1 /***************************************************************************** 2 3 Copyright (c) 2012, 2018, Oracle and/or its affiliates. All Rights Reserved. 4 5 This program is free software; you can redistribute it and/or modify it under 6 the terms of the GNU General Public License, version 2.0, as published by the 7 Free Software Foundation. 8 9 This program is also distributed with certain software (including but not 10 limited to OpenSSL) that is licensed under separate terms, as designated in a 11 particular file or component or in included license documentation. The authors 12 of MySQL hereby grant you an additional permission to link the program and 13 your derivative works with the separately licensed software that they have 14 included with MySQL. 15 16 This program is distributed in the hope that it will be useful, but WITHOUT 17 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 18 FOR A PARTICULAR PURPOSE. See the GNU General Public License, version 2.0, 19 for more details. 20 21 You should have received a copy of the GNU General Public License along with 22 this program; if not, write to the Free Software Foundation, Inc., 23 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 24 25 *****************************************************************************/ 26 27 /** @file include/dict0stats_bg.h 28 Code used for background table and index stats gathering. 29 30 Created Apr 26, 2012 Vasil Dimov 31 *******************************************************/ 32 33 #ifndef dict0stats_bg_h 34 #define dict0stats_bg_h 35 36 #include "univ.i" 37 38 #include "dict0types.h" 39 #include "os0event.h" 40 #include "os0thread.h" 41 42 /** Event to wake up the stats thread */ 43 extern os_event_t dict_stats_event; 44 45 #ifdef HAVE_PSI_INTERFACE 46 extern mysql_pfs_key_t dict_stats_recalc_pool_mutex_key; 47 #endif /* HAVE_PSI_INTERFACE */ 48 49 #ifdef UNIV_DEBUG 50 /** Value of MySQL global used to disable dict_stats thread. */ 51 extern bool innodb_dict_stats_disabled_debug; 52 #endif /* UNIV_DEBUG */ 53 54 /** Add a table to the recalc pool, which is processed by the 55 background stats gathering thread. Only the table id is added to the 56 list, so the table can be closed after being enqueued and it will be 57 opened when needed. If the table does not exist later (has been DROPped), 58 then it will be removed from the pool and skipped. */ 59 void dict_stats_recalc_pool_add( 60 const dict_table_t *table); /*!< in: table to add */ 61 62 /** Delete a given table from the auto recalc pool. 63 dict_stats_recalc_pool_del() */ 64 void dict_stats_recalc_pool_del( 65 const dict_table_t *table); /*!< in: table to remove */ 66 67 /** Yield the data dictionary latch when waiting 68 for the background thread to stop accessing a table. 69 @param trx transaction holding the data dictionary locks */ 70 #define DICT_STATS_BG_YIELD(trx) \ 71 do { \ 72 row_mysql_unlock_data_dictionary(trx); \ 73 os_thread_sleep(250000); \ 74 row_mysql_lock_data_dictionary(trx); \ 75 } while (0) 76 77 /** Request the background collection of statistics to stop for a table. 78 @retval true when no background process is active 79 @retval false when it is not safe to modify the table definition */ 80 UNIV_INLINE 81 bool dict_stats_stop_bg(dict_table_t *table) /*!< in/out: table */ 82 MY_ATTRIBUTE((warn_unused_result)); 83 84 /** Wait until background stats thread has stopped using the specified table. 85 The caller must have locked the data dictionary using 86 row_mysql_lock_data_dictionary() and this function may unlock it temporarily 87 and restore the lock before it exits. 88 The background stats thread is guaranteed not to start using the specified 89 table after this function returns and before the caller unlocks the data 90 dictionary because it sets the BG_STAT_IN_PROGRESS bit in table->stats_bg_flag 91 under dict_sys->mutex. */ 92 void dict_stats_wait_bg_to_stop_using_table( 93 dict_table_t *table, /*!< in/out: table */ 94 trx_t *trx); /*!< in/out: transaction to use for 95 unlocking/locking the data dict */ 96 /** Initialize global variables needed for the operation of dict_stats_thread(). 97 Must be called before dict_stats_thread() is started. */ 98 void dict_stats_thread_init(); 99 100 /** Free resources allocated by dict_stats_thread_init(), must be called 101 after dict_stats_thread() has exited. */ 102 void dict_stats_thread_deinit(); 103 104 #ifdef UNIV_DEBUG 105 /** Disables dict stats thread. It's used by: 106 SET GLOBAL innodb_dict_stats_disabled_debug = 1 (0). 107 @param[in] thd thread handle 108 @param[in] var pointer to system variable 109 @param[out] var_ptr where the formal string goes 110 @param[in] save immediate result from check function */ 111 void dict_stats_disabled_debug_update(THD *thd, SYS_VAR *var, void *var_ptr, 112 const void *save); 113 #endif /* UNIV_DEBUG */ 114 115 /** This is the thread for background stats gathering. It pops tables, from 116 the auto recalc list and proceeds them, eventually recalculating their 117 statistics. */ 118 void dict_stats_thread(); 119 120 /** Shutdown the dict stats thread. */ 121 void dict_stats_shutdown(); 122 123 #include "dict0stats_bg.ic" 124 125 #endif /* dict0stats_bg_h */ 126