Edit: table_cache.h
#ifndef TABLE_CACHE_H_INCLUDED #define TABLE_CACHE_H_INCLUDED /* Copyright (c) 2000, 2012, Oracle and/or its affiliates. Copyright (c) 2010, 2011 Monty Program Ab Copyright (C) 2013 Sergey Vojtovich and MariaDB Foundation 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 */ struct Share_free_tables { typedef I_P_List <TABLE, TABLE_share> List; List list; /** Avoid false sharing between instances */ char pad[CPU_LEVEL1_DCACHE_LINESIZE]; }; struct TDC_element { uchar m_key[NAME_LEN + 1 + NAME_LEN + 1]; uint m_key_length; bool flushed; TABLE_SHARE *share; /** Protects ref_count, m_flush_tickets, all_tables, flushed, all_tables_refs. */ mysql_mutex_t LOCK_table_share; mysql_cond_t COND_release; TDC_element *next, **prev; /* Link to unused shares */ uint ref_count; /* How many TABLE objects uses this */ uint all_tables_refs; /* Number of refs to all_tables */ /** List of tickets representing threads waiting for the share to be flushed. */ Wait_for_flush_list m_flush_tickets; /* Doubly-linked (back-linked) lists of used and unused TABLE objects for this share. */ All_share_tables_list all_tables; /** Avoid false sharing between TDC_element and free_tables */ char pad[CPU_LEVEL1_DCACHE_LINESIZE]; Share_free_tables free_tables[1]; inline void wait_for_refs(uint my_refs); void flush(THD *thd, bool mark_flushed); void flush_unused(bool mark_flushed); }; extern ulong tdc_size; extern ulong tc_size; extern uint32 tc_instances; extern bool tdc_init(void); extern void tdc_start_shutdown(void); extern void tdc_deinit(void); extern ulong tdc_records(void); extern void tdc_purge(bool all); extern TDC_element *tdc_lock_share(THD *thd, const char *db, const char *table_name); extern void tdc_unlock_share(TDC_element *element); int tdc_share_is_cached(THD *thd, const char *db, const char *table_name); extern TABLE_SHARE *tdc_acquire_share(THD *thd, TABLE_LIST *tl, uint flags, TABLE **out_table= 0); extern void tdc_release_share(TABLE_SHARE *share); void tdc_remove_referenced_share(THD *thd, TABLE_SHARE *share); void tdc_remove_table(THD *thd, const char *db, const char *table_name); extern int tdc_wait_for_old_version(THD *thd, const char *db, const char *table_name, ulong wait_timeout, uint deadlock_weight); extern int tdc_iterate(THD *thd, my_hash_walk_action action, void *argument, bool no_dups= false); extern uint tc_records(void); int show_tc_active_instances(THD *thd, SHOW_VAR *var, void *buff, system_status_var *, enum enum_var_type scope); extern void tc_purge(); extern void tc_add_table(THD *thd, TABLE *table); extern void tc_release_table(TABLE *table); extern TABLE *tc_acquire_table(THD *thd, TDC_element *element); /** Create a table cache key for non-temporary table. @param key Buffer for key (must be at least NAME_LEN*2+2 bytes). @param db Database name. @param table_name Table name. @return Length of key. */ inline uint tdc_create_key(char *key, const char *db, const char *table_name) { /* In theory caller should ensure that both db and table_name are not longer than NAME_LEN bytes. In practice we play safe to avoid buffer overruns. */ return (uint) (strmake(strmake(key, db, NAME_LEN) + 1, table_name, NAME_LEN) - key + 1); } #endif /* TABLE_CACHE_H_INCLUDED */
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