fix for bug #17494 (The algorithm for calculating execution times is not fully correct)

This also should fix 17493 and 17346, and probably 16397 (not tested).
WL#1034 (Internal CRON)
(post-review commit)

mysql-test/r/events.result

@@ -106,7 +106,6 @@ drop event if exists event3;
 Warnings:
 Note	1305	Event event3 does not exist
 create event event3 on schedule every 50 + 10 minute starts date_add("20100101", interval 5 minute) ends date_add("20151010", interval 5 day) comment "portokala_comment" DO insert into t_event3 values (unix_timestamp(), rand());
-set max_allowed_packet=128000000;
 select count(*) from t_event3;
 count(*)
 0
@@ -232,6 +231,9 @@ Db	Name	Definer	Type	Execute at	Interval value	Interval field	Starts	Ends	Status
 events_test	intact_check	root@localhost	RECURRING	NULL	10	HOUR	#	#	ENABLED
 CREATE TABLE event_like LIKE mysql.event;
 INSERT INTO event_like SELECT * FROM mysql.event;
+ALTER TABLE mysql.event MODIFY db char(64) character set cp1251 default '';
+SELECT event_name FROM INFORMATION_SCHEMA.EVENTS;
+ERROR HY000: Cannot load from mysql.event. Table probably corrupted. See error log.
 ALTER TABLE mysql.event MODIFY db char(20) character set utf8 collate utf8_bin default '';
 SHOW CREATE TABLE mysql.event;
 Table	Create Table
@@ -260,11 +262,10 @@ ALTER TABLE mysql.event MODIFY db char(64) character set utf8 collate utf8_bin d
 "This should work"
 SHOW EVENTS;
 Db	Name	Definer	Type	Execute at	Interval value	Interval field	Starts	Ends	Status
-events_test	intact_check	root@localhost	RECURRING	NULL	10	HOUR	#	#	ENABLED
-ALTER TABLE mysql.event MODIFY db char(64) character set cp1251 default '';
-SELECT event_name FROM INFORMATION_SCHEMA.EVENTS;
-ERROR HY000: Cannot load from mysql.event. Table probably corrupted. See error log.
+events_test                                                 	intact_check	root@localhost	RECURRING	NULL	10	HOUR	#	#	ENABLED
 ALTER TABLE mysql.event MODIFY db varchar(64) character set utf8 collate utf8_bin default '';
+Warnings:
+Warning	1265	Data truncated for column 'db' at row 1
 SELECT event_name FROM INFORMATION_SCHEMA.EVENTS;
 ERROR HY000: Cannot load from mysql.event. Table probably corrupted. See error log.
 ALTER TABLE mysql.event DROP comment, DROP starts;

mysql-test/r/events_scheduling.result

+CREATE DATABASE IF NOT EXISTS events_test;
+USE events_test;
+CREATE TABLE table_1(a int);
+CREATE TABLE table_2(a int);
+CREATE TABLE table_3(a int);
+CREATE TABLE table_4(a int);
+SET GLOBAL event_scheduler=1;
+CREATE EVENT two_sec ON SCHEDULE EVERY 2 SECOND DO INSERT INTO table_1 VALUES(1);
+CREATE EVENT start_n_end
+ON SCHEDULE EVERY 1 SECOND
+ENDS NOW() + INTERVAL 6 SECOND
+ON COMPLETION PRESERVE
+DO INSERT INTO table_2 VALUES(1);
+CREATE EVENT only_one_time ON SCHEDULE EVERY 2 SECOND ENDS NOW() + INTERVAL 1 SECOND DO INSERT INTO table_3 VALUES(1);
+CREATE EVENT two_time ON SCHEDULE EVERY 1 SECOND ENDS NOW() + INTERVAL 1 SECOND DO INSERT INTO table_4 VALUES(1);
+SELECT IF(SUM(a) >= 4, 'OK', 'ERROR') FROM table_1;
+IF(SUM(a) >= 4, 'OK', 'ERROR')
+OK
+SELECT IF(SUM(a) >= 5, 'OK', 'ERROR') FROM table_2;
+IF(SUM(a) >= 5, 'OK', 'ERROR')
+OK
+SELECT IF(SUM(a) >  0, 'OK', 'ERROR') FROM table_3;
+IF(SUM(a) >  0, 'OK', 'ERROR')
+OK
+SELECT IF(SUM(a) >  0, 'OK', 'ERROR') FROM table_4;
+IF(SUM(a) >  0, 'OK', 'ERROR')
+OK
+DROP EVENT two_sec;
+SELECT IF(TIME_TO_SEC(TIMEDIFF(ENDS,STARTS))=6, 'OK', 'ERROR') FROM INFORMATION_SCHEMA.EVENTS WHERE EVENT_SCHEMA=DATABASE() AND EVENT_NAME='start_n_end' AND ENDS IS NOT NULL;
+IF(TIME_TO_SEC(TIMEDIFF(ENDS,STARTS))=6, 'OK', 'ERROR')
+OK
+SELECT IF(LAST_EXECUTED-ENDS < 2, 'OK', 'ERROR') FROM INFORMATION_SCHEMA.EVENTS WHERE EVENT_SCHEMA=DATABASE() AND EVENT_NAME='start_n_end' AND ENDS IS NOT NULL;
+IF(LAST_EXECUTED-ENDS < 2, 'OK', 'ERROR')
+OK
+DROP EVENT start_n_end;
+"Already dropped because ended. Therefore an error."
+DROP EVENT only_one_time;
+ERROR HY000: Unknown event 'only_one_time'
+"Already dropped because ended. Therefore an error."
+DROP EVENT two_time;
+ERROR HY000: Unknown event 'two_time'
+DROP TABLE table_1;
+DROP TABLE table_2;
+DROP TABLE table_3;
+DROP TABLE table_4;
+DROP DATABASE events_test;

mysql-test/t/events.test

@@ -101,7 +101,6 @@ set global event_scheduler = 0;
 create table t_event3 (a int, b float);
 drop event if exists event3;
 create event event3 on schedule every 50 + 10 minute starts date_add("20100101", interval 5 minute) ends date_add("20151010", interval 5 day) comment "portokala_comment" DO insert into t_event3 values (unix_timestamp(), rand());
-set max_allowed_packet=128000000;
 select count(*) from t_event3;
 drop event event3;
 drop table t_event3;
@@ -202,29 +201,25 @@ CREATE TABLE event_like LIKE mysql.event;
 INSERT INTO event_like SELECT * FROM mysql.event;
 #sleep a bit or we won't catch the change of time
 --sleep 1
+ALTER TABLE mysql.event MODIFY db char(64) character set cp1251 default '';
+--error 1526
+SELECT event_name FROM INFORMATION_SCHEMA.EVENTS;
 ALTER TABLE mysql.event MODIFY db char(20) character set utf8 collate utf8_bin default '';
 #wait a bit or we won't see the difference because of seconds resolution
---sleep 1
 SHOW CREATE TABLE mysql.event;
 --error 1526
 SELECT event_name FROM INFORMATION_SCHEMA.EVENTS;
 --sleep 1
 ALTER TABLE mysql.event MODIFY db char(64) character set utf8 collate utf8_bin default '';
---sleep 1
 --echo "This should work"
 --replace_column 8 # 9 #
 SHOW EVENTS;
 --sleep 1
-ALTER TABLE mysql.event MODIFY db char(64) character set cp1251 default '';
---error 1526
-SELECT event_name FROM INFORMATION_SCHEMA.EVENTS;
---sleep 1
 ALTER TABLE mysql.event MODIFY db varchar(64) character set utf8 collate utf8_bin default '';
+--sleep 2
 --error 1526
 SELECT event_name FROM INFORMATION_SCHEMA.EVENTS;
---sleep 1
 ALTER TABLE mysql.event DROP comment, DROP starts;
---sleep 1
 --error 1525
 SELECT event_name FROM INFORMATION_SCHEMA.EVENTS;
 DROP TABLE mysql.event;

mysql-test/t/events_scheduling.test

+CREATE DATABASE IF NOT EXISTS events_test;
+USE events_test;
+CREATE TABLE table_1(a int);
+CREATE TABLE table_2(a int);
+CREATE TABLE table_3(a int);
+CREATE TABLE table_4(a int);
+SET GLOBAL event_scheduler=1;
+CREATE EVENT two_sec ON SCHEDULE EVERY 2 SECOND DO INSERT INTO table_1 VALUES(1);
+CREATE EVENT start_n_end
+  ON SCHEDULE EVERY 1 SECOND
+  ENDS NOW() + INTERVAL 6 SECOND
+  ON COMPLETION PRESERVE
+  DO INSERT INTO table_2 VALUES(1);
+--sleep 5
+CREATE EVENT only_one_time ON SCHEDULE EVERY 2 SECOND ENDS NOW() + INTERVAL 1 SECOND DO INSERT INTO table_3 VALUES(1);
+CREATE EVENT two_time ON SCHEDULE EVERY 1 SECOND ENDS NOW() + INTERVAL 1 SECOND DO INSERT INTO table_4 VALUES(1);
+--sleep 5
+SELECT IF(SUM(a) >= 4, 'OK', 'ERROR') FROM table_1;
+SELECT IF(SUM(a) >= 5, 'OK', 'ERROR') FROM table_2;
+SELECT IF(SUM(a) >  0, 'OK', 'ERROR') FROM table_3;
+SELECT IF(SUM(a) >  0, 'OK', 'ERROR') FROM table_4;
+DROP EVENT two_sec;
+SELECT IF(TIME_TO_SEC(TIMEDIFF(ENDS,STARTS))=6, 'OK', 'ERROR') FROM INFORMATION_SCHEMA.EVENTS WHERE EVENT_SCHEMA=DATABASE() AND EVENT_NAME='start_n_end' AND ENDS IS NOT NULL;
+SELECT IF(LAST_EXECUTED-ENDS < 2, 'OK', 'ERROR') FROM INFORMATION_SCHEMA.EVENTS WHERE EVENT_SCHEMA=DATABASE() AND EVENT_NAME='start_n_end' AND ENDS IS NOT NULL;
+DROP EVENT start_n_end;
+--echo "Already dropped because ended. Therefore an error."
+--error 1517
+DROP EVENT only_one_time;
+--echo "Already dropped because ended. Therefore an error."
+--error 1517
+DROP EVENT two_time;
+DROP TABLE table_1;
+DROP TABLE table_2;
+DROP TABLE table_3;
+DROP TABLE table_4;
+DROP DATABASE events_test;

sql/event.cc

@@ -1047,13 +1047,6 @@ evex_load_and_compile_event(THD * thd, sp_name *spn, LEX_STRING definer,
   thd->restore_backup_open_tables_state(&backup);
   if (ret)
     goto done;
-
-  /*
-    allocate on evex_mem_root. if you call without evex_mem_root
-    then sphead will not be cleared!
-  */
-  if ((ret= ett->compile(thd, &evex_mem_root)))
-    goto done;
   
   ett->compute_next_execution_time();
   if (use_lock)

sql/event_executor.cc

@@ -42,6 +42,8 @@ pthread_mutex_t LOCK_event_arrays,              // mutex for when working with t
                 LOCK_workers_count,             // mutex for when inc/dec uint workers_count
                 LOCK_evex_running;              // mutes for managing bool evex_is_running
 
+static pthread_mutex_t LOCK_evex_main_thread;   // mutex for when working with the queue
+bool scheduler_main_thread_running= false;
 
 bool evex_is_running= false;
 
@@ -111,6 +113,7 @@ evex_init_mutexes()
   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);
+  pthread_mutex_init(&LOCK_evex_main_thread, MY_MUTEX_INIT_FAST);
 
   event_executor_running_global_var= opt_event_executor;
 }
@@ -241,6 +244,7 @@ shutdown_events()
     pthread_mutex_destroy(&LOCK_event_arrays);
     pthread_mutex_destroy(&LOCK_workers_count);
     pthread_mutex_destroy(&LOCK_evex_running);
+    pthread_mutex_destroy(&LOCK_evex_main_thread);
   }
   DBUG_VOID_RETURN;
 }
@@ -351,6 +355,7 @@ executor_wait_till_next_event_exec(THD *thd)
   t2sleep= evex_time_diff(&et->execute_at, &time_now);
   VOID(pthread_mutex_unlock(&LOCK_event_arrays));
 
+  t2sleep*=20;
   DBUG_PRINT("evex main thread",("unlocked LOCK_event_arrays"));
   if (t2sleep > 0)
   {
@@ -366,7 +371,7 @@ executor_wait_till_next_event_exec(THD *thd)
              modified))
     {
       DBUG_PRINT("evex main thread",("will sleep a bit more."));
-      my_sleep(1000000);
+      my_sleep(50000);
     }
     DBUG_PRINT("info",("saved_modified=%llu current=%llu", modified,
                evex_queue_num_elements(EVEX_EQ_NAME)? 
@@ -407,10 +412,23 @@ event_executor_main(void *arg)
   THD *thd;			/* needs to be first for thread_stack */
   uint i=0, j=0;
   my_ulonglong cnt= 0;
-
+  
   DBUG_ENTER("event_executor_main");
   DBUG_PRINT("event_executor_main", ("EVEX thread started"));
-
+  
+  pthread_mutex_lock(&LOCK_evex_main_thread);
+  if (!scheduler_main_thread_running)
+    scheduler_main_thread_running= true;
+  else 
+  {
+    DBUG_PRINT("event_executor_main", ("already running. thd_id=%d",
+                                      evex_main_thread_id));
+    pthread_mutex_unlock(&LOCK_evex_main_thread);
+    my_thread_end();
+    pthread_exit(0);
+    DBUG_RETURN(0);                               // Can't return anything here    
+  }
+  pthread_mutex_unlock(&LOCK_evex_main_thread);
 
   /* init memory root */
   init_alloc_root(&evex_mem_root, MEM_ROOT_BLOCK_SIZE, MEM_ROOT_PREALLOC);
@@ -489,7 +507,7 @@ event_executor_main(void *arg)
 
     if (!evex_queue_num_elements(EVEX_EQ_NAME))
     {
-      my_sleep(1000000);// sleep 1s
+      my_sleep(100000);// sleep 0.1s
       continue;
     }
 
@@ -652,12 +670,17 @@ finish:
 err_no_thd:
   VOID(pthread_mutex_lock(&LOCK_evex_running));
   evex_is_running= false;  
+  event_executor_running_global_var= false;
   VOID(pthread_mutex_unlock(&LOCK_evex_running));
 
   free_root(&evex_mem_root, MYF(0));
   sql_print_information("SCHEDULER: Stopped.");
 
 #ifndef DBUG_FAULTY_THR
+  pthread_mutex_lock(&LOCK_evex_main_thread);
+  scheduler_main_thread_running= false;
+  pthread_mutex_unlock(&LOCK_evex_main_thread);
+
   my_thread_end();
   pthread_exit(0);
 #endif

sql/event_timed.cc

@@ -567,28 +567,9 @@ Event_timed::load_from_row(MEM_ROOT *mem_root, TABLE *table)
   et->created= table->field[EVEX_FIELD_CREATED]->val_int();
   et->modified= table->field[EVEX_FIELD_MODIFIED]->val_int();
 
-  /*
-    ToDo Andrey : Ask PeterG & Serg what to do in this case.
-                  Whether on load last_executed_at should be loaded
-                  or it must be 0ed. If last_executed_at is loaded
-                  then an event can be scheduled for execution
-                  instantly. Let's say an event has to be executed
-                  every 15 mins. The server has been stopped for
-                  more than this time and then started. If L_E_AT
-                  is loaded from DB, execution at L_E_AT+15min
-                  will be scheduled. However this time is in the past.
-                  Hence immediate execution. Due to patch of
-                  ::mark_last_executed() last_executed gets time_now
-                  and not execute_at. If not like this a big
-                  queue can be scheduled for times which are still in
-                  the past (2, 3 and more executions which will be
-                  consequent).
-  */
-  set_zero_time(&last_executed, MYSQL_TIMESTAMP_DATETIME);
-#ifdef ANDREY_0
   table->field[EVEX_FIELD_LAST_EXECUTED]->
                      get_date(&et->last_executed, TIME_NO_ZERO_DATE);
-#endif
+
   last_executed_changed= false;
 
   /* ToDo : Andrey . Find a way not to allocate ptr on event_mem_root */
@@ -622,70 +603,164 @@ error:
 
 
 /*
-  Computes the sum of a timestamp plus interval
+  Computes the sum of a timestamp plus interval. Presumed is that at least one
+  previous execution has occured.
 
   SYNOPSIS
     get_next_time(TIME *start, int interval_value, interval_type interval)
       next          the sum
       start         add interval_value to this time
+      time_now      current time
       i_value       quantity of time type interval to add
       i_type        type of interval to add (SECOND, MINUTE, HOUR, WEEK ...)
+  
+  RETURNS
+    0  OK
+    1  Error
+
+  NOTES
+    1) If the interval is conversible to SECOND, like MINUTE, HOUR, DAY, WEEK.
+       Then we use TIMEDIFF()'s implementation as underlying and number of
+       seconds as resolution for computation.
+    2) In all other cases - MONTH, QUARTER, YEAR we use MONTH as resolution
+       and PERIOD_DIFF()'s implementation
+    3) We get the difference between time_now and `start`, then divide it
+       by the months, respectively seconds and round up. Then we multiply
+       monts/seconds by the rounded value and add it to `start` -> we get
+       the next execution time.
 */
 
 static
-bool get_next_time(TIME *next, TIME *start, int i_value, interval_type i_type)
+bool get_next_time(TIME *next, TIME *start, TIME *time_now, TIME *last_exec,
+                   int i_value, interval_type i_type)
 {
   bool ret;
   INTERVAL interval;
   TIME tmp;
+  longlong months=0, seconds=0;
+  DBUG_ENTER("get_next_time");
+  DBUG_PRINT("enter", ("start=%llu now=%llu", TIME_to_ulonglong_datetime(start),
+                      TIME_to_ulonglong_datetime(time_now)));
 
   bzero(&interval, sizeof(interval));
 
   switch (i_type) {
   case INTERVAL_YEAR:
-    interval.year= (ulong) i_value;
+    months= i_value*12;
     break;
   case INTERVAL_QUARTER:
-    interval.month= (ulong)(i_value*3);
-    break;
+    /* Has already been converted to months */
   case INTERVAL_YEAR_MONTH:
   case INTERVAL_MONTH:
-    interval.month= (ulong) i_value;
+    months= i_value;
     break;
   case INTERVAL_WEEK:
-    interval.day= (ulong)(i_value*7);
-    break;
+    /* WEEK has already been converted to days */
   case INTERVAL_DAY:
-    interval.day= (ulong) i_value;
+    seconds= i_value*24*3600;
     break;
   case INTERVAL_DAY_HOUR:
   case INTERVAL_HOUR:
-    interval.hour= (ulong) i_value;
+    seconds= i_value*3600;
     break;
   case INTERVAL_DAY_MINUTE:
   case INTERVAL_HOUR_MINUTE:
   case INTERVAL_MINUTE:
-    interval.minute=i_value;
+    seconds= i_value*60;
     break;
   case INTERVAL_DAY_SECOND:
   case INTERVAL_HOUR_SECOND:
   case INTERVAL_MINUTE_SECOND:
   case INTERVAL_SECOND:
-    interval.second=i_value;
+    seconds= i_value;
     break;
   case INTERVAL_DAY_MICROSECOND:
   case INTERVAL_HOUR_MICROSECOND:
   case INTERVAL_MINUTE_MICROSECOND:
   case INTERVAL_SECOND_MICROSECOND:
   case INTERVAL_MICROSECOND:
-    interval.second_part=i_value;
+    /*
+     We should return an error here so SHOW EVENTS/ SELECT FROM I_S.EVENTS
+     would give an error then.
+    */
+    DBUG_RETURN(1);
     break;
   }
-  tmp= *start;
-  if (!(ret= date_add_interval(&tmp, i_type, interval)))
+  DBUG_PRINT("info", ("seconds=%ld months=%ld", seconds, months));
+  if (seconds)
+  {
+    longlong seconds_diff;
+    long microsec_diff;
+    
+    if (calc_time_diff(time_now, start, 1, &seconds_diff, &microsec_diff))
+    {
+      DBUG_PRINT("error", ("negative difference"));
+      DBUG_ASSERT(0);
+    }
+    uint multiplier= seconds_diff / seconds;
+    /*
+      Increase the multiplier is the modulus is not zero to make round up.
+      Or if time_now==start then we should not execute the same 
+      event two times for the same time
+      get the next exec if the modulus is not
+    */
+    DBUG_PRINT("info", ("multiplier=%d", multiplier));
+    if (seconds_diff % seconds || (!seconds_diff && last_exec->year))
+      ++multiplier;
+    interval.second= seconds * multiplier;
+    DBUG_PRINT("info", ("multiplier=%u interval.second=%u", multiplier,
+                        interval.second));
+    tmp= *start;
+    if (!(ret= date_add_interval(&tmp, INTERVAL_SECOND, interval)))
+      *next= tmp;
+  }
+  else
+  {
+    /* PRESUMED is that at least one execution took already place */
+    int diff_months= (time_now->year - start->year)*12 +
+                     (time_now->month - start->month);
+    /*
+      Note: If diff_months is 0 that means we are in the same month as the
+      last execution which is also the first execution.
+    */
+    /*
+      First we try with the smaller if not then + 1, because if we try with
+      directly with +1 we will be after the current date but it could be that
+      we will be 1 month ahead, so 2 steps are necessary.
+    */
+    interval.month= (diff_months / months)*months;
+    /*
+      Check if the same month as last_exec (always set - prerequisite)
+      An event happens at most once per month so there is no way to schedule
+      it two times for the current month. This saves us from two calls to
+      date_add_interval() if the event was just executed.  But if the scheduler
+      is started and there was at least 1 scheduled date skipped this one does
+      not help and two calls to date_add_interval() will be done, which is a
+      bit more expensive but compared to the rareness of the case is neglectable.
+    */
+    if (time_now->year==last_exec->year && time_now->month==last_exec->month)
+      interval.month+= months;
+
+    tmp= *start;
+    if ((ret= date_add_interval(&tmp, INTERVAL_MONTH, interval)))
+      goto done;
+    
+    /* If `tmp` is still before time_now just add one more time the interval */
+    if (my_time_compare(&tmp, time_now) == -1)
+    { 
+      interval.month+= months;
+      tmp= *start;
+      if ((ret= date_add_interval(&tmp, INTERVAL_MONTH, interval)))
+        goto done;
+    }
     *next= tmp;
+    /* assert on that the next is after now */
+    DBUG_ASSERT(1==my_time_compare(next, time_now));
+  }
 
-  return ret;
+done:
+  DBUG_PRINT("info", ("next=%llu", TIME_to_ulonglong_datetime(next)));
+  DBUG_RETURN(ret);
 }
 
 
@@ -708,6 +783,10 @@ Event_timed::compute_next_execution_time()
   int tmp;
 
   DBUG_ENTER("Event_timed::compute_next_execution_time");
+  DBUG_PRINT("enter", ("starts=%llu ends=%llu last_executed=%llu",
+                        TIME_to_ulonglong_datetime(&starts),
+                        TIME_to_ulonglong_datetime(&ends),
+                        TIME_to_ulonglong_datetime(&last_executed)));
 
   if (status == MYSQL_EVENT_DISABLED)
   {
@@ -731,29 +810,14 @@ Event_timed::compute_next_execution_time()
     }
     goto ret;
   }
-  time((time_t *)&now);
-  my_tz_UTC->gmt_sec_to_TIME(&time_now, now);
+  my_tz_UTC->gmt_sec_to_TIME(&time_now, current_thd->query_start());
 
-#ifdef ANDREY_0
-  sql_print_information("[%s.%s]", dbname.str, name.str);
-  sql_print_information("time_now : [%d-%d-%d %d:%d:%d ]",
-                         time_now.year, time_now.month, time_now.day,
-                         time_now.hour, time_now.minute, time_now.second);
-  sql_print_information("starts : [%d-%d-%d %d:%d:%d ]", starts.year,
-                        starts.month, starts.day, starts.hour,
-                        starts.minute, starts.second);
-  sql_print_information("ends   : [%d-%d-%d %d:%d:%d ]", ends.year,
-                        ends.month, ends.day, ends.hour,
-                        ends.minute, ends.second);
-  sql_print_information("m_last_ex: [%d-%d-%d %d:%d:%d ]", last_executed.year,
-                        last_executed.month, last_executed.day,
-                        last_executed.hour, last_executed.minute,
-                        last_executed.second);
-#endif
+  DBUG_PRINT("info",("NOW=[%llu]", TIME_to_ulonglong_datetime(&time_now)));
 
   /* if time_now is after ends don't execute anymore */
   if (!ends_null && (tmp= my_time_compare(&ends, &time_now)) == -1)
   {
+    DBUG_PRINT("info", ("NOW after ENDS, don't execute anymore"));
     /* time_now is after ends. don't execute anymore */
     set_zero_time(&execute_at, MYSQL_TIMESTAMP_DATETIME);
     execute_at_null= TRUE;
@@ -781,6 +845,7 @@ Event_timed::compute_next_execution_time()
     }
     else
     {
+      DBUG_PRINT("info", ("STARTS is future, NOW <= STARTS,sched for STARTS"));
       /*
         starts is in the future
         time_now before starts. Scheduling for starts
@@ -799,8 +864,10 @@ Event_timed::compute_next_execution_time()
       after m_ends set execute_at to 0. And check for on_completion
       If not set then schedule for now.
     */
+    DBUG_PRINT("info", ("Both STARTS & ENDS are set"));
     if (!last_executed.year)
     {
+      DBUG_PRINT("info", ("Not executed so far. Execute NOW."));
       execute_at= time_now;
       execute_at_null= FALSE;
     }
@@ -808,12 +875,15 @@ Event_timed::compute_next_execution_time()
     {
       TIME next_exec;
 
-      if (get_next_time(&next_exec, &last_executed, expression, interval))
+      DBUG_PRINT("info", ("Executed at least once"));
+      if (get_next_time(&next_exec, &starts, &time_now, &last_executed,
+                        expression, interval))
         goto err;
 
       /* There was previous execution */
       if (my_time_compare(&ends, &next_exec) == -1)
       {
+        DBUG_PRINT("info", ("Next execution after ENDS. Stop executing."));
         /* Next execution after ends. No more executions */
         set_zero_time(&execute_at, MYSQL_TIMESTAMP_DATETIME);
         execute_at_null= TRUE;
@@ -822,6 +892,7 @@ Event_timed::compute_next_execution_time()
       }
       else
       {
+        DBUG_PRINT("info",("Next[%llu]",TIME_to_ulonglong_datetime(&next_exec)));
         execute_at= next_exec;
         execute_at_null= FALSE;
       }
@@ -830,18 +901,24 @@ Event_timed::compute_next_execution_time()
   }
   else if (starts_null && ends_null)
   {
+    DBUG_PRINT("info", ("Neither STARTS nor ENDS are set"));
     /*
       Both starts and m_ends are not set, so we schedule for the next
       based on last_executed.
     */
     if (last_executed.year)
     {
-      if (get_next_time(&execute_at, &last_executed, expression, interval))
+      TIME next_exec;
+      if (get_next_time(&next_exec, &starts, &time_now, &last_executed,
+                        expression, interval))
         goto err;
+      execute_at= next_exec;
+      DBUG_PRINT("info",("Next[%llu]",TIME_to_ulonglong_datetime(&next_exec)));
     }
     else
     {
       /* last_executed not set. Schedule the event for now */
+      DBUG_PRINT("info", ("Execute NOW"));
       execute_at= time_now;
     }
     execute_at_null= FALSE;
@@ -851,6 +928,7 @@ Event_timed::compute_next_execution_time()
     /* either starts or m_ends is set */
     if (!starts_null)
     {
+      DBUG_PRINT("info", ("STARTS is set"));
       /*
         - starts is set.
         - starts is not in the future according to check made before
@@ -859,15 +937,24 @@ Event_timed::compute_next_execution_time()
       */
       if (last_executed.year)
       {
-        if (get_next_time(&execute_at, &last_executed, expression, interval))
+        TIME next_exec;
+        DBUG_PRINT("info", ("Executed at least once."));
+        if (get_next_time(&next_exec, &starts, &time_now, &last_executed,
+                          expression, interval))
           goto err;
+        execute_at= next_exec;
+        DBUG_PRINT("info",("Next[%llu]",TIME_to_ulonglong_datetime(&next_exec)));
       }
       else
+      {
+        DBUG_PRINT("info", ("Not executed so far. Execute at STARTS"));
         execute_at= starts;
+      }
       execute_at_null= FALSE;
     }
     else
     {
+      DBUG_PRINT("info", ("STARTS is not set. ENDS is set"));
       /*
         - m_ends is set
         - m_ends is after time_now or is equal
@@ -881,11 +968,13 @@ Event_timed::compute_next_execution_time()
       {
         TIME next_exec;
 
-        if (get_next_time(&next_exec, &last_executed, expression, interval))
+        if (get_next_time(&next_exec, &starts, &time_now, &last_executed,
+                          expression, interval))
           goto err;
 
         if (my_time_compare(&ends, &next_exec) == -1)
         {
+          DBUG_PRINT("info", ("Next execution after ENDS. Stop executing."));
           set_zero_time(&execute_at, MYSQL_TIMESTAMP_DATETIME);
           execute_at_null= TRUE;
           if (on_completion == MYSQL_EVENT_ON_COMPLETION_DROP)
@@ -893,6 +982,8 @@ Event_timed::compute_next_execution_time()
         }
         else
         {
+          DBUG_PRINT("info", ("Next[%llu]",
+                              TIME_to_ulonglong_datetime(&next_exec)));
           execute_at= next_exec;
           execute_at_null= FALSE;
         }
@@ -901,9 +992,10 @@ Event_timed::compute_next_execution_time()
     goto ret;
   }
 ret:
-
+  DBUG_PRINT("info", ("ret=0"));
   DBUG_RETURN(false);
 err:
+  DBUG_PRINT("info", ("ret=1"));
   DBUG_RETURN(true);
 }
 
@@ -1437,6 +1529,7 @@ Event_timed::spawn_now(void * (*thread_func)(void*))
   int ret= EVENT_EXEC_STARTED;
   static uint exec_num= 0;
   DBUG_ENTER("Event_timed::spawn_now");
+  DBUG_PRINT("info", ("this=0x%lx", this));
   DBUG_PRINT("info", ("[%s.%s]", dbname.str, name.str));
 
   VOID(pthread_mutex_lock(&this->LOCK_running));

sql/item_timefunc.cc

@@ -772,81 +772,6 @@ static bool get_interval_info(const char *str,uint length,CHARSET_INFO *cs,
 }
 
 
-/*
-  Calculate difference between two datetime values as seconds + microseconds.
-
-  SYNOPSIS
-    calc_time_diff()
-      l_time1         - TIME/DATE/DATETIME value
-      l_time2         - TIME/DATE/DATETIME value
-      l_sign          - 1 absolute values are substracted,
-                        -1 absolute values are added.
-      seconds_out     - Out parameter where difference between
-                        l_time1 and l_time2 in seconds is stored.
-      microseconds_out- Out parameter where microsecond part of difference
-                        between l_time1 and l_time2 is stored.
-
-  NOTE
-    This function calculates difference between l_time1 and l_time2 absolute
-    values. So one should set l_sign and correct result if he want to take
-    signs into account (i.e. for TIME values).
-
-  RETURN VALUES
-    Returns sign of difference.
-    1 means negative result
-    0 means positive result
-
-*/
-
-static bool calc_time_diff(TIME *l_time1, TIME *l_time2, int l_sign,
-                           longlong *seconds_out, long *microseconds_out)
-{
-  long days;
-  bool neg;
-  longlong microseconds;
-
-  /*
-    We suppose that if first argument is MYSQL_TIMESTAMP_TIME
-    the second argument should be TIMESTAMP_TIME also.
-    We should check it before calc_time_diff call.
-  */
-  if (l_time1->time_type == MYSQL_TIMESTAMP_TIME)  // Time value
-    days= (long)l_time1->day - l_sign * (long)l_time2->day;
-  else
-  {
-    days= calc_daynr((uint) l_time1->year,
-		     (uint) l_time1->month,
-		     (uint) l_time1->day);
-    if (l_time2->time_type == MYSQL_TIMESTAMP_TIME)
-      days-= l_sign * (long)l_time2->day;
-    else
-      days-= l_sign*calc_daynr((uint) l_time2->year,
-			       (uint) l_time2->month,
-			       (uint) l_time2->day);
-  }
-
-  microseconds= ((longlong)days*LL(86400) +
-                 (longlong)(l_time1->hour*3600L +
-                            l_time1->minute*60L +
-                            l_time1->second) -
-                 l_sign*(longlong)(l_time2->hour*3600L +
-                                   l_time2->minute*60L +
-                                   l_time2->second)) * LL(1000000) +
-                (longlong)l_time1->second_part -
-                l_sign*(longlong)l_time2->second_part;
-
-  neg= 0;
-  if (microseconds < 0)
-  {
-    microseconds= -microseconds;
-    neg= 1;
-  }
-  *seconds_out= microseconds/1000000L;
-  *microseconds_out= (long) (microseconds%1000000L);
-  return neg;
-}
-
-
 longlong Item_func_period_add::val_int()
 {
   DBUG_ASSERT(fixed == 1);
@@ -2032,16 +1957,13 @@ bool Item_date_add_interval::get_date(TIME *ltime, uint fuzzy_date)
   INTERVAL interval;
 
   if (args[0]->get_date(ltime, TIME_NO_ZERO_DATE) ||
-      get_interval_value(args[1],int_type,&value,&interval))
-    goto null_date;
+      get_interval_value(args[1], int_type, &value, &interval))
+    return (null_value=1);
 
   if (date_sub_interval)
     interval.neg = !interval.neg;
 
   return (null_value= date_add_interval(ltime, int_type, interval));
-
- null_date:
-  return (null_value=1);
 }
 
 

sql/mysql_priv.h

@@ -1544,6 +1544,8 @@ void make_truncated_value_warning(THD *thd, const char *str_val,
                                   const char *field_name);
 
 bool date_add_interval(TIME *ltime, interval_type int_type, INTERVAL interval);
+bool calc_time_diff(TIME *l_time1, TIME *l_time2, int l_sign,
+                    longlong *seconds_out, long *microseconds_out);
 
 extern DATE_TIME_FORMAT *date_time_format_make(timestamp_type format_type,
 					       const char *format_str,

sql/sql_show.cc

@@ -3956,7 +3956,7 @@ fill_events_copy_to_schema_table(THD *thd, TABLE *sch_table, TABLE *event_table)
   if (!(!wild || !wild[0] || !wild_compare(et.name.str, wild, 0)))
     DBUG_RETURN(0);
   
-  //->field[0] is EVENT_CATALOG and is by default NULL
+  /* ->field[0] is EVENT_CATALOG and is by default NULL */
   
   sch_table->field[1]->store(et.dbname.str, et.dbname.length, scs);
   sch_table->field[2]->store(et.name.str, et.name.length, scs);
@@ -3976,12 +3976,9 @@ fill_events_copy_to_schema_table(THD *thd, TABLE *sch_table, TABLE *event_table)
   if (et.expression)
   {
     String show_str;
-    //type
+    /* type */
     sch_table->field[5]->store(STRING_WITH_LEN("RECURRING"), scs);
-    /* execute_at */
-    sch_table->field[6]->set_null();
-    /* interval_value */
-    //interval_type
+
     if (event_reconstruct_interval_expression(&show_str, et.interval,
                                               et.expression))
       DBUG_RETURN(1);
@@ -4034,9 +4031,10 @@ fill_events_copy_to_schema_table(THD *thd, TABLE *sch_table, TABLE *event_table)
   sch_table->field[15]->store_time(&time, MYSQL_TIMESTAMP_DATETIME);
 
   if (et.last_executed.year)
+  {
+    sch_table->field[16]->set_notnull();
     sch_table->field[16]->store_time(&et.last_executed,MYSQL_TIMESTAMP_DATETIME);
-  else
-    sch_table->field[16]->set_null();
+  }
 
   sch_table->field[17]->store(et.comment.str, et.comment.length, scs);
 

sql/time.cc

@@ -833,4 +833,80 @@ invalid_date:
 }
 
 
+/*
+  Calculate difference between two datetime values as seconds + microseconds.
+
+  SYNOPSIS
+    calc_time_diff()
+      l_time1         - TIME/DATE/DATETIME value
+      l_time2         - TIME/DATE/DATETIME value
+      l_sign          - 1 absolute values are substracted,
+                        -1 absolute values are added.
+      seconds_out     - Out parameter where difference between
+                        l_time1 and l_time2 in seconds is stored.
+      microseconds_out- Out parameter where microsecond part of difference
+                        between l_time1 and l_time2 is stored.
+
+  NOTE
+    This function calculates difference between l_time1 and l_time2 absolute
+    values. So one should set l_sign and correct result if he want to take
+    signs into account (i.e. for TIME values).
+
+  RETURN VALUES
+    Returns sign of difference.
+    1 means negative result
+    0 means positive result
+
+*/
+
+bool
+calc_time_diff(TIME *l_time1, TIME *l_time2, int l_sign, longlong *seconds_out,
+               long *microseconds_out)
+{
+  long days;
+  bool neg;
+  longlong microseconds;
+
+  /*
+    We suppose that if first argument is MYSQL_TIMESTAMP_TIME
+    the second argument should be TIMESTAMP_TIME also.
+    We should check it before calc_time_diff call.
+  */
+  if (l_time1->time_type == MYSQL_TIMESTAMP_TIME)  // Time value
+    days= (long)l_time1->day - l_sign * (long)l_time2->day;
+  else
+  {
+    days= calc_daynr((uint) l_time1->year,
+		     (uint) l_time1->month,
+		     (uint) l_time1->day);
+    if (l_time2->time_type == MYSQL_TIMESTAMP_TIME)
+      days-= l_sign * (long)l_time2->day;
+    else
+      days-= l_sign*calc_daynr((uint) l_time2->year,
+			       (uint) l_time2->month,
+			       (uint) l_time2->day);
+  }
+
+  microseconds= ((longlong)days*LL(86400) +
+                 (longlong)(l_time1->hour*3600L +
+                            l_time1->minute*60L +
+                            l_time1->second) -
+                 l_sign*(longlong)(l_time2->hour*3600L +
+                                   l_time2->minute*60L +
+                                   l_time2->second)) * LL(1000000) +
+                (longlong)l_time1->second_part -
+                l_sign*(longlong)l_time2->second_part;
+
+  neg= 0;
+  if (microseconds < 0)
+  {
+    microseconds= -microseconds;
+    neg= 1;
+  }
+  *seconds_out= microseconds/1000000L;
+  *microseconds_out= (long) (microseconds%1000000L);
+  return neg;
+}
+
+
 #endif