Session_consistency_gtids_ctx Class Reference

This class is an interface for session consistency instrumentation in the server. More...

#include <rpl_context.h>

Classes
class	Ctx_change_listener
	This is an interface to be implemented by classes that want to listen to changes to this context. More...

Public Member Functions
	Session_consistency_gtids_ctx ()
	Simple constructor. More...
virtual	~Session_consistency_gtids_ctx ()
	The destructor. More...
void	register_ctx_change_listener (Session_consistency_gtids_ctx::Ctx_change_listener *listener, THD *thd)
	Registers the listener. More...
void	unregister_ctx_change_listener (Session_consistency_gtids_ctx::Ctx_change_listener *listener)
	Unregisters the listener. More...
Gtid_set *	state ()
	This member function MUST return a reference to the set of collected GTIDs so far. More...
virtual bool	notify_after_response_packet (const THD *thd)
	This function MUST be called after the response packet is set to the client connected. More...
virtual bool	notify_after_gtid_executed_update (const THD *thd)
	This function SHALL be called once the GTID for the given transaction has has been added to GTID_EXECUTED. More...
virtual bool	notify_after_transaction_commit (const THD *thd)
	This function MUST be called after a transaction is committed in the server. More...
virtual bool	notify_after_xa_prepare (const THD *thd)
void	update_tracking_activeness_from_session_variable (const THD *thd)
	Update session tracker (m_curr_session_track_gtids) from thd. More...

Protected Member Functions
bool	shall_collect (const THD *thd)
void	notify_ctx_change_listener ()
	Auxiliary function that allows notification of ctx change listeners. More...

Private Member Functions
	Session_consistency_gtids_ctx (const Session_consistency_gtids_ctx &rsc)
Session_consistency_gtids_ctx &	operator= (const Session_consistency_gtids_ctx &rsc)

Private Attributes
Tsid_map *	m_tsid_map
Gtid_set *	m_gtid_set
	Set holding the transaction identifiers of the gtids to reply back on the response packet. More...
Session_consistency_gtids_ctx::Ctx_change_listener *	m_listener
	If a listener is registered, e.g., the session track gtids, then this points to an instance of such listener. More...
ulong	m_curr_session_track_gtids
	Keeps track of the current session track gtids, so that we capture according to what was set before. More...

Detailed Description

This class is an interface for session consistency instrumentation in the server.

It holds the context information for a given session.

It does not require locking since access to this content is mutually exclusive by design (only one thread reading or writing to this object at a time).

Constructor & Destructor Documentation

Session_consistency_gtids_ctx() [1/2]

Session_consistency_gtids_ctx::Session_consistency_gtids_ctx

(

)

Simple constructor.

~Session_consistency_gtids_ctx()

Session_consistency_gtids_ctx::~Session_consistency_gtids_ctx ( )

virtual

The destructor.

Deletes the m_gtid_set and the tsid_map.

Session_consistency_gtids_ctx() [2/2]

Session_consistency_gtids_ctx::Session_consistency_gtids_ctx ( const Session_consistency_gtids_ctx &  rsc )

private

Member Function Documentation

notify_after_gtid_executed_update()

bool Session_consistency_gtids_ctx::notify_after_gtid_executed_update ( const THD *  thd )

virtual

This function SHALL be called once the GTID for the given transaction has has been added to GTID_EXECUTED.

This function SHALL store the data if the thd->variables.session_track_gtids is set to a value other than NONE.

Parameters

thd	The thread context.

Returns

true on error, false otherwise.

notify_after_response_packet()

bool Session_consistency_gtids_ctx::notify_after_response_packet ( const THD *  thd )

virtual

This function MUST be called after the response packet is set to the client connected.

The implementation may act on the collected state for instance to do garbage collection.

Parameters

thd	The thread context.

Returns

true on error, false otherwise.

notify_after_transaction_commit()

bool Session_consistency_gtids_ctx::notify_after_transaction_commit ( const THD *  thd )

virtual

This function MUST be called after a transaction is committed in the server.

It should be called regardless whether it is a RO or RW transaction. Also, DDLs, DDS are considered transaction for what is worth.

This function SHALL store relevant data for the session consistency.

Parameters

thd	The thread context.

Returns

true on error, false otherwise.

notify_after_xa_prepare()

virtual bool Session_consistency_gtids_ctx::notify_after_xa_prepare ( const THD *  thd )

inlinevirtual

notify_ctx_change_listener()

void Session_consistency_gtids_ctx::notify_ctx_change_listener ( )

inlineprotected

Auxiliary function that allows notification of ctx change listeners.

operator=()

Session_consistency_gtids_ctx & Session_consistency_gtids_ctx::operator= ( const Session_consistency_gtids_ctx &  rsc )

private

register_ctx_change_listener()

void Session_consistency_gtids_ctx::register_ctx_change_listener	(	Session_consistency_gtids_ctx::Ctx_change_listener *	listener,
		THD *	thd
	)

Registers the listener.

The pointer MUST not be NULL.

Parameters

listener	a pointer to the listener to register.
thd	THD context associated to this listener.

shall_collect()

bool Session_consistency_gtids_ctx::shall_collect ( const THD *  thd )

inlineprotected

state()

Gtid_set * Session_consistency_gtids_ctx::state ( )

inline

This member function MUST return a reference to the set of collected GTIDs so far.

Returns

the set of collected GTIDs so far.

unregister_ctx_change_listener()

void Session_consistency_gtids_ctx::unregister_ctx_change_listener

(

Session_consistency_gtids_ctx::Ctx_change_listener *

listener

)

Unregisters the listener.

The listener MUST have registered previously.

Parameters

listener

a pointer to the listener to register.

update_tracking_activeness_from_session_variable()

void Session_consistency_gtids_ctx::update_tracking_activeness_from_session_variable

(

const THD *

thd

)

Update session tracker (m_curr_session_track_gtids) from thd.

Member Data Documentation

m_curr_session_track_gtids

ulong Session_consistency_gtids_ctx::m_curr_session_track_gtids

private

Keeps track of the current session track gtids, so that we capture according to what was set before.

For instance, if the user does: SET @SESSION.SESSION_TRACK_GTIDS='ALL_GTIDS'; ... SET @SESSION.SESSION_TRACK_GTIDS='OWN_GTID';

The last statement should return a set of GTIDs.

m_gtid_set

Gtid_set* Session_consistency_gtids_ctx::m_gtid_set

private

Set holding the transaction identifiers of the gtids to reply back on the response packet.

Lifecycle: Emptied after the reply is sent back to the application. Remains empty until:

• a RW transaction commits and a GTID is written to the binary log.
• a RO transaction is issued, the consistency level is set to "Check Potential Writes" and the transaction is committed.

m_listener

Session_consistency_gtids_ctx::Ctx_change_listener* Session_consistency_gtids_ctx::m_listener

private

If a listener is registered, e.g., the session track gtids, then this points to an instance of such listener.

Since this context is valid only for one session, there is no need to protect this with locks.

m_tsid_map

Tsid_map* Session_consistency_gtids_ctx::m_tsid_map

private

---

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

• sql/rpl_context.h
• sql/rpl_context.cc