0;
+  MEM_ROOT *tmp_mem_root;
+  Event_timed *et_loaded= NULL;
+  Open_tables_state backup;
+
+  DBUG_ENTER("Event_db_repository::load_named_event_job");
+  DBUG_PRINT("enter",("thd=%p name:%*s",thd, name.length, name.str));
+#if 0
+  thd->reset_n_backup_open_tables_state(&backup);
+  /* No need to use my_error() here because db_find_event() has done it */
+  ret= find_event(thd, dbname, name, &et_loaded, NULL);
+  thd->restore_backup_open_tables_state(&backup);
+  /* In this case no memory was allocated so we don't need to clean */
+  if (ret)
+    DBUG_RETURN(OP_LOAD_ERROR);
+
+  if (et_loaded->status != Event_timed::ENABLED)
+  {
+    /*
+      We don't load non-enabled events.
+      In db_find_event() `et_new` was allocated on the heap and not on
+      scheduler_root therefore we delete it here.
+    */
+    delete et_loaded;
+    DBUG_RETURN(OP_DISABLED_EVENT);
+  }
+
+  et_loaded->compute_next_execution_time();
+  *etn_new= et_loaded;
+#endif
+  DBUG_RETURN(OP_OK);
+}

sql/event_db_repository.h

@@ -56,6 +56,7 @@ fill_schema_events(THD *thd, TABLE_LIST *tables, COND * /* cond */);
 class Event_timed;
 class Event_parse_data;
 class Event_queue_element;
+class Event_job_data;
 
 class Event_db_repository
 {
@@ -88,10 +89,15 @@ class Event_db_repository
 
   int
   find_event(THD *thd, LEX_STRING dbname, LEX_STRING name, Event_timed **ett,
-             TABLE *tbl, MEM_ROOT *root);
+             TABLE *tbl);
 
   int
-  load_named_event(THD *thd, LEX_STRING dbname, LEX_STRING name, Event_timed **etn_new);
+  load_named_event_timed(THD *thd, LEX_STRING dbname, LEX_STRING name,
+                         Event_timed **etn_new);
+
+  int
+  load_named_event_job(THD *thd, LEX_STRING dbname, LEX_STRING name,
+                       Event_job_data **etn_new);
 
   int
   find_event_by_name(THD *thd, LEX_STRING db, LEX_STRING name, TABLE *table);
@@ -116,8 +122,6 @@ class Event_db_repository
   static bool
   check_system_tables(THD *thd);
 
-  MEM_ROOT repo_root;
-
   /* Prevent use of these */
   Event_db_repository(const Event_db_repository &);
   void operator=(Event_db_repository &);

sql/event_queue.h

@@ -38,15 +38,15 @@ class Event_queue
   deinit_mutexes();
   
   bool
-  init(Event_db_repository *db_repo);
+  init_queue(Event_db_repository *db_repo, Event_scheduler_ng *sched);
   
   void
-  deinit();
+  deinit_queue();
 
   /* Methods for queue management follow */
 
   int
-  create_event(THD *thd, Event_parse_data *et, bool check_existence);
+  create_event(THD *thd, Event_parse_data *et);
 
   int
   update_event(THD *thd, Event_parse_data *et, LEX_STRING *new_schema,
@@ -55,13 +55,9 @@ class Event_queue
   bool
   drop_event(THD *thd, sp_name *name);
 
-  int
+  void
   drop_schema_events(THD *thd, LEX_STRING schema);
 
-  int
-  drop_user_events(THD *thd, LEX_STRING *definer)
-  { DBUG_ASSERT(0); return 0;}
-
   uint
   events_count();
 
@@ -89,7 +85,7 @@ class Event_queue
   void
   top_changed();
 
-///////////////protected
+protected:
   Event_timed *
   find_event(LEX_STRING db, LEX_STRING name, bool remove_from_q);
 
@@ -105,8 +101,6 @@ class Event_queue
 
   Event_db_repository *db_repository;
 
-  /* The sorted queue with the Event_timed objects */
-  QUEUE queue;
   
   uint mutex_last_locked_at_line;
   uint mutex_last_unlocked_at_line;
@@ -122,10 +116,16 @@ class Event_queue
   unlock_data(const char *func, uint line);
 
   void
-  on_queue_change();
-  
+  notify_observers();
+
+  void
+  dbug_dump_queue(time_t now);
+
   Event_scheduler_ng *scheduler;
-protected:
+
+//public:
+  /* The sorted queue with the Event_timed objects */
+  QUEUE queue;
 
 };
 

sql/event_scheduler.h

@@ -16,191 +16,4 @@
    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_timed;
-class Event_db_repository;
-class Event_queue;
-
-class THD;
-
-int
-events_init();
-
-void
-events_shutdown();
-
-#include "event_queue.h"
-#include "event_scheduler.h"
-
-class Event_scheduler
-{
-public:
-  enum enum_state
-  {
-    UNINITIALIZED= 0,
-    INITIALIZED,
-    COMMENCING,
-    CANTSTART,
-    RUNNING,
-    SUSPENDED,
-    IN_SHUTDOWN
-  };
-
-  enum enum_suspend_or_resume
-  {
-    SUSPEND= 1,
-    RESUME= 2
-  };
-
-  /* This is the current status of the life-cycle of the scheduler. */
-  enum enum_state state;
-
-
-  static void
-  create_instance(Event_queue *queue);
-
-  static void
-  init_mutexes();
-  
-  static void
-  destroy_mutexes();
-
-  /* Singleton access */
-  static Event_scheduler*
-  get_instance();
-
-  bool 
-  init(Event_db_repository *db_repo);
-
-  void
-  destroy();
-
-  /* State changing methods follow */
-
-  bool
-  start();
-
-  int
-  stop();
-
-  bool
-  start_suspended();
-
-  /*
-    Need to be public because has to be called from the function 
-    passed to pthread_create.
-  */
-  bool
-  run(THD *thd);
-
-  int
-  suspend_or_resume(enum enum_suspend_or_resume action);
-/*  
-  static void
-  init_mutexes();
-  
-  static void
-  destroy_mutexes();
-*/
-  void
-  report_error_during_start();
-
-  /* Information retrieving methods follow */
-
-  enum enum_state
-  get_state();
-
-  bool
-  initialized();
-
-  static int
-  dump_internal_status(THD *thd);
-
-  /* helper functions for working with mutexes & conditionals */
-  void
-  lock_data(const char *func, uint line);
-
-  void
-  unlock_data(const char *func, uint line);
-
-  int
-  cond_wait(int cond, pthread_mutex_t *mutex);
-
-  void
-  queue_changed();
-
-  Event_queue *event_queue;
-
-protected:
-
-  uint
-  workers_count();
-
-  /* helper functions */
-  bool
-  execute_top(THD *thd, Event_timed *et);
-
-  void
-  clean_memory(THD *thd);
-  
-  void
-  stop_all_running_events(THD *thd);
-
-
-  bool
-  check_n_suspend_if_needed(THD *thd);
-
-  bool
-  check_n_wait_for_non_empty_queue(THD *thd);
-
-  /* Singleton DP is used */
-  Event_scheduler();
-  
-  pthread_mutex_t LOCK_data;
-  pthread_mutex_t *LOCK_scheduler_data;
-
-  /* The MEM_ROOT of the object */
-  MEM_ROOT scheduler_root;
-
-  /* Set to start the scheduler in suspended state */
-  bool start_scheduler_suspended;
-
-  /*
-    Holds the thread id of the executor thread or 0 if the executor is not
-    running. It is used by ::shutdown() to know which thread to kill with
-    kill_one_thread(). The latter wake ups a thread if it is waiting on a
-    conditional variable and sets thd->killed to non-zero.
-  */
-  ulong thread_id;
-
-  enum enum_cond_vars
-  {
-    COND_NONE= -1,
-    COND_new_work= 0,
-    COND_started_or_stopped,
-    COND_suspend_or_resume,
-    /* Must be always last */
-    COND_LAST
-  };
-
-  uint mutex_last_locked_at_line;
-  uint mutex_last_unlocked_at_line;
-  const char* mutex_last_locked_in_func;
-  const char* mutex_last_unlocked_in_func;
-  int cond_waiting_on;
-  bool mutex_scheduler_data_locked;
-
-  static const char * const cond_vars_names[COND_LAST];
-
-  pthread_cond_t cond_vars[COND_LAST];
-
-  /* Singleton instance */
-  static Event_scheduler *singleton;
-
-private:
-  /* Prevent use of these */
-  Event_scheduler(const Event_scheduler &);
-  void operator=(Event_scheduler &);
-};
-
 #endif /* _EVENT_SCHEDULER_H_ */

sql/event_scheduler_ng.cc

@@ -212,6 +212,7 @@ event_scheduler_ng_thread(void *arg)
   pthread_mutex_unlock(&LOCK_thread_count);
 
   my_thread_end();
+  DBUG_RETURN(0);                               // Against gcc warnings
 }
 
 
@@ -296,26 +297,22 @@ event_worker_ng_thread(void *arg)
   delete event;
 
   my_thread_end();
+  DBUG_RETURN(0);                               // Against gcc warnings
 }
 
 
 bool
-Event_scheduler_ng::init(Event_queue *q)
+Event_scheduler_ng::init_scheduler(Event_queue *q)
 {
   thread_id= 0;
   state= INITIALIZED;
-  /* init memory root */
-
   queue= q;
-
   return FALSE;
 }
 
 
 void
-Event_scheduler_ng::deinit()
-{
-}
+Event_scheduler_ng::deinit_scheduler() {}
 
 
 void
@@ -477,7 +474,6 @@ Event_scheduler_ng::run(THD *thd)
   pthread_cond_signal(&COND_state);
 error:
   state= INITIALIZED;
-  stop_all_running_events(thd);
   UNLOCK_SCHEDULER_DATA();
   sql_print_information("SCHEDULER: Stopped");
 
@@ -560,98 +556,18 @@ Event_scheduler_ng::workers_count()
 }
 
 
-/*
-  Stops all running events
-
-  SYNOPSIS
-    Event_scheduler::stop_all_running_events()
-      thd  Thread
-
-  NOTE
-    LOCK_scheduler data must be acquired prior to call to this method
-*/
-
-void
-Event_scheduler_ng::stop_all_running_events(THD *thd)
-{
-  CHARSET_INFO *scs= system_charset_info;
-  uint i;
-  DYNAMIC_ARRAY running_threads;
-  THD *tmp;
-  DBUG_ENTER("Event_scheduler::stop_all_running_events");
-  DBUG_PRINT("enter", ("workers_count=%d", workers_count()));
-
-  my_init_dynamic_array(&running_threads, sizeof(ulong), 10, 10);
-
-  bool had_super= FALSE;
-  VOID(pthread_mutex_lock(&LOCK_thread_count)); // For unlink from list
-  I_List_iterator<THD> it(threads);
-  while ((tmp=it++))
-  {
-    if (tmp->command == COM_DAEMON)
-      continue;
-    if (tmp->system_thread == SYSTEM_THREAD_EVENT_WORKER)
-      push_dynamic(&running_threads, (gptr) &tmp->thread_id);
-  }
-  VOID(pthread_mutex_unlock(&LOCK_thread_count));
-
-  /* We need temporarily SUPER_ACL to be able to kill our offsprings */
-  if (!(thd->security_ctx->master_access & SUPER_ACL))
-    thd->security_ctx->master_access|= SUPER_ACL;
-  else
-    had_super= TRUE;
-
-  char tmp_buff[10*STRING_BUFFER_USUAL_SIZE];
-  char int_buff[STRING_BUFFER_USUAL_SIZE];
-  String tmp_string(tmp_buff, sizeof(tmp_buff), scs);
-  String int_string(int_buff, sizeof(int_buff), scs);
-  tmp_string.length(0);
-
-  for (i= 0; i < running_threads.elements; ++i)
-  {
-    int ret;
-    ulong thd_id= *dynamic_element(&running_threads, i, ulong*);
-
-    int_string.set((longlong) thd_id,scs);
-    tmp_string.append(int_string);
-    if (i < running_threads.elements - 1)
-      tmp_string.append(' ');
-
-    if ((ret= kill_one_thread(thd, thd_id, FALSE)))
-    {
-      sql_print_error("SCHEDULER: Error killing %lu code=%d", thd_id, ret);
-      break;
-    }
-  }
-  if (running_threads.elements)
-    sql_print_information("SCHEDULER: Killing workers :%s", tmp_string.c_ptr());
-
-  if (!had_super)
-    thd->security_ctx->master_access &= ~SUPER_ACL;
-
-  delete_dynamic(&running_threads);
-
-  sql_print_information("SCHEDULER: Waiting for worker threads to finish");
-
-  while (workers_count())
-    my_sleep(100000);
-
-  DBUG_VOID_RETURN;
-}
-
-
 /*
   Signals the main scheduler thread that the queue has changed
   its state.
 
   SYNOPSIS
-    Event_scheduler::queue_changed()
+    Event_scheduler_ng::queue_changed()
 */
 
 void
 Event_scheduler_ng::queue_changed()
 {
-  DBUG_ENTER("Event_scheduler::queue_changed");
+  DBUG_ENTER("Event_scheduler_ng::queue_changed");
   DBUG_PRINT("info", ("Sending COND_state"));
   pthread_cond_signal(&COND_state);
   DBUG_VOID_RETURN;
@@ -662,8 +578,7 @@ void
 Event_scheduler_ng::lock_data(const char *func, uint line)
 {
   DBUG_ENTER("Event_scheduler_ng::lock_mutex");
-  DBUG_PRINT("enter", ("mutex_lock=%p func=%s line=%u",
-             &LOCK_scheduler_state, func, line));
+  DBUG_PRINT("enter", ("func=%s line=%u", func, line));
   pthread_mutex_lock(&LOCK_scheduler_state);
   mutex_last_locked_in_func= func;
   mutex_last_locked_at_line= line;
@@ -675,9 +590,8 @@ Event_scheduler_ng::lock_data(const char *func, uint line)
 void
 Event_scheduler_ng::unlock_data(const char *func, uint line)
 {
-  DBUG_ENTER("Event_scheduler_ng::UNLOCK_mutex");
-  DBUG_PRINT("enter", ("mutex_unlock=%p func=%s line=%u",
-             &LOCK_scheduler_state, func, line));
+  DBUG_ENTER("Event_scheduler_ng::unlock_mutex");
+  DBUG_PRINT("enter", ("func=%s line=%u", func, line));
   mutex_last_unlocked_at_line= line;
   mutex_scheduler_data_locked= FALSE;
   mutex_last_unlocked_in_func= func;

sql/event_scheduler_ng.h

@@ -48,10 +48,10 @@ class Event_scheduler_ng
   run(THD *thd);
   
   bool 
-  init(Event_queue *queue);
+  init_scheduler(Event_queue *queue);
 
   void
-  deinit();
+  deinit_scheduler();
 
   void
   init_mutexes();
@@ -78,9 +78,6 @@ class Event_scheduler_ng
   bool
   execute_top(THD *thd, Event_timed *job_data);
 
-  void
-  stop_all_running_events(THD *thd);
-
   /* helper functions for working with mutexes & conditionals */
   void
   lock_data(const char *func, uint line);
@@ -104,7 +101,6 @@ class Event_scheduler_ng
   pthread_cond_t COND_state;
   
   Event_queue *queue;
-  Event_db_repository *db_repository;
 
   uint mutex_last_locked_at_line;
   uint mutex_last_unlocked_at_line;

sql/events.cc

@@ -17,10 +17,10 @@
 #include "mysql_priv.h"
 #include "events.h"
 #include "event_data_objects.h"
-#include "event_scheduler.h"
 #include "event_db_repository.h"
-#include "sp_head.h"
+#include "event_queue.h"
 #include "event_scheduler_ng.h"
+#include "sp_head.h"
 
 /*
  TODO list :
@@ -48,6 +48,21 @@
 */
 
 
+/*
+  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.
+*/
+
 const char *event_scheduler_state_names[]=
     { "OFF", "0", "ON", "1", "SUSPEND", "2", NullS };
 
@@ -284,17 +299,15 @@ Events::open_event_table(THD *thd, enum thr_lock_type lock_type,
 */
 
 int
-Events::create_event(THD *thd, Event_parse_data *parse_data, uint create_options,
+Events::create_event(THD *thd, Event_parse_data *parse_data, bool if_not_exists,
                      uint *rows_affected)
 {
   int ret;
   DBUG_ENTER("Events::create_event");
-  if (!(ret= db_repository->
-                 create_event(thd, parse_data,
-                              create_options & HA_LEX_CREATE_IF_NOT_EXISTS,
-                              rows_affected)))
+  if (!(ret= db_repository->create_event(thd, parse_data, if_not_exists,
+                                         rows_affected)))
   {
-    if ((ret= event_queue->create_event(thd, parse_data, true)))
+    if ((ret= event_queue->create_event(thd, parse_data)))
       my_error(ER_EVENT_MODIFY_QUEUE_ERROR, MYF(0), ret);
   }
   /* No need to close the table, it will be closed in sql_parse::do_command */
@@ -350,9 +363,10 @@ Events::update_event(THD *thd, Event_parse_data *parse_data, sp_name *new_name,
   SYNOPSIS
     Events::drop_event()
       thd             THD
-      name            event's name
-      drop_if_exists  if set and the event not existing => warning onto the stack
-      rows_affected   affected number of rows is returned heres
+      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
 
   RETURN VALUE
      0  OK
@@ -360,15 +374,13 @@ Events::update_event(THD *thd, Event_parse_data *parse_data, sp_name *new_name,
 */
 
 int
-Events::drop_event(THD *thd, sp_name *name, bool drop_if_exists,
-                   uint *rows_affected)
+Events::drop_event(THD *thd, sp_name *name, bool if_exists, uint *rows_affected)
 {
   int ret;
-
   DBUG_ENTER("Events::drop_event");
 
-  if (!(ret= db_repository->drop_event(thd, name->m_db, name->m_name,
-                                      drop_if_exists, rows_affected)))
+  if (!(ret= db_repository->drop_event(thd, name->m_db, name->m_name, if_exists,
+                                       rows_affected)))
   {
     if ((ret= event_queue->drop_event(thd, name)))
       my_error(ER_EVENT_MODIFY_QUEUE_ERROR, MYF(0), ret);
@@ -401,7 +413,7 @@ Events::show_create_event(THD *thd, sp_name *spn)
   DBUG_PRINT("enter", ("name: %*s", spn->m_name.length, spn->m_name.str));
 
   thd->reset_n_backup_open_tables_state(&backup);
-  ret= db_repository->find_event(thd, spn->m_db, spn->m_name, &et, NULL, thd->mem_root);
+  ret= db_repository->find_event(thd, spn->m_db, spn->m_name, &et, NULL);
   thd->restore_backup_open_tables_state(&backup);
 
   if (!ret)
@@ -472,7 +484,7 @@ Events::drop_schema_events(THD *thd, char *db)
   DBUG_ENTER("evex_drop_db_events");  
   DBUG_PRINT("enter", ("dropping events from %s", db));
 
-  ret= event_queue->drop_schema_events(thd, db_lex);
+  event_queue->drop_schema_events(thd, db_lex);
   ret= db_repository->drop_schema_events(thd, db_lex);
 
   DBUG_RETURN(ret);
@@ -500,9 +512,8 @@ Events::init()
   Event_db_repository *db_repo;
   DBUG_ENTER("Events::init");
   db_repository->init_repository();
-  event_queue->init(db_repository);
-  event_queue->scheduler= scheduler_ng;
-  scheduler_ng->init(event_queue);
+  event_queue->init_queue(db_repository, scheduler_ng);
+  scheduler_ng->init_scheduler(event_queue);
 
   /* it should be an assignment! */
   if (opt_event_scheduler)
@@ -532,8 +543,9 @@ Events::deinit()
   DBUG_ENTER("Events::deinit");
 
   scheduler_ng->stop();
-  scheduler_ng->deinit();
-  event_queue->deinit();
+  scheduler_ng->deinit_scheduler();
+
+  event_queue->deinit_queue();
   db_repository->deinit_repository();
 
   DBUG_VOID_RETURN;

sql/events.h

@@ -75,7 +75,7 @@ class Events
   get_instance();
 
   int
-  create_event(THD *thd, Event_parse_data *parse_data, uint create_options,
+  create_event(THD *thd, Event_parse_data *parse_data, bool if_exists,
                uint *rows_affected);
 
   int
@@ -83,7 +83,7 @@ class Events
                uint *rows_affected);
 
   int
-  drop_event(THD *thd, sp_name *name, bool drop_if_exists, uint *rows_affected);
+  drop_event(THD *thd, sp_name *name, bool if_exists, uint *rows_affected);
 
   int
   drop_schema_events(THD *thd, char *db);
@@ -105,9 +105,9 @@ class Events
   int
   dump_internal_status(THD *thd);
 
+  Event_queue         *event_queue;
+  Event_scheduler_ng  *scheduler_ng;
   Event_db_repository *db_repository;
-  Event_queue *event_queue;
-  Event_scheduler_ng *scheduler_ng;
 
 private:
   /* Singleton DP is used */

sql/set_var.cc

@@ -57,7 +57,6 @@
 #include <myisam.h>
 #include <my_dir.h>
 
-#include "event_scheduler.h"
 #include "events.h"
 
 /* WITH_BERKELEY_STORAGE_ENGINE */
@@ -3894,7 +3893,6 @@ bool
 sys_var_event_scheduler::update(THD *thd, set_var *var)
 {
   int res;
-  Event_scheduler *scheduler= Event_scheduler::get_instance();
   /* here start the thread if not running. */
   DBUG_ENTER("sys_var_event_scheduler::update");
   if (Events::opt_event_scheduler == 0)
@@ -3927,8 +3925,6 @@ sys_var_event_scheduler::update(THD *thd, set_var *var)
 byte *sys_var_event_scheduler::value_ptr(THD *thd, enum_var_type type,
                                          LEX_STRING *base)
 {
-  Event_scheduler *scheduler= Event_scheduler::get_instance();
-
   if (Events::opt_event_scheduler == 0)
     thd->sys_var_tmp.long_value= 0;
   else if (Events::get_instance()->is_started())

sql/sql_parse.cc

@@ -3832,25 +3832,26 @@ mysql_execute_command(THD *thd)
   case SQLCOM_CREATE_EVENT:
   case SQLCOM_ALTER_EVENT:
   {
-    uint rows_affected= 1;
+    uint affected= 1;
     DBUG_ASSERT(lex->event_parse_data);
     switch (lex->sql_command) {
     case SQLCOM_CREATE_EVENT:
-      res= Events::get_instance()->create_event(thd, lex->event_parse_data,
-                                               (uint) lex->create_info.options,
-                                               &rows_affected);
+      res= Events::get_instance()->
+            create_event(thd, lex->event_parse_data,
+                         lex->create_info.options & HA_LEX_CREATE_IF_NOT_EXISTS,
+                         &affected);
       break;
     case SQLCOM_ALTER_EVENT:
-      res= Events::get_instance()->update_event(thd, lex->event_parse_data,
-                                                  lex->spname, &rows_affected);
+      res= Events::get_instance()->
+             update_event(thd, lex->event_parse_data, lex->spname, &affected);
       break;
     default:;
     }
-    DBUG_PRINT("info", ("CREATE/ALTER/DROP returned error code=%d af_rows=%d",
-               res, rows_affected));
+    DBUG_PRINT("info",("DDL error code=%d affected=%d", res, affected));
     if (!res)
-      send_ok(thd, rows_affected);
+      send_ok(thd, affected);
 
+    /* Don't do it, if we are inside a SP */
     if (!thd->spcont)
     {
       delete lex->sphead;
@@ -3867,8 +3868,7 @@ mysql_execute_command(THD *thd)
     if (! lex->spname->m_db.str)
     {
       my_message(ER_NO_DB_ERROR, ER(ER_NO_DB_ERROR), MYF(0));
-      res= true;
-      break;
+      goto error;
     }
     if (check_access(thd, EVENT_ACL, lex->spname->m_db.str, 0, 0, 0,
                      is_schema_db(lex->spname->m_db.str)))
@@ -3885,11 +3885,10 @@ mysql_execute_command(THD *thd)
       res= Events::get_instance()->show_create_event(thd, lex->spname);
     else
     {
-      uint rows_affected= 1;
-      if (!(res= Events::get_instance()->drop_event(thd, lex->spname,
-                                                    lex->drop_if_exists,
-                                                    &rows_affected)))
-        send_ok(thd, rows_affected);     
+      uint affected= 1;
+      if (!(res= Events::get_instance()->
+                  drop_event(thd, lex->spname, lex->drop_if_exists, &affected)))
+        send_ok(thd, affected);     
     }
     break;
   }