MDEV-4011 Added per thread memory counting and usage

Base code and idea from a patch from by plinux at Taobao.

The idea is that we mark all memory that are thread specific with MY_THREAD_SPECIFIC.
Memory counting is done per thread in the my_malloc_size_cb_func callback function from my_malloc().
There are plenty of new asserts to ensure that for a debug server the counting is correct.

Information_schema.processlist gets two new columns: MEMORY_USED and EXAMINED_ROWS.
- The later is there mainly to show how query is progressing.

The following changes in interfaces was needed to get this to work:
- init_alloc_root() amd init_sql_alloc() has extra option so that one can mark memory with MY_THREAD_SPECIFIC
- One now have to use alloc_root_set_min_malloc() to set min memory to be allocated by alloc_root()
- my_init_dynamic_array()  has extra option so that one can mark memory with MY_THREAD_SPECIFIC
- my_net_init() has extra option so that one can mark memory with MY_THREAD_SPECIFIC
- Added flag for hash_init() so that one can mark hash table to be thread specific.
- Added flags to init_tree() so that one can mark tree to be thread specific.
- Removed with_delete option to init_tree(). Now one should instead use MY_TREE_WITH_DELETE_FLAG.
- Added flag to Warning_info::Warning_info() if the structure should be fully initialized.
- String elements can now be marked as thread specific.
- Internal HEAP tables are now marking it's memory as MY_THREAD_SPECIFIC.
- Changed type of myf from int to ulong, as this is always a set of bit flags.

Other things:
- Removed calls to net_end() and thd->cleanup() as these are now done in ~THD()
- We now also show EXAMINED_ROWS in SHOW PROCESSLIST
- Added new variable 'memory_used'
- Fixed bug where kill_threads_for_user() was using the wrong mem_root to allocate memory.
- Removed calls to the obsoleted function init_dynamic_array()
- Use set_current_thd() instead of my_pthread_setspecific_ptr(THR_THD,...)


client/completion_hash.cc:
  Updated call to init_alloc_root()
client/mysql.cc:
  Updated call to init_alloc_root()
client/mysqlbinlog.cc:
  init_dynamic_array() -> my_init_dynamic_array()
  Updated call to init_alloc_root()
client/mysqlcheck.c:
  Updated call to my_init_dynamic_array()
client/mysqldump.c:
  Updated call to init_alloc_root()
client/mysqltest.cc:
  Updated call to init_alloc_root()
  Updated call to my_init_dynamic_array()
  Fixed compiler warnings
extra/comp_err.c:
  Updated call to my_init_dynamic_array()
extra/resolve_stack_dump.c:
  Updated call to my_init_dynamic_array()
include/hash.h:
  Added HASH_THREAD_SPECIFIC
include/heap.h:
  Added flag is internal temporary table.
include/my_dir.h:
  Safety fix: Ensure that MY_DONT_SORT and MY_WANT_STAT don't interfer with other mysys flags
include/my_global.h:
  Changed type of myf from int to ulong, as this is always a set of bit flags.
include/my_sys.h:
  Added MY_THREAD_SPECIFIC and MY_THREAD_MOVE
  Added malloc_flags to DYNAMIC_ARRAY
  Added extra mysys flag argument to my_init_dynamic_array()
  Removed deprecated functions init_dynamic_array() and my_init_dynamic_array.._ci
  Updated paramaters for init_alloc_root()
include/my_tree.h:
  Added my_flags to allow one to use MY_THREAD_SPECIFIC with hash tables.
  Removed with_delete. One should now instead use MY_TREE_WITH_DELETE_FLAG
  Updated parameters to init_tree()
include/myisamchk.h:
  Added malloc_flags to allow one to use MY_THREAD_SPECIFIC for checks.
include/mysql.h:
  Added MYSQL_THREAD_SPECIFIC_MALLOC
  Used 'unused1' to mark memory as thread specific.
include/mysql.h.pp:
  Updated file
include/mysql_com.h:
  Used 'unused1' to mark memory as thread specific.
  Updated parameters for my_net_init()
libmysql/libmysql.c:
  Updated call to init_alloc_root() to mark memory thread specific.
libmysqld/emb_qcache.cc:
  Updated call to init_alloc_root()
libmysqld/lib_sql.cc:
  Updated call to init_alloc_root()
mysql-test/r/create.result:
  Updated results
mysql-test/r/user_var.result:
  Updated results
mysql-test/suite/funcs_1/datadict/processlist_priv.inc:
  Update to handle new format of SHOW PROCESSLIST
mysql-test/suite/funcs_1/datadict/processlist_val.inc:
  Update to handle new format of SHOW PROCESSLIST
mysql-test/suite/funcs_1/r/is_columns_is.result:
  Update to handle new format of SHOW PROCESSLIST
mysql-test/suite/funcs_1/r/processlist_priv_no_prot.result:
  Updated results
mysql-test/suite/funcs_1/r/processlist_val_no_prot.result:
  Updated results
mysql-test/t/show_explain.test:
  Fixed usage of debug variable so that one can run test with --debug
mysql-test/t/user_var.test:
  Added test of memory_usage variable.
mysys/array.c:
  Added extra my_flags option to init_dynamic_array() and init_dynamic_array2() so that one can mark memory with MY_THREAD_SPECIFIC
  All allocated memory is marked with the given my_flags.
  Removed obsolete function init_dynamic_array()
mysys/default.c:
  Updated call to init_alloc_root()
  Updated call to my_init_dynamic_array()
mysys/hash.c:
  Updated call to my_init_dynamic_array_ci().
  Allocated memory is marked with MY_THREAD_SPECIFIC if HASH_THREAD_SPECIFIC is used.
mysys/ma_dyncol.c:
  init_dynamic_array() -> my_init_dynamic_array()
  Added #if to get rid of compiler warnings
mysys/mf_tempdir.c:
  Updated call to my_init_dynamic_array()
mysys/my_alloc.c:
  Added extra parameter to init_alloc_root() so that one can mark memory with MY_THREAD_SPECIFIC
  Extend MEM_ROOT with a flag if memory is thread specific.
  This is stored in block_size, to keep the size of the MEM_ROOT object identical as before.
  Allocated memory is marked with MY_THREAD_SPECIFIC if used with init_alloc_root()
mysys/my_chmod.c:
  Updated DBUG_PRINT because of change of myf type
mysys/my_chsize.c:
  Updated DBUG_PRINT because of change of myf type
mysys/my_copy.c:
  Updated DBUG_PRINT because of change of myf type
mysys/my_create.c:
  Updated DBUG_PRINT because of change of myf type
mysys/my_delete.c:
  Updated DBUG_PRINT because of change of myf type
mysys/my_error.c:
  Updated DBUG_PRINT because of change of myf type
mysys/my_fopen.c:
  Updated DBUG_PRINT because of change of myf type
mysys/my_fstream.c:
  Updated DBUG_PRINT because of change of myf type
mysys/my_getwd.c:
  Updated DBUG_PRINT because of change of myf type
mysys/my_lib.c:
  Updated call to init_alloc_root()
  Updated call to my_init_dynamic_array()
  Updated DBUG_PRINT because of change of myf type
mysys/my_lock.c:
  Updated DBUG_PRINT because of change of myf type
mysys/my_malloc.c:
  Store at start of each allocated memory block the size of the block and if the block is thread specific.
  Call malloc_size_cb_func, if set, with the memory allocated/freed.
  Updated DBUG_PRINT because of change of myf type
mysys/my_open.c:
  Updated DBUG_PRINT because of change of myf type
mysys/my_pread.c:
  Updated DBUG_PRINT because of change of myf type
mysys/my_read.c:
  Updated DBUG_PRINT because of change of myf type
mysys/my_redel.c:
  Updated DBUG_PRINT because of change of myf type
mysys/my_rename.c:
  Updated DBUG_PRINT because of change of myf type
mysys/my_seek.c:
  Updated DBUG_PRINT because of change of myf type
mysys/my_sync.c:
  Updated DBUG_PRINT because of change of myf type
mysys/my_thr_init.c:
  Ensure that one can call my_thread_dbug_id() even if thread is not properly initialized.
mysys/my_write.c:
  Updated DBUG_PRINT because of change of myf type
mysys/mysys_priv.h:
  Updated parameters to sf_malloc and sf_realloc()
mysys/safemalloc.c:
  Added checking that for memory marked with MY_THREAD_SPECIFIC that it's the same thread that is allocation and freeing the memory.
  Added sf_malloc_dbug_id() to allow MariaDB to specify which THD is handling the memory.
  Added my_flags arguments to sf_malloc() and sf_realloc() to be able to mark memory with MY_THREAD_SPECIFIC.
  Added sf_report_leaked_memory() to get list of memory not freed by a thread.
mysys/tree.c:
  Added flags to init_tree() so that one can mark tree to be thread specific.
  Removed with_delete option to init_tree(). Now one should instead use MY_TREE_WITH_DELETE_FLAG.
  Updated call to init_alloc_root()
  All allocated memory is marked with the given malloc flags
mysys/waiting_threads.c:
  Updated call to my_init_dynamic_array()
sql-common/client.c:
  Updated call to init_alloc_root() and my_net_init() to mark memory thread specific.
  Updated call to my_init_dynamic_array().
  Added MYSQL_THREAD_SPECIFIC_MALLOC so that client can mark memory as MY_THREAD_SPECIFIC.
sql-common/client_plugin.c:
  Updated call to init_alloc_root()
sql/debug_sync.cc:
  Added MY_THREAD_SPECIFIC to allocated memory.
sql/event_scheduler.cc:
  Removed calls to net_end() as this is now done in ~THD()
  Call set_current_thd() to ensure that memory is assigned to right thread.
sql/events.cc:
  my_pthread_setspecific_ptr(THR_THD,...) -> set_current_thd()
sql/filesort.cc:
  Added MY_THREAD_SPECIFIC to allocated memory.
sql/filesort_utils.cc:
  Added MY_THREAD_SPECIFIC to allocated memory.
sql/ha_ndbcluster.cc:
  Updated call to init_alloc_root()
  Updated call to my_net_init()
  Removed calls to net_end() and thd->cleanup() as these are now done in ~THD()
sql/ha_ndbcluster_binlog.cc:
  Updated call to my_net_init()
  Updated call to init_sql_alloc()
  Removed calls to net_end() and thd->cleanup() as these are now done in ~THD()
sql/ha_partition.cc:
  Updated call to init_alloc_root()
sql/handler.cc:
  Added MY_THREAD_SPECIFIC to allocated memory.
  Added missing call to my_dir_end()
sql/item_func.cc:
  Added MY_THREAD_SPECIFIC to allocated memory.
sql/item_subselect.cc:
  Added MY_THREAD_SPECIFIC to allocated memory.
sql/item_sum.cc:
  Added MY_THREAD_SPECIFIC to allocated memory.
sql/log.cc:
  More DBUG
  Updated call to init_alloc_root()
sql/mdl.cc:
  Added MY_THREAD_SPECIFIC to allocated memory.
sql/mysqld.cc:
  Added total_memory_used
  Updated call to init_alloc_root()
  Move mysql_cond_broadcast() before my_thread_end()
  Added mariadb_dbug_id() to count memory per THD instead of per thread.
  Added my_malloc_size_cb_func() callback function for my_malloc() to count memory.
  Move initialization of mysqld_server_started and mysqld_server_initialized earlier.
  Updated call to my_init_dynamic_array().
  Updated call to my_net_init().
  Call my_pthread_setspecific_ptr(THR_THD,...) to ensure that memory is assigned to right thread.
  Added status variable 'memory_used'.
  Updated call to init_alloc_root()
  my_pthread_setspecific_ptr(THR_THD,...) -> set_current_thd()
sql/mysqld.h:
  Added set_current_thd()
sql/net_serv.cc:
  Added new parameter to my_net_init() so that one can mark memory with MY_THREAD_SPECIFIC.
  Store in net->thread_specific_malloc if memory is thread specific.
  Mark memory to be thread specific if requested.
sql/opt_range.cc:
  Updated call to my_init_dynamic_array()
  Updated call to init_sql_alloc()
  Added MY_THREAD_SPECIFIC to allocated memory.
sql/opt_subselect.cc:
  Updated call to init_sql_alloc() to mark memory thread specific.
sql/protocol.cc:
  Fixed compiler warning
sql/records.cc:
  Added MY_THREAD_SPECIFIC to allocated memory.
sql/rpl_filter.cc:
  Updated call to my_init_dynamic_array()
sql/rpl_handler.cc:
  Updated call to my_init_dynamic_array2()
sql/rpl_handler.h:
  Updated call to init_sql_alloc()
sql/rpl_mi.cc:
  Updated call to my_init_dynamic_array()
sql/rpl_tblmap.cc:
  Updated call to init_alloc_root()
sql/rpl_utility.cc:
  Updated call to my_init_dynamic_array()
sql/slave.cc:
  Initialize things properly before calling functions that allocate memory.
  Removed calls to net_end() as this is now done in ~THD()
sql/sp_head.cc:
  Updated call to init_sql_alloc()
  Updated call to my_init_dynamic_array()
  Added parameter to warning_info() that it should be fully initialized.
sql/sp_pcontext.cc:
  Updated call to my_init_dynamic_array()
sql/sql_acl.cc:
  Updated call to init_sql_alloc()
  Updated call to my_init_dynamic_array()
  my_pthread_setspecific_ptr(THR_THD,...) -> set_current_thd()
sql/sql_admin.cc:
  Added parameter to warning_info() that it should be fully initialized.
sql/sql_analyse.h:
  Updated call to init_tree() to mark memory thread specific.
sql/sql_array.h:
  Updated call to my_init_dynamic_array() to mark memory thread specific.
sql/sql_audit.cc:
  Updated call to my_init_dynamic_array()
sql/sql_base.cc:
  Updated call to init_sql_alloc()
  my_pthread_setspecific_ptr(THR_THD,...) -> set_current_thd()
sql/sql_cache.cc:
  Updated comment
sql/sql_class.cc:
  Added parameter to warning_info() that not initialize it until THD is fully created.
  Updated call to init_sql_alloc()
  Mark THD::user_vars has to be thread specific.
  Updated call to my_init_dynamic_array()
  Ensure that memory allocated by THD is assigned to the THD.
  More DBUG
  Always acll net_end() in ~THD()
  Assert that all memory signed to this THD is really deleted at ~THD.
  Fixed set_status_var_init() to not reset memory_used.
  my_pthread_setspecific_ptr(THR_THD,...) -> set_current_thd()
sql/sql_class.h:
  Added MY_THREAD_SPECIFIC to allocated memory.
  Added malloc_size to THD to record allocated memory per THD.
sql/sql_delete.cc:
  Added MY_THREAD_SPECIFIC to allocated memory.
sql/sql_error.cc:
  Added 'initialize' parameter to Warning_info() to say if should allocate memory for it's structures.
  This is used by THD::THD() to not allocate memory until THD is ready.
  Added Warning_info::free_memory()
sql/sql_error.h:
  Updated Warning_info() class.
sql/sql_handler.cc:
  Updated call to init_alloc_root() to mark memory thread specific.
sql/sql_insert.cc:
  More DBUG
sql/sql_join_cache.cc:
  Added MY_THREAD_SPECIFIC to allocated memory.
sql/sql_lex.cc:
  Updated call to my_init_dynamic_array()
sql/sql_lex.h:
  Updated call to my_init_dynamic_array()
sql/sql_load.cc:
  Added MY_THREAD_SPECIFIC to allocated memory.
sql/sql_parse.cc:
  Removed calls to net_end() and thd->cleanup() as these are now done in ~THD()
  Ensure that examined_row_count() is reset before query.
  Fixed bug where kill_threads_for_user() was using the wrong mem_root to allocate memory.
  my_pthread_setspecific_ptr(THR_THD,...) -> set_current_thd()
  Don't restore thd->status_var.memory_used when restoring thd->status_var
sql/sql_plugin.cc:
  Updated call to init_alloc_root()
  Updated call to my_init_dynamic_array()
  Don't allocate THD on the stack, as this causes problems with valgrind when doing thd memory counting.
  my_pthread_setspecific_ptr(THR_THD,...) -> set_current_thd()
sql/sql_prepare.cc:
  Added parameter to warning_info() that it should be fully initialized.
  Updated call to init_sql_alloc() to mark memory thread specific.
sql/sql_reload.cc:
  my_pthread_setspecific_ptr(THR_THD,...) -> set_current_thd()
sql/sql_select.cc:
  Updated call to my_init_dynamic_array() and init_sql_alloc() to mark memory thread specific.
  Added MY_THREAD_SPECIFIC to allocated memory.
  More DBUG
sql/sql_servers.cc:
  Updated call to init_sql_alloc() to mark memory some memory thread specific.
  my_pthread_setspecific_ptr(THR_THD,...) -> set_current_thd()
sql/sql_show.cc:
  Updated call to my_init_dynamic_array()
  Mark my_dir() memory thread specific.
  Use my_pthread_setspecific_ptr(THR_THD,...) to mark that allocated memory should be allocated to calling thread.
  More DBUG.
  Added malloc_size and examined_row_count to SHOW PROCESSLIST.
  Added MY_THREAD_SPECIFIC to allocated memory.
  Updated call to init_sql_alloc()
  Added parameter to warning_info() that it should be fully initialized.
sql/sql_statistics.cc:
  Fixed compiler warning
sql/sql_string.cc:
  String elements can now be marked as thread specific.
sql/sql_string.h:
  String elements can now be marked as thread specific.
sql/sql_table.cc:
  Updated call to init_sql_alloc() and my_malloc() to mark memory thread specific
  my_pthread_setspecific_ptr(THR_THD,...) -> set_current_thd()
  Fixed compiler warning
sql/sql_test.cc:
  Updated call to my_init_dynamic_array() to mark memory thread specific.
sql/sql_trigger.cc:
  Updated call to init_sql_alloc()
sql/sql_udf.cc:
  Updated call to init_sql_alloc()
  my_pthread_setspecific_ptr(THR_THD,...) -> set_current_thd()
sql/sql_update.cc:
  Added MY_THREAD_SPECIFIC to allocated memory.
sql/table.cc:
  Updated call to init_sql_alloc().
  Mark memory used by temporary tables, that are not for slave threads, as MY_THREAD_SPECIFIC
  Updated call to init_sql_alloc()
sql/thr_malloc.cc:
  Added my_flags argument to init_sql_alloc() to be able to mark memory as MY_THREAD_SPECIFIC.
sql/thr_malloc.h:
  Updated prototype for init_sql_alloc()
sql/tztime.cc:
  Updated call to init_sql_alloc()
  Updated call to init_alloc_root() to mark memory thread specific.
  my_pthread_setspecific_ptr(THR_THD,...) -> set_current_thd()
sql/uniques.cc:
  Updated calls to init_tree(), my_init_dynamic_array() and my_malloc() to mark memory thread specific.
sql/unireg.cc:
  Added MY_THREAD_SPECIFIC to allocated memory.
storage/csv/ha_tina.cc:
  Updated call to init_alloc_root()
storage/federated/ha_federated.cc:
  Updated call to init_alloc_root()
  Updated call to my_init_dynamic_array()
  Ensure that memory allocated by fedarated is registered for the system, not for the thread.
storage/federatedx/federatedx_io_mysql.cc:
  Updated call to my_init_dynamic_array()
storage/federatedx/ha_federatedx.cc:
  Updated call to init_alloc_root()
  Updated call to my_init_dynamic_array()
storage/heap/ha_heap.cc:
  Added MY_THREAD_SPECIFIC to allocated memory.
storage/heap/heapdef.h:
  Added parameter to hp_get_new_block() to be able to do thread specific memory tagging.
storage/heap/hp_block.c:
  Added parameter to hp_get_new_block() to be able to do thread specific memory tagging.
storage/heap/hp_create.c:
  - Internal HEAP tables are now marking it's memory as MY_THREAD_SPECIFIC.
  - Use MY_TREE_WITH_DELETE instead of removed option 'with_delete'.
storage/heap/hp_open.c:
  Internal HEAP tables are now marking it's memory as MY_THREAD_SPECIFIC.
storage/heap/hp_write.c:
  Added new parameter to hp_get_new_block()
storage/maria/ma_bitmap.c:
  Updated call to my_init_dynamic_array()
storage/maria/ma_blockrec.c:
  Updated call to my_init_dynamic_array()
storage/maria/ma_check.c:
  Updated call to init_alloc_root()
storage/maria/ma_ft_boolean_search.c:
  Updated calls to init_tree() and init_alloc_root()
storage/maria/ma_ft_nlq_search.c:
  Updated call to init_tree()
storage/maria/ma_ft_parser.c:
  Updated call to init_tree()
  Updated call to init_alloc_root()
storage/maria/ma_loghandler.c:
  Updated call to my_init_dynamic_array()
storage/maria/ma_open.c:
  Updated call to my_init_dynamic_array()
storage/maria/ma_sort.c:
  Updated call to my_init_dynamic_array()
storage/maria/ma_write.c:
  Updated calls to my_init_dynamic_array() and init_tree()
storage/maria/maria_pack.c:
  Updated call to init_tree()
storage/maria/unittest/sequence_storage.c:
  Updated call to my_init_dynamic_array()
storage/myisam/ft_boolean_search.c:
  Updated call to init_tree()
  Updated call to init_alloc_root()
storage/myisam/ft_nlq_search.c:
  Updated call to init_tree()
storage/myisam/ft_parser.c:
  Updated call to init_tree()
  Updated call to init_alloc_root()
storage/myisam/ft_stopwords.c:
  Updated call to init_tree()
storage/myisam/mi_check.c:
  Updated call to init_alloc_root()
storage/myisam/mi_write.c:
  Updated call to my_init_dynamic_array()
  Updated call to init_tree()
storage/myisam/myisamlog.c:
  Updated call to init_tree()
storage/myisam/myisampack.c:
  Updated call to init_tree()
storage/myisam/sort.c:
  Updated call to my_init_dynamic_array()
storage/myisammrg/ha_myisammrg.cc:
  Updated call to init_sql_alloc()
storage/perfschema/pfs_check.cc:
  Rest current_thd
storage/perfschema/pfs_instr.cc:
  Removed DBUG_ENTER/DBUG_VOID_RETURN as at this point my_thread_var is not allocated anymore, which can cause problems.
support-files/compiler_warnings.supp:
  Disable compiler warning from offsetof macro.

1 files changed, 88 insertions, 75 deletions

diff --git a/mysql-test/t/show_explain.test b/mysql-test/t/show_explain.test
index ee2eccbc95f..2df9df65996 100644
--- a/mysql-test/t/show_explain.test
+++ b/mysql-test/t/show_explain.test
@@ -8,6 +8,7 @@
 drop table if exists t0, t1, t2, t3, t4;
 drop view if exists v1;
 --enable_warnings
+SET @old_debug= @@session.debug;
 
 # 
 # Testcases in this file do not work with embedded server. The reason for this
@@ -56,6 +57,7 @@ let $thr1=`select connection_id()`;
 connect (con1, localhost, root,,);
 connection con1;
 let $thr2=`select connection_id()`;
+SET @old_debug= @@session.debug;
 connection default;
 
 # SHOW EXPLAIN FOR <idle thread>
@@ -73,7 +75,7 @@ let $wait_condition= select State='show_explain_trap' from information_schema.pr
 #
 connection con1;
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 send select count(*) from t1 where a < 100000;
 
 connection default;
@@ -101,95 +103,102 @@ evalp show explain for $thr2;
 connection con1;
 reap;
 set optimizer_switch= @show_expl_tmp;
-
+set debug_dbug=@old_debug;
 
 --echo # UNION, first branch 
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 send explain select a from t0 A union select a+1 from t0 B;
 connection default;
 --source include/wait_condition.inc
 evalp show explain for $thr2;
 connection con1;
 reap;
+set debug_dbug=@old_debug;
 
 
 --echo # UNION, second branch
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 send explain select a from t0 A union select a+1 from t0 B;
 connection default;
 --source include/wait_condition.inc
 evalp show explain for $thr2;
 connection con1;
 reap;
+set debug_dbug=@old_debug;
 
 
 --echo # Uncorrelated  subquery, select
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 send select a, (select max(a) from t0 B) from t0 A where a<1;
 connection default;
 --source include/wait_condition.inc
 evalp show explain for $thr2;
 connection con1;
 reap;
+set debug_dbug=@old_debug;
 
 
 --echo # Uncorrelated  subquery, explain
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 send explain select a, (select max(a) from t0 B) from t0 A where a<1;
 connection default;
 --source include/wait_condition.inc
 evalp show explain for $thr2;
 connection con1;
 reap;
+set debug_dbug=@old_debug;
 
 --echo # correlated  subquery, select
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 send select a, (select max(a) from t0 b where b.a+a.a<10) from t0 a where a<1;
 connection default;
 --source include/wait_condition.inc
 evalp show explain for $thr2;
 connection con1;
 reap;
+set debug_dbug=@old_debug;
 
 --echo # correlated  subquery, explain
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 send select a, (select max(a) from t0 b where b.a+a.a<10) from t0 a where a<1;
 connection default;
 --source include/wait_condition.inc
 evalp show explain for $thr2;
 connection con1;
 reap;
+set debug_dbug=@old_debug;
 
 --echo # correlated  subquery, select, while inside the subquery
 set @show_explain_probe_select_id=2; # <---
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 send select a, (select max(a) from t0 b where b.a+a.a<10) from t0 a where a<1;
 connection default;
 --source include/wait_condition.inc
 evalp show explain for $thr2;
 connection con1;
 reap;
+set debug_dbug=@old_debug;
 
 --echo # correlated  subquery, explain, while inside the subquery
 set @show_explain_probe_select_id=2;
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 send select a, (select max(a) from t0 b where b.a+a.a<10) from t0 a where a<1;
 connection default;
 --source include/wait_condition.inc
 evalp show explain for $thr2;
 connection con1;
 reap;
-
+set debug_dbug=@old_debug;
 
 --echo # correlated  subquery, explain, while inside the subquery
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_end';
+set debug_dbug='+d,show_explain_probe_join_exec_end';
 send select a, (select max(a) from t0 b where b.a+a.a<10) from t0 a where a<1;
 connection default;
 --source include/wait_condition.inc
@@ -197,6 +206,7 @@ connection default;
 evalp show explain for $thr2;
 connection con1;
 reap;
+set debug_dbug=@old_debug;
 
 # TODO: explain in the parent subuqery when the un-correlated child has been
 # run (and have done irreversible cleanups)
@@ -209,7 +219,7 @@ reap;
 --echo #   I've found experimentally that select_id==2 here...
 --echo # 
 set @show_explain_probe_select_id=2;
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 send set @foo= (select max(a) from t0 where sin(a) >0);
 connection default;
 --source include/wait_condition.inc
@@ -217,13 +227,14 @@ connection default;
 evalp show explain for $thr2;
 connection con1;
 reap;
+set debug_dbug=@old_debug;
 
 --echo #
 --echo # Attempt SHOW EXPLAIN for an UPDATE
 --echo #
 create table t2 as select a as a, a as dummy from t0 limit 2;
 set @show_explain_probe_select_id=2;
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 send update t2 set dummy=0 where (select max(a) from t0 where t2.a + t0.a <3) >3 ;
 connection default;
 --source include/wait_condition.inc
@@ -234,13 +245,14 @@ evalp show explain for $thr2;
 connection con1;
 reap;
 drop table t2;
+set debug_dbug=@old_debug;
 
 --echo #
 --echo # Attempt SHOW EXPLAIN for a DELETE
 --echo # 
 create table t2 as select a as a, a as dummy from t0 limit 2;
 set @show_explain_probe_select_id=2;
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 send delete from t2 where (select max(a) from t0 where t2.a + t0.a <3) >3 ;
 connection default;
 --source include/wait_condition.inc
@@ -251,14 +263,14 @@ evalp show explain for $thr2;
 connection con1;
 reap;
 drop table t2;
-
+set debug_dbug=@old_debug;
 
 --echo #
 --echo # Multiple SHOW EXPLAIN calls for one select 
 --echo # 
 create table t2 as select a as a, a as dummy from t0 limit 3;
 set @show_explain_probe_select_id=2;
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 send select t2.a, ((select max(a) from t0 where t2.a + t0.a <3) >3) as SUBQ from t2;
 connection default;
 --source include/wait_condition.inc
@@ -268,13 +280,14 @@ evalp show explain for $thr2;
 connection con1;
 reap;
 drop table t2;
+set debug_dbug=@old_debug;
 
 --echo #
 --echo # SHOW EXPLAIN for SELECT ... ORDER BY with "Using filesort"
 --echo #
 explain select * from t0 order by a;
 
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 set @show_explain_probe_select_id=1;
 send select * from t0 order by a; 
 connection default;
@@ -282,6 +295,7 @@ connection default;
 evalp show explain for $thr2;
 connection con1;
 reap;
+set debug_dbug=@old_debug;
 
 --echo #
 --echo # SHOW EXPLAIN for SELECT ... with "Using temporary"
@@ -290,7 +304,7 @@ connection default;
 explain select distinct a from t0;
 connection con1;
 
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 set @show_explain_probe_select_id=1;
 send select distinct a from t0; 
 connection default;
@@ -298,6 +312,7 @@ connection default;
 evalp show explain for $thr2;
 connection con1;
 reap;
+set debug_dbug=@old_debug;
 
 --echo #
 --echo # SHOW EXPLAIN for SELECT ... with "Using temporary; Using filesort"
@@ -306,7 +321,7 @@ connection default;
 explain select distinct a from t0;
 connection con1;
 
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 set @show_explain_probe_select_id=1;
 send select distinct a from t0; 
 connection default;
@@ -314,7 +329,7 @@ connection default;
 evalp show explain for $thr2;
 connection con1;
 reap;
-set debug_dbug='';
+set debug_dbug=@old_debug;
 
 --echo #
 --echo # MDEV-238: SHOW EXPLAIN: Server crashes in JOIN::print_explain with FROM subquery and GROUP BY
@@ -323,7 +338,7 @@ CREATE TABLE t2 ( a INT );
 INSERT INTO t2 VALUES (1),(2),(1),(4),(2);
 explain SELECT alias.a FROM t2, ( SELECT * FROM t2 ) AS alias GROUP BY alias.a;
 
-set debug_dbug='d,show_explain_in_find_all_keys';
+set debug_dbug='+d,show_explain_in_find_all_keys';
 send SELECT alias.a FROM t2, ( SELECT * FROM t2 ) AS alias GROUP BY alias.a;
 
 connection default;
@@ -334,7 +349,7 @@ connection default;
 evalp show explain for $thr2;
 connection con1;
 reap;
-set debug_dbug='';
+set debug_dbug=@old_debug;
 DROP TABLE t2;
 
 
@@ -350,7 +365,7 @@ INSERT INTO t2 VALUES (1),(2),(1),(4),(2);
 EXPLAIN EXTENDED SELECT alias.a FROM t2, ( SELECT * FROM t2 ) AS alias GROUP BY alias.a ;
 
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_end';
+set debug_dbug='+d,show_explain_probe_join_exec_end';
 send EXPLAIN EXTENDED SELECT alias.a FROM t2, ( SELECT * FROM t2 ) AS alias GROUP BY alias.a ;
 
 connection default;
@@ -358,7 +373,7 @@ connection default;
 evalp show explain for $thr2;
 connection con1;
 reap;
-set debug_dbug='';
+set debug_dbug=@old_debug;
 DROP TABLE t2;
 
 
@@ -374,7 +389,7 @@ INSERT INTO t2 VALUES (4),(5),(6),(7),(8),(9);
 explain SELECT * FROM v1, t2;
 
 set @show_explain_probe_select_id=2;
-set debug_dbug='d,show_explain_probe_join_exec_end';
+set debug_dbug='+d,show_explain_probe_join_exec_end';
 send SELECT * FROM v1, t2;
 
 connection default;
@@ -383,7 +398,7 @@ connection default;
 evalp show explain for $thr2;
 connection con1;
 reap;
-set debug_dbug='';
+set debug_dbug=@old_debug;
 DROP VIEW v1;
 DROP TABLE t2, t3;
 
@@ -391,21 +406,21 @@ DROP TABLE t2, t3;
 --echo # MDEV-267: SHOW EXPLAIN: Server crashes in JOIN::print_explain on most of queries
 --echo #
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_end';
+set debug_dbug='+d,show_explain_probe_join_exec_end';
 send select sleep(1);
 connection default;
 --source include/wait_condition.inc
 evalp show explain for $thr2;
 connection con1;
 reap;
-set debug_dbug='';
+set debug_dbug=@old_debug;
 
 
 --echo #
 --echo # Same as above, but try another reason for JOIN to be degenerate
 --echo #
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_end';
+set debug_dbug='+d,show_explain_probe_join_exec_end';
 send select * from t0 where 1>10;
 connection default;
 --source include/wait_condition.inc
@@ -413,7 +428,7 @@ connection default;
 evalp show explain for $thr2;
 connection con1;
 reap;
-set debug_dbug='';
+set debug_dbug=@old_debug;
 
 --echo #
 --echo # Same as above, but try another reason for JOIN to be degenerate (2)
@@ -421,7 +436,7 @@ set debug_dbug='';
 create table t3(a int primary key);
 insert into t3 select a from t0;
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_end';
+set debug_dbug='+d,show_explain_probe_join_exec_end';
 send select * from t0,t3 where t3.a=112233;
 connection default;
 --source include/wait_condition.inc
@@ -429,7 +444,7 @@ connection default;
 evalp show explain for $thr2;
 connection con1;
 reap;
-set debug_dbug='';
+set debug_dbug=@old_debug;
 drop table t3;
 
 --echo #
@@ -448,7 +463,7 @@ explain SELECT * FROM t2 WHERE a =
        );
 
 set @show_explain_probe_select_id=2;
-set debug_dbug='d,show_explain_probe_do_select';
+set debug_dbug='+d,show_explain_probe_do_select';
 send SELECT * FROM t2 WHERE a = 
        (SELECT MAX(a) FROM t2 
         WHERE pk= (SELECT MAX(pk) FROM t2 WHERE pk = 3)
@@ -458,7 +473,7 @@ connection default;
 evalp show explain for $thr2;
 connection con1;
 reap;
-set debug_dbug='';
+set debug_dbug=@old_debug;
 drop table t2;
 
 
@@ -491,7 +506,7 @@ WHERE a1 < ALL (
 );
 
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_do_select';
+set debug_dbug='+d,show_explain_probe_do_select';
 send
 SELECT count(*) FROM t2, t3
 WHERE a1 < ALL ( 
@@ -504,7 +519,7 @@ connection default;
 evalp show explain for $thr2;
 connection con1;
 reap;
-set debug_dbug='';
+set debug_dbug=@old_debug;
 drop table t2, t3, t4;
 
 --echo #
@@ -516,7 +531,7 @@ INSERT INTO t2 VALUES
   (11,23),(12,3),(13,45),(14,16),(15,2),(16,33),(17,2),(18,5),(19,9),(20,2);
 
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_end';
+set debug_dbug='+d,show_explain_probe_join_exec_end';
 send
   SELECT * FROM t2 WHERE (5, 78) IN (SELECT `a1`, MAX(`a1`) FROM t2 GROUP BY `a1`);
 connection default;
@@ -525,10 +540,9 @@ connection default;
 evalp show explain for $thr2;
 connection con1;
 reap;
-set debug_dbug='';
+set debug_dbug=@old_debug;
 
 DROP TABLE t2;
-
 DROP TABLE t1;
 
 --echo #
@@ -538,7 +552,7 @@ CREATE TABLE t1(a INT, KEY(a));
 INSERT INTO t1 VALUES (3),(1),(5),(1);
 
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 
 send SELECT 'test' FROM t1 WHERE a=1;
 connection default;
@@ -546,7 +560,7 @@ connection default;
 evalp show explain for $thr2;
 connection con1;
 reap;
-set debug_dbug='';
+set debug_dbug=@old_debug;
 
 DROP TABLE t1;
 
@@ -570,7 +584,7 @@ set join_cache_level=0;
 explain select count(*) from t1 A, t1 B where B.key1 < A.col2 and A.col1=3 AND B.col2 + 1 < 100;
 
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_test_if_quick_select';
+set debug_dbug='+d,show_explain_probe_test_if_quick_select';
 
 send 
 select count(*) from t1 A, t1 B where B.key1 < A.col2 and A.col1=3 AND B.col2 + 1 < 100;
@@ -587,7 +601,7 @@ evalp show explain for $thr2;
 connection con1;
 reap;
 
-set debug_dbug='';
+set debug_dbug=@old_debug;
 drop table t1;
 
 --echo #
@@ -598,7 +612,7 @@ CREATE TABLE t1(a INT, b INT, c INT, KEY(a), KEY(b), KEY(c));
 INSERT INTO t1 (a) VALUES (3),(1),(5),(1);
 
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 
 send SHOW INDEX FROM t1;
 connection default;
@@ -606,7 +620,7 @@ connection default;
 evalp show explain for $thr2;
 connection con1;
 reap;
-set debug_dbug='';
+set debug_dbug=@old_debug;
 
 DROP TABLE t1;
 
@@ -620,7 +634,7 @@ CREATE ALGORITHM=TEMPTABLE VIEW v1 AS SELECT * FROM t1;
 
 EXPLAIN SELECT a + 1 FROM v1;
 
-set debug_dbug='d,show_explain_probe_join_tab_preread';
+set debug_dbug='+d,show_explain_probe_join_tab_preread';
 set @show_explain_probe_select_id=1;
 
 send
@@ -630,7 +644,7 @@ connection default;
 evalp show explain for $thr2;
 connection con1;
 reap;
-set debug_dbug='';
+set debug_dbug=@old_debug;
 
 DROP VIEW v1;
 DROP TABLE t1;
@@ -646,7 +660,7 @@ INSERT INTO t1 VALUES (4),(6);
 EXPLAIN 
 SELECT a FROM t1 WHERE a IN ( SELECT 1+SLEEP(0.01) UNION SELECT 2 );
 
-set debug_dbug='d,show_explain_probe_union_read';
+set debug_dbug='+d,show_explain_probe_union_read';
 send
 SELECT a FROM t1 WHERE a IN ( SELECT 1+SLEEP(0.01) UNION SELECT 2 );
 
@@ -660,8 +674,7 @@ evalp show explain for $thr2;
 connection con1;
 reap;
 
-set debug_dbug='';
-
+set debug_dbug=@old_debug;
 DROP TABLE t1;
 
 --echo #
@@ -683,7 +696,7 @@ SELECT * FROM t1, ( SELECT * FROM t2 ) AS alias
 WHERE a < ALL ( SELECT b FROM t1, t2 WHERE a = b );
 
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 --send
 SELECT * FROM t1, ( SELECT * FROM t2 ) AS alias
 WHERE a < ALL ( SELECT b FROM t1, t2 WHERE a = b );
@@ -694,7 +707,7 @@ evalp show explain for $thr2;
 
 connection con1;
 reap;
-set debug_dbug='';
+set debug_dbug=@old_debug;
 DROP TABLE t1, t2;
 
 --echo # 
@@ -717,7 +730,7 @@ insert into t3 select * from t4;
 explain select distinct t1.a from t1,t3 where t1.a=t3.a;
 
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 --send
 select distinct t1.a from t1,t3 where t1.a=t3.a;
 connection default;
@@ -726,7 +739,7 @@ evalp show explain for $thr2;
 
 connection con1;
 reap;
-set debug_dbug='';
+set debug_dbug=@old_debug;
 
 drop table t1,t3,t4;
 
@@ -744,7 +757,7 @@ connection con1;
 --echo #  First, make sure that user 'test2' cannot do SHOW EXPLAIN on us
 --echo #
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 send
 select * from t0 where a < 3;
 
@@ -760,7 +773,7 @@ evalp show explain for $thr2;
 
 connection con1;
 reap;
-set debug_dbug='';
+set debug_dbug=@old_debug;
 
 --echo #
 --echo # Check that user test2 can do SHOW EXPLAIN on its own queries 
@@ -770,7 +783,7 @@ connect (con3, localhost, test2,,);
 connection con2;
 let $thr_con2=`select connection_id()`;
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 send
 select * from t0 where a < 3;
 
@@ -796,9 +809,10 @@ disconnect con2;
 grant process on *.* to test2@localhost;
 connect (con2, localhost, test2,,);
 connection con1;
+set debug_dbug=@old_debug;
 
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 send
 select * from t0 where a < 3;
 
@@ -810,7 +824,7 @@ evalp show explain for $thr2;
 
 connection con1;
 reap;
-set debug_dbug='';
+set debug_dbug=@old_debug;
 
 revoke all privileges on test.* from test2@localhost;
 drop user test2@localhost;
@@ -890,7 +904,7 @@ WHERE a IN ( 255, 0 ) OR b BETWEEN 6 AND 129
 ORDER BY b;
 
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 --send
 SELECT a+SLEEP(0.01) FROM t1
 WHERE a IN ( 255, 0 ) OR b BETWEEN 6 AND 129
@@ -902,9 +916,10 @@ evalp show explain for $thr2;
 
 connection con1;
 reap;
+set debug_dbug=@old_debug;
 
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_do_select';
+set debug_dbug='+d,show_explain_probe_do_select';
 --send
 SELECT a+SLEEP(0.01) FROM t1
 WHERE a IN ( 255, 0 ) OR b BETWEEN 6 AND 129
@@ -917,7 +932,7 @@ evalp show explain for $thr2;
 connection con1;
 reap;
 
-set debug_dbug='';
+set debug_dbug=@old_debug;
 
 drop table t1;
 
@@ -933,7 +948,7 @@ INSERT INTO t1 SELECT t11.a FROM t1 t11, t1 t12, t1 t13;
 EXPLAIN SELECT a FROM t1 GROUP BY a;
 
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 --send
 SELECT a FROM t1 GROUP BY a;
 
@@ -944,7 +959,7 @@ evalp show explain for $thr2;
 connection con1;
 reap;
 
-set debug_dbug='';
+set debug_dbug=@old_debug;
 
 drop table t1;
 
@@ -960,7 +975,7 @@ INSERT INTO t2 VALUES (86,'English'),(87,'Russian');
 explain SELECT SUM(a + SLEEP(0.1)) FROM t1 WHERE a IN ( SELECT c FROM t2 WHERE d < b ) OR b < 's';
 
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 --send
 SELECT SUM(a + SLEEP(0.1)) FROM t1 WHERE a IN ( SELECT c FROM t2 WHERE d < b ) OR b < 's';
 
@@ -971,8 +986,7 @@ evalp show explain for $thr2;
 connection con1;
 reap;
 
-set debug_dbug='';
-
+set debug_dbug=@old_debug;
 drop table t1, t2;
 
 --echo #
@@ -1011,7 +1025,7 @@ explain
 SELECT b AS field1, b AS field2 FROM t1, t2, t3 WHERE d = b ORDER BY field1, field2;
 
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_do_select';
+set debug_dbug='+d,show_explain_probe_do_select';
 
 send
 SELECT b AS field1, b AS field2 FROM t1, t2, t3 WHERE d = b ORDER BY field1, field2;
@@ -1023,7 +1037,7 @@ evalp show explain for $thr2;
 connection con1;
 reap;
 
-set debug_dbug='';
+set debug_dbug=@old_debug;
 
 DROP TABLE t1,t2,t3;
 
@@ -1047,7 +1061,7 @@ SELECT max(a+b+c) FROM t1 AS alias1, ( SELECT * FROM t2 ) AS alias
 WHERE EXISTS ( SELECT * FROM t3 WHERE b = c )  OR a <= 10;
 
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 
 send
 SELECT max(a+b+c) FROM t1 AS alias1, ( SELECT * FROM t2 ) AS alias 
@@ -1060,8 +1074,7 @@ evalp show explain for $thr2;
 connection con1;
 reap;
 
-set debug_dbug='';
-
+set debug_dbug=@old_debug;
 DROP TABLE t1,t2,t3;
 
 --echo #
@@ -1088,7 +1101,7 @@ select charset('ãû');
 select hex('ãû');
 
 set @show_explain_probe_select_id=1;
-set debug_dbug='d,show_explain_probe_join_exec_start';
+set debug_dbug='+d,show_explain_probe_join_exec_start';
 
 send
 select * from t0 where length('ãû') = a;
@@ -1103,7 +1116,7 @@ connection con1;
 # The constant should be two letters, the last looking like 'bl'
 reap;
 
-set debug_dbug='';
+set debug_dbug=@old_debug;
 set names default;
 
 --echo #