Mini-transaction handle and buffer. More...

#include <mtr0mtr.h>

Classes
class	Command

struct	Impl
	State variables of the mtr. More...

class	Logging
	mtr global logging More...

Public Member Functions
void	check_nolog_and_mark ()
	Check if redo logging is disabled globally and mark the global counter till mtr ends. More...

void	check_nolog_and_unmark ()
	Check if the mtr has marked the global no log counter and unmark it. More...

	mtr_t ()

	~mtr_t ()

void	remove_from_debug_list () const
	Removed the MTR from the s_my_thread_active_mtrs list. More...

void	check_is_not_latching () const
	Assure that there are no slots that are latching any resources. More...

void	start (bool sync=true)
	Start a mini-transaction. More...

bool	is_async () const

void	set_sync ()
	Request a future commit to be synchronous. More...

void	commit ()
	Commit the mini-transaction. More...

ulint	get_savepoint () const
	Return current size of the buffer. More...

void	release_s_latch_at_savepoint (ulint savepoint, rw_lock_t *lock)
	Release the (index tree) s-latch stored in an mtr memo after a savepoint. More...

void	release_block_at_savepoint (ulint savepoint, buf_block_t *block)
	Release the block in an mtr memo after a savepoint. More...

void	sx_latch_at_savepoint (ulint savepoint, buf_block_t *block)
	SX-latch a not yet latched block after a savepoint. More...

void	x_latch_at_savepoint (ulint savepoint, buf_block_t *block)
	X-latch a not yet latched block after a savepoint. More...

mtr_log_t	get_log_mode () const
	Get the logging mode. More...

mtr_log_t	set_log_mode (mtr_log_t mode)
	Change the logging mode. More...

uint32_t	read_ulint (const byte *ptr, mlog_id_t type) const
	Read 1 - 4 bytes from a file page buffered in the buffer pool. More...

void	s_lock (rw_lock_t *lock, ut::Location location)
	Locks a rw-latch in S mode. More...

void	x_lock (rw_lock_t *lock, ut::Location location)
	Locks a rw-latch in X mode. More...

void	sx_lock (rw_lock_t *lock, ut::Location location)
	Locks a rw-latch in X mode. More...

void	x_lock_space (fil_space_t *space, ut::Location location)
	Acquire a tablespace X-latch. More...

void	memo_release (const void *object, ulint type)
	Release an object in the memo stack. More...

void	release_page (const void *ptr, mtr_memo_type_t type)
	Release a page latch. More...

void	set_modified ()
	Note that the mini-transaction might have modified a buffer pool page. More...

bool	has_modifications () const
	Checks if this mtr has modified any buffer pool page. More...

lsn_t	commit_lsn () const
	Get the LSN of commit(). More...

void	enter_ibuf ()
	Note that we are inside the change buffer code. More...

void	exit_ibuf ()
	Note that we have exited from the change buffer code. More...

bool	is_inside_ibuf () const

bool	is_active () const

Flush_observer *	get_flush_observer () const
	Get flush observer. More...

void	set_flush_observer (Flush_observer *observer)
	Set flush observer. More...

std::ostream &	print_memos (std::ostream &out) const
	Print the memo objects (mtr_memo_slot_t) of mtr_t to the given output stream. More...

bool	memo_contains_flagged (const void *ptr, ulint flags) const
	Check if memo contains the given item. More...

buf_block_t *	memo_contains_page_flagged (const byte *ptr, ulint flags) const
	Check if memo contains the given page. More...

void	memo_modify_page (const byte *ptr)
	Mark the given latched page as modified. More...

void	print () const
	Print info of an mtr handle. More...

bool	has_committed () const

bool	is_committing () const

bool	conflicts_with (const mtr_t *mtr2) const
	Check if the changes done in this mtr conflicts with changes done in the given mtr. More...

const mtr_buf_t *	get_memo () const

mtr_buf_t *	get_memo ()

size_t	get_expected_log_size () const
	Computes the number of bytes that would be written to the redo log if mtr was committed right now (excluding headers of log blocks). More...

void	wait_for_flush ()

void	added_rec ()
	Note that a record has been added to the log. More...

bool	has_any_log_record ()
	Checks if this mtr has generated any redo log records which should be written to the redo log during commit(). More...

const mtr_buf_t *	get_log () const
	Get the buffered redo log of this mini-transaction. More...

mtr_buf_t *	get_log ()
	Get the buffered redo log of this mini-transaction. More...

void	memo_push (void *object, mtr_memo_type_t type)
	Push an object to an mtr memo stack. More...

Static Public Member Functions
static bool	memo_contains (const mtr_buf_t memo, const void object, ulint type)
	Check if memo contains the given item. More...

static void	check_my_thread_mtrs_are_not_latching ()
	Iterate all MTRs created in this thread to assure they are not latching any resources. More...

static bool	is_this_thread_inside_mtr ()
	This method is useful to detect if the thread is already inside an mtr. More...

Public Attributes
size_t	m_restart_count {}
	Count the number of times the same mtr object has been committed and restarted. More...

Static Public Attributes
static bool	s_mode_update [MTR_LOG_MODE_MAX][MTR_LOG_MODE_MAX]
	Matrix to check if a mode update request should be ignored. More...

static bool	s_mode_update_valid [MTR_LOG_MODE_MAX][MTR_LOG_MODE_MAX]
	For checking invalid mode update requests. More...

static Logging	s_logging
	Instance level logging information for all mtrs. More...

Private Attributes
Impl	m_impl

lsn_t	m_commit_lsn
	LSN at commit time. More...

bool	m_sync
	true if it is synchronous mini-transaction More...

Static Private Attributes
static thread_local ut::unordered_set< const mtr_t * >	s_my_thread_active_mtrs
	List of all non-committed MTR instances created in this thread. More...

Friends
class	Command

Detailed Description

Mini-transaction handle and buffer.

Constructor & Destructor Documentation

◆ mtr_t()

mtr_t::mtr_t ( )

inline

◆ ~mtr_t()

mtr_t::~mtr_t ( )

inline

Member Function Documentation

◆ added_rec()

void mtr_t::added_rec ( )

inline

Note that a record has been added to the log.

◆ check_is_not_latching()

void mtr_t::check_is_not_latching ( ) const

Assure that there are no slots that are latching any resources.

Only buffer fixing a page is allowed.

◆ check_my_thread_mtrs_are_not_latching()

static void mtr_t::check_my_thread_mtrs_are_not_latching ( )

inlinestatic

Iterate all MTRs created in this thread to assure they are not latching any resources.

Violating this could lead to deadlocks under log_free_check().

◆ check_nolog_and_mark()

void mtr_t::check_nolog_and_mark ( )

Check if redo logging is disabled globally and mark the global counter till mtr ends.

◆ check_nolog_and_unmark()

void mtr_t::check_nolog_and_unmark ( )

Check if the mtr has marked the global no log counter and unmark it.

◆ commit()

void mtr_t::commit ( )

Commit the mini-transaction.

Commit a mini-transaction.

◆ commit_lsn()

lsn_t mtr_t::commit_lsn ( ) const

inline

Get the LSN of commit().

Returns: the commit LSN

Return values

0	if the transaction only modified temporary tablespaces or logging is disabled globally.

◆ conflicts_with()

bool mtr_t::conflicts_with ( const mtr_t * mtr2 ) const

Check if the changes done in this mtr conflicts with changes done in the given mtr.

Two mtrs are said to conflict with each other, if they modify the same buffer block.

Parameters

[in] mtr2 the given mtr.

Returns: true if there is conflict, false otherwise.

◆ enter_ibuf()

void mtr_t::enter_ibuf ( )

inline

Note that we are inside the change buffer code.

◆ exit_ibuf()

void mtr_t::exit_ibuf ( )

inline

Note that we have exited from the change buffer code.

◆ get_expected_log_size()

size_t mtr_t::get_expected_log_size ( ) const

inline

Computes the number of bytes that would be written to the redo log if mtr was committed right now (excluding headers of log blocks).

Returns: number of bytes of the collected log records increased by 1 if MLOG_MULTI_REC_END would already be required

◆ get_flush_observer()

Flush_observer * mtr_t::get_flush_observer ( ) const

inline

Get flush observer.

Returns: flush observer

◆ get_log() [1/2]

mtr_buf_t * mtr_t::get_log ( )

inline

Get the buffered redo log of this mini-transaction.

Returns: redo log

◆ get_log() [2/2]

const mtr_buf_t * mtr_t::get_log ( ) const

inline

Get the buffered redo log of this mini-transaction.

Returns: redo log

◆ get_log_mode()

mtr_log_t mtr_t::get_log_mode ( ) const

inline

Get the logging mode.

Gets the logging mode of a mini-transaction.

Returns: logging mode; logging mode: MTR_LOG_NONE, ...

◆ get_memo() [1/2]

mtr_buf_t * mtr_t::get_memo ( )

inline

Returns: the memo stack

◆ get_memo() [2/2]

const mtr_buf_t * mtr_t::get_memo ( ) const

inline

Returns: the memo stack

◆ get_savepoint()

ulint mtr_t::get_savepoint ( ) const

inline

Return current size of the buffer.

Returns: savepoint

◆ has_any_log_record()

bool mtr_t::has_any_log_record ( )

inline

Checks if this mtr has generated any redo log records which should be written to the redo log during commit().

Note: If redo logging is disabled by set_log_mode(MTR_LOG_NONE) or set_log_mode(MTR_LOG_NO_REDO) or globally by s_logging.disable(..), then it will return false, even if set_modified() was called. Note: Redo log records can be generated for things other than page modifications, for example for tablespace rename, or other metadata updates. Note: Redo log records can be generated for modifications of pages which were already marked as dirty in BP.

Returns: true iff there is at least one redo log record generated

◆ has_committed()

bool mtr_t::has_committed ( ) const

inline

Returns: true if the mini-transaction has committed

◆ has_modifications()

bool mtr_t::has_modifications ( ) const

inline

Checks if this mtr has modified any buffer pool page.

It errs on the safe side: may return true even if it didn't modify any page. This is used in MTR_LOG_NO_REDO mode to detect that pages should be added to flush lists during commit() even though no redo log will be produced.

Returns: true if the mini-transaction might have modified buffer pool pages.

◆ is_active()

bool mtr_t::is_active ( ) const

inline

◆ is_async()

bool mtr_t::is_async ( ) const

inline

Returns: whether this is an asynchronous mini-transaction.

◆ is_committing()

bool mtr_t::is_committing ( ) const

inline

Returns: true if the mini-transaction is committing

◆ is_inside_ibuf()

bool mtr_t::is_inside_ibuf ( ) const

inline

Returns: true if we are inside the change buffer code

◆ is_this_thread_inside_mtr()

static bool mtr_t::is_this_thread_inside_mtr ( )

inlinestatic

This method is useful to detect if the thread is already inside an mtr.

We should not do the log_free_check() in the child mtrs if a thread is already inside an mtr.

Returns: true if thread is not inside an mtr, false otherwise

◆ memo_contains()

bool mtr_t::memo_contains	(	const mtr_buf_t *	memo,
		const void *	object,
		ulint	type
	)

static

Check if memo contains the given item.

Parameters

memo	memo stack
object	object to search
type	type of object

Returns: true if contains; true if contains

◆ memo_contains_flagged()

bool mtr_t::memo_contains_flagged	(	const void *	ptr,
		ulint	flags
	)		const

Check if memo contains the given item.

Parameters

ptr	object to search
flags	specify types of object (can be ORred) of MTR_MEMO_PAGE_S_FIX ... values

Returns: true if contains

◆ memo_contains_page_flagged()

buf_block_t * mtr_t::memo_contains_page_flagged	(	const byte *	ptr,
		ulint	flags
	)		const

Check if memo contains the given page.

Parameters

[in]	ptr	pointer to within buffer frame
[in]	flags	specify types of object with OR of MTR_MEMO_PAGE_S_FIX... values

Returns: the block

Return values

NULL	if not found

◆ memo_modify_page()

void mtr_t::memo_modify_page ( const byte * ptr )

Mark the given latched page as modified.

Parameters

[in] ptr pointer to within buffer frame

◆ memo_push()

void mtr_t::memo_push	(	void *	object,
		mtr_memo_type_t	type
	)

inline

Push an object to an mtr memo stack.

Pushes an object to an mtr memo stack.

Parameters

object	object
type	object type: MTR_MEMO_S_LOCK, ...

◆ memo_release()

void mtr_t::memo_release	(	const void *	object,
		ulint	type
	)

Release an object in the memo stack.

Parameters

object	object
type	object type: MTR_MEMO_S_LOCK, ...

◆ print()

void mtr_t::print ( ) const

Print info of an mtr handle.

◆ print_memos()

std::ostream & mtr_t::print_memos ( std::ostream & out ) const

Print the memo objects (mtr_memo_slot_t) of mtr_t to the given output stream.

Parameters

[in] out the output stream for printing

Returns: the output stream.

◆ read_ulint()

uint32_t mtr_t::read_ulint	(	const byte *	ptr,
		mlog_id_t	type
	)		const

inline

Read 1 - 4 bytes from a file page buffered in the buffer pool.

Reads 1 - 4 bytes from a file page buffered in the buffer pool.

Parameters

ptr	pointer from where to read
type	MLOG_1BYTE, MLOG_2BYTES, MLOG_4BYTES

Returns: value read; value read

◆ release_block_at_savepoint()

void mtr_t::release_block_at_savepoint	(	ulint	savepoint,
		buf_block_t *	block
	)

inline

Release the block in an mtr memo after a savepoint.

Releases the block in an mtr memo after a savepoint.

◆ release_page()

void mtr_t::release_page	(	const void *	ptr,
		mtr_memo_type_t	type
	)

Release a page latch.

Parameters

[in]	ptr	pointer to within a page frame
[in]	type	object type: MTR_MEMO_PAGE_X_FIX, ...

◆ release_s_latch_at_savepoint()

void mtr_t::release_s_latch_at_savepoint	(	ulint	savepoint,
		rw_lock_t *	lock
	)

inline

Release the (index tree) s-latch stored in an mtr memo after a savepoint.

Releases the (index tree) s-latch stored in an mtr memo after a savepoint.

Parameters

savepoint value returned by

See also: set_savepoint.

Parameters

lock	latch to release

◆ remove_from_debug_list()

void mtr_t::remove_from_debug_list ( ) const

Removed the MTR from the s_my_thread_active_mtrs list.

◆ s_lock()

void mtr_t::s_lock	(	rw_lock_t *	lock,
		ut::Location	location
	)

inline

Locks a rw-latch in S mode.

Locks a lock in s-mode.

NOTE: use mtr_s_lock().

Parameters

lock	rw-lock
location	location from where called

◆ set_flush_observer()

void mtr_t::set_flush_observer ( Flush_observer * observer )

inline

Set flush observer.

Parameters

[in] observer flush observer

◆ set_log_mode()

mtr_log_t mtr_t::set_log_mode ( mtr_log_t mode )

Change the logging mode.

Parameters

mode	logging mode

Returns: old mode

◆ set_modified()

void mtr_t::set_modified ( )

inline

Note that the mini-transaction might have modified a buffer pool page.

As it's called from mlog_open(), which is called from fil_op_write_log() and perhaps other places which do not modify any page, this can be a false positive.

◆ set_sync()

void mtr_t::set_sync ( )

inline

Request a future commit to be synchronous.

◆ start()

void mtr_t::start ( bool sync = true )

Start a mini-transaction.

Parameters

sync	true if it is a synchronous mini-transaction

◆ sx_latch_at_savepoint()

void mtr_t::sx_latch_at_savepoint	(	ulint	savepoint,
		buf_block_t *	block
	)

inline

SX-latch a not yet latched block after a savepoint.

SX-latches the not yet latched block after a savepoint.

◆ sx_lock()

void mtr_t::sx_lock	(	rw_lock_t *	lock,
		ut::Location	location
	)

inline

Locks a rw-latch in X mode.

Locks a lock in sx-mode.

NOTE: use mtr_sx_lock().

Parameters

lock	rw-lock
location	location from where called

◆ wait_for_flush()

void mtr_t::wait_for_flush ( )

◆ x_latch_at_savepoint()

void mtr_t::x_latch_at_savepoint	(	ulint	savepoint,
		buf_block_t *	block
	)

inline

X-latch a not yet latched block after a savepoint.

X-latches the not yet latched block after a savepoint.

◆ x_lock()

void mtr_t::x_lock	(	rw_lock_t *	lock,
		ut::Location	location
	)

inline

Locks a rw-latch in X mode.

Locks a lock in x-mode.

NOTE: use mtr_x_lock().

Parameters

lock	rw-lock
location	location where name from where called

◆ x_lock_space()

void mtr_t::x_lock_space	(	fil_space_t *	space,
		ut::Location	location
	)

Acquire a tablespace X-latch.

NOTE: use mtr_x_lock_space().

Parameters

[in]	space	tablespace instance
[in]	location	location from where called

Friends And Related Function Documentation

◆ Command

friend class Command

friend

Member Data Documentation

◆ m_commit_lsn

lsn_t mtr_t::m_commit_lsn

private

LSN at commit time.

◆ m_impl

Impl mtr_t::m_impl

private

◆ m_restart_count

size_t mtr_t::m_restart_count {}

Count the number of times the same mtr object has been committed and restarted.

◆ m_sync

bool mtr_t::m_sync

private

true if it is synchronous mini-transaction

◆ s_logging

mtr_t::Logging mtr_t::s_logging

static

Instance level logging information for all mtrs.

◆ s_mode_update

bool mtr_t::s_mode_update

static

Initial value:

= {
    
     {false, true, true, true},   
     {true, false, true, false},  
     {false, true, false, false}, 
     {true, false, false, false}  
}

Matrix to check if a mode update request should be ignored.

◆ s_mode_update_valid

bool mtr_t::s_mode_update_valid

static

Initial value:

= {
    
     {true, true, true, true}, 
 
     {true, true, true, true},
 
     {true, true, true, true}, 
 
     {true, false, false, true} 
}

For checking invalid mode update requests.

◆ s_my_thread_active_mtrs

thread_local ut::unordered_set< const mtr_t * > mtr_t::s_my_thread_active_mtrs

staticprivate

List of all non-committed MTR instances created in this thread.

Used for debug purposes in the log_free_check().

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

storage/innobase/include/mtr0mtr.h
storage/innobase/include/mtr0mtr.ic
storage/innobase/mtr/mtr0mtr.cc

Classes

Public Member Functions

Static Public Member Functions

Public Attributes

Static Public Attributes

Private Attributes

Static Private Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

◆ mtr_t()

◆ ~mtr_t()

Member Function Documentation

◆ added_rec()

◆ check_is_not_latching()

◆ check_my_thread_mtrs_are_not_latching()

◆ check_nolog_and_mark()

◆ check_nolog_and_unmark()

◆ commit()

◆ commit_lsn()

◆ conflicts_with()

◆ enter_ibuf()

◆ exit_ibuf()

◆ get_expected_log_size()

◆ get_flush_observer()

◆ get_log() [1/2]

◆ get_log() [2/2]

◆ get_log_mode()

◆ get_memo() [1/2]

◆ get_memo() [2/2]

◆ get_savepoint()

◆ has_any_log_record()

◆ has_committed()

◆ has_modifications()

◆ is_active()

◆ is_async()

◆ is_committing()

◆ is_inside_ibuf()

◆ is_this_thread_inside_mtr()

◆ memo_contains()

◆ memo_contains_flagged()

◆ memo_contains_page_flagged()

◆ memo_modify_page()

◆ memo_push()

◆ memo_release()

◆ print()

◆ print_memos()

◆ read_ulint()

◆ release_block_at_savepoint()

◆ release_page()

◆ release_s_latch_at_savepoint()

◆ remove_from_debug_list()

◆ s_lock()

◆ set_flush_observer()

◆ set_log_mode()

◆ set_modified()

◆ set_sync()

◆ start()

◆ sx_latch_at_savepoint()

◆ sx_lock()

◆ wait_for_flush()

◆ x_latch_at_savepoint()

◆ x_lock()

◆ x_lock_space()

Friends And Related Function Documentation

◆ Command

Member Data Documentation

◆ m_commit_lsn

◆ m_impl

◆ m_restart_count

◆ m_sync

◆ s_logging

◆ s_mode_update

◆ s_mode_update_valid

◆ s_my_thread_active_mtrs