Locks_hashtable Struct Reference

A hashmap used by lock sys, to organize locks by page (block), so that it is easy to maintain a list of all locks related to a given page by append(lock,..), prepend(lock,..), erase(lock,..), move_to_front(lock,...) while also providing ability to iterate over all locks related for a given page in that order. More...

#include <lock0lock.h>

Public Types
using	Cells_in_use = ut::Sharded_bitset< locksys::Latches::SHARDS_COUNT >

Public Member Functions
	Locks_hashtable (size_t n_cells)
void	append (lock_t *lock, uint64_t hash_value)
void	prepend (lock_t *lock, uint64_t hash_value)
void	erase (lock_t *lock, uint64_t hash_value)
void	move_to_front (lock_t *lock, uint64_t hash_value)
void	resize (size_t n_cells)
template<typename F >
lock_t *	find_in_cell (size_t cell_id, F &&f)
template<typename F >
lock_t *	find_on_page (page_id_t page_id, F &&f)
template<typename F >
lock_t *	find_on_block (const buf_block_t *block, F &&f)
template<typename F >
lock_t *	find_on_record (const struct RecID &rec_id, F &&f)
template<typename F >
lock_t *	find (F &&f)
size_t	get_n_cells ()
size_t	find_set_in_this_shard (size_t start_pos)
size_t	get_cell_id (uint64_t hash_value)

Private Member Functions
bool	append (hash_cell_t *cell, lock_t *lock)
bool	prepend (hash_cell_t *cell, lock_t *lock)
bool	erase (hash_cell_t *cell, lock_t *lock)
	Locks_hashtable (Locks_hashtable &&)=delete
	Locks_hashtable (const Locks_hashtable &)=delete
Locks_hashtable &	operator= (Locks_hashtable &&)=delete
Locks_hashtable &	operator= (const Locks_hashtable &)=delete

Private Attributes
ut::unique_ptr< hash_table_t >	ht
Cells_in_use	cells_in_use

Detailed Description

A hashmap used by lock sys, to organize locks by page (block), so that it is easy to maintain a list of all locks related to a given page by append(lock,..), prepend(lock,..), erase(lock,..), move_to_front(lock,...) while also providing ability to iterate over all locks related for a given page in that order.

The hash has a configurable number of cells, and handles conflicts by using a singly linked list for each cell - locks related to same page are guaranteed to hash to the same cell. This detail is exposed because, for performance reasons you might want to resize(n) it, or inspect all locks from a given cell with find_in_cell(cell_id, visitor), or find a next non-empty cell with find_set_in_this_shard(..), or cell to which a given hash_value is mapped with get_cell_id(hash_value).

Member Typedef Documentation

Cells_in_use

using Locks_hashtable::Cells_in_use = ut::Sharded_bitset<locksys::Latches::SHARDS_COUNT>

Constructor & Destructor Documentation

Locks_hashtable() [1/3]

Locks_hashtable::Locks_hashtable ( size_t  n_cells )

inline

Locks_hashtable() [2/3]

Locks_hashtable::Locks_hashtable ( Locks_hashtable &&  )

privatedelete

Locks_hashtable() [3/3]

Locks_hashtable::Locks_hashtable ( const Locks_hashtable &  )

privatedelete

Member Function Documentation

append() [1/2]

bool Locks_hashtable::append ( hash_cell_t *  cell, lock_t *  lock  )

private

append() [2/2]

void Locks_hashtable::append	(	lock_t *	lock,
		uint64_t	hash_value
	)

erase() [1/2]

bool Locks_hashtable::erase ( hash_cell_t *  cell, lock_t *  lock  )

private

erase() [2/2]

void Locks_hashtable::erase	(	lock_t *	lock,
		uint64_t	hash_value
	)

find()

template<typename F >

lock_t * Locks_hashtable::find

(

F &&

f

)

find_in_cell()

template<typename F >

lock_t * Locks_hashtable::find_in_cell	(	size_t	cell_id,
		F &&	f
	)

find_on_block()

template<typename F >

lock_t * Locks_hashtable::find_on_block	(	const buf_block_t *	block,
		F &&	f
	)

find_on_page()

template<typename F >

lock_t * Locks_hashtable::find_on_page	(	page_id_t	page_id,
		F &&	f
	)

find_on_record()

template<typename F >

lock_t * Locks_hashtable::find_on_record	(	const struct RecID &	rec_id,
		F &&	f
	)

find_set_in_this_shard()

size_t Locks_hashtable::find_set_in_this_shard ( size_t  start_pos )

inline

get_cell_id()

size_t Locks_hashtable::get_cell_id

(

uint64_t

hash_value

)

get_n_cells()

size_t Locks_hashtable::get_n_cells ( )

inline

move_to_front()

void Locks_hashtable::move_to_front	(	lock_t *	lock,
		uint64_t	hash_value
	)

operator=() [1/2]

Locks_hashtable & Locks_hashtable::operator= ( const Locks_hashtable &  )

privatedelete

operator=() [2/2]

Locks_hashtable & Locks_hashtable::operator= ( Locks_hashtable &&  )

privatedelete

prepend() [1/2]

bool Locks_hashtable::prepend ( hash_cell_t *  cell, lock_t *  lock  )

private

prepend() [2/2]

void Locks_hashtable::prepend	(	lock_t *	lock,
		uint64_t	hash_value
	)

resize()

void Locks_hashtable::resize

(

size_t

n_cells

)

Member Data Documentation

cells_in_use

Cells_in_use Locks_hashtable::cells_in_use

private

ht

ut::unique_ptr<hash_table_t> Locks_hashtable::ht

private

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The documentation for this struct was generated from the following files:

• storage/innobase/include/lock0lock.h
• storage/innobase/include/lock0priv.h
• storage/innobase/lock/lock0lock.cc