Commit 99eb6eb6 authored by unknown's avatar unknown
Browse files

- fix for bug #16414 (Events: Crash or hang if event drops itself) 

WL#1034 (Internal CRON)
(with post-review fix)


mysql-test/r/events.result:
  update the result
mysql-test/t/events.test:
  use --sleep instead of select sleep()
  enable some scheduler related tests. They were disabled because of a hang that
  happened. The hang is fixed with this bugfix.
sql/event.cc:
  - evex_remove_from_cache reports back whether the in_memory
    object was deleted or was scheduled. In case scheduling then
    don't delete it from outside but let it do it itself
  - move out db interaction code out of evex_drop_event to db_drop_event
    so it can be called from outter space :)
sql/event_priv.h:
  - export the new function db_drop_event()
sql/event_timed.cc:
  - use db_drop_event() and don't implement the dropping ourselves
sql/sql_parse.cc:
  - some debug info about the status code returned.
parent 5f67b29f

mysql-test/r/events.result

+67 −9
Original line number Diff line number Diff line
@@ -15,20 +15,11 @@ create event event2 on schedule every 2 second starts now() ends date_add(now(), 
drop event event2;

create event e_43 on schedule every 1 second do set @a = 5;

set global event_scheduler = 1;

select sleep(2);

sleep(2)

0

alter event e_43 do alter event e_43 do set @a = 4;

select sleep(3);

sleep(3)

0

select db, name, body, status, interval_field, interval_value from mysql.event;

db	name	body	status	interval_field	interval_value

events_test	e_43	 set @a = 4	ENABLED	SECOND	1

drop event e_43;

select sleep(1);

sleep(1)

0

set global event_scheduler = 0;

create table t_event3 (a int, b float);

drop event if exists event3;
@@ -121,6 +112,7 @@ drop event two_event; 
drop event three_event;

drop user ev_test@localhost;

drop event one_event;

"Sleep a bit so the server closes the second connection"

create event e_26 on schedule at '2017-01-01 00:00:00' disable do set @a = 5;

select db, name, body, definer, convert_tz(execute_at, 'UTC', 'SYSTEM'), on_completion from mysql.event;

db	name	body	definer	convert_tz(execute_at, 'UTC', 'SYSTEM')	on_completion
@@ -137,4 +129,70 @@ set event_scheduler=0; 
ERROR HY000: Variable 'event_scheduler' is a GLOBAL variable and should be set with SET GLOBAL

set global event_scheduler=2;

ERROR 42000: Variable 'event_scheduler' can't be set to the value of '2'

"DISABLE the scheduler. Testing that it does not work when the variable is 0"

set global event_scheduler=0;

select definer, name, db from mysql.event;

definer	name	db

select get_lock("test_lock1", 20);

get_lock("test_lock1", 20)

1

create event закачка on schedule every 10 hour do select get_lock("test_lock1", 20);

"Should return 1 row"

select definer, name, db from mysql.event;

definer	name	db

root@localhost	закачка	events_test

"Should be only 1 process"

show processlist;

Id	User	Host	db	Command	Time	State	Info

#	root	localhost	events_test	Query	#	NULL	show processlist

select release_lock("test_lock1");

release_lock("test_lock1")

1

drop event закачка;

"Should have 0 events"

select count(*) from mysql.event;

count(*)

0

"ENABLE the scheduler and get a lock"

set global event_scheduler=1;

select get_lock("test_lock2", 20);

get_lock("test_lock2", 20)

1

"Create an event which tries to acquire a mutex. The event locks on the mutex"

create event закачка on schedule every 10 hour do select get_lock("test_lock2", 20);

"Let some time pass to the event starts"

"Should have only 3 processes: the scheduler, our conn and the locked event"

show processlist;

Id	User	Host	db	Command	Time	State	Info

#	root	localhost	events_test	Query	#	NULL	show processlist

#	event_scheduler		NULL	Connect	#	Sleeping	NULL

#	root		events_test	Connect	#	User lock	select get_lock("test_lock2", 20)

"Release the mutex, the event worker should finish."

select release_lock("test_lock2");

release_lock("test_lock2")

1

drop event закачка;

set global event_scheduler=1;

select get_lock("test_lock2_1", 20);

get_lock("test_lock2_1", 20)

1

create event закачка21 on schedule every 10 hour do select get_lock("test_lock2_1", 20);

"Should see 2 processes, one locked on get_lock("

"Shutting down the scheduler, it should wait for the running event"

set global event_scheduler=0;

"Should have only 3 processes: the scheduler, our conn and the locked event"

show processlist;

Id	User	Host	db	Command	Time	State	Info

#	root	localhost	events_test	Query	#	NULL	show processlist

#	event_scheduler		NULL	Connect	#	Sleeping	NULL

#	root		events_test	Connect	#	User lock	select get_lock("test_lock2_1", 20)

"Release the lock so the child process should finish. Hence the scheduler also"

select release_lock("test_lock2_1");

release_lock("test_lock2_1")

1

"Should have only our process now:"

show processlist;

Id	User	Host	db	Command	Time	State	Info

#	root	localhost	events_test	Query	#	NULL	show processlist

drop event закачка21;

drop database events_test;

mysql-test/t/events.test

+66 −43
Original line number Diff line number Diff line
@@ -17,12 +17,12 @@ drop event event2; 


create event e_43 on schedule every 1 second do set @a = 5;

set global event_scheduler = 1;

select sleep(2);

--sleep 2

alter event e_43 do alter event e_43 do set @a = 4;

select sleep(3);

--sleep 2

select db, name, body, status, interval_field, interval_value from mysql.event;

drop event e_43;

select sleep(1);

--sleep 1

set global event_scheduler = 0;



create table t_event3 (a int, b float);
@@ -107,8 +107,8 @@ drop event one_event; 
##INFORMATION_SCHEMA.EVENTS test end

#







--echo "Sleep a bit so the server closes the second connection"

--sleep 2



create event e_26 on schedule at '2017-01-01 00:00:00' disable do set @a = 5;

select db, name, body, definer, convert_tz(execute_at, 'UTC', 'SYSTEM'), on_completion from mysql.event;
@@ -129,23 +129,38 @@ set event_scheduler=0; 
--error 1231

set global event_scheduler=2;



#set global event_scheduler=0;

#select count(*) from mysql.event;

#select get_lock("test_lock1", 20);

#create event закачка on schedule every 10 hour do select get_lock("test_lock1", 20);

#select count(*) from mysql.event;

##show processlist;

#select release_lock("test_lock1");

#drop event закачка;

#select count(*) from mysql.event;

--echo "DISABLE the scheduler. Testing that it does not work when the variable is 0"

set global event_scheduler=0;

select definer, name, db from mysql.event;

select get_lock("test_lock1", 20);

create event закачка on schedule every 10 hour do select get_lock("test_lock1", 20);

--echo "Should return 1 row"

select definer, name, db from mysql.event;



--echo "Should be only 1 process"

--replace_column 1 # 6 #

show processlist;

select release_lock("test_lock1");

drop event закачка;

--echo "Should have 0 events"

select count(*) from mysql.event;



#

#set global event_scheduler=1;

#select get_lock("test_lock2", 20);

#create event закачка on schedule every 10 hour do select get_lock("test_lock2", 20);

#select sleep(2);

#show processlist;

#select release_lock("test_lock2");

#drop event закачка;

#

#

--echo "ENABLE the scheduler and get a lock"

set global event_scheduler=1;

select get_lock("test_lock2", 20);

--echo "Create an event which tries to acquire a mutex. The event locks on the mutex"

create event закачка on schedule every 10 hour do select get_lock("test_lock2", 20);

--echo "Let some time pass to the event starts"

--sleep 2

--echo "Should have only 3 processes: the scheduler, our conn and the locked event"

--replace_column 1 # 6 #

show processlist;

--echo "Release the mutex, the event worker should finish."

select release_lock("test_lock2");

drop event закачка;



##

## 1. get a lock
@@ -155,26 +170,33 @@ set global event_scheduler=2; 
## 5. kill the scheduler, it will wait for the child to stop

## 6. both processes should be there on show processlist

## 7. release the lock and sleep, both scheduler and child should end

#set global event_scheduler=1;

#select get_lock("test_lock2_1", 20);

#create event закачка21 on schedule every 10 hour do select get_lock("test_lock2_1", 20);

#select sleep(2);

##show processlist;

#set global event_scheduler=0;

#select sleep(2);

##show processlist;

#select release_lock("test_lock2_1");

#select sleep(2);

##show processlist;

#drop event закачка21;



#set global event_scheduler=1;

#select get_lock("test_lock3", 20);

#create event закачка on schedule every 10 hour do select get_lock("test_lock3", 20);

#select sleep(2);

set global event_scheduler=1;

select get_lock("test_lock2_1", 20);

create event закачка21 on schedule every 10 hour do select get_lock("test_lock2_1", 20);

--sleep 1

--echo "Should see 2 processes, one locked on get_lock("

#show processlist;

#drop event закачка;

#select release_lock("test_lock3");

--echo "Shutting down the scheduler, it should wait for the running event"

set global event_scheduler=0;

--sleep 1

--echo "Should have only 3 processes: the scheduler, our conn and the locked event"

--replace_column 1 # 6 #

show processlist;

--echo "Release the lock so the child process should finish. Hence the scheduler also"

select release_lock("test_lock2_1");

--sleep 1

--echo "Should have only our process now:"

--replace_column 1 # 6 #

show processlist;

drop event закачка21;



##set global event_scheduler=1;

##select get_lock("test_lock3", 20);

##create event закачка on schedule every 10 hour do select get_lock("test_lock3", 20);

##select sleep(2);

##show processlist;

##drop event закачка;

##select release_lock("test_lock3");



#

# test with very often occuring event
@@ -182,14 +204,15 @@ set global event_scheduler=2; 
##select get_lock("test_lock4", 20);

##create event закачка4 on schedule every 1 second do select get_lock("test_lock4", 20);

##select sleep(3);

##--replace_column 1 # 6 #

##show processlist;

##drop event закачка4;

##select release_lock("test_lock4");



#set global event_scheduler=0;

#select sleep(2);

##set global event_scheduler=0;

##select sleep(2);

##--replace_column 1 # 6 #

##show processlist;

##the following locks for some reason and is a bug, commented for now

##select count(*) from mysql.event;



drop database events_test;

sql/event.cc

+57 −12
Original line number Diff line number Diff line
@@ -704,11 +704,17 @@ evex_load_and_compile_event(THD * thd, sp_name *spn, LEX_STRING definer, 
}





/*

   0 - OK can drop from outside

   1 - Scheduled from dropping, don't drop from outside

*/



static int

evex_remove_from_cache(LEX_STRING *db, LEX_STRING *name, bool use_lock,

                       bool is_drop)

{

  uint i;

  int ret= 0;



  DBUG_ENTER("evex_remove_from_cache");

  /*
@@ -738,7 +744,8 @@ evex_remove_from_cache(LEX_STRING *db, LEX_STRING *name, bool use_lock, 
        DBUG_PRINT("evex_remove_from_cache",

               ("running.defer mem free. is_drop=%d", is_drop));

        et->flags|= EVENT_EXEC_NO_MORE;

        et->dropped= is_drop;

        if ((et->dropped= is_drop))

          ret= 1;

      }

      DBUG_PRINT("evex_remove_from_cache", ("delete from queue"));

      evex_queue_delete_element(&EVEX_EQ_NAME, i);
@@ -751,7 +758,7 @@ evex_remove_from_cache(LEX_STRING *db, LEX_STRING *name, bool use_lock, 
  if (use_lock)

    VOID(pthread_mutex_unlock(&LOCK_event_arrays));



  DBUG_RETURN(0);

  DBUG_RETURN(ret);

}
@@ -866,21 +873,25 @@ evex_update_event(THD *thd, event_timed *et, sp_name *new_name, 
 Drops an event



 SYNOPSIS

   evex_drop_event()

   db_drop_event()

     thd             THD

     et              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

          

*/



int

evex_drop_event(THD *thd, event_timed *et, bool drop_if_exists,

int db_drop_event(THD *thd, event_timed *et, bool drop_if_exists,

                  uint *rows_affected)

{

  TABLE *table;

  int ret= EVEX_OPEN_TABLE_FAILED;

  DBUG_ENTER("evex_drop_event");

  Open_tables_state backup;

  uint ret;



  DBUG_ENTER("db_drop_event");

  ret= EVEX_OPEN_TABLE_FAILED;



  thd->reset_n_backup_open_tables_state(&backup);

  if (evex_open_event_table(thd, TL_WRITE, &table))

  {

    my_error(ER_EVENT_OPEN_TABLE_FAILED, MYF(0));
@@ -908,10 +919,6 @@ evex_drop_event(THD *thd, event_timed *et, bool drop_if_exists, 
    goto done;

  }



  VOID(pthread_mutex_lock(&LOCK_evex_running));

  if (evex_is_running)

    ret= evex_remove_from_cache(&et->dbname, &et->name, true, true);

  VOID(pthread_mutex_unlock(&LOCK_evex_running));



done:

  /*
@@ -919,6 +926,44 @@ evex_drop_event(THD *thd, event_timed *et, bool drop_if_exists, 
    we have to close our thread tables.

  */

  close_thread_tables(thd);

  thd->restore_backup_open_tables_state(&backup);

  DBUG_RETURN(ret);

}





/*

 Drops an event



 SYNOPSIS

   evex_drop_event()

     thd             THD

     et              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

          

*/



int

evex_drop_event(THD *thd, event_timed *et, bool drop_if_exists,

                uint *rows_affected)

{

  TABLE *table;

  int ret= 0;



  DBUG_ENTER("evex_drop_event");





  VOID(pthread_mutex_lock(&LOCK_evex_running));

  if (evex_is_running)

    ret= evex_remove_from_cache(&et->dbname, &et->name, true, true);

  VOID(pthread_mutex_unlock(&LOCK_evex_running));

  

  if (ret == 1)

    ret= 0;

  else if (ret == 0)   

    ret= db_drop_event(thd, et, drop_if_exists, rows_affected);

  else

    my_error(ER_UNKNOWN_ERROR, MYF(0));



  DBUG_RETURN(ret);

}

sql/event_priv.h

+3 −0
Original line number Diff line number Diff line
@@ -40,6 +40,9 @@ evex_db_find_event_aux(THD *thd, const LEX_STRING dbname, 
int 

event_timed_compare_q(void *vptr, byte* a, byte *b);



int db_drop_event(THD *thd, event_timed *et, bool drop_if_exists,

                uint *rows_affected);





#define EXEC_QUEUE_QUEUE_NAME executing_queue

#define EXEC_QUEUE_DARR_NAME evex_executing_queue

sql/event_timed.cc

+2 −12
Original line number Diff line number Diff line
@@ -877,20 +877,10 @@ int 
event_timed::drop(THD *thd)

{

  TABLE *table;

  int ret= 0;

  uint tmp= 0;

  DBUG_ENTER("event_timed::drop");



  if (evex_open_event_table(thd, TL_WRITE, &table))

    DBUG_RETURN(-1);



  if (evex_db_find_event_aux(thd, dbname, name, definer, table))

    DBUG_RETURN(-2);



  if ((ret= table->file->ha_delete_row(table->record[0])))

    DBUG_RETURN(ret);

    

  close_thread_tables(thd);

  DBUG_RETURN(0);

  DBUG_RETURN(db_drop_event(thd, this, false, &tmp));

}