summaryrefslogtreecommitdiffstats
path: root/sql/mysqld.h
blob: 2139b9b676ee6ba95bd19b94c117549051ed3c5a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
/* Copyright (c) 2006, 2016, Oracle and/or its affiliates.
   Copyright (c) 2010, 2021, MariaDB Corporation.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1335  USA */

#ifndef MYSQLD_INCLUDED
#define MYSQLD_INCLUDED

#include "sql_basic_types.h"			/* query_id_t */
#include "sql_mode.h"                           /* Sql_mode_dependency */
#include "sql_plugin.h"
#include "sql_bitmap.h"                         /* Bitmap */
#include "my_decimal.h"                         /* my_decimal */
#include "mysql_com.h"                     /* SERVER_VERSION_LENGTH */
#include "my_counter.h"
#include "mysql/psi/mysql_file.h"          /* MYSQL_FILE */
#include "mysql/psi/mysql_socket.h"        /* MYSQL_SOCKET */
#include "sql_list.h"                      /* I_List */
#include "sql_cmd.h"
#include <my_rnd.h>
#include "my_pthread.h"
#include "my_rdtsc.h"

class THD;
class CONNECT;
struct handlerton;
class Time_zone;

struct scheduler_functions;

typedef struct st_mysql_show_var SHOW_VAR;

/* Bits from testflag */
#define TEST_PRINT_CACHED_TABLES 1U
#define TEST_NO_KEY_GROUP	 2U
#define TEST_MIT_THREAD		4U
#define TEST_BLOCKING		8U
#define TEST_KEEP_TMP_TABLES	16U
#define TEST_READCHECK		64U	/**< Force use of readcheck */
#define TEST_NO_EXTRA		128U
#define TEST_CORE_ON_SIGNAL	256U	/**< Give core if signal */
#define TEST_SIGINT		1024U	/**< Allow sigint on threads */
#define TEST_SYNCHRONIZATION    2048U   /**< get server to do sleep in
                                           some places */

/* Keep things compatible */
#define OPT_DEFAULT SHOW_OPT_DEFAULT
#define OPT_SESSION SHOW_OPT_SESSION
#define OPT_GLOBAL SHOW_OPT_GLOBAL

extern MYSQL_PLUGIN_IMPORT MY_TIMER_INFO sys_timer_info;

/*
  Values for --slave-parallel-mode
  Must match order in slave_parallel_mode_typelib in sys_vars.cc.
*/
enum enum_slave_parallel_mode {
  SLAVE_PARALLEL_NONE,
  SLAVE_PARALLEL_MINIMAL,
  SLAVE_PARALLEL_CONSERVATIVE,
  SLAVE_PARALLEL_OPTIMISTIC,
  SLAVE_PARALLEL_AGGRESSIVE
};

/* Function prototypes */
void kill_mysql(THD *thd);
void close_connection(THD *thd, uint sql_errno= 0);
void handle_connection_in_main_thread(CONNECT *thd);
void create_thread_to_handle_connection(CONNECT *connect);
void unlink_thd(THD *thd);
void refresh_status(THD *thd);
bool is_secure_file_path(char *path);
extern void init_net_server_extension(THD *thd);
extern void handle_accepted_socket(MYSQL_SOCKET new_sock, MYSQL_SOCKET sock);
extern void create_new_thread(CONNECT *connect);

extern void ssl_acceptor_stats_update(int sslaccept_ret);
extern int reinit_ssl();

extern "C" MYSQL_PLUGIN_IMPORT CHARSET_INFO *system_charset_info;
extern MYSQL_PLUGIN_IMPORT CHARSET_INFO *files_charset_info ;
extern MYSQL_PLUGIN_IMPORT CHARSET_INFO *national_charset_info;
extern MYSQL_PLUGIN_IMPORT CHARSET_INFO *table_alias_charset;

/**
  Character set of the buildin error messages loaded from errmsg.sys.
*/
extern CHARSET_INFO *error_message_charset_info;

extern CHARSET_INFO *character_set_filesystem;

void temp_pool_clear_bit(uint bit);
uint temp_pool_set_next();

extern bool opt_large_files;
extern bool opt_update_log, opt_bin_log, opt_error_log, opt_bin_log_compress; 
extern uint opt_bin_log_compress_min_len;
extern my_bool opt_log, opt_bootstrap;
extern my_bool opt_backup_history_log;
extern my_bool opt_backup_progress_log;
extern my_bool opt_support_flashback;
extern ulonglong log_output_options;
extern ulong log_backup_output_options;
extern bool opt_disable_networking, opt_skip_show_db;
extern bool opt_skip_name_resolve;
extern bool opt_ignore_builtin_innodb;
extern my_bool opt_character_set_client_handshake;
extern my_bool debug_assert_on_not_freed_memory;
extern MYSQL_PLUGIN_IMPORT bool volatile abort_loop;
extern my_bool opt_safe_user_create;
extern my_bool opt_safe_show_db, opt_local_infile, opt_myisam_use_mmap;
extern my_bool opt_slave_compressed_protocol, use_temp_pool;
extern ulong slave_exec_mode_options, slave_ddl_exec_mode_options;
extern ulong slave_retried_transactions;
extern ulong transactions_multi_engine;
extern ulong rpl_transactions_multi_engine;
extern ulong transactions_gtid_foreign_engine;
extern ulong slave_run_triggers_for_rbr;
extern ulonglong slave_type_conversions_options;
extern my_bool read_only, opt_readonly;
extern MYSQL_PLUGIN_IMPORT my_bool lower_case_file_system;
extern my_bool opt_enable_named_pipe, opt_sync_frm, opt_allow_suspicious_udfs;
extern my_bool opt_secure_auth;
extern my_bool opt_require_secure_transport;
extern const char *current_dbug_option;
extern char* opt_secure_file_priv;
extern char* opt_secure_backup_file_priv;
extern size_t opt_secure_backup_file_priv_len;
extern my_bool sp_automatic_privileges, opt_noacl;
extern ulong use_stat_tables;
extern my_bool opt_old_style_user_limits, trust_function_creators;
extern uint opt_crash_binlog_innodb;
extern const char *shared_memory_base_name;
extern MYSQL_PLUGIN_IMPORT char *mysqld_unix_port;
extern my_bool opt_enable_shared_memory;
extern ulong opt_replicate_events_marked_for_skip;
extern char *default_tz_name;
extern Time_zone *default_tz;
extern char *my_bind_addr_str;
extern char *default_storage_engine, *default_tmp_storage_engine;
extern char *enforced_storage_engine;
extern char *gtid_pos_auto_engines;
extern plugin_ref *opt_gtid_pos_auto_plugins;
extern bool opt_endinfo, using_udf_functions;
extern my_bool locked_in_memory;
extern bool opt_using_transactions;
extern ulong current_pid;
extern double expire_logs_days;
extern ulong binlog_expire_logs_seconds;
extern my_bool relay_log_recovery;
extern uint sync_binlog_period, sync_relaylog_period, 
            sync_relayloginfo_period, sync_masterinfo_period;
extern ulong opt_tc_log_size, tc_log_max_pages_used, tc_log_page_size;
extern ulong tc_log_page_waits;
extern my_bool relay_log_purge, opt_innodb_safe_binlog, opt_innodb;
extern my_bool relay_log_recovery;
extern uint select_errors,ha_open_options;
extern ulonglong test_flags;
extern uint protocol_version, dropping_tables;
extern MYSQL_PLUGIN_IMPORT uint mysqld_port;
extern ulong delay_key_write_options;
extern char *opt_logname, *opt_slow_logname, *opt_bin_logname, 
            *opt_relay_logname;
extern char *opt_binlog_index_name;
extern char *opt_backup_history_logname, *opt_backup_progress_logname,
            *opt_backup_settings_name;
extern const char *log_output_str;
extern const char *log_backup_output_str;

/* System Versioning begin */
enum vers_system_time_t
{
  SYSTEM_TIME_UNSPECIFIED = 0,
  SYSTEM_TIME_AS_OF,
  SYSTEM_TIME_FROM_TO,
  SYSTEM_TIME_BETWEEN,
  SYSTEM_TIME_BEFORE,  // used for DELETE HISTORY ... BEFORE
  SYSTEM_TIME_HISTORY, // used for DELETE HISTORY
  SYSTEM_TIME_ALL
};

struct vers_asof_timestamp_t
{
  ulong type;
  my_time_t unix_time;
  ulong second_part;
};

enum vers_alter_history_enum
{
  VERS_ALTER_HISTORY_ERROR= 0,
  VERS_ALTER_HISTORY_KEEP
};
/* System Versioning end */

extern char *mysql_home_ptr, *pidfile_name_ptr;
extern MYSQL_PLUGIN_IMPORT char glob_hostname[FN_REFLEN];
extern char mysql_home[FN_REFLEN];
extern char pidfile_name[FN_REFLEN], system_time_zone[30], *opt_init_file;
extern char default_logfile_name[FN_REFLEN];
extern char log_error_file[FN_REFLEN], *opt_tc_log_file, *opt_ddl_recovery_file;
extern const double log_10[309];
extern ulonglong keybuff_size;
extern ulonglong thd_startup_options;
extern my_thread_id global_thread_id;
extern ulong binlog_cache_use, binlog_cache_disk_use;
extern ulong binlog_stmt_cache_use, binlog_stmt_cache_disk_use;
extern ulong aborted_threads, aborted_connects, aborted_connects_preauth;
extern ulong delayed_insert_timeout;
extern ulong delayed_insert_limit, delayed_queue_size;
extern ulong delayed_insert_threads, delayed_insert_writes;
extern ulong delayed_rows_in_use,delayed_insert_errors;
extern Atomic_counter<uint32_t> slave_open_temp_tables;
extern ulonglong query_cache_size;
extern ulong query_cache_limit;
extern ulong query_cache_min_res_unit;
extern ulong slow_launch_threads, slow_launch_time;
extern MYSQL_PLUGIN_IMPORT ulong max_connections;
extern uint max_digest_length;
extern ulong max_connect_errors, connect_timeout;
extern uint max_password_errors;
extern my_bool slave_allow_batching;
extern my_bool allow_slave_start;
extern LEX_CSTRING reason_slave_blocked;
extern ulong slave_trans_retries;
extern ulong slave_trans_retry_interval;
extern uint  slave_net_timeout;
extern int max_user_connections;
extern ulong what_to_log,flush_time;
extern uint max_prepared_stmt_count, prepared_stmt_count;
extern MYSQL_PLUGIN_IMPORT ulong open_files_limit;
extern ulonglong binlog_cache_size, binlog_stmt_cache_size, binlog_file_cache_size;
extern ulonglong max_binlog_cache_size, max_binlog_stmt_cache_size;
extern ulong max_binlog_size;
extern ulong slave_max_allowed_packet;
extern ulonglong slave_max_statement_time;
extern double slave_max_statement_time_double;
extern ulong opt_binlog_rows_event_max_size;
extern ulong binlog_row_metadata;
extern ulong thread_cache_size;
extern ulong stored_program_cache_size;
extern ulong opt_slave_parallel_threads;
extern ulong opt_slave_domain_parallel_threads;
extern ulong opt_slave_parallel_max_queued;
extern ulong opt_slave_parallel_mode;
extern ulong opt_binlog_commit_wait_count;
extern ulong opt_binlog_commit_wait_usec;
extern my_bool opt_gtid_ignore_duplicates;
extern uint opt_gtid_cleanup_batch_size;
extern ulong back_log;
extern ulong executed_events;
extern char language[FN_REFLEN];
extern "C" MYSQL_PLUGIN_IMPORT ulong server_id;
extern ulong concurrency;
extern time_t server_start_time, flush_status_time;
extern char *opt_mysql_tmpdir, mysql_charsets_dir[];
extern size_t mysql_unpacked_real_data_home_len;
extern MYSQL_PLUGIN_IMPORT MY_TMPDIR mysql_tmpdir_list;
extern const char *first_keyword, *delayed_user;
extern MYSQL_PLUGIN_IMPORT const char  *my_localhost;
extern MYSQL_PLUGIN_IMPORT const char **errmesg;			/* Error messages */
extern const char *myisam_recover_options_str;
extern const LEX_CSTRING in_left_expr_name, in_additional_cond, in_having_cond;
extern const LEX_CSTRING NULL_clex_str;
extern const LEX_CSTRING error_clex_str;
extern SHOW_VAR status_vars[];
extern struct system_variables max_system_variables;
extern struct system_status_var global_status_var;
extern struct my_rnd_struct sql_rand;
extern const char *opt_date_time_formats[];
extern handlerton *partition_hton;
extern handlerton *myisam_hton;
extern handlerton *heap_hton;
extern const char *load_default_groups[];
extern struct my_option my_long_options[];
int handle_early_options();
extern int MYSQL_PLUGIN_IMPORT mysqld_server_started;
extern int mysqld_server_initialized;
extern "C" MYSQL_PLUGIN_IMPORT int orig_argc;
extern "C" MYSQL_PLUGIN_IMPORT char **orig_argv;
extern pthread_attr_t connection_attrib;
extern my_bool old_mode;
extern LEX_STRING opt_init_connect, opt_init_slave;
extern char err_shared_dir[];
extern ulong connection_errors_select;
extern ulong connection_errors_accept;
extern ulong connection_errors_tcpwrap;
extern ulong connection_errors_internal;
extern ulong connection_errors_max_connection;
extern ulong connection_errors_peer_addr;
extern ulong log_warnings;
extern my_bool encrypt_binlog;
extern my_bool encrypt_tmp_disk_tables, encrypt_tmp_files;
extern ulong encryption_algorithm;
extern const char *encryption_algorithm_names[];
extern long opt_secure_timestamp;
extern uint default_password_lifetime;
extern my_bool disconnect_on_expired_password;

enum secure_timestamp { SECTIME_NO, SECTIME_SUPER, SECTIME_REPL, SECTIME_YES };
bool is_set_timestamp_forbidden(THD *thd);

#ifdef HAVE_MMAP
extern PSI_mutex_key key_PAGE_lock, key_LOCK_sync, key_LOCK_active,
       key_LOCK_pool, key_LOCK_pending_checkpoint;
#endif /* HAVE_MMAP */

#ifdef HAVE_OPENSSL
extern PSI_mutex_key key_LOCK_des_key_file;
#endif

extern PSI_mutex_key key_BINLOG_LOCK_index, key_BINLOG_LOCK_xid_list,
  key_BINLOG_LOCK_binlog_background_thread,
  key_LOCK_binlog_end_pos,
  key_delayed_insert_mutex, key_hash_filo_lock, key_LOCK_active_mi,
  key_LOCK_crypt, key_LOCK_delayed_create,
  key_LOCK_delayed_insert, key_LOCK_delayed_status, key_LOCK_error_log,
  key_LOCK_gdl, key_LOCK_global_system_variables,
  key_LOCK_logger, key_LOCK_manager,
  key_LOCK_prepared_stmt_count,
  key_LOCK_rpl_status, key_LOCK_server_started,
  key_LOCK_status,
  key_LOCK_thd_data, key_LOCK_thd_kill,
  key_LOCK_user_conn, key_LOG_LOCK_log,
  key_master_info_data_lock, key_master_info_run_lock,
  key_master_info_sleep_lock, key_master_info_start_stop_lock,
  key_master_info_start_alter_lock,
  key_master_info_start_alter_list_lock,
  key_mutex_slave_reporting_capability_err_lock, key_relay_log_info_data_lock,
  key_relay_log_info_log_space_lock, key_relay_log_info_run_lock,
  key_rpl_group_info_sleep_lock,
  key_structure_guard_mutex, key_TABLE_SHARE_LOCK_ha_data,
  key_TABLE_SHARE_LOCK_statistics,
  key_LOCK_start_thread,
  key_LOCK_error_messages,
  key_PARTITION_LOCK_auto_inc;
extern PSI_mutex_key key_RELAYLOG_LOCK_index;
extern PSI_mutex_key key_LOCK_relaylog_end_pos;
extern PSI_mutex_key key_LOCK_slave_state, key_LOCK_binlog_state,
  key_LOCK_rpl_thread, key_LOCK_rpl_thread_pool, key_LOCK_parallel_entry;

extern PSI_mutex_key key_TABLE_SHARE_LOCK_share, key_LOCK_stats,
  key_LOCK_global_user_client_stats, key_LOCK_global_table_stats,
  key_LOCK_global_index_stats, key_LOCK_wakeup_ready, key_LOCK_wait_commit,
  key_TABLE_SHARE_LOCK_rotation;
extern PSI_mutex_key key_LOCK_gtid_waiting;

extern PSI_rwlock_key key_rwlock_LOCK_grant, key_rwlock_LOCK_logger,
  key_rwlock_LOCK_sys_init_connect, key_rwlock_LOCK_sys_init_slave,
  key_rwlock_LOCK_system_variables_hash, key_rwlock_query_cache_query_lock,
  key_LOCK_SEQUENCE,
  key_rwlock_LOCK_vers_stats, key_rwlock_LOCK_stat_serial,
  key_rwlock_THD_list;

#ifdef HAVE_MMAP
extern PSI_cond_key key_PAGE_cond, key_COND_active, key_COND_pool;
#endif /* HAVE_MMAP */

extern PSI_cond_key key_BINLOG_COND_xid_list, key_BINLOG_update_cond,
  key_BINLOG_COND_binlog_background_thread,
  key_BINLOG_COND_binlog_background_thread_end,
  key_COND_cache_status_changed, key_COND_manager,
  key_COND_rpl_status, key_COND_server_started,
  key_delayed_insert_cond, key_delayed_insert_cond_client,
  key_item_func_sleep_cond, key_master_info_data_cond,
  key_master_info_start_cond, key_master_info_stop_cond,
  key_master_info_sleep_cond,
  key_relay_log_info_data_cond, key_relay_log_info_log_space_cond,
  key_relay_log_info_start_cond, key_relay_log_info_stop_cond,
  key_rpl_group_info_sleep_cond,
  key_TABLE_SHARE_cond, key_user_level_lock_cond,
  key_COND_start_thread;
extern PSI_cond_key key_RELAYLOG_COND_relay_log_updated,
  key_RELAYLOG_COND_bin_log_updated, key_COND_wakeup_ready,
  key_COND_wait_commit;
extern PSI_cond_key key_RELAYLOG_COND_queue_busy;
extern PSI_cond_key key_TC_LOG_MMAP_COND_queue_busy;
extern PSI_cond_key key_COND_rpl_thread, key_COND_rpl_thread_queue,
  key_COND_rpl_thread_stop, key_COND_rpl_thread_pool,
  key_COND_parallel_entry, key_COND_group_commit_orderer;
extern PSI_cond_key key_COND_wait_gtid, key_COND_gtid_ignore_duplicates;
extern PSI_cond_key key_TABLE_SHARE_COND_rotation;

extern PSI_thread_key key_thread_delayed_insert,
  key_thread_handle_manager, key_thread_kill_server, key_thread_main,
  key_thread_one_connection, key_thread_signal_hand,
  key_thread_slave_background, key_rpl_parallel_thread;

extern PSI_file_key key_file_binlog, key_file_binlog_cache,
       key_file_binlog_index, key_file_binlog_index_cache, key_file_casetest,
  key_file_dbopt, key_file_des_key_file, key_file_ERRMSG, key_select_to_file,
  key_file_fileparser, key_file_frm, key_file_global_ddl_log, key_file_load,
  key_file_loadfile, key_file_log_event_data, key_file_log_event_info,
  key_file_master_info, key_file_misc, key_file_partition_ddl_log,
  key_file_pid, key_file_relay_log_info, key_file_send_file, key_file_tclog,
  key_file_trg, key_file_trn, key_file_init, key_file_log_ddl;
extern PSI_file_key key_file_query_log, key_file_slow_log;
extern PSI_file_key key_file_relaylog, key_file_relaylog_index,
                    key_file_relaylog_cache, key_file_relaylog_index_cache;
extern PSI_socket_key key_socket_tcpip, key_socket_unix,
  key_socket_client_connection;
extern PSI_file_key key_file_binlog_state;

#ifdef HAVE_PSI_INTERFACE
void init_server_psi_keys();
#endif /* HAVE_PSI_INTERFACE */

extern PSI_memory_key key_memory_locked_table_list;
extern PSI_memory_key key_memory_locked_thread_list;
extern PSI_memory_key key_memory_thd_transactions;
extern PSI_memory_key key_memory_delegate;
extern PSI_memory_key key_memory_acl_mem;
extern PSI_memory_key key_memory_acl_memex;
extern PSI_memory_key key_memory_acl_cache;
extern PSI_memory_key key_memory_thd_main_mem_root;
extern PSI_memory_key key_memory_help;
extern PSI_memory_key key_memory_frm;
extern PSI_memory_key key_memory_table_share;
extern PSI_memory_key key_memory_gdl;
extern PSI_memory_key key_memory_table_triggers_list;
extern PSI_memory_key key_memory_prepared_statement_map;
extern PSI_memory_key key_memory_prepared_statement_main_mem_root;
extern PSI_memory_key key_memory_protocol_rset_root;
extern PSI_memory_key key_memory_warning_info_warn_root;
extern PSI_memory_key key_memory_sp_cache;
extern PSI_memory_key key_memory_sp_head_main_root;
extern PSI_memory_key key_memory_sp_head_execute_root;
extern PSI_memory_key key_memory_sp_head_call_root;
extern PSI_memory_key key_memory_table_mapping_root;
extern PSI_memory_key key_memory_quick_range_select_root;
extern PSI_memory_key key_memory_quick_index_merge_root;
extern PSI_memory_key key_memory_quick_ror_intersect_select_root;
extern PSI_memory_key key_memory_quick_ror_union_select_root;
extern PSI_memory_key key_memory_quick_group_min_max_select_root;
extern PSI_memory_key key_memory_test_quick_select_exec;
extern PSI_memory_key key_memory_prune_partitions_exec;
extern PSI_memory_key key_memory_binlog_recover_exec;
extern PSI_memory_key key_memory_blob_mem_storage;

extern PSI_memory_key key_memory_Sys_var_charptr_value;
extern PSI_memory_key key_memory_THD_db;
extern PSI_memory_key key_memory_user_var_entry;
extern PSI_memory_key key_memory_user_var_entry_value;
extern PSI_memory_key key_memory_Slave_job_group_group_relay_log_name;
extern PSI_memory_key key_memory_Relay_log_info_group_relay_log_name;
extern PSI_memory_key key_memory_binlog_cache_mngr;
extern PSI_memory_key key_memory_Row_data_memory_memory;
extern PSI_memory_key key_memory_errmsgs;
extern PSI_memory_key key_memory_Event_queue_element_for_exec_names;
extern PSI_memory_key key_memory_Event_scheduler_scheduler_param;
extern PSI_memory_key key_memory_Gis_read_stream_err_msg;
extern PSI_memory_key key_memory_Geometry_objects_data;
extern PSI_memory_key key_memory_host_cache_hostname;
extern PSI_memory_key key_memory_User_level_lock;
extern PSI_memory_key key_memory_Filesort_info_record_pointers;
extern PSI_memory_key key_memory_Sort_param_tmp_buffer;
extern PSI_memory_key key_memory_Filesort_info_merge;
extern PSI_memory_key key_memory_Filesort_buffer_sort_keys;
extern PSI_memory_key key_memory_handler_errmsgs;
extern PSI_memory_key key_memory_handlerton;
extern PSI_memory_key key_memory_XID;
extern PSI_memory_key key_memory_MYSQL_LOCK;
extern PSI_memory_key key_memory_MYSQL_LOG_name;
extern PSI_memory_key key_memory_TC_LOG_MMAP_pages;
extern PSI_memory_key key_memory_my_str_malloc;
extern PSI_memory_key key_memory_MYSQL_BIN_LOG_basename;
extern PSI_memory_key key_memory_MYSQL_BIN_LOG_index;
extern PSI_memory_key key_memory_MYSQL_RELAY_LOG_basename;
extern PSI_memory_key key_memory_MYSQL_RELAY_LOG_index;
extern PSI_memory_key key_memory_rpl_filter;
extern PSI_memory_key key_memory_Security_context;
extern PSI_memory_key key_memory_NET_buff;
extern PSI_memory_key key_memory_NET_compress_packet;
extern PSI_memory_key key_memory_my_bitmap_map;
extern PSI_memory_key key_memory_QUICK_RANGE_SELECT_mrr_buf_desc;
extern PSI_memory_key key_memory_TABLE_RULE_ENT;
extern PSI_memory_key key_memory_Mutex_cond_array_Mutex_cond;
extern PSI_memory_key key_memory_Owned_gtids_sidno_to_hash;
extern PSI_memory_key key_memory_Sid_map_Node;
extern PSI_memory_key key_memory_bison_stack;
extern PSI_memory_key key_memory_TABLE_sort_io_cache;
extern PSI_memory_key key_memory_DATE_TIME_FORMAT;
extern PSI_memory_key key_memory_DDL_LOG_MEMORY_ENTRY;
extern PSI_memory_key key_memory_ST_SCHEMA_TABLE;
extern PSI_memory_key key_memory_ignored_db;
extern PSI_memory_key key_memory_SLAVE_INFO;
extern PSI_memory_key key_memory_log_event_old;
extern PSI_memory_key key_memory_HASH_ROW_ENTRY;
extern PSI_memory_key key_memory_table_def_memory;
extern PSI_memory_key key_memory_MPVIO_EXT_auth_info;
extern PSI_memory_key key_memory_LOG_POS_COORD;
extern PSI_memory_key key_memory_XID_STATE;
extern PSI_memory_key key_memory_Rpl_info_file_buffer;
extern PSI_memory_key key_memory_Rpl_info_table;
extern PSI_memory_key key_memory_binlog_pos;
extern PSI_memory_key key_memory_db_worker_hash_entry;
extern PSI_memory_key key_memory_rpl_slave_command_buffer;
extern PSI_memory_key key_memory_binlog_ver_1_event;
extern PSI_memory_key key_memory_rpl_slave_check_temp_dir;
extern PSI_memory_key key_memory_TABLE;
extern PSI_memory_key key_memory_binlog_statement_buffer;
extern PSI_memory_key key_memory_user_conn;
extern PSI_memory_key key_memory_dboptions_hash;
extern PSI_memory_key key_memory_dbnames_cache;
extern PSI_memory_key key_memory_hash_index_key_buffer;
extern PSI_memory_key key_memory_THD_handler_tables_hash;
extern PSI_memory_key key_memory_JOIN_CACHE;
extern PSI_memory_key key_memory_READ_INFO;
extern PSI_memory_key key_memory_partition_syntax_buffer;
extern PSI_memory_key key_memory_global_system_variables;
extern PSI_memory_key key_memory_THD_variables;
extern PSI_memory_key key_memory_PROFILE;
extern PSI_memory_key key_memory_LOG_name;
extern PSI_memory_key key_memory_string_iterator;
extern PSI_memory_key key_memory_frm_extra_segment_buff;
extern PSI_memory_key key_memory_frm_form_pos;
extern PSI_memory_key key_memory_frm_string;
extern PSI_memory_key key_memory_Unique_sort_buffer;
extern PSI_memory_key key_memory_Unique_merge_buffer;
extern PSI_memory_key key_memory_shared_memory_name;
extern PSI_memory_key key_memory_opt_bin_logname;
extern PSI_memory_key key_memory_Query_cache;
extern PSI_memory_key key_memory_READ_RECORD_cache;
extern PSI_memory_key key_memory_Quick_ranges;
extern PSI_memory_key key_memory_File_query_log_name;
extern PSI_memory_key key_memory_Table_trigger_dispatcher;
extern PSI_memory_key key_memory_show_slave_status_io_gtid_set;
extern PSI_memory_key key_memory_write_set_extraction;
extern PSI_memory_key key_memory_thd_timer;
extern PSI_memory_key key_memory_THD_Session_tracker;
extern PSI_memory_key key_memory_THD_Session_sysvar_resource_manager;
extern PSI_memory_key key_memory_get_all_tables;
extern PSI_memory_key key_memory_fill_schema_schemata;
extern PSI_memory_key key_memory_native_functions;
extern PSI_memory_key key_memory_JSON;
extern PSI_memory_key key_memory_WSREP;

/*
  MAINTAINER: Please keep this list in order, to limit merge collisions.
  Hint: grep PSI_stage_info | sort -u
*/
extern PSI_stage_info stage_apply_event;
extern PSI_stage_info stage_after_create;
extern PSI_stage_info stage_after_opening_tables;
extern PSI_stage_info stage_after_table_lock;
extern PSI_stage_info stage_allocating_local_table;
extern PSI_stage_info stage_alter_inplace_prepare;
extern PSI_stage_info stage_alter_inplace;
extern PSI_stage_info stage_alter_inplace_commit;
extern PSI_stage_info stage_after_apply_event;
extern PSI_stage_info stage_changing_master;
extern PSI_stage_info stage_checking_master_version;
extern PSI_stage_info stage_checking_permissions;
extern PSI_stage_info stage_checking_privileges_on_cached_query;
extern PSI_stage_info stage_checking_query_cache_for_query;
extern PSI_stage_info stage_cleaning_up;
extern PSI_stage_info stage_closing_tables;
extern PSI_stage_info stage_connecting_to_master;
extern PSI_stage_info stage_converting_heap_to_myisam;
extern PSI_stage_info stage_copying_to_group_table;
extern PSI_stage_info stage_copying_to_tmp_table;
extern PSI_stage_info stage_copy_to_tmp_table;
extern PSI_stage_info stage_creating_delayed_handler;
extern PSI_stage_info stage_creating_sort_index;
extern PSI_stage_info stage_creating_table;
extern PSI_stage_info stage_creating_tmp_table;
extern PSI_stage_info stage_deleting_from_main_table;
extern PSI_stage_info stage_deleting_from_reference_tables;
extern PSI_stage_info stage_discard_or_import_tablespace;
extern PSI_stage_info stage_end;
extern PSI_stage_info stage_enabling_keys;
extern PSI_stage_info stage_executing;
extern PSI_stage_info stage_execution_of_init_command;
extern PSI_stage_info stage_explaining;
extern PSI_stage_info stage_finding_key_cache;
extern PSI_stage_info stage_finished_reading_one_binlog_switching_to_next_binlog;
extern PSI_stage_info stage_flushing_relay_log_and_master_info_repository;
extern PSI_stage_info stage_flushing_relay_log_info_file;
extern PSI_stage_info stage_freeing_items;
extern PSI_stage_info stage_fulltext_initialization;
extern PSI_stage_info stage_got_handler_lock;
extern PSI_stage_info stage_got_old_table;
extern PSI_stage_info stage_init;
extern PSI_stage_info stage_init_update;
extern PSI_stage_info stage_insert;
extern PSI_stage_info stage_invalidating_query_cache_entries_table;
extern PSI_stage_info stage_invalidating_query_cache_entries_table_list;
extern PSI_stage_info stage_killing_slave;
extern PSI_stage_info stage_logging_slow_query;
extern PSI_stage_info stage_making_temp_file_append_before_load_data;
extern PSI_stage_info stage_making_temp_file_create_before_load_data;
extern PSI_stage_info stage_manage_keys;
extern PSI_stage_info stage_master_has_sent_all_binlog_to_slave;
extern PSI_stage_info stage_opening_tables;
extern PSI_stage_info stage_optimizing;
extern PSI_stage_info stage_preparing;
extern PSI_stage_info stage_purging_old_relay_logs;
extern PSI_stage_info stage_query_end;
extern PSI_stage_info stage_starting_cleanup;
extern PSI_stage_info stage_rollback;
extern PSI_stage_info stage_rollback_implicit;
extern PSI_stage_info stage_commit;
extern PSI_stage_info stage_commit_implicit;
extern PSI_stage_info stage_queueing_master_event_to_the_relay_log;
extern PSI_stage_info stage_reading_event_from_the_relay_log;
extern PSI_stage_info stage_recreating_table;
extern PSI_stage_info stage_registering_slave_on_master;
extern PSI_stage_info stage_removing_duplicates;
extern PSI_stage_info stage_removing_tmp_table;
extern PSI_stage_info stage_rename;
extern PSI_stage_info stage_rename_result_table;
extern PSI_stage_info stage_requesting_binlog_dump;
extern PSI_stage_info stage_reschedule;
extern PSI_stage_info stage_searching_rows_for_update;
extern PSI_stage_info stage_sending_binlog_event_to_slave;
extern PSI_stage_info stage_sending_cached_result_to_client;
extern PSI_stage_info stage_sending_data;
extern PSI_stage_info stage_setup;
extern PSI_stage_info stage_slave_has_read_all_relay_log;
extern PSI_stage_info stage_show_explain;
extern PSI_stage_info stage_sorting;
extern PSI_stage_info stage_sorting_for_group;
extern PSI_stage_info stage_sorting_for_order;
extern PSI_stage_info stage_sorting_result;
extern PSI_stage_info stage_sql_thd_waiting_until_delay;
extern PSI_stage_info stage_statistics;
extern PSI_stage_info stage_storing_result_in_query_cache;
extern PSI_stage_info stage_storing_row_into_queue;
extern PSI_stage_info stage_system_lock;
extern PSI_stage_info stage_unlocking_tables;
extern PSI_stage_info stage_table_lock;
extern PSI_stage_info stage_filling_schema_table;
extern PSI_stage_info stage_update;
extern PSI_stage_info stage_updating;
extern PSI_stage_info stage_updating_main_table;
extern PSI_stage_info stage_updating_reference_tables;
extern PSI_stage_info stage_upgrading_lock;
extern PSI_stage_info stage_user_lock;
extern PSI_stage_info stage_user_sleep;
extern PSI_stage_info stage_verifying_table;
extern PSI_stage_info stage_waiting_for_ddl;
extern PSI_stage_info stage_waiting_for_delay_list;
extern PSI_stage_info stage_waiting_for_flush;
extern PSI_stage_info stage_waiting_for_gtid_to_be_written_to_binary_log;
extern PSI_stage_info stage_waiting_for_handler_insert;
extern PSI_stage_info stage_waiting_for_handler_lock;
extern PSI_stage_info stage_waiting_for_handler_open;
extern PSI_stage_info stage_waiting_for_insert;
extern PSI_stage_info stage_waiting_for_master_to_send_event;
extern PSI_stage_info stage_waiting_for_master_update;
extern PSI_stage_info stage_waiting_for_relay_log_space;
extern PSI_stage_info stage_waiting_for_slave_mutex_on_exit;
extern PSI_stage_info stage_waiting_for_slave_thread_to_start;
extern PSI_stage_info stage_waiting_for_query_cache_lock;
extern PSI_stage_info stage_waiting_for_table_flush;
extern PSI_stage_info stage_waiting_for_the_next_event_in_relay_log;
extern PSI_stage_info stage_waiting_for_the_slave_thread_to_advance_position;
extern PSI_stage_info stage_waiting_to_finalize_termination;
extern PSI_stage_info stage_binlog_waiting_background_tasks;
extern PSI_stage_info stage_binlog_write;
extern PSI_stage_info stage_binlog_processing_checkpoint_notify;
extern PSI_stage_info stage_binlog_stopping_background_thread;
extern PSI_stage_info stage_waiting_for_work_from_sql_thread;
extern PSI_stage_info stage_waiting_for_prior_transaction_to_commit;
extern PSI_stage_info stage_waiting_for_prior_transaction_to_start_commit;
extern PSI_stage_info stage_waiting_for_room_in_worker_thread;
extern PSI_stage_info stage_waiting_for_workers_idle;
extern PSI_stage_info stage_waiting_for_ftwrl;
extern PSI_stage_info stage_waiting_for_ftwrl_threads_to_pause;
extern PSI_stage_info stage_waiting_for_rpl_thread_pool;
extern PSI_stage_info stage_master_gtid_wait_primary;
extern PSI_stage_info stage_master_gtid_wait;
extern PSI_stage_info stage_gtid_wait_other_connection;
extern PSI_stage_info stage_slave_background_process_request;
extern PSI_stage_info stage_slave_background_wait_request;
extern PSI_stage_info stage_waiting_for_deadlock_kill;
extern PSI_stage_info stage_starting;
#ifdef WITH_WSREP
// Aditional Galera thread states
extern PSI_stage_info stage_waiting_isolation;
extern PSI_stage_info stage_waiting_certification;
extern PSI_stage_info stage_waiting_ddl;
extern PSI_stage_info stage_waiting_flow;
#endif /* WITH_WSREP */

#ifdef HAVE_PSI_STATEMENT_INTERFACE
/**
  Statement instrumentation keys (sql).
  The last entry, at [SQLCOM_END], is for parsing errors.
*/
extern PSI_statement_info sql_statement_info[(uint) SQLCOM_END + 1];

/**
  Statement instrumentation keys (com).
  The last entry, at [COM_END], is for packet errors.
*/
extern PSI_statement_info com_statement_info[(uint) COM_END + 1];

/**
  Statement instrumentation key for replication.
*/
extern PSI_statement_info stmt_info_rpl;

void init_sql_statement_info();
void init_com_statement_info();
#endif /* HAVE_PSI_STATEMENT_INTERFACE */

#ifndef _WIN32
extern pthread_t signal_thread;
#endif

#ifdef HAVE_OPENSSL
extern struct st_VioSSLFd * ssl_acceptor_fd;
#endif /* HAVE_OPENSSL */

/*
  The following variables were under INNODB_COMPABILITY_HOOKS
 */
extern my_bool opt_large_pages;
extern uint opt_large_page_size;
extern MYSQL_PLUGIN_IMPORT char lc_messages_dir[FN_REFLEN];
extern char *lc_messages_dir_ptr, *log_error_file_ptr;
extern MYSQL_PLUGIN_IMPORT char reg_ext[FN_EXTLEN];
extern MYSQL_PLUGIN_IMPORT uint reg_ext_length;
extern MYSQL_PLUGIN_IMPORT uint lower_case_table_names;
extern MYSQL_PLUGIN_IMPORT bool mysqld_embedded;
extern ulong specialflag;
extern uint mysql_data_home_len;
extern uint mysql_real_data_home_len;
extern const char *mysql_real_data_home_ptr;
extern ulong thread_handling;
extern "C" MYSQL_PLUGIN_IMPORT char server_version[SERVER_VERSION_LENGTH];
extern char *server_version_ptr;
extern bool using_custom_server_version;
extern MYSQL_PLUGIN_IMPORT char mysql_real_data_home[];
extern char mysql_unpacked_real_data_home[];
extern MYSQL_PLUGIN_IMPORT struct system_variables global_system_variables;
extern char default_logfile_name[FN_REFLEN];
extern char *my_proxy_protocol_networks;

#define mysql_tmpdir (my_tmpdir(&mysql_tmpdir_list))

extern MYSQL_PLUGIN_IMPORT const key_map key_map_empty;
extern MYSQL_PLUGIN_IMPORT key_map key_map_full;          /* Should be threaded as const */

/*
  Server mutex locks and condition variables.
 */
extern mysql_mutex_t
       LOCK_item_func_sleep, LOCK_status,
       LOCK_error_log, LOCK_delayed_insert, LOCK_short_uuid_generator,
       LOCK_delayed_status, LOCK_delayed_create, LOCK_crypt, LOCK_timezone,
       LOCK_active_mi, LOCK_manager, LOCK_user_conn,
       LOCK_prepared_stmt_count, LOCK_error_messages,  LOCK_backup_log;
extern MYSQL_PLUGIN_IMPORT mysql_mutex_t LOCK_global_system_variables;
extern mysql_rwlock_t LOCK_all_status_vars;
extern mysql_mutex_t LOCK_start_thread;
#ifdef HAVE_OPENSSL
extern char* des_key_file;
extern mysql_mutex_t LOCK_des_key_file;
#endif
extern MYSQL_PLUGIN_IMPORT mysql_mutex_t LOCK_server_started;
extern MYSQL_PLUGIN_IMPORT mysql_cond_t COND_server_started;
extern mysql_rwlock_t LOCK_grant, LOCK_sys_init_connect, LOCK_sys_init_slave;
extern mysql_rwlock_t LOCK_ssl_refresh;
extern mysql_prlock_t LOCK_system_variables_hash;
extern mysql_cond_t COND_start_thread;
extern mysql_cond_t COND_manager;

extern my_bool opt_use_ssl;
extern char *opt_ssl_ca, *opt_ssl_capath, *opt_ssl_cert, *opt_ssl_cipher,
  *opt_ssl_key, *opt_ssl_crl, *opt_ssl_crlpath;
extern ulonglong tls_version;

#ifdef MYSQL_SERVER

/**
  only options that need special treatment in get_one_option() deserve
  to be listed below
*/
enum options_mysqld
{
  OPT_to_set_the_start_number=256,
  OPT_BINLOG_DO_DB,
  OPT_BINLOG_FORMAT,
  OPT_BINLOG_IGNORE_DB,
  OPT_BIN_LOG,
  OPT_BOOTSTRAP,
  OPT_EXPIRE_LOGS_DAYS,
  OPT_BINLOG_EXPIRE_LOGS_SECONDS,
  OPT_CONSOLE,
  OPT_DEBUG_SYNC_TIMEOUT,
  OPT_REMOVED_OPTION,
  OPT_IGNORE_DB_DIRECTORY,
  OPT_ISAM_LOG,
  OPT_KEY_BUFFER_SIZE,
  OPT_KEY_CACHE_AGE_THRESHOLD,
  OPT_KEY_CACHE_BLOCK_SIZE,
  OPT_KEY_CACHE_DIVISION_LIMIT,
  OPT_KEY_CACHE_PARTITIONS,
  OPT_KEY_CACHE_CHANGED_BLOCKS_HASH_SIZE,
  OPT_LOG_BASENAME,
  OPT_LOG_ERROR,
  OPT_LOWER_CASE_TABLE_NAMES,
  OPT_PLUGIN_LOAD,
  OPT_PLUGIN_LOAD_ADD,
  OPT_PFS_INSTRUMENT,
  OPT_REPLICATE_DO_DB,
  OPT_REPLICATE_DO_TABLE,
  OPT_REPLICATE_IGNORE_DB,
  OPT_REPLICATE_IGNORE_TABLE,
  OPT_REPLICATE_REWRITE_DB,
  OPT_REPLICATE_WILD_DO_TABLE,
  OPT_REPLICATE_WILD_IGNORE_TABLE,
  OPT_SAFE,
  OPT_SERVER_ID,
  OPT_SILENT,
  OPT_SKIP_HOST_CACHE,
  OPT_SLAVE_PARALLEL_MODE,
  OPT_SSL_CA,
  OPT_SSL_CAPATH,
  OPT_SSL_CERT,
  OPT_SSL_CIPHER,
  OPT_SSL_CRL,
  OPT_SSL_CRLPATH,
  OPT_SSL_KEY,
  OPT_THREAD_CONCURRENCY,
  OPT_WANT_CORE,
#ifdef WITH_WSREP
  OPT_WSREP_CAUSAL_READS,
  OPT_WSREP_SYNC_WAIT,
#endif /* WITH_WSREP */
  OPT_MYSQL_COMPATIBILITY,
  OPT_TLS_VERSION,
  OPT_MYSQL_TO_BE_IMPLEMENTED,
  OPT_SEQURE_FILE_PRIV,
  OPT_which_is_always_the_last
};
#endif

/**
   Query type constants (usable as bitmap flags).
*/
enum enum_query_type
{
  /// Nothing specific, ordinary SQL query.
  QT_ORDINARY= 0,
  /// In utf8.
  QT_TO_SYSTEM_CHARSET= (1 << 0),
  /// Without character set introducers.
  QT_WITHOUT_INTRODUCERS= (1 << 1),
  /// view internal representation (like QT_ORDINARY except ORDER BY clause)
  QT_VIEW_INTERNAL= (1 << 2),
  /// If identifiers should not include database names, where unambiguous
  QT_ITEM_IDENT_SKIP_DB_NAMES= (1 << 3),
  /// If identifiers should not include table names, where unambiguous
  QT_ITEM_IDENT_SKIP_TABLE_NAMES= (1 << 4),
  /// If Item_cache_wrapper should not print <expr_cache>
  QT_ITEM_CACHE_WRAPPER_SKIP_DETAILS= (1 << 5),
  /// If Item_subselect should print as just "(subquery#1)"
  /// rather than display the subquery body
  QT_ITEM_SUBSELECT_ID_ONLY= (1 << 6),
  /// If NULLIF(a,b) should print itself as
  /// CASE WHEN a_for_comparison=b THEN NULL ELSE a_for_return_value END
  /// when "a" was replaced to two different items
  /// (e.g. by equal fields propagation in optimize_cond())
  /// or always as NULLIF(a, b).
  /// The default behaviour is to use CASE syntax when
  /// a_for_return_value is not the same as a_for_comparison.
  /// SHOW CREATE {VIEW|PROCEDURE|FUNCTION} and other cases where the
  /// original representation is required, should set this flag.
  QT_ITEM_ORIGINAL_FUNC_NULLIF= (1 << 7),
  /// good for parsing
  QT_PARSABLE= (1 << 8),

  /// This value means focus on readability, not on ability to parse back, etc.
  QT_EXPLAIN=           QT_TO_SYSTEM_CHARSET |
                        QT_ITEM_IDENT_SKIP_DB_NAMES |
                        QT_ITEM_CACHE_WRAPPER_SKIP_DETAILS |
                        QT_ITEM_SUBSELECT_ID_ONLY,

  QT_SHOW_SELECT_NUMBER= (1<<10),

  /// Do not print database name or table name in the identifiers (even if
  /// this means the printout will be ambigous). It is assumed that the caller
  ///  passing this flag knows what they are doing.
  QT_ITEM_IDENT_DISABLE_DB_TABLE_NAMES= (1 <<11),

  /// This is used for EXPLAIN EXTENDED extra warnings / Be more detailed
  /// Be more detailed than QT_EXPLAIN.
  /// Perhaps we should eventually include QT_ITEM_IDENT_SKIP_CURRENT_DATABASE
  /// here, as it would give better readable results
  QT_EXPLAIN_EXTENDED=  QT_TO_SYSTEM_CHARSET|
                        QT_SHOW_SELECT_NUMBER,

  // If an expression is constant, print the expression, not the value
  // it evaluates to. Should be used for error messages, so that they
  // don't reveal values.
  QT_NO_DATA_EXPANSION= (1 << 9),
  // Remove wrappers added for TVC when creating or showing view
  QT_NO_WRAPPERS_FOR_TVC_IN_VIEW= (1 << 12)
};


/* query_id */
extern Atomic_counter<query_id_t> global_query_id;

/* increment query_id and return it.  */
inline __attribute__((warn_unused_result)) query_id_t next_query_id()
{
  return global_query_id++;
}

inline query_id_t get_query_id()
{
  return global_query_id;
}

/* increment global_thread_id and return it.  */
extern __attribute__((warn_unused_result)) my_thread_id next_thread_id(void);

/*
  TODO: Replace this with an inline function.
 */
#ifndef EMBEDDED_LIBRARY
extern "C" void unireg_abort(int exit_code) __attribute__((noreturn));
#else
extern "C" void unireg_clear(int exit_code);
#define unireg_abort(exit_code) do { unireg_clear(exit_code); DBUG_RETURN(exit_code); } while(0)
#endif

inline void table_case_convert(char * name, uint length)
{
  if (lower_case_table_names)
    files_charset_info->casedn(name, length, name, length);
}

extern void set_server_version(char *buf, size_t size);

#define current_thd _current_thd()
void set_current_thd(THD *thd);

/*
  @todo remove, make it static in ha_maria.cc
  currently it's needed for sql_select.cc
*/
extern handlerton *maria_hton;

extern uint64 global_gtid_counter;
extern my_bool opt_gtid_strict_mode;
extern my_bool opt_userstat_running, debug_assert_if_crashed_table;
extern uint mysqld_extra_port;
extern ulong opt_progress_report_time;
extern ulong extra_max_connections;
extern ulonglong denied_connections;
extern ulong thread_created;
extern scheduler_functions *thread_scheduler, *extra_thread_scheduler;
extern char *opt_log_basename;
extern my_bool opt_master_verify_checksum;
extern my_bool opt_stack_trace, disable_log_notes;
extern my_bool opt_expect_abort;
extern my_bool opt_slave_sql_verify_checksum;
extern my_bool opt_mysql56_temporal_format, strict_password_validation;
extern ulong binlog_checksum_options;
extern bool max_user_connections_checking;
extern ulong opt_binlog_dbug_fsync_sleep;

extern uint volatile global_disable_checkpoint;
extern my_bool opt_help;

extern int mysqld_main(int argc, char **argv);

#ifdef _WIN32
extern HANDLE hEventShutdown;
extern void mysqld_win_initiate_shutdown();
extern void mysqld_win_set_startup_complete();
extern void mysqld_win_extend_service_timeout(DWORD sec);
extern void mysqld_set_service_status_callback(void (*)(DWORD, DWORD, DWORD));
extern void mysqld_win_set_service_name(const char *name);
#endif

#endif /* MYSQLD_INCLUDED */