cs::apply::Csa_worker_context Class Reference

Class representing the interface for parallel worker context. More...

#include <csa_worker_context.h>

Inheritance diagram for cs::apply::Csa_worker_context:

Public Types
using	Trx_id = Parallel_worker_context::Trx_id
using	Worker_id = Parallel_worker_context::Worker_id
Public Types inherited from cs::apply::Parallel_worker_context
using	Trx_id = int64_t
using	Worker_id = uint64_t
using	Channel_id = std::string

Public Member Functions
	Csa_worker_context (Trx_id trx_seq_num, Worker_id worker_id, const std::string &channel_id, THD *trx_ctx, int current_retry, int retries_num)
void	report_commit_order_deadlock (bool for_self=false) override
	Indicates that commit order deadlock has been found. More...
bool	found_commit_order_deadlock () const override
	Checks if commit order deadlock has been found. More...
void	reset_commit_order_deadlock () override
	Resets commit order deadlock. More...
bool	is_same_channel (const Parallel_worker_context *arg) const override
	Checks if arg parallel worker executes transaction coming from the same channel. More...
THD *	get_transaction_ctx () override
	Returns transaction id (we use sequence number) More...
Worker_id	get_worker_id () const override
	Returns worker id. More...
instruments::Worker_metrics &	get_worker_metrics () override
	Obtains worker metrics. More...
MDL_context *	get_mdl_context () override
	MDL context accessor. More...
const std::string &	get_channel_id () const
	Channel identifier accessor. More...
Trx_id	get_trx_id () override
	Obtain transaction id (sequence number) More...
const char *	get_for_channel_id (bool upper_case) const override
	Get "for channel" id. More...
void	update (Trx_id trx_seq_num, Worker_id worker_id, THD *trx_ctx, int current_retry)
	Updates internal data for a new transaction. More...
void	update (Worker_id worker_id, int current_retry)
	Updates internal data for ongoing transaction. More...
void	update (Trx_id trx_seq_num, Worker_id worker_id, const std::string &channel_id, THD *trx_ctx, int current_retry, int retries_num)
	Updates all internal data for new transaction and channel. More...
bool	can_be_retried (THD *thd) override
	Returns information on whether THD transaction can be retried. More...
bool	has_temporary_error (THD *thd, int error)
	Checks whether this transaction error is temporary. More...
void	set_applied ()
	Mark transaction as prepared and externally rollbackable. More...
void	set_committing ()
	Move transaction from prepared into committing state. More...
bool	is_rollback_requested () const
	Check if external rollback is on-going. More...
void	handle_commit_order_deadlock ()
	Handle commit order deadlock - one of the callers will request transaction rollback due to rpco deadlock. More...
bool	wait_for_rollback ()
	Waits for external rollback to finish. More...
bool	is_csa () const override
	Checks whether this worker is CSA worker. More...
Public Member Functions inherited from cs::apply::Parallel_worker_context
	Parallel_worker_context ()=default
virtual	~Parallel_worker_context ()=default

Static Public Attributes
static instruments::Dummy_worker_metrics	m_disabled_worker_metrics {}
	Worker metrics. More...

Private Types
enum class	Rpco_state : std::uint8_t { preparing , prepared , commit }
	RPCO lifecycle visible to deadlock reporting: More...

Private Attributes
std::atomic< bool >	m_is_commit_order_deadlock {false}
	Sticky indicator that this transaction was reported as an RPCO victim. More...
std::atomic< bool >	m_rollback {false}
	Set once an external rollback request has been enqueued. More...
std::atomic< Rpco_state >	m_rpco_state {Rpco_state::preparing}
	Current RPCO lifecycle state used to decide how to handle reports. More...
std::promise< bool >	m_rollback_promise
	Completes when the external rollback worker finishes rescue handling. More...
Trx_id	m_trx_id {0}
	Transaction identifier reused by commit-order logic. More...
Worker_id	m_worker_id {0}
	Current worker slot owning this transaction context. More...
std::string	m_channel_id {""}
	Replication channel this transaction belongs to. More...
THD *	m_trx_ctx {nullptr}
	THD currently bound to this transaction context. More...
int	m_current_retry {0}
	Retry number of the current attempt. More...
int	m_retries_num {0}
	Maximum number of retries allowed for this transaction. More...
std::string	m_for_channel_id {""}
	Cached "for channel" suffix, built lazily for diagnostics. More...

Detailed Description

Class representing the interface for parallel worker context.

It accesses basic information like worker id, transaction id, channel id and other functionatlities needed by the commit order manager.

Note

This context is needed to disconnect Slave_worker class from execution path, Slave_worker implements Parallel_worker_context interface

Member Typedef Documentation

Trx_id

using cs::apply::Csa_worker_context::Trx_id = Parallel_worker_context::Trx_id

Worker_id

using cs::apply::Csa_worker_context::Worker_id = Parallel_worker_context::Worker_id

Member Enumeration Documentation

Rpco_state

enum class cs::apply::Csa_worker_context::Rpco_state : std::uint8_t

strongprivate

RPCO lifecycle visible to deadlock reporting:

• preparing: transaction is still in apply/prepare work
• prepared: transaction left apply and may be rescued externally
• commit: transaction entered commit ownership and must resolve there

Enumerator
preparing
prepared
commit

Constructor & Destructor Documentation

Csa_worker_context()

cs::apply::Csa_worker_context::Csa_worker_context	(	Trx_id	trx_seq_num,
		Worker_id	worker_id,
		const std::string &	channel_id,
		THD *	trx_ctx,
		int	current_retry,
		int	retries_num
	)

Member Function Documentation

can_be_retried()

bool cs::apply::Csa_worker_context::can_be_retried ( THD *  thd )

overridevirtual

Returns information on whether THD transaction can be retried.

Returns

true if transaction can be retried

Implements cs::apply::Parallel_worker_context.

found_commit_order_deadlock()

bool cs::apply::Csa_worker_context::found_commit_order_deadlock ( ) const

overridevirtual

Checks if commit order deadlock has been found.

Returns

True if commit order deadlock has been found, false otherwise

Implements cs::apply::Parallel_worker_context.

get_channel_id()

const std::string & cs::apply::Csa_worker_context::get_channel_id

(

)

const

Channel identifier accessor.

Returns

channel identifier

get_for_channel_id()

const char * cs::apply::Csa_worker_context::get_for_channel_id ( bool  upper_case ) const

overridevirtual

Get "for channel" id.

Builds string in flight when needed

Parameters

upper_case

Pass true if upper case is needed

Returns

"for channel" string

Reimplemented from cs::apply::Parallel_worker_context.

get_mdl_context()

MDL_context * cs::apply::Csa_worker_context::get_mdl_context ( )

overridevirtual

MDL context accessor.

Returns

MDL context obj pointer

Implements cs::apply::Parallel_worker_context.

get_transaction_ctx()

THD * cs::apply::Csa_worker_context::get_transaction_ctx ( )

overridevirtual

Returns transaction id (we use sequence number)

Returns

transaction id

Implements cs::apply::Parallel_worker_context.

get_trx_id()

Csa_worker_context::Trx_id cs::apply::Csa_worker_context::get_trx_id ( )

overridevirtual

Obtain transaction id (sequence number)

Returns

Transaction sequence number

Implements cs::apply::Parallel_worker_context.

get_worker_id()

Csa_worker_context::Worker_id cs::apply::Csa_worker_context::get_worker_id ( ) const

overridevirtual

Returns worker id.

Returns

Worker identifier

Implements cs::apply::Parallel_worker_context.

get_worker_metrics()

instruments::Worker_metrics & cs::apply::Csa_worker_context::get_worker_metrics ( )

overridevirtual

Obtains worker metrics.

Returns

Reference to worker metrics object

Implements cs::apply::Parallel_worker_context.

handle_commit_order_deadlock()

void cs::apply::Csa_worker_context::handle_commit_order_deadlock

(

)

Handle commit order deadlock - one of the callers will request transaction rollback due to rpco deadlock.

has_temporary_error()

bool cs::apply::Csa_worker_context::has_temporary_error	(	THD *	thd,
		int	error
	)

Checks whether this transaction error is temporary.

Parameters

thd	THD handle
error	Additional error information

is_csa()

bool cs::apply::Csa_worker_context::is_csa ( ) const

overridevirtual

Checks whether this worker is CSA worker.

Returns

true for CSA parallel worker context. False otherwise

Reimplemented from cs::apply::Parallel_worker_context.

is_rollback_requested()

bool cs::apply::Csa_worker_context::is_rollback_requested ( ) const

inline

Check if external rollback is on-going.

Returns

True when external rollback was already requested.

is_same_channel()

bool cs::apply::Csa_worker_context::is_same_channel ( const Parallel_worker_context *  arg ) const

overridevirtual

Checks if arg parallel worker executes transaction coming from the same channel.

Parameters

arg	Context to compare against

Implements cs::apply::Parallel_worker_context.

report_commit_order_deadlock()

void cs::apply::Csa_worker_context::report_commit_order_deadlock ( bool  for_self = false )

overridevirtual

Indicates that commit order deadlock has been found.

Parameters

for_self

When true, a thread reports for its own

Implements cs::apply::Parallel_worker_context.

reset_commit_order_deadlock()

void cs::apply::Csa_worker_context::reset_commit_order_deadlock ( )

overridevirtual

Resets commit order deadlock.

Implements cs::apply::Parallel_worker_context.

set_applied()

void cs::apply::Csa_worker_context::set_applied

(

)

Mark transaction as prepared and externally rollbackable.

set_committing()

void cs::apply::Csa_worker_context::set_committing

(

)

Move transaction from prepared into committing state.

update() [1/3]

void cs::apply::Csa_worker_context::update	(	Trx_id	trx_seq_num,
		Worker_id	worker_id,
		const std::string &	channel_id,
		THD *	trx_ctx,
		int	current_retry,
		int	retries_num
	)

Updates all internal data for new transaction and channel.

Parameters

trx_seq_num	Transaction sequence number
worker_id	Worker identifier
channel_id	Channel identifier
trx_ctx	Transaction THD
current_retry	Current retry number
retries_num	Number of possible retries for this transaction

update() [2/3]

void cs::apply::Csa_worker_context::update	(	Trx_id	trx_seq_num,
		Worker_id	worker_id,
		THD *	trx_ctx,
		int	current_retry
	)

Updates internal data for a new transaction.

Parameters

trx_seq_num	Transaction sequence number
worker_id	Worker identifier
trx_ctx	Transaction THD
current_retry	Current retry number

update() [3/3]

void cs::apply::Csa_worker_context::update	(	Worker_id	worker_id,
		int	current_retry
	)

Updates internal data for ongoing transaction.

Parameters

worker_id	Worker identifier
current_retry	Current retry number

wait_for_rollback()

bool cs::apply::Csa_worker_context::wait_for_rollback

(

)

Waits for external rollback to finish.

Member Data Documentation

m_channel_id

std::string cs::apply::Csa_worker_context::m_channel_id {""}

private

Replication channel this transaction belongs to.

m_current_retry

int cs::apply::Csa_worker_context::m_current_retry {0}

private

Retry number of the current attempt.

m_disabled_worker_metrics

instruments::Dummy_worker_metrics cs::apply::Csa_worker_context::m_disabled_worker_metrics {}

static

Worker metrics.

m_for_channel_id

std::string cs::apply::Csa_worker_context::m_for_channel_id {""}

mutableprivate

Cached "for channel" suffix, built lazily for diagnostics.

m_is_commit_order_deadlock

std::atomic<bool> cs::apply::Csa_worker_context::m_is_commit_order_deadlock {false}

private

Sticky indicator that this transaction was reported as an RPCO victim.

m_retries_num

int cs::apply::Csa_worker_context::m_retries_num {0}

private

Maximum number of retries allowed for this transaction.

m_rollback

std::atomic<bool> cs::apply::Csa_worker_context::m_rollback {false}

private

Set once an external rollback request has been enqueued.

m_rollback_promise

std::promise<bool> cs::apply::Csa_worker_context::m_rollback_promise

private

Completes when the external rollback worker finishes rescue handling.

m_rpco_state

std::atomic<Rpco_state> cs::apply::Csa_worker_context::m_rpco_state {Rpco_state::preparing}

private

Current RPCO lifecycle state used to decide how to handle reports.

m_trx_ctx

THD* cs::apply::Csa_worker_context::m_trx_ctx {nullptr}

private

THD currently bound to this transaction context.

m_trx_id

Trx_id cs::apply::Csa_worker_context::m_trx_id {0}

private

Transaction identifier reused by commit-order logic.

m_worker_id

Worker_id cs::apply::Csa_worker_context::m_worker_id {0}

private

Current worker slot owning this transaction context.

---

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

• sql/changestreams/apply/csa_worker_context.h
• sql/changestreams/apply/csa_worker_context.cc