mariadb/sql/mysqld.h

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2014-01-06 06:22:35 +01:00
/* Copyright (c) 2006, 2013, 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;
/*
This forward declaration is used from C files where the real
definition is included before. Since C does not allow repeated
typedef declarations, even when identical, the definition may not be
repeated.
*/
#ifndef CHARSET_INFO_DEFINED
typedef struct charset_info_st CHARSET_INFO;
#endif /* CHARSET_INFO_DEFINED */
#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_NO_STACKTRACE 512
#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 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;
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;
Patch that refactors global read lock implementation and fixes bug #57006 "Deadlock between HANDLER and FLUSH TABLES WITH READ LOCK" and bug #54673 "It takes too long to get readlock for 'FLUSH TABLES WITH READ LOCK'". The first bug manifested itself as a deadlock which occurred when a connection, which had some table open through HANDLER statement, tried to update some data through DML statement while another connection tried to execute FLUSH TABLES WITH READ LOCK concurrently. What happened was that FTWRL in the second connection managed to perform first step of GRL acquisition and thus blocked all upcoming DML. After that it started to wait for table open through HANDLER statement to be flushed. When the first connection tried to execute DML it has started to wait for GRL/the second connection creating deadlock. The second bug manifested itself as starvation of FLUSH TABLES WITH READ LOCK statements in cases when there was a constant stream of concurrent DML statements (in two or more connections). This has happened because requests for protection against GRL which were acquired by DML statements were ignoring presence of pending GRL and thus the latter was starved. This patch solves both these problems by re-implementing GRL using metadata locks. Similar to the old implementation acquisition of GRL in new implementation is two-step. During the first step we block all concurrent DML and DDL statements by acquiring global S metadata lock (each DML and DDL statement acquires global IX lock for its duration). During the second step we block commits by acquiring global S lock in COMMIT namespace (commit code acquires global IX lock in this namespace). Note that unlike in old implementation acquisition of protection against GRL in DML and DDL is semi-automatic. We assume that any statement which should be blocked by GRL will either open and acquires write-lock on tables or acquires metadata locks on objects it is going to modify. For any such statement global IX metadata lock is automatically acquired for its duration. The first problem is solved because waits for GRL become visible to deadlock detector in metadata locking subsystem and thus deadlocks like one in the first bug become impossible. The second problem is solved because global S locks which are used for GRL implementation are given preference over IX locks which are acquired by concurrent DML (and we can switch to fair scheduling in future if needed). Important change: FTWRL/GRL no longer blocks DML and DDL on temporary tables. Before this patch behavior was not consistent in this respect: in some cases DML/DDL statements on temporary tables were blocked while in others they were not. Since the main use cases for FTWRL are various forms of backups and temporary tables are not preserved during backups we have opted for consistently allowing DML/DDL on temporary tables during FTWRL/GRL. Important change: This patch changes thread state names which are used when DML/DDL of FTWRL is waiting for global read lock. It is now either "Waiting for global read lock" or "Waiting for commit lock" depending on the stage on which FTWRL is. Incompatible change: To solve deadlock in events code which was exposed by this patch we have to replace LOCK_event_metadata mutex with metadata locks on events. As result we have to prohibit DDL on events under LOCK TABLES. This patch also adds extensive test coverage for interaction of DML/DDL and FTWRL. Performance of new and old global read lock implementations in sysbench tests were compared. There were no significant difference between new and old implementations.
2010-11-11 18:11:05 +01:00
extern uint volatile thread_count;
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;
2010-08-05 14:34:19 +02:00
extern ulong slave_exec_mode_options;
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 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 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;
2010-08-05 14:34:19 +02:00
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;
BUG#57275 binlog_cache_size affects trx- and stmt-cache and gets twice the expected memory After the WL#2687, the binlog_cache_size and max_binlog_cache_size affect both the stmt-cache and the trx-cache. This means that the resource used is twice the amount expected/defined by the user. The binlog_cache_use is incremented when the stmt-cache or the trx-cache is used and binlog_cache_disk_use is incremented when the disk space from the stmt-cache or the trx-cache is used. This behavior does not allow to distinguish which cache may be harming performance due to the extra disk accesses and needs to have its in-memory cache increased. To fix the problem, we introduced two new options and status variables related to the stmt-cache: Options: . binlog_stmt_cache_size . max_binlog_stmt_cache_size Status Variables: . binlog_stmt_cache_use . binlog_stmt_cache_disk_use So there are . binlog_cache_size that defines the size of the transactional cache for updates to transactional engines for the binary log. . binlog_stmt_cache_size that defines the size of the statement cache for updates to non-transactional engines for the binary log. . max_binlog_cache_size that sets the total size of the transactional cache. . max_binlog_stmt_cache_size that sets the total size of the statement cache. . binlog_cache_use that identifies the number of transactions that used the temporary transactional binary log cache. . binlog_cache_disk_use that identifies the number of transactions that used the temporary transactional binary log cache but that exceeded the value of binlog_cache_size. . binlog_stmt_cache_use that identifies the number of statements that used the temporary non-transactional binary log cache. . binlog_stmt_cache_disk_use that identifies the number of statements that used the temporary non-transactional binary log cache but that exceeded the value of binlog_stmt_cache_size.
2010-11-05 18:42:37 +01:00
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 ulong query_cache_size, 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 uint max_user_connections;
extern ulong what_to_log,flush_time;
extern ulong max_prepared_stmt_count, prepared_stmt_count;
BUG#57275 binlog_cache_size affects trx- and stmt-cache and gets twice the expected memory After the WL#2687, the binlog_cache_size and max_binlog_cache_size affect both the stmt-cache and the trx-cache. This means that the resource used is twice the amount expected/defined by the user. The binlog_cache_use is incremented when the stmt-cache or the trx-cache is used and binlog_cache_disk_use is incremented when the disk space from the stmt-cache or the trx-cache is used. This behavior does not allow to distinguish which cache may be harming performance due to the extra disk accesses and needs to have its in-memory cache increased. To fix the problem, we introduced two new options and status variables related to the stmt-cache: Options: . binlog_stmt_cache_size . max_binlog_stmt_cache_size Status Variables: . binlog_stmt_cache_use . binlog_stmt_cache_disk_use So there are . binlog_cache_size that defines the size of the transactional cache for updates to transactional engines for the binary log. . binlog_stmt_cache_size that defines the size of the statement cache for updates to non-transactional engines for the binary log. . max_binlog_cache_size that sets the total size of the transactional cache. . max_binlog_stmt_cache_size that sets the total size of the statement cache. . binlog_cache_use that identifies the number of transactions that used the temporary transactional binary log cache. . binlog_cache_disk_use that identifies the number of transactions that used the temporary transactional binary log cache but that exceeded the value of binlog_cache_size. . binlog_stmt_cache_use that identifies the number of statements that used the temporary non-transactional binary log cache. . binlog_stmt_cache_disk_use that identifies the number of statements that used the temporary non-transactional binary log cache but that exceeded the value of binlog_stmt_cache_size.
2010-11-05 18:42:37 +01:00
extern ulong open_files_limit;
extern ulong binlog_cache_size, binlog_stmt_cache_size;
extern ulonglong max_binlog_cache_size, max_binlog_stmt_cache_size;
extern ulong max_binlog_size, max_relay_log_size;
extern ulong slave_max_allowed_packet;
extern ulong opt_binlog_rows_event_max_size;
extern ulong rpl_recovery_rank, thread_cache_size;
Fixed bug#11753187 (formerly known as bug 44585): SP_CACHE BEHAVES AS MEMORY LEAK. Background: - There are caches for stored functions and stored procedures (SP-cache); - There is no similar cache for events; - Triggers are cached together with TABLE objects; - Those SP-caches are per-session (i.e. specific to each session); - A stored routine is represented by a sp_head-instance internally; - SP-cache basically contains sp_head-objects of stored routines, which have been executed in a session; - sp_head-object is added into the SP-cache before the corresponding stored routine is executed; - SP-cache is flushed in the end of the session. The problem was that SP-cache might grow without any limit. Although this was not a pure memory leak (the SP-cache is flushed when session is closed), this is still a problem, because the user might take much memory by executing many stored routines. The patch fixes this problem in the least-intrusive way. A soft limit (similar to the size of table definition cache) is introduced. To represent such limit the new runtime configuration parameter 'stored_program_cache' is introduced. The value of this parameter is stored in the new global variable stored_program_cache_size that used to control the size of SP-cache to overflow. The parameter 'stored_program_cache' limits number of cached routines for each thread. It has the following min/default/max values given from support: min = 256, default = 256, max = 512 * 1024. Also it should be noted that this parameter limits the size of each cache (for stored procedures and for stored functions) separately. The SP-cache size is checked after top-level statement is parsed. If SP-cache size exceeds the limit specified by parameter 'stored_program_cache' then SP-cache is flushed and memory allocated for cache objects is freed. Such approach allows to flush cache safely when there are dependencies among stored routines.
2012-01-25 10:59:30 +01:00
extern ulong stored_program_cache_size;
extern ulong back_log;
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 rand_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;
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;
extern my_decimal decimal_zero;
void init_sql_statement_names();
2011-05-18 16:17:29 +02:00
/*
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;
#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_prep_xids,
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,
Patch that refactors global read lock implementation and fixes bug #57006 "Deadlock between HANDLER and FLUSH TABLES WITH READ LOCK" and bug #54673 "It takes too long to get readlock for 'FLUSH TABLES WITH READ LOCK'". The first bug manifested itself as a deadlock which occurred when a connection, which had some table open through HANDLER statement, tried to update some data through DML statement while another connection tried to execute FLUSH TABLES WITH READ LOCK concurrently. What happened was that FTWRL in the second connection managed to perform first step of GRL acquisition and thus blocked all upcoming DML. After that it started to wait for table open through HANDLER statement to be flushed. When the first connection tried to execute DML it has started to wait for GRL/the second connection creating deadlock. The second bug manifested itself as starvation of FLUSH TABLES WITH READ LOCK statements in cases when there was a constant stream of concurrent DML statements (in two or more connections). This has happened because requests for protection against GRL which were acquired by DML statements were ignoring presence of pending GRL and thus the latter was starved. This patch solves both these problems by re-implementing GRL using metadata locks. Similar to the old implementation acquisition of GRL in new implementation is two-step. During the first step we block all concurrent DML and DDL statements by acquiring global S metadata lock (each DML and DDL statement acquires global IX lock for its duration). During the second step we block commits by acquiring global S lock in COMMIT namespace (commit code acquires global IX lock in this namespace). Note that unlike in old implementation acquisition of protection against GRL in DML and DDL is semi-automatic. We assume that any statement which should be blocked by GRL will either open and acquires write-lock on tables or acquires metadata locks on objects it is going to modify. For any such statement global IX metadata lock is automatically acquired for its duration. The first problem is solved because waits for GRL become visible to deadlock detector in metadata locking subsystem and thus deadlocks like one in the first bug become impossible. The second problem is solved because global S locks which are used for GRL implementation are given preference over IX locks which are acquired by concurrent DML (and we can switch to fair scheduling in future if needed). Important change: FTWRL/GRL no longer blocks DML and DDL on temporary tables. Before this patch behavior was not consistent in this respect: in some cases DML/DDL statements on temporary tables were blocked while in others they were not. Since the main use cases for FTWRL are various forms of backups and temporary tables are not preserved during backups we have opted for consistently allowing DML/DDL on temporary tables during FTWRL/GRL. Important change: This patch changes thread state names which are used when DML/DDL of FTWRL is waiting for global read lock. It is now either "Waiting for global read lock" or "Waiting for commit lock" depending on the stage on which FTWRL is. Incompatible change: To solve deadlock in events code which was exposed by this patch we have to replace LOCK_event_metadata mutex with metadata locks on events. As result we have to prohibit DDL on events under LOCK TABLES. This patch also adds extensive test coverage for interaction of DML/DDL and FTWRL. Performance of new and old global read lock implementations in sysbench tests were compared. There were no significant difference between new and old implementations.
2010-11-11 18:11:05 +01:00
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_LOCK_uuid_generator, 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_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;
extern PSI_mutex_key key_LOCK_thread_created;
#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_prep_xids, key_BINLOG_update_cond,
Patch that refactors global read lock implementation and fixes bug #57006 "Deadlock between HANDLER and FLUSH TABLES WITH READ LOCK" and bug #54673 "It takes too long to get readlock for 'FLUSH TABLES WITH READ LOCK'". The first bug manifested itself as a deadlock which occurred when a connection, which had some table open through HANDLER statement, tried to update some data through DML statement while another connection tried to execute FLUSH TABLES WITH READ LOCK concurrently. What happened was that FTWRL in the second connection managed to perform first step of GRL acquisition and thus blocked all upcoming DML. After that it started to wait for table open through HANDLER statement to be flushed. When the first connection tried to execute DML it has started to wait for GRL/the second connection creating deadlock. The second bug manifested itself as starvation of FLUSH TABLES WITH READ LOCK statements in cases when there was a constant stream of concurrent DML statements (in two or more connections). This has happened because requests for protection against GRL which were acquired by DML statements were ignoring presence of pending GRL and thus the latter was starved. This patch solves both these problems by re-implementing GRL using metadata locks. Similar to the old implementation acquisition of GRL in new implementation is two-step. During the first step we block all concurrent DML and DDL statements by acquiring global S metadata lock (each DML and DDL statement acquires global IX lock for its duration). During the second step we block commits by acquiring global S lock in COMMIT namespace (commit code acquires global IX lock in this namespace). Note that unlike in old implementation acquisition of protection against GRL in DML and DDL is semi-automatic. We assume that any statement which should be blocked by GRL will either open and acquires write-lock on tables or acquires metadata locks on objects it is going to modify. For any such statement global IX metadata lock is automatically acquired for its duration. The first problem is solved because waits for GRL become visible to deadlock detector in metadata locking subsystem and thus deadlocks like one in the first bug become impossible. The second problem is solved because global S locks which are used for GRL implementation are given preference over IX locks which are acquired by concurrent DML (and we can switch to fair scheduling in future if needed). Important change: FTWRL/GRL no longer blocks DML and DDL on temporary tables. Before this patch behavior was not consistent in this respect: in some cases DML/DDL statements on temporary tables were blocked while in others they were not. Since the main use cases for FTWRL are various forms of backups and temporary tables are not preserved during backups we have opted for consistently allowing DML/DDL on temporary tables during FTWRL/GRL. Important change: This patch changes thread state names which are used when DML/DDL of FTWRL is waiting for global read lock. It is now either "Waiting for global read lock" or "Waiting for commit lock" depending on the stage on which FTWRL is. Incompatible change: To solve deadlock in events code which was exposed by this patch we have to replace LOCK_event_metadata mutex with metadata locks on events. As result we have to prohibit DDL on events under LOCK TABLES. This patch also adds extensive test coverage for interaction of DML/DDL and FTWRL. Performance of new and old global read lock implementations in sysbench tests were compared. There were no significant difference between new and old implementations.
2010-11-11 18:11:05 +01:00
key_COND_cache_status_changed, key_COND_manager,
Fix for bug #52044 "FLUSH TABLES WITH READ LOCK and FLUSH TABLES <list> WITH READ LOCK are incompatible". The problem was that FLUSH TABLES <list> WITH READ LOCK which was issued when other connection has acquired global read lock using FLUSH TABLES WITH READ LOCK was blocked and has to wait until global read lock is released. This issue stemmed from the fact that FLUSH TABLES <list> WITH READ LOCK implementation has acquired X metadata locks on tables to be flushed. Since these locks required acquiring of global IX lock this statement was incompatible with global read lock. This patch addresses problem by using SNW metadata type of lock for tables to be flushed by FLUSH TABLES <list> WITH READ LOCK. It is OK to acquire them without global IX lock as long as we won't try to upgrade those locks. Since SNW locks allow concurrent statements using same table FLUSH TABLE <list> WITH READ LOCK now has to wait until old versions of tables to be flushed go away after acquiring metadata locks. Since such waiting can lead to deadlock MDL deadlock detector was extended to take into account waits for flush and resolve such deadlocks. As a bonus code in open_tables() which was responsible for waiting old versions of tables to go away was refactored. Now when we encounter old version of table in open_table() we don't back-off and wait for all old version to go away, but instead wait for this particular table to be flushed. Such approach supported by deadlock detection should reduce number of scenarios in which FLUSH TABLES aborts concurrent multi-statement transactions. Note that active FLUSH TABLES <list> WITH READ LOCK still blocks concurrent FLUSH TABLES WITH READ LOCK statement as the former keeps tables open and thus prevents the latter statement from doing flush.
2010-07-27 15:34:58 +02:00
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;
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;
#ifdef HAVE_MMAP
extern PSI_file_key key_file_map;
#endif /* HAVE_MMAP */
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;
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;
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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_user_locks, LOCK_status,
LOCK_error_log, LOCK_delayed_insert, LOCK_uuid_generator,
LOCK_delayed_status, LOCK_delayed_create, LOCK_crypt, LOCK_timezone,
Patch that refactors global read lock implementation and fixes bug #57006 "Deadlock between HANDLER and FLUSH TABLES WITH READ LOCK" and bug #54673 "It takes too long to get readlock for 'FLUSH TABLES WITH READ LOCK'". The first bug manifested itself as a deadlock which occurred when a connection, which had some table open through HANDLER statement, tried to update some data through DML statement while another connection tried to execute FLUSH TABLES WITH READ LOCK concurrently. What happened was that FTWRL in the second connection managed to perform first step of GRL acquisition and thus blocked all upcoming DML. After that it started to wait for table open through HANDLER statement to be flushed. When the first connection tried to execute DML it has started to wait for GRL/the second connection creating deadlock. The second bug manifested itself as starvation of FLUSH TABLES WITH READ LOCK statements in cases when there was a constant stream of concurrent DML statements (in two or more connections). This has happened because requests for protection against GRL which were acquired by DML statements were ignoring presence of pending GRL and thus the latter was starved. This patch solves both these problems by re-implementing GRL using metadata locks. Similar to the old implementation acquisition of GRL in new implementation is two-step. During the first step we block all concurrent DML and DDL statements by acquiring global S metadata lock (each DML and DDL statement acquires global IX lock for its duration). During the second step we block commits by acquiring global S lock in COMMIT namespace (commit code acquires global IX lock in this namespace). Note that unlike in old implementation acquisition of protection against GRL in DML and DDL is semi-automatic. We assume that any statement which should be blocked by GRL will either open and acquires write-lock on tables or acquires metadata locks on objects it is going to modify. For any such statement global IX metadata lock is automatically acquired for its duration. The first problem is solved because waits for GRL become visible to deadlock detector in metadata locking subsystem and thus deadlocks like one in the first bug become impossible. The second problem is solved because global S locks which are used for GRL implementation are given preference over IX locks which are acquired by concurrent DML (and we can switch to fair scheduling in future if needed). Important change: FTWRL/GRL no longer blocks DML and DDL on temporary tables. Before this patch behavior was not consistent in this respect: in some cases DML/DDL statements on temporary tables were blocked while in others they were not. Since the main use cases for FTWRL are various forms of backups and temporary tables are not preserved during backups we have opted for consistently allowing DML/DDL on temporary tables during FTWRL/GRL. Important change: This patch changes thread state names which are used when DML/DDL of FTWRL is waiting for global read lock. It is now either "Waiting for global read lock" or "Waiting for commit lock" depending on the stage on which FTWRL is. Incompatible change: To solve deadlock in events code which was exposed by this patch we have to replace LOCK_event_metadata mutex with metadata locks on events. As result we have to prohibit DDL on events under LOCK TABLES. This patch also adds extensive test coverage for interaction of DML/DDL and FTWRL. Performance of new and old global read lock implementations in sysbench tests were compared. There were no significant difference between new and old implementations.
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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_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;
Fix for bug #52044 "FLUSH TABLES WITH READ LOCK and FLUSH TABLES <list> WITH READ LOCK are incompatible". The problem was that FLUSH TABLES <list> WITH READ LOCK which was issued when other connection has acquired global read lock using FLUSH TABLES WITH READ LOCK was blocked and has to wait until global read lock is released. This issue stemmed from the fact that FLUSH TABLES <list> WITH READ LOCK implementation has acquired X metadata locks on tables to be flushed. Since these locks required acquiring of global IX lock this statement was incompatible with global read lock. This patch addresses problem by using SNW metadata type of lock for tables to be flushed by FLUSH TABLES <list> WITH READ LOCK. It is OK to acquire them without global IX lock as long as we won't try to upgrade those locks. Since SNW locks allow concurrent statements using same table FLUSH TABLE <list> WITH READ LOCK now has to wait until old versions of tables to be flushed go away after acquiring metadata locks. Since such waiting can lead to deadlock MDL deadlock detector was extended to take into account waits for flush and resolve such deadlocks. As a bonus code in open_tables() which was responsible for waiting old versions of tables to go away was refactored. Now when we encounter old version of table in open_table() we don't back-off and wait for all old version to go away, but instead wait for this particular table to be flushed. Such approach supported by deadlock detection should reduce number of scenarios in which FLUSH TABLES aborts concurrent multi-statement transactions. Note that active FLUSH TABLES <list> WITH READ LOCK still blocks concurrent FLUSH TABLES WITH READ LOCK statement as the former keeps tables open and thus prevents the latter statement from doing flush.
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extern mysql_cond_t COND_manager;
extern int32 thread_running;
extern my_atomic_rwlock_t thread_running_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);
/**
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_ISAM_LOG,
OPT_KEY_BUFFER_SIZE,
OPT_KEY_CACHE_AGE_THRESHOLD,
OPT_KEY_CACHE_BLOCK_SIZE,
OPT_KEY_CACHE_DIVISION_LIMIT,
OPT_LOWER_CASE_TABLE_NAMES,
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_NEW,
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_ENGINE_CONDITION_PUSHDOWN,
OPT_LOG_ERROR,
OPT_MAX_LONG_DATA_SIZE
};
/**
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)
};
/* query_id */
typedef int64 query_id_t;
extern query_id_t global_query_id;
extern my_atomic_rwlock_t global_query_id_lock;
void unireg_end(void) __attribute__((noreturn));
/* increment query_id and return it. */
inline __attribute__((warn_unused_result)) 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+1);
}
/*
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 ulong sql_rnd_with_mutex()
{
mysql_mutex_lock(&LOCK_thread_count);
ulong tmp=(ulong) (my_rnd(&sql_rand) * 0xffffffff); /* make all bits random */
mysql_mutex_unlock(&LOCK_thread_count);
return tmp;
}
inline int32
inc_thread_running()
{
int32 num_thread_running;
my_atomic_rwlock_wrlock(&thread_running_lock);
num_thread_running= my_atomic_add32(&thread_running, 1);
my_atomic_rwlock_wrunlock(&thread_running_lock);
return (num_thread_running+1);
}
inline int32
dec_thread_running()
{
int32 num_thread_running;
my_atomic_rwlock_wrlock(&thread_running_lock);
num_thread_running= my_atomic_add32(&thread_running, -1);
my_atomic_rwlock_wrunlock(&thread_running_lock);
return (num_thread_running-1);
}
inline int32
get_thread_running()
{
int32 num_thread_running;
my_atomic_rwlock_wrlock(&thread_running_lock);
num_thread_running= my_atomic_load32(&thread_running);
my_atomic_rwlock_wrunlock(&thread_running_lock);
return num_thread_running;
}
#if defined(MYSQL_DYNAMIC_PLUGIN) && defined(_WIN32)
extern "C" THD *_current_thd_noinline();
#define _current_thd() _current_thd_noinline()
#else
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/*
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()
#endif /* MYSQLD_INCLUDED */