mysql::csa::Session_service Class Reference

Service that provides a free session to executing transactions. More...

#include <session_service.h>

Inheritance diagram for mysql::csa::Session_service:

Public Types
using	Task_id = mysql::scheduler::Task_id
	Alias for task identifier. More...

Public Member Functions
virtual	~Session_service ()=default
	Virtual destructor. More...
virtual bool	init (std::size_t session_number, Relay_log_info *channel_rli)=0
	Initializes the session service. More...
virtual bool	deinit ()=0
	Deinitializes the session service. More...
std::optional< Session_legacy_stats >	get_session_stats (std::size_t session_id)
	Obtains session statistics. More...
virtual std::size_t	get_session_number ()
	Obtains the number of all sessions. More...
virtual Relay_context_ptr	acquire_session (Task_id id)=0
	Acquires session. More...
virtual void	release_session (Relay_context_ptr session, Task_id id)=0
	Releases a session back to the pool. More...
void	clean_sessions ()
	Performs clean up of sessions, including rollback. More...
void	enable_stop_error_suppression_for_clean_sessions ()
	Enables stop error suppression for sessions that have no reported error. More...
bool	has_thd_id (unsigned int thd_id) const
	Checks whether session service contains a given THD thread id. More...
void	awake_sessions (bool force_kill)
	Awakes sessions to faster end execution. More...

Protected Attributes
std::unordered_map< std::size_t, Relay_context_ptr >	m_all_sessions
	Aggregates all sessions in order to look at specific session data. More...
std::unordered_set< unsigned int >	m_thd_ids
	Captured THD identifiers for easy access. More...

Detailed Description

Service that provides a free session to executing transactions.

Base class for maintaining session pool available for CSA workers

Member Typedef Documentation

Task_id

using mysql::csa::Session_service::Task_id = mysql::scheduler::Task_id

Alias for task identifier.

Constructor & Destructor Documentation

~Session_service()

virtual mysql::csa::Session_service::~Session_service ( )

virtualdefault

Virtual destructor.

Member Function Documentation

acquire_session()

virtual Relay_context_ptr mysql::csa::Session_service::acquire_session ( Task_id  id )

pure virtual

Acquires session.

Parameters

id	Attach id for the session (internal sequence session id)

Returns

Acquired session shared pointer

Implemented in mysql::csa::Session_service_bounded_queue.

awake_sessions()

void mysql::csa::Session_service::awake_sessions

(

bool

force_kill

)

Awakes sessions to faster end execution.

Parameters

force_kill

When true, kills THDs

clean_sessions()

void mysql::csa::Session_service::clean_sessions

(

)

Performs clean up of sessions, including rollback.

deinit()

virtual bool mysql::csa::Session_service::deinit ( )

pure virtual

Deinitializes the session service.

Returns

False if deinitialization succeeds, true otherwise

Implemented in mysql::csa::Session_service_bounded_queue.

enable_stop_error_suppression_for_clean_sessions()

void mysql::csa::Session_service::enable_stop_error_suppression_for_clean_sessions

(

)

Enables stop error suppression for sessions that have no reported error.

get_session_number()

std::size_t mysql::csa::Session_service::get_session_number ( )

virtual

Obtains the number of all sessions.

Returns

Number of session in this session pool

get_session_stats()

std::optional< Session_legacy_stats > mysql::csa::Session_service::get_session_stats

(

std::size_t

session_id

)

Obtains session statistics.

Returns

Upon success, returns corresponding legacy stats. If they are unavailable due to e.g. non-existing session id, returns an empty object

has_thd_id()

bool mysql::csa::Session_service::has_thd_id

(

unsigned int

thd_id

)

const

Checks whether session service contains a given THD thread id.

Parameters

thd_id

THD thread identifier to check

Returns

When true, session service contains THD with a given thd_id. False otherwise.

init()

virtual bool mysql::csa::Session_service::init ( std::size_t  session_number, Relay_log_info *  channel_rli  )

pure virtual

Initializes the session service.

Parameters

session_number	The number of sessions to add to the initial pool
channel_rli	Parent RLI - channel RLI to share common applier config

Returns

False if initialization succeeds, true otherwise

Implemented in mysql::csa::Session_service_bounded_queue.

release_session()

virtual void mysql::csa::Session_service::release_session ( Relay_context_ptr  session, Task_id  id  )

pure virtual

Releases a session back to the pool.

Parameters

session	Session to return to the session pool
id	Session internal ID

Implemented in mysql::csa::Session_service_bounded_queue.

Member Data Documentation

m_all_sessions

std::unordered_map<std::size_t, Relay_context_ptr> mysql::csa::Session_service::m_all_sessions

protected

Aggregates all sessions in order to look at specific session data.

m_thd_ids

std::unordered_set<unsigned int> mysql::csa::Session_service::m_thd_ids

protected

Captured THD identifiers for easy access.

---

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

• sql/changestreams/apply/session/session_service.h
• sql/changestreams/apply/session/session_service.cpp