- fix bug #16435 (Weekly events execute every second) (WL#1034 Internal CRON)

Before the interval expression was considered to be in seconds, now it is
just a number and the type of interval is considered.

- this changeset introduces also fix for bug#16432 (Events: error re interval
  misrepresents the facts)
  the code of event_timed::set_interval() was refactored anyway so it is meaningful to
  fix the bug in the same changeset.


include/my_time.h:
  - move enum interval_type to include/my_time.h so it can be used by functions
    in the whole server
sql/event.cc:
  - don't use second_part
  - fix small problem with create event xyz, when xyz exists -> make it error
    instead of warning if create_if_not is false.
sql/event.h:
  pass thd to mark_last_executed() to be able to call thd->end_time()
sql/event_executor.cc:
  - pass thd to event_timed::compute_next_execution_time()
  - a bit more DBUG info in the server log
  - handle error returned by event_timed::compute_next_execution_time()
sql/event_priv.h:
  - define the maximal possible value for interval_value
sql/event_timed.cc:
  - more docs
  - add static get_next_time() which sums a TIME with an interval
  - fix bug #16435 (Weekly events execute every second)
  Before the interval expression was considered to be in seconds, now it is
  just a number and the type of interval is considered.
  - fix for bug#16432 (Events: error re interval misrepresents the facts)
    (return an error if a value is too big or is negative - errmsg changed)
sql/item_timefunc.cc:
  - export get_interval_date()
  - refactor Item_date_add_interval::get_date() and extract the core
    to date_add_interval() in time.cc so it can be reused by the
    scheduler code in event_timed.cc
sql/item_timefunc.h:
  - export get_interval_value() so it can be reused in event_timed.cc in
    function static get_next_time()
  - move enum interval_type to include/my_time.h so it can be used by functions
    in the whole server
sql/mysql_priv.h:
  export the new function date_add_interval() added to time.cc
sql/share/errmsg.txt:
  - change error message to be appropriate as fix for bug#16432
    (Events: error re interval misrepresents the facts)
sql/sql_yacc.yy:
  - change error message to be appropriate as fix for bug#16432
    (Events: error re interval misrepresents the facts)
sql/time.cc:
  extract the core of Item_date_add_interval::get_date()
  to a function per Serg's request. The code can be reused
  to add und substract interval from a date.

1 files changed, 19 insertions, 4 deletions

diff --git a/sql/event_executor.cc b/sql/event_executor.cc
index dd426c32545..1cb289efc74 100644
--- a/sql/event_executor.cc
+++ b/sql/event_executor.cc
@@ -334,9 +334,19 @@ event_executor_main(void *arg)
     {
       pthread_t th;
 
-      DBUG_PRINT("evex main thread",("mark_last_executed"));
-      et->mark_last_executed();
-      et->compute_next_execution_time();
+      DBUG_PRINT("evex main thread", ("[%10s] this exec at [%llu]", et->name.str,
+                               TIME_to_ulonglong_datetime(&et->execute_at)));
+      et->mark_last_executed(thd);
+      if (et->compute_next_execution_time())
+      {
+        sql_print_error("Error while computing time of %s.%s . "
+                        "Disabling after execution.",
+                        et->dbname.str, et->name.str);
+        et->status= MYSQL_EVENT_DISABLED;
+      }
+      DBUG_PRINT("evex main thread", ("[%10s] next exec at [%llu]", et->name.str,
+                               TIME_to_ulonglong_datetime(&et->execute_at)));
+
       et->update_fields(thd);
       DBUG_PRINT("info", ("  Spawning a thread %d", ++iter_num));
 #ifndef DBUG_FAULTY_THR
@@ -599,7 +609,12 @@ evex_load_events_from_db(THD *thd)
     }
     
     // let's find when to be executed  
-    et->compute_next_execution_time();
+    if (et->compute_next_execution_time())
+    {
+      sql_print_error("Error while computing execution time of %s.%s. Skipping",
+                       et->dbname.str, et->name.str);
+      continue;
+    }
     
     DBUG_PRINT("evex_load_events_from_db", ("Adding to the exec list."));