MySQL  8.0.20
Source Code Documentation
dict0stats_bg.h
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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 */
44 
45 #ifdef HAVE_PSI_INTERFACE
47 #endif /* HAVE_PSI_INTERFACE */
48 
49 #ifdef UNIV_DEBUG
50 /** Value of MySQL global used to disable dict_stats thread. */
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. */
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() */
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. */
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. */
99 
100 /** Free resources allocated by dict_stats_thread_init(), must be called
101  after dict_stats_thread() has exited. */
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 */
void dict_stats_recalc_pool_del(const dict_table_t *table)
Delete a given table from the auto recalc pool.
Definition: dict0stats_bg.cc:168
bool innodb_dict_stats_disabled_debug
Value of MySQL global used to disable dict_stats thread.
Definition: dict0stats_bg.cc:59
Definition: plugin.h:62
os_event_t dict_stats_event
Event to wake up the stats thread.
Definition: dict0stats_bg.cc:55
Definition: trx0trx.h:800
The interface to the operating system process and thread control primitives.
Data structure for a database table.
Definition: dict0mem.h:1520
void dict_stats_disabled_debug_update(THD *thd, SYS_VAR *var, void *var_ptr, const void *save)
Disables dict stats thread.
Definition: dict0stats_bg.cc:341
void dict_stats_thread_deinit()
Free resources allocated by dict_stats_thread_init(), must be called after dict_stats_thread() has ex...
Definition: dict0stats_bg.cc:238
UNIV_INLINE bool dict_stats_stop_bg(dict_table_t *table)
Request the background collection of statistics to stop for a table.
Data dictionary global types.
void dict_stats_recalc_pool_add(const dict_table_t *table)
Add a table to the recalc pool, which is processed by the background stats gathering thread...
Definition: dict0stats_bg.cc:118
InnoDB condition variable.
Definition: os0event.cc:66
void dict_stats_shutdown()
Shutdown the dict stats thread.
Definition: dict0stats_bg.cc:397
The interface to the operating system condition variables.
Define for performance schema registration key.
Definition: sync0sync.h:50
void dict_stats_thread_init()
Initialize global variables needed for the operation of dict_stats_thread().
Definition: dict0stats_bg.cc:210
mysql_pfs_key_t dict_stats_recalc_pool_mutex_key
void dict_stats_thread()
This is the thread for background stats gathering.
Definition: dict0stats_bg.cc:362
void dict_stats_wait_bg_to_stop_using_table(dict_table_t *table, trx_t *trx)
Wait until background stats thread has stopped using the specified table.
Definition: dict0stats_bg.cc:198
For each client connection we create a separate thread with THD serving as a thread/connection descri...
Definition: sql_class.h:765