thr_lock.h File Reference

#include <sys/types.h>
#include "my_inttypes.h"
#include "my_list.h"
#include "my_thread_local.h"
#include "mysql/psi/mysql_cond.h"
#include "mysql/psi/mysql_mutex.h"

Go to the source code of this file.

Classes
struct	Lock_descriptor
struct	THR_LOCK_INFO
struct	THR_LOCK_DATA
struct	st_lock_list
struct	THR_LOCK

Enumerations
enum	thr_lock_type {   TL_IGNORE = -1 , TL_UNLOCK , TL_READ_DEFAULT , TL_READ ,   TL_READ_WITH_SHARED_LOCKS , TL_READ_HIGH_PRIORITY , TL_READ_NO_INSERT , TL_WRITE_ALLOW_WRITE ,   TL_WRITE_CONCURRENT_DEFAULT , TL_WRITE_CONCURRENT_INSERT , TL_WRITE_DEFAULT , TL_WRITE_LOW_PRIORITY ,   TL_WRITE , TL_WRITE_ONLY , TL_IGNORE = -1 , TL_UNLOCK ,   TL_READ_DEFAULT , TL_READ , TL_READ_WITH_SHARED_LOCKS , TL_READ_HIGH_PRIORITY ,   TL_READ_NO_INSERT , TL_WRITE_ALLOW_WRITE , TL_WRITE_CONCURRENT_DEFAULT , TL_WRITE_CONCURRENT_INSERT ,   TL_WRITE_DEFAULT , TL_WRITE_LOW_PRIORITY , TL_WRITE , TL_WRITE_ONLY }
enum	thr_locked_row_action { THR_DEFAULT , THR_WAIT , THR_NOWAIT , THR_SKIP }
enum	enum_thr_lock_result { THR_LOCK_SUCCESS = 0 , THR_LOCK_ABORTED = 1 , THR_LOCK_WAIT_TIMEOUT = 2 , THR_LOCK_DEADLOCK = 3 }

Functions
void	thr_lock_info_init (THR_LOCK_INFO *info, my_thread_id thread_id, mysql_cond_t *suspend)
void	thr_lock_init (THR_LOCK *lock)
void	thr_lock_delete (THR_LOCK *lock)
void	thr_lock_data_init (THR_LOCK *lock, THR_LOCK_DATA *data, void *status_param)
enum enum_thr_lock_result	thr_lock (THR_LOCK_DATA *data, THR_LOCK_INFO *owner, enum thr_lock_type lock_type, ulong lock_wait_timeout)
void	thr_unlock (THR_LOCK_DATA *data)
enum enum_thr_lock_result	thr_multi_lock (THR_LOCK_DATA **data, uint count, THR_LOCK_INFO *owner, ulong lock_wait_timeout)
void	thr_multi_unlock (THR_LOCK_DATA **data, uint count)
void	thr_lock_merge_status (THR_LOCK_DATA **data, uint count)
	Ensure that all locks for a given table have the same status_param. More...
void	thr_abort_locks_for_thread (THR_LOCK *lock, my_thread_id thread)
void	thr_print_locks (void)
void	thr_set_lock_wait_callback (void(*before_wait)(void), void(*after_wait)(void))

Variables
mysql_mutex_t	THR_LOCK_lock
ulong	locks_immediate
ulong	locks_waited
ulong	max_write_lock_count
enum thr_lock_type	thr_upgraded_concurrent_insert_lock
LIST *	thr_lock_thread_list

Enumeration Type Documentation

enum_thr_lock_result

enum enum_thr_lock_result

Enumerator
THR_LOCK_SUCCESS
THR_LOCK_ABORTED
THR_LOCK_WAIT_TIMEOUT
THR_LOCK_DEADLOCK

thr_lock_type

enum thr_lock_type

Enumerator
TL_IGNORE
TL_UNLOCK
TL_READ_DEFAULT
TL_READ
TL_READ_WITH_SHARED_LOCKS
TL_READ_HIGH_PRIORITY
TL_READ_NO_INSERT
TL_WRITE_ALLOW_WRITE
TL_WRITE_CONCURRENT_DEFAULT
TL_WRITE_CONCURRENT_INSERT
TL_WRITE_DEFAULT
TL_WRITE_LOW_PRIORITY
TL_WRITE
TL_WRITE_ONLY
TL_IGNORE
TL_UNLOCK
TL_READ_DEFAULT
TL_READ
TL_READ_WITH_SHARED_LOCKS
TL_READ_HIGH_PRIORITY
TL_READ_NO_INSERT
TL_WRITE_ALLOW_WRITE
TL_WRITE_CONCURRENT_DEFAULT
TL_WRITE_CONCURRENT_INSERT
TL_WRITE_DEFAULT
TL_WRITE_LOW_PRIORITY
TL_WRITE
TL_WRITE_ONLY

thr_locked_row_action

enum thr_locked_row_action

Enumerator
THR_DEFAULT
THR_WAIT
THR_NOWAIT
THR_SKIP

Function Documentation

thr_abort_locks_for_thread()

void thr_abort_locks_for_thread	(	THR_LOCK *	lock,
		my_thread_id	thread
	)

thr_lock()

enum enum_thr_lock_result thr_lock	(	THR_LOCK_DATA *	data,
		THR_LOCK_INFO *	owner,
		enum thr_lock_type	lock_type,
		ulong	lock_wait_timeout
	)

thr_lock_data_init()

void thr_lock_data_init	(	THR_LOCK *	lock,
		THR_LOCK_DATA *	data,
		void *	status_param
	)

thr_lock_delete()

void thr_lock_delete

(

THR_LOCK *

lock

)

thr_lock_info_init()

void thr_lock_info_init	(	THR_LOCK_INFO *	info,
		my_thread_id	thread_id,
		mysql_cond_t *	suspend
	)

thr_lock_init()

void thr_lock_init

(

THR_LOCK *

lock

)

thr_lock_merge_status()

void thr_lock_merge_status	(	THR_LOCK_DATA **	data,
		uint	count
	)

Ensure that all locks for a given table have the same status_param.

This is a MyISAM and possibly Maria specific crutch. MyISAM engine stores data file length, record count and other table properties in status_param member of handler. When a table is locked, connection-local copy is made from a global copy (myisam_share) by mi_get_status(). When a table is unlocked, the changed status is transferred back to the global share by mi_update_status().

One thing MyISAM doesn't do is to ensure that when the same table is opened twice in a connection all instances share the same status_param. This is necessary, however: for one, to keep all instances of a connection "on the same page" with regard to the current state of the table. For other, unless this is done, myisam_share will always get updated from the last unlocked instance (in mi_update_status()), and when this instance was not the one that was used to update data, records may be lost.

For each table, this function looks up the last lock_data in the list of acquired locks, and makes sure that all other instances share status_param with it.

thr_multi_lock()

enum enum_thr_lock_result thr_multi_lock	(	THR_LOCK_DATA **	data,
		uint	count,
		THR_LOCK_INFO *	owner,
		ulong	lock_wait_timeout
	)

thr_multi_unlock()

void thr_multi_unlock	(	THR_LOCK_DATA **	data,
		uint	count
	)

thr_print_locks()

void thr_print_locks

(

void

)

thr_set_lock_wait_callback()

void thr_set_lock_wait_callback	(	void(*)(void)	before_wait,
		void(*)(void)	after_wait
	)

thr_unlock()

void thr_unlock

(

THR_LOCK_DATA *

data

)

Variable Documentation

locks_immediate

ulong locks_immediate

extern

locks_waited

ulong locks_waited

max_write_lock_count

ulong max_write_lock_count

extern

THR_LOCK_lock

mysql_mutex_t THR_LOCK_lock

extern

thr_lock_thread_list

LIST* thr_lock_thread_list

extern

thr_upgraded_concurrent_insert_lock

enum thr_lock_type thr_upgraded_concurrent_insert_lock

extern