Class for creating a new thread that allows to stop the new transactions allowing some management queries to run. More...

#include <group_actions_transaction_controller.h>

Public Member Functions
	Transaction_monitor_thread (const Transaction_monitor_thread &)=delete
	Deleted copy constructor. More...

	Transaction_monitor_thread (const Transaction_monitor_thread &&)=delete
	Deleted move constructor. More...

Transaction_monitor_thread &	operator= (const Transaction_monitor_thread &)=delete
	Deleted assignment operator. More...

Transaction_monitor_thread &	operator= (const Transaction_monitor_thread &&)=delete
	Deleted move operator. More...

	Transaction_monitor_thread (uint32 timeout_arg)
	Initializes the synchronization primitives of the thread. More...

	~Transaction_monitor_thread ()
	The destructor for the thread will destroy the mutex and cond_var. More...

bool	terminate ()
	Terminates the thread. More...

int	start ()
	Starts the process of monitoring transactions. More...

Private Member Functions
void	transaction_thread_handle ()
	The thread handle, i.e. More...

bool	acquire_services ()
	This function acquires the below services: mysql_new_transaction_control mysql_before_commit_transaction_control mysql_close_connection_of_binloggable_transaction_not_reached_commit. More...

bool	release_services ()
	This function releases the services. More...

Static Private Member Functions
static void *	launch_thread (void *arg)
	The thread callback passed onto mysql_thread_create. More...

Private Attributes
thread_state	m_transaction_monitor_thd_state
	the state of the thread. More...

my_thread_handle	m_handle
	the thread handle. More...

mysql_mutex_t	m_run_lock
	the mutex for controlling access to the thread itself. More...

mysql_cond_t	m_run_cond
	the cond_var used to signal the thread. More...

bool	m_abort
	flag to indicate whether or not the thread is to be aborted. More...

int32	m_transaction_timeout {-1}
	The number of seconds to wait before setting the THD::KILL_CONNECTION flag for the transactions that did not reach commit stage. More...

std::chrono::time_point< std::chrono::steady_clock >	m_time_start_of_operation
	Stores operation start time. More...

mysql_service_mysql_new_transaction_control_t *	m_mysql_new_transaction_control {nullptr}
	Pointer to the `mysql_new_transaction_control_imp` service. More...

mysql_service_mysql_before_commit_transaction_control_t *	m_mysql_before_commit_transaction_control {nullptr}
	Pointer to the `mysql_before_commit_transaction_control` service. More...

mysql_service_mysql_close_connection_of_binloggable_transaction_not_reached_commit_t *	m_mysql_close_connection_of_binloggable_transaction_not_reached_commit
	Pointer to the `mysql_close_connection_of_binloggable_transaction_not_reached_commit` service. More...

Detailed Description

Class for creating a new thread that allows to stop the new transactions allowing some management queries to run.

This thread also gracefully disconnects the client which are running the binloggable transaction after specified time.

Constructor & Destructor Documentation

◆ Transaction_monitor_thread() [1/3]

Transaction_monitor_thread::Transaction_monitor_thread ( const Transaction_monitor_thread & )

delete

Deleted copy constructor.

◆ Transaction_monitor_thread() [2/3]

Transaction_monitor_thread::Transaction_monitor_thread ( const Transaction_monitor_thread && )

delete

Deleted move constructor.

◆ Transaction_monitor_thread() [3/3]

Transaction_monitor_thread::Transaction_monitor_thread ( uint32 timeout_arg )

Initializes the synchronization primitives of the thread.

◆ ~Transaction_monitor_thread()

Transaction_monitor_thread::~Transaction_monitor_thread ( )

The destructor for the thread will destroy the mutex and cond_var.

Member Function Documentation

◆ acquire_services()

bool Transaction_monitor_thread::acquire_services ( )

private

This function acquires the below services: mysql_new_transaction_control mysql_before_commit_transaction_control mysql_close_connection_of_binloggable_transaction_not_reached_commit.

Returns: false success true fail

◆ launch_thread()

void * Transaction_monitor_thread::launch_thread ( void * arg )

staticprivate

The thread callback passed onto mysql_thread_create.

Parameters

[in] arg a pointer to an Transaction_monitor_thread instance.

Returns: nullptr, since the return value is not used.

◆ operator=() [1/2]

Transaction_monitor_thread & Transaction_monitor_thread::operator= ( const Transaction_monitor_thread && )

delete

Deleted move operator.

◆ operator=() [2/2]

Transaction_monitor_thread & Transaction_monitor_thread::operator= ( const Transaction_monitor_thread & )

delete

Deleted assignment operator.

◆ release_services()

bool Transaction_monitor_thread::release_services ( )

private

This function releases the services.

Returns: false success true fail

◆ start()

int Transaction_monitor_thread::start ( )

Starts the process of monitoring transactions.

Returns: whether or not we managed to launch the transaction_monitor_thread thread.

Return values

0	the thread launched successfully
!=	0 the thread couldn't be launched

See also: mysql_thread_create

◆ terminate()

bool Transaction_monitor_thread::terminate ( )

Terminates the thread.

Thread sets the abort flag and affectively waits for the operations to terminate.

Returns: success

Return values

true	failed to terminate
false	thread terminated successfully.

◆ transaction_thread_handle()

void Transaction_monitor_thread::transaction_thread_handle ( )

private

The thread handle, i.e.

setups and tearsdown the infrastructure for this mysql_thread.

If time has elapsed disconnect the client connections running the transaction which have yet not reached commit. Else wait for 1 second periods for the primary change to happen until the specified timeout elapses.

Note: if UDF finishes it will call terminate to terminate this thread. terminate will awake this thread and thread will exit due to m_abort flag.; ongoing transactions does not impact this thread. If ongoing transactions finishes UDF will finish execution at Primary_election_action::execute_action later calling the terminate function of this thread. Terminate will simply unblock the wait, allow the transactions and end the execution of this thread.; before closing the client connection, time elapse is checked, so it safe to come out of sleep early.; clients_disconnected makes sure client disconnection only happens once.; post client disconnection this thread waits for UDF to finish so that new queries are still blocked. Once UDF finishes at time of after_primary_election terminate will be called. Terminate will simply unblock the wait, allow the transactions and end the execution of this thread.

Refresh time_now.
Disconnect the clients only once.
Check time has elapsed before disconnecting the clients

Member Data Documentation

◆ m_abort

bool Transaction_monitor_thread::m_abort

private

flag to indicate whether or not the thread is to be aborted.

◆ m_handle

my_thread_handle Transaction_monitor_thread::m_handle

private

the thread handle.

◆ m_mysql_before_commit_transaction_control

mysql_service_mysql_before_commit_transaction_control_t* Transaction_monitor_thread::m_mysql_before_commit_transaction_control {nullptr}

private

Pointer to the mysql_before_commit_transaction_control service.

◆ m_mysql_close_connection_of_binloggable_transaction_not_reached_commit

mysql_service_mysql_close_connection_of_binloggable_transaction_not_reached_commit_t* Transaction_monitor_thread::m_mysql_close_connection_of_binloggable_transaction_not_reached_commit

private

Initial value:

{

nullptr}

Pointer to the mysql_close_connection_of_binloggable_transaction_not_reached_commit service.

◆ m_mysql_new_transaction_control

mysql_service_mysql_new_transaction_control_t* Transaction_monitor_thread::m_mysql_new_transaction_control {nullptr}

private

Pointer to the mysql_new_transaction_control_imp service.

◆ m_run_cond

mysql_cond_t Transaction_monitor_thread::m_run_cond

private

the cond_var used to signal the thread.

◆ m_run_lock

mysql_mutex_t Transaction_monitor_thread::m_run_lock

private

the mutex for controlling access to the thread itself.

◆ m_time_start_of_operation

std::chrono::time_point<std::chrono::steady_clock> Transaction_monitor_thread::m_time_start_of_operation

private

Stores operation start time.

◆ m_transaction_monitor_thd_state

thread_state Transaction_monitor_thread::m_transaction_monitor_thd_state

private

the state of the thread.

◆ m_transaction_timeout

int32 Transaction_monitor_thread::m_transaction_timeout {-1}

private

The number of seconds to wait before setting the THD::KILL_CONNECTION flag for the transactions that did not reach commit stage.

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

plugin/group_replication/include/group_actions/group_actions_transaction_controller.h
plugin/group_replication/src/group_actions/group_actions_transaction_controller.cc

Public Member Functions

Private Member Functions

Static Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ Transaction_monitor_thread() [1/3]

◆ Transaction_monitor_thread() [2/3]

◆ Transaction_monitor_thread() [3/3]

◆ ~Transaction_monitor_thread()

Member Function Documentation

◆ acquire_services()

◆ launch_thread()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ release_services()

◆ start()

◆ terminate()

◆ transaction_thread_handle()

Member Data Documentation

◆ m_abort

◆ m_handle

◆ m_mysql_before_commit_transaction_control

◆ m_mysql_close_connection_of_binloggable_transaction_not_reached_commit

◆ m_mysql_new_transaction_control

◆ m_run_cond

◆ m_run_lock

◆ m_time_start_of_operation

◆ m_transaction_monitor_thd_state

◆ m_transaction_timeout