WL#3337 (Event scheduler new architecture)

This is a post-review patch.

Fixes the typelib implementation, available only in 5.1.11.

--event-scheduler cmdline : DISABLED | ON | OFF | 0 | 1
DISABLED - makes the scheduler unavailable during the server run
(ON|1)-  When the server is started the scheduler will be started. It can
         be stopped and restarted by setting appropriate values to
         GLOBAL event_scheduler
(OFF|0)- When the server is started, the scheduler won't be started. It
         can be started and again stopped by setting appropriate values to
         GLOBAL event_scheduler. _DEFAULT_ value

The GLOBAL variable event_scheduler can have the following values:
OFF | ON | 0 | 1
DISABLED is not possible and every attempt will end with an error that
it's not a valid value for the variable.
OFF | 0 - This is the pre-5.1.11 behavior - The scheduler stops, if not
          already stopped, and can be started again  by setting
          the value of the variable to ON|1.
ON | 1  - This is the pre-5.1.11 behavior - The scheduler starts, if not
          already started, and can be stopped again by setting the value
          of the variable to OFF|0.


mysql-test/r/events.result:
  update result
mysql-test/r/events_bugs.result:
  update result
mysql-test/r/events_logs_tests.result:
  update result
mysql-test/r/events_restart_phase1.result:
  update result
mysql-test/r/events_restart_phase3.result:
  update result
mysql-test/r/events_scheduling.result:
  update result
mysql-test/r/events_stress.result:
  update result
mysql-test/t/events.test:
  update test:
  2 -> off
  1 -> on
mysql-test/t/events_bugs.test:
  update test:
  2 -> off
  1 -> on
mysql-test/t/events_logs_tests.test:
  update test:
  2 -> off
  1 -> on
mysql-test/t/events_restart_phase1.test:
  update test:
  2 -> off
  1 -> on
mysql-test/t/events_restart_phase2-master.opt:
  update master file : 1 => on
mysql-test/t/events_scheduling.test:
  update test:
  2 -> off
  1 -> on
  
  add tests for event_scheduler global variable representation from
  SHOW VARIABLES.
mysql-test/t/events_stress.test:
  update test:
  2 -> off
  1 -> on
sql/events.cc:
  Implement two different TYPELIBs for --event-scheduler cmd line
  option and for GLOBAL variable event_scheduler
  
  --event-scheduler cmdline : DISABLED | ON | OFF | 0 | 1
  DISABLED - makes the scheduler unavailable during the server run
  (ON|1)-  When the server is started the scheduler will be started. It can
           be stopped and restarted by setting appropriate values to
           GLOBAL event_scheduler
  (OFF|0)- When the server is started, the scheduler won't be started. It
           can be started and again stopped by setting appropriate values to
           GLOBAL event_scheduler. _DEFAULT_ value
  
  The GLOBAL variable event_scheduler can have the following values:
  OFF | ON | 0 | 1
  DISABLED is not possible and every attempt will end with an error that
  it's not a valid value for the variable.
  OFF | 0 - This is the pre-5.1.11 behavior - The scheduler stops, if not
            already stopped, and can be started again  by setting
            the value of the variable to ON|1.
  ON | 1  - This is the pre-5.1.11 behavior - The scheduler starts, if not
            already started, and can be stopped again by setting the value
            of the variable to OFF|0.
sql/events.h:
  additional TYPELIB for GLOBAL event_scheduler
sql/mysqld.cc:
  --event-scheduler should be checked against a TYPELIB and
  therefore should be GET_STR, as well as we make the parameter optional.
  When not provided OFF|0 is used.
sql/set_var.cc:
  Implement typelib for event_scheduler variable.
  If allows both INT_RESULT -> 0 | 1 
  and STRING_RESULT -> OFF | ON
  The variable is shown as DISABLED | ON | OFF
sql/set_var.h:
  Implement typelib, which expects both STRING and INT,
  for event_scheduler.

1 files changed, 24 insertions, 18 deletions

diff --git a/sql/set_var.cc b/sql/set_var.cc
index f10df7fa6f8..d2764e13ae3 100644
--- a/sql/set_var.cc
+++ b/sql/set_var.cc
@@ -3914,6 +3914,7 @@ bool sys_var_thd_dbug::update(THD *thd, set_var *var)
   return 0;
 }
 
+
 byte *sys_var_thd_dbug::value_ptr(THD *thd, enum_var_type type, LEX_STRING *b)
 {
   char buf[256];
@@ -3925,6 +3926,12 @@ byte *sys_var_thd_dbug::value_ptr(THD *thd, enum_var_type type, LEX_STRING *b)
 }
 
 
+bool sys_var_event_scheduler::check(THD *thd, set_var *var)
+{
+  return check_enum(thd, var, &Events::var_typelib);
+}
+
+
 /*
    The update method of the global variable event_scheduler.
    If event_scheduler is switched from 0 to 1 then the scheduler main
@@ -3946,29 +3953,27 @@ sys_var_event_scheduler::update(THD *thd, set_var *var)
   int res;
   /* here start the thread if not running. */
   DBUG_ENTER("sys_var_event_scheduler::update");
-  if (Events::opt_event_scheduler == 0)
+  if (Events::opt_event_scheduler == Events::EVENTS_DISABLED)
   {
-    my_error(ER_OPTION_PREVENTS_STATEMENT, MYF(0), "--event-scheduler=0");
+    my_error(ER_OPTION_PREVENTS_STATEMENT, MYF(0), "--event-scheduler=DISABLED");
     DBUG_RETURN(TRUE);
   }
 
   DBUG_PRINT("new_value", ("%lu", (bool)var->save_result.ulong_value));
 
-  if (var->save_result.ulonglong_value < 1 ||
-      var->save_result.ulonglong_value > 2)
-  {
-    char buf[64];
-    my_error(ER_WRONG_VALUE_FOR_VAR, MYF(0), "event_scheduler",
-             llstr(var->save_result.ulonglong_value, buf));
-    DBUG_RETURN(TRUE);
-  }
-  if (var->save_result.ulonglong_value == 1)
+  Item_result var_type= var->value->result_type();
+
+  if (var->save_result.ulong_value == Events::EVENTS_ON)
     res= Events::get_instance()->start_execution_of_events();
-  else
+  else if (var->save_result.ulong_value == Events::EVENTS_OFF)
     res= Events::get_instance()->stop_execution_of_events();
-
+  else
+  {
+    DBUG_ASSERT(0);
+  }
   if (res)
     my_error(ER_EVENT_SET_VAR_ERROR, MYF(0));
+
   DBUG_RETURN((bool) res);
 }
 
@@ -3976,14 +3981,15 @@ 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)
 {
-  if (Events::opt_event_scheduler == 0)
-    thd->sys_var_tmp.long_value= 0;
+  int state;
+  if (Events::opt_event_scheduler == Events::EVENTS_DISABLED)
+    state= Events::EVENTS_DISABLED;              // This should be DISABLED
   else if (Events::get_instance()->is_execution_of_events_started())
-    thd->sys_var_tmp.long_value= 1;
+    state= Events::EVENTS_ON;                    // This should be ON
   else
-    thd->sys_var_tmp.long_value= 2;
+    state= Events::EVENTS_OFF;                   // This should be OFF
 
-  return (byte*) &thd->sys_var_tmp;
+  return (byte*) Events::opt_typelib.type_names[state];
 }