mysql::csa::Session Class Reference

Wraps up THD object and provides simple function to manage its execution within CSA. More...

#include <session.h>

Public Member Functions
	Session (THD *parent_thd, std::size_t seq_num)
	Construct from configuration in parent_thd. More...
virtual	~Session ()
	Destructor. More...
bool	is_valid () const
	Checks if created session is valid True when session is valid, false otherwise. More...
unsigned int	get_thd_id () const
	Obtains handled THD identifier. More...
THD *	get_thd ()
	Obtains THD handle. More...
ulonglong	get_thread_id () const
	Obtains thread identifier. More...
void	awake (bool force_kill)
	Awakes the handled session. More...
void	attach (TABLE *temporary_tables)
	Attach current thread to session. More...
void	detach ()
	Detach current thread from session. More...
bool	self_killed () const
	Check if CSA killed this session. More...
bool	is_killed () const

Protected Attributes
THD *	m_thd
	The base server session associated with this processor. More...
ulonglong	m_psi_id {0}
	PSI thread id. More...
const char *	m_saved_thread_stack {""}
	Saved THD stack. More...
long	m_stack_ptr {0}
	Saved stack pointer. More...
bool	m_is_valid {false}
	Validity flag. More...
bool	m_is_attached {false}
	Attach flag. More...
bool	m_is_killed {false}
	We save our own kill flag and protect modifications with LOCK_thd_data. More...
concurrency::Spin_lock_mutex	m_session_lock
	Session lock for protecting attach/detach operations. More...

Detailed Description

Wraps up THD object and provides simple function to manage its execution within CSA.

Constructor & Destructor Documentation

Session()

mysql::csa::Session::Session	(	THD *	parent_thd,
		std::size_t	seq_num
	)

Construct from configuration in parent_thd.

Parameters

parent_thd	Configuration THD
seq_num	Session sequence number

~Session()

mysql::csa::Session::~Session ( )

virtual

Destructor.

Member Function Documentation

attach()

void mysql::csa::Session::attach

(

TABLE *

temporary_tables

)

Attach current thread to session.

Must succeed.

Parameters

temporary_tables

Temporary tables we attach

awake()

void mysql::csa::Session::awake

(

bool

force_kill

)

Awakes the handled session.

Parameters

force_kill

If true, kills session

detach()

void mysql::csa::Session::detach

(

)

Detach current thread from session.

get_thd()

THD * mysql::csa::Session::get_thd

(

)

Obtains THD handle.

get_thd_id()

unsigned int mysql::csa::Session::get_thd_id

(

)

const

Obtains handled THD identifier.

Returns

THD identifier

get_thread_id()

ulonglong mysql::csa::Session::get_thread_id

(

)

const

Obtains thread identifier.

is_killed()

bool mysql::csa::Session::is_killed ( ) const

inline

Returns

True only if this session was killed; false otherwise

is_valid()

bool mysql::csa::Session::is_valid

(

void

)

const

Checks if created session is valid True when session is valid, false otherwise.

self_killed()

bool mysql::csa::Session::self_killed ( ) const

inline

Check if CSA killed this session.

Returns

True only if this session was killed by CSA; false otherwise

Member Data Documentation

m_is_attached

bool mysql::csa::Session::m_is_attached {false}

protected

Attach flag.

m_is_killed

bool mysql::csa::Session::m_is_killed {false}

protected

We save our own kill flag and protect modifications with LOCK_thd_data.

m_is_valid

bool mysql::csa::Session::m_is_valid {false}

protected

Validity flag.

m_psi_id

ulonglong mysql::csa::Session::m_psi_id {0}

protected

PSI thread id.

m_saved_thread_stack

const char* mysql::csa::Session::m_saved_thread_stack {""}

protected

Saved THD stack.

m_session_lock

concurrency::Spin_lock_mutex mysql::csa::Session::m_session_lock

protected

Session lock for protecting attach/detach operations.

While LOCK_thd_data could be used, in a large session pool we avoid its potential syscalls by using a spinlock instead.

m_stack_ptr

long mysql::csa::Session::m_stack_ptr {0}

protected

Saved stack pointer.

m_thd

THD* mysql::csa::Session::m_thd

protected

The base server session associated with this processor.

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

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