• unknown's avatar
    MDEV-4506: Parallel replication. Intermediate commit. · 7e5dc4f0
    unknown authored
    Implement facility for the commit in one thread to wait for the commit of
    another to complete first. The wait is done in a way that does not hinder
    that a waiter and a waitee can group commit together with a single fsync()
    in both binlog and InnoDB. The wait is done efficiently with respect to
    locking.
    
    The patch was originally made to support TaoBao parallel replication with
    in-order commit; now it will be adapted to also be used for parallel
    replication of group-committed transactions.
    
    A waiter THD registers itself with a prior waitee THD. The waiter will then
    complete its commit at the earliest in the same group commit of the waitee
    (when using binlog). The wait can also be done explicitly by the waitee.
    7e5dc4f0
mysqld.h 20.3 KB
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
/* Copyright (c) 2006, 2012, Oracle and/or its affiliates. All rights reserved.

   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  02110-1301  USA */

#ifndef MYSQLD_INCLUDED
#define MYSQLD_INCLUDED

#include "my_global.h" /* MYSQL_PLUGIN_IMPORT, FN_REFLEN, FN_EXTLEN */
#include "sql_bitmap.h"                         /* Bitmap */
#include "my_decimal.h"                         /* my_decimal */
#include "mysql_com.h"                     /* SERVER_VERSION_LENGTH */
#include "my_atomic.h"                     /* my_atomic_rwlock_t */
#include "mysql/psi/mysql_file.h"          /* MYSQL_FILE */
#include "sql_list.h"                      /* I_List */

class THD;
struct handlerton;
class Time_zone;

struct scheduler_functions;

typedef struct st_mysql_const_lex_string LEX_CSTRING;
typedef struct st_mysql_show_var SHOW_VAR;

#if MAX_INDEXES <= 64
typedef Bitmap<64>  key_map;          /* Used for finding keys */
#else
typedef Bitmap<((MAX_INDEXES+7)/8*8)> key_map; /* Used for finding keys */
#endif

	/* Bits from testflag */
#define TEST_PRINT_CACHED_TABLES 1
#define TEST_NO_KEY_GROUP	 2
#define TEST_MIT_THREAD		4
#define TEST_BLOCKING		8
#define TEST_KEEP_TMP_TABLES	16
#define TEST_READCHECK		64	/**< Force use of readcheck */
#define TEST_NO_EXTRA		128
#define TEST_CORE_ON_SIGNAL	256	/**< Give core if signal */
#define TEST_SIGINT		1024	/**< Allow sigint on threads */
#define TEST_SYNCHRONIZATION    2048    /**< get server to do sleep in
                                           some places */
/* Function prototypes */
void kill_mysql(void);
void close_connection(THD *thd, uint sql_errno= 0);
void handle_connection_in_main_thread(THD *thd);
void create_thread_to_handle_connection(THD *thd);
void delete_running_thd(THD *thd);
void unlink_thd(THD *thd);
bool one_thread_per_connection_end(THD *thd, bool put_in_cache);
void flush_thread_cache();
void refresh_status(THD *thd);
bool is_secure_file_path(char *path);

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;

extern MY_BITMAP temp_pool;
extern bool opt_large_files, server_id_supplied;
extern bool opt_update_log, opt_bin_log, opt_error_log;
extern my_bool opt_log, opt_slow_log, opt_bootstrap;
extern my_bool opt_backup_history_log;
extern my_bool opt_backup_progress_log;
extern ulonglong log_output_options;
extern ulong log_backup_output_options;
extern my_bool opt_log_queries_not_using_indexes;
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 bool volatile abort_loop;
extern bool in_bootstrap;
extern uint connection_count;
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;
extern ulong slave_retried_transactions;
extern ulonglong slave_type_conversions_options;
extern my_bool read_only, opt_readonly;
extern 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 char* opt_secure_file_priv;
extern char* opt_secure_backup_file_priv;
extern size_t opt_secure_backup_file_priv_len;
extern my_bool opt_log_slow_admin_statements, opt_log_slow_slave_statements;
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 char *shared_memory_base_name, *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 *default_storage_engine;
extern bool opt_endinfo, using_udf_functions;
extern my_bool locked_in_memory;
extern bool opt_using_transactions;
extern ulong max_long_data_size;
extern ulong current_pid;
extern ulong expire_logs_days;
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 test_flags,select_errors,ha_open_options;
extern uint protocol_version, mysqld_port, dropping_tables;
extern ulong delay_key_write_options;
extern char *opt_logname, *opt_slow_logname, *opt_bin_logname, 
            *opt_relay_logname;
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;
extern char *mysql_home_ptr, *pidfile_name_ptr;
extern char glob_hostname[FN_REFLEN], 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;
extern const double log_10[309];
extern ulonglong keybuff_size;
extern ulonglong thd_startup_options;
extern ulong 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;
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 ulong slave_open_temp_tables;
extern ulonglong query_cache_size;
extern ulong query_cache_min_res_unit;
extern ulong slow_launch_threads, slow_launch_time;
extern ulong table_cache_size, table_def_size;
extern MYSQL_PLUGIN_IMPORT ulong max_connections;
extern ulong max_connect_errors, connect_timeout;
extern my_bool slave_allow_batching;
extern my_bool allow_slave_start;
extern LEX_CSTRING reason_slave_blocked;
extern ulong slave_trans_retries;
extern uint  slave_net_timeout;
extern int max_user_connections;
extern ulong what_to_log,flush_time;
extern ulong max_prepared_stmt_count, prepared_stmt_count;
extern ulong open_files_limit;
extern ulonglong binlog_cache_size, binlog_stmt_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 ulong opt_binlog_rows_event_max_size;
extern ulong rpl_recovery_rank, thread_cache_size;
extern ulong stored_program_cache_size;
extern ulong opt_slave_parallel_threads;
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 int mysql_unpacked_real_data_home_len;
extern MYSQL_PLUGIN_IMPORT MY_TMPDIR mysql_tmpdir_list;
extern const char *first_keyword, *delayed_user, *binary_keyword;
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 char *in_left_expr_name, *in_additional_cond, *in_having_cond;
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[];
extern int mysqld_server_started, 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 MYSQL_FILE *bootstrap_file;
extern my_bool old_mode;
extern LEX_STRING opt_init_connect, opt_init_slave;
extern int bootstrap_error;
extern I_List<THD> threads;
extern char err_shared_dir[];
extern TYPELIB thread_handling_typelib;

/*
  THR_MALLOC is a key which will be used to set/get MEM_ROOT** for a thread,
  using my_pthread_setspecific_ptr()/my_thread_getspecific_ptr().
*/
extern pthread_key(MEM_ROOT**,THR_MALLOC);

#ifdef HAVE_PSI_INTERFACE
#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_delayed_insert_mutex, key_hash_filo_lock, key_LOCK_active_mi,
  key_LOCK_connection_count, 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_table_share, key_LOCK_thd_data,
  key_LOCK_user_conn, key_LOG_LOCK_log,
  key_master_info_data_lock, key_master_info_run_lock,
  key_master_info_sleep_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_relay_log_info_sleep_lock,
  key_structure_guard_mutex, key_TABLE_SHARE_LOCK_ha_data,
  key_LOCK_error_messages, key_LOCK_thread_count, key_PARTITION_LOCK_auto_inc;
extern PSI_mutex_key key_RELAYLOG_LOCK_index;
extern PSI_mutex_key key_LOCK_slave_state, key_LOCK_binlog_state,
  key_LOCK_rpl_thread, key_LOCK_rpl_thread_pool;

extern PSI_mutex_key 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;

extern PSI_mutex_key key_LOCK_rpl_gtid_state;

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;

#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_relay_log_info_sleep_cond,
  key_TABLE_SHARE_cond, key_user_level_lock_cond,
  key_COND_thread_count, key_COND_thread_cache, key_COND_flush_thread_cache;
extern PSI_cond_key key_RELAYLOG_update_cond, 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_pool;

extern PSI_thread_key key_thread_bootstrap, 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_init,
  key_rpl_parallel_thread;

extern PSI_file_key key_file_binlog, key_file_binlog_index, 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,
  key_file_pid, key_file_relay_log_info, key_file_send_file, key_file_tclog,
  key_file_trg, key_file_trn, key_file_init;
extern PSI_file_key key_file_query_log, key_file_slow_log;
extern PSI_file_key key_file_relaylog, key_file_relaylog_index;
extern PSI_file_key key_file_binlog_state;

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

#ifndef __WIN__
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 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 MYSQL_PLUGIN_IMPORT char  *mysql_data_home;
extern "C" MYSQL_PLUGIN_IMPORT char server_version[SERVER_VERSION_LENGTH];
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];

#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_slave_list, LOCK_active_mi, LOCK_manager,
       LOCK_global_system_variables, LOCK_user_conn,
       LOCK_prepared_stmt_count, LOCK_error_messages, LOCK_connection_count;
extern mysql_mutex_t LOCK_rpl_gtid_state;
extern MYSQL_PLUGIN_IMPORT mysql_mutex_t LOCK_thread_count;
#ifdef HAVE_OPENSSL
extern mysql_mutex_t LOCK_des_key_file;
#endif
extern mysql_mutex_t LOCK_server_started;
extern 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_system_variables_hash;
extern mysql_cond_t COND_thread_count;
extern mysql_cond_t COND_manager;
extern int32 thread_running;
extern int32 thread_count;
extern my_atomic_rwlock_t thread_running_lock, thread_count_lock;

extern char *opt_ssl_ca, *opt_ssl_capath, *opt_ssl_cert, *opt_ssl_cipher,
            *opt_ssl_key;

extern MYSQL_PLUGIN_IMPORT pthread_key(THD*, THR_THD);

#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_BIND_ADDRESS,
  OPT_BINLOG_DO_DB,
  OPT_BINLOG_FORMAT,
  OPT_BINLOG_IGNORE_DB,
  OPT_BIN_LOG,
  OPT_BOOTSTRAP,
  OPT_CONSOLE,
  OPT_DEBUG_SYNC_TIMEOUT,
  OPT_DELAY_KEY_WRITE_ALL,
  OPT_DEPRECATED_OPTION,
  OPT_ENGINE_CONDITION_PUSHDOWN,
  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_LOG_BASENAME,
  OPT_LOG_ERROR,
  OPT_LOWER_CASE_TABLE_NAMES,
  OPT_MAX_LONG_DATA_SIZE,
  OPT_ONE_THREAD,
  OPT_POOL_OF_THREADS,
  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_SKIP_HOST_CACHE,
  OPT_SKIP_LOCK,
  OPT_SKIP_PRIOR,
  OPT_SKIP_RESOLVE,
  OPT_SKIP_STACK_TRACE,
  OPT_SKIP_SYMLINKS,
  OPT_SLOW_QUERY_LOG,
  OPT_SSL_CA,
  OPT_SSL_CAPATH,
  OPT_SSL_CERT,
  OPT_SSL_CIPHER,
  OPT_SSL_KEY,
  OPT_UPDATE_LOG,
  OPT_WANT_CORE,
  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)
};

/* query_id */
typedef int64 query_id_t;
extern query_id_t global_query_id;
extern my_atomic_rwlock_t global_query_id_lock;
extern my_atomic_rwlock_t statistics_lock;

void unireg_end(void) __attribute__((noreturn));

/* increment query_id and return it.  */
inline query_id_t next_query_id()
{
  query_id_t id;
  my_atomic_rwlock_wrlock(&global_query_id_lock);
  id= my_atomic_add64(&global_query_id, 1);
  my_atomic_rwlock_wrunlock(&global_query_id_lock);
  return (id);
}

inline query_id_t get_query_id()
{
  query_id_t id;
  my_atomic_rwlock_wrlock(&global_query_id_lock);
  id= my_atomic_load64(&global_query_id);
  my_atomic_rwlock_wrunlock(&global_query_id_lock);
  return id;
}


/*
  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->cset->casedn(files_charset_info,
                                     name, length, name, length);
}

inline void thread_safe_increment32(int32 *value, my_atomic_rwlock_t *lock)
{
  my_atomic_rwlock_wrlock(lock);
  (void) my_atomic_add32(value, 1);
  my_atomic_rwlock_wrunlock(lock);
}

inline void thread_safe_decrement32(int32 *value, my_atomic_rwlock_t *lock)
{
  my_atomic_rwlock_wrlock(lock);
  (void) my_atomic_add32(value, -1);
  my_atomic_rwlock_wrunlock(lock);
}

inline void
inc_thread_running()
{
  thread_safe_increment32(&thread_running, &thread_running_lock);
}

inline void
dec_thread_running()
{
  thread_safe_decrement32(&thread_running, &thread_running_lock);
}

void set_server_version(void);

#if defined(MYSQL_DYNAMIC_PLUGIN) && defined(_WIN32)
extern "C" THD *_current_thd_noinline();
#define _current_thd() _current_thd_noinline()
#else
/*
  THR_THD is a key which will be used to set/get THD* for a thread,
  using my_pthread_setspecific_ptr()/my_thread_getspecific_ptr().
*/
extern pthread_key(THD*, THR_THD);
inline THD *_current_thd(void)
{
  return my_pthread_getspecific_ptr(THD*,THR_THD);
}
#endif
#define current_thd _current_thd()
inline int set_current_thd(THD *thd)
{
  return my_pthread_setspecific_ptr(THR_THD, thd);
}

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

extern uint extra_connection_count;
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;
extern my_bool opt_expect_abort;
extern my_bool opt_slave_sql_verify_checksum;
extern ulong binlog_checksum_options;
extern bool max_user_connections_checking;
extern ulong opt_binlog_dbug_fsync_sleep;

extern uint internal_tmp_table_max_key_length;
extern uint internal_tmp_table_max_key_segments;

extern uint volatile global_disable_checkpoint;
extern my_bool opt_help;

#endif /* MYSQLD_INCLUDED */