#include <gcs_xcom_communication_interface.h>

Inheritance diagram for Gcs_xcom_communication:

Public Member Functions
	Gcs_xcom_communication (Gcs_xcom_statistics_updater stats, Gcs_xcom_proxy proxy, Gcs_xcom_view_change_control_interface view_control, Gcs_xcom_engine gcs_engine, Gcs_group_identifier const &group_id, std::unique_ptr< Network_provider_management_interface > comms_mgmt)
	Gcs_xcom_communication_interface constructor. More...

	~Gcs_xcom_communication () override

enum_gcs_error	send_message (const Gcs_message &message_to_send) override
	Implementation of the public send_message method defined in Gcs_xcom_communication. More...

int	add_event_listener (const Gcs_communication_event_listener &event_listener) override
	Registers an implementation of a Gcs_communication_event_listener that will receive Communication Events. More...

void	remove_event_listener (int event_listener_handle) override
	Removes a previously registered event listener. More...

enum_gcs_error	do_send_message (const Gcs_message &message_to_send, unsigned long long *message_length, Cargo_type cargo) override
	Sends a message that is internal to the binding implementation. More...

std::map< int, const Gcs_communication_event_listener & > *	get_event_listeners ()

Gcs_message_pipeline &	get_msg_pipeline () override

void	buffer_incoming_packet (Gcs_packet &&packet, std::unique_ptr< Gcs_xcom_nodes > &&xcom_nodes) override
	Buffer packets when a view is not installed yet and the state exchange phase is being executed. More...

void	deliver_buffered_packets () override
	The state exchange phase has been executed and the view has been installed so this is used to send any buffered packet to upper layers. More...

void	cleanup_buffered_packets () override

size_t	number_buffered_packets () override
	Return the number of buffered packets. More...

void	update_members_information (const Gcs_member_identifier &me, const Gcs_xcom_nodes &members) override
	Notify the pipeline about the new XCom membership when a state exchange begins. More...

bool	recover_packets (Gcs_xcom_synode_set const &synodes) override
	Attempts to recover the missing packets that are required for a node to join the group successfully. More...

Gcs_message *	convert_packet_to_message (Gcs_packet &&packet, std::unique_ptr< Gcs_xcom_nodes > &&xcom_nodes) override
	Converts the packet into a message that can be delivered to the upper layer. More...

void	process_user_data_packet (Gcs_packet &&packet, std::unique_ptr< Gcs_xcom_nodes > &&xcom_nodes) override
	The purpose of this method is to be called when in Gcs_xcom_interface callback method xcom_receive_data is invoked. More...

Gcs_protocol_version	get_protocol_version () const override
	Retrieves the current GCS protocol version in use. More...

std::pair< bool, std::future< void > >	set_protocol_version (Gcs_protocol_version new_version) override
	Modifies the GCS protocol version in use. More...

Gcs_protocol_version	get_maximum_supported_protocol_version () const override
	Get the maximum protocol version currently supported by the group. More...

void	set_maximum_supported_protocol_version (Gcs_protocol_version version)

void	set_communication_protocol (enum_transport_protocol protocol) override
	Sets the communication protocol to use. More...

enum_transport_protocol	get_incoming_connections_protocol () override
	Get the incoming connections protocol which is currently active. More...

Public Member Functions inherited from Gcs_xcom_communication_interface
	~Gcs_xcom_communication_interface () override=default

Public Member Functions inherited from Gcs_communication_interface
virtual	~Gcs_communication_interface ()=default

Private Types
enum class	packet_recovery_result { OK , PACKETS_UNRECOVERABLE , NO_MEMORY , PIPELINE_ERROR , PIPELINE_UNEXPECTED_OUTPUT , PACKET_UNEXPECTED_CARGO , ERROR }
	Error code for the packet recovery proceess. More...

Private Member Functions
void	notify_received_message (std::unique_ptr< Gcs_message > &&message)
	Notify upper layers that a message has been received. More...

void	deliver_user_data_packet (Gcs_packet &&packet, std::unique_ptr< Gcs_xcom_nodes > &&xcom_nodes)
	Delivers the packet to the upper layer. More...

std::vector< Gcs_xcom_node_information >	possible_packet_recovery_donors () const

packet_recovery_result	recover_packets_from_donor (Gcs_xcom_node_information const &donor, Gcs_xcom_synode_set const &synodes, synode_app_data_array &recovered_data)
	Attempts to recover the packets delivered in `synodes` from `donor`. More...

packet_recovery_result	process_recovered_packets (synode_app_data_array const &recovered_data)
	Processes all the recovered packets. More...

packet_recovery_result	process_recovered_packet (synode_app_data const &recovered_data)
	Processes a single recovered packet. More...

void	log_packet_recovery_failure (packet_recovery_result const &error_code, Gcs_xcom_node_information const &donor) const
	Logs the packet recovery failure. More...

	Gcs_xcom_communication (const Gcs_xcom_communication &)

Gcs_xcom_communication &	operator= (const Gcs_xcom_communication &)

Private Attributes
std::map< int, const Gcs_communication_event_listener & >	event_listeners

Gcs_xcom_statistics_updater *	stats

Gcs_xcom_proxy *	m_xcom_proxy

Gcs_xcom_view_change_control_interface *	m_view_control

Gcs_message_pipeline	m_msg_pipeline
	The pipeline of stages a message has to go through before it is delivered to the application or sent to the network. More...

std::vector< std::pair< Gcs_packet, std::unique_ptr< Gcs_xcom_nodes > > >	m_buffered_packets
	Buffer that is used to store packets while the node is about to install a view and is running the state exchange phase. More...

Gcs_xcom_nodes	m_xcom_nodes
	Most recent XCom membership known. More...

unsigned int	m_gid_hash
	Hash of the group. More...

Gcs_xcom_communication_protocol_changer	m_protocol_changer
	Protocol changer. More...

std::unique_ptr< Network_provider_management_interface >	m_comms_mgmt_interface

Member Enumeration Documentation

◆ packet_recovery_result

enum class Gcs_xcom_communication::packet_recovery_result

strongprivate

Error code for the packet recovery proceess.

Enumerator
OK
PACKETS_UNRECOVERABLE
NO_MEMORY
PIPELINE_ERROR
PIPELINE_UNEXPECTED_OUTPUT
PACKET_UNEXPECTED_CARGO
ERROR

Constructor & Destructor Documentation

◆ Gcs_xcom_communication() [1/2]

Gcs_xcom_communication::Gcs_xcom_communication	(	Gcs_xcom_statistics_updater *	stats,
		Gcs_xcom_proxy *	proxy,
		Gcs_xcom_view_change_control_interface *	view_control,
		Gcs_xcom_engine *	gcs_engine,
		Gcs_group_identifier const &	group_id,
		std::unique_ptr< Network_provider_management_interface >	comms_mgmt
	)

explicit

Gcs_xcom_communication_interface constructor.

Parameters

[in]	stats	a reference to the statistics interface
[in]	proxy	a reference to an implementation of Gcs_xcom_communication_proxy
[in]	view_control	a reference to a gcs_xcom_view_change_control_interface implementation
[in]	gcs_engine	Pointer to gcs engine
[in]	group_id	reference to the group identifier
[in]	comms_mgmt	an unique_ptr to a Network_provider_management_interface

◆ ~Gcs_xcom_communication()

Gcs_xcom_communication::~Gcs_xcom_communication ( )

overridedefault

◆ Gcs_xcom_communication() [2/2]

Gcs_xcom_communication::Gcs_xcom_communication ( const Gcs_xcom_communication & )

private

Member Function Documentation

◆ add_event_listener()

int Gcs_xcom_communication::add_event_listener ( const Gcs_communication_event_listener & event_listener )

overridevirtual

Registers an implementation of a Gcs_communication_event_listener that will receive Communication Events.

Note that a binding implementation shall not offer the possibility of changing listeners while the system is up and running. In that sense, listeners must be added to it only when booting up the system.

Parameters

[in] event_listener a class that implements Gcs_communication_event_listener

Returns: an handle representing the registration of this object to be used in remove_event_listener

Implements Gcs_communication_interface.

◆ buffer_incoming_packet()

void Gcs_xcom_communication::buffer_incoming_packet	(	Gcs_packet &&	packet,
		std::unique_ptr< Gcs_xcom_nodes > &&	xcom_nodes
	)

overridevirtual

Buffer packets when a view is not installed yet and the state exchange phase is being executed.

Note that this method must be executed by the same thread that processes global view messages and data message in order to avoid any concurrency issue.

Parameters

packet	Packet to buffer.
xcom_nodes	Membership at the time the packet was received

Implements Gcs_xcom_communication_interface.

◆ cleanup_buffered_packets()

void Gcs_xcom_communication::cleanup_buffered_packets ( )

overridevirtual

Implements Gcs_xcom_communication_interface.

◆ convert_packet_to_message()

Gcs_message * Gcs_xcom_communication::convert_packet_to_message	(	Gcs_packet &&	packet,
		std::unique_ptr< Gcs_xcom_nodes > &&	xcom_nodes
	)

overridevirtual

Converts the packet into a message that can be delivered to the upper layer.

Parameters

packet	The packet to convert
xcom_nodes	The membership at the time the packet was delivered

Return values

Gcs_message*	if successful
nullptr	if unsuccessful

Implements Gcs_xcom_communication_interface.

◆ deliver_buffered_packets()

void Gcs_xcom_communication::deliver_buffered_packets ( )

overridevirtual

The state exchange phase has been executed and the view has been installed so this is used to send any buffered packet to upper layers.

Note that this method must be executed by the same thread that processes global view messages and data message in order to avoid any concurrency issue.

Implements Gcs_xcom_communication_interface.

◆ deliver_user_data_packet()

void Gcs_xcom_communication::deliver_user_data_packet	(	Gcs_packet &&	packet,
		std::unique_ptr< Gcs_xcom_nodes > &&	xcom_nodes
	)

private

Delivers the packet to the upper layer.

◆ do_send_message()

enum_gcs_error Gcs_xcom_communication::do_send_message	(	const Gcs_message &	message_to_send,
		unsigned long long *	message_length,
		Cargo_type	cargo
	)

overridevirtual

Sends a message that is internal to the binding implementation.

This message will not be subject to the same restrictions of send_message. As such, it will not observe view safety nor will count for the statistics of messages sent.

Parameters

[in]	message_to_send	the message to send
[out]	message_length	the length of message which was send if GCS_OK, unspecified otherwise
[in]	cargo	internal message header cargo type

Returns: the xcom broadcast message error

Return values

GCS_OK	message is transmitted successfully
GCS_NOK	error occurred while transmitting message
GCS_MESSAGE_TOO_BIG	message is bigger then xcom can handle

Implements Gcs_xcom_communication_interface.

◆ get_event_listeners()

std::map< int, const Gcs_communication_event_listener & > * Gcs_xcom_communication::get_event_listeners ( )

◆ get_incoming_connections_protocol()

enum_transport_protocol Gcs_xcom_communication::get_incoming_connections_protocol ( )

overridevirtual

Get the incoming connections protocol which is currently active.

Returns: GcsRunningProtocol

Implements Gcs_communication_interface.

◆ get_maximum_supported_protocol_version()

Gcs_protocol_version Gcs_xcom_communication::get_maximum_supported_protocol_version ( ) const

overridevirtual

Get the maximum protocol version currently supported by the group.

Returns: the maximum protocol version currently supported by the group

Implements Gcs_communication_interface.

◆ get_msg_pipeline()

Gcs_message_pipeline & Gcs_xcom_communication::get_msg_pipeline ( )

inlineoverridevirtual

Implements Gcs_xcom_communication_interface.

◆ get_protocol_version()

Gcs_protocol_version Gcs_xcom_communication::get_protocol_version ( ) const

overridevirtual

Retrieves the current GCS protocol version in use.

Implements Gcs_communication_interface.

◆ log_packet_recovery_failure()

void Gcs_xcom_communication::log_packet_recovery_failure	(	packet_recovery_result const &	error_code,
		Gcs_xcom_node_information const &	donor
	)		const

private

Logs the packet recovery failure.

◆ notify_received_message()

void Gcs_xcom_communication::notify_received_message ( std::unique_ptr< Gcs_message > && message )

private

Notify upper layers that a message has been received.

◆ number_buffered_packets()

size_t Gcs_xcom_communication::number_buffered_packets ( )

overridevirtual

Return the number of buffered packets.

Note that this method must be executed by the same thread that processes global view messages and data message in order to avoid any concurrency issue.

Implements Gcs_xcom_communication_interface.

◆ operator=()

Gcs_xcom_communication & Gcs_xcom_communication::operator= ( const Gcs_xcom_communication & )

private

◆ possible_packet_recovery_donors()

std::vector< Gcs_xcom_node_information > Gcs_xcom_communication::possible_packet_recovery_donors ( ) const

private

Returns: the list of possible donors from which to recover the missing packets this server requires to successfully join the group.

◆ process_recovered_packet()

Gcs_xcom_communication::packet_recovery_result Gcs_xcom_communication::process_recovered_packet ( synode_app_data const & recovered_data )

private

Processes a single recovered packet.

◆ process_recovered_packets()

Gcs_xcom_communication::packet_recovery_result Gcs_xcom_communication::process_recovered_packets ( synode_app_data_array const & recovered_data )

private

Processes all the recovered packets.

◆ process_user_data_packet()

void Gcs_xcom_communication::process_user_data_packet	(	Gcs_packet &&	packet,
		std::unique_ptr< Gcs_xcom_nodes > &&	xcom_nodes
	)

overridevirtual

The purpose of this method is to be called when in Gcs_xcom_interface callback method xcom_receive_data is invoked.

This allows, in terms of software architecture, to concentrate all the message delivery logic and processing in a single place.

The deliver_message callback that is registered in XCom (in gcs_xcom_interface.h) and that actually receives the low-level messages, is implemented as a delegator to this method.

Note that the method will be responsible for deleting the message passed as parameter and must be executed by the same thread that processes global view messages and data message in order to avoid any concurrency issue.

Implements Gcs_xcom_communication_interface.

◆ recover_packets()

bool Gcs_xcom_communication::recover_packets ( Gcs_xcom_synode_set const & synodes )

overridevirtual

Attempts to recover the missing packets that are required for a node to join the group successfully.

For example, the missing packets may be some fragments of a message that have already been delivered by XCom to the existing members of the group. The joining node needs those fragments in order to be able to deliver the reassembled message when the final fragments are delivered by XCom.

Note that this method must be executed by the same thread that processes global view messages and data message in order to avoid any concurrency issue.

Parameters

synodes The synodes where the required packets were decided

Returns: true If successful, false otherwise

Implements Gcs_xcom_communication_interface.

◆ recover_packets_from_donor()

Gcs_xcom_communication::packet_recovery_result Gcs_xcom_communication::recover_packets_from_donor	(	Gcs_xcom_node_information const &	donor,
		Gcs_xcom_synode_set const &	synodes,
		synode_app_data_array &	recovered_data
	)

private

Attempts to recover the packets delivered in synodes from donor.

recovered_data is an out parameter.

◆ remove_event_listener()

void Gcs_xcom_communication::remove_event_listener ( int event_listener_handle )

overridevirtual

Removes a previously registered event listener.

Note that a binding implementation shall not offer the possibility of changing listeners while the system is up and running. In that sense listeners must be removed from it only when shutting down the system.

Parameters

[in] event_listener_handle the handle returned when the listener was registered

Implements Gcs_communication_interface.

◆ send_message()

enum_gcs_error Gcs_xcom_communication::send_message ( const Gcs_message & message_to_send )

overridevirtual

Implementation of the public send_message method defined in Gcs_xcom_communication.

Besides sending a message to the group, this method does two extra things:

Guarantees view safety, in which no messages can be sent when a view change is occurring.
Registers in the statistics interface that a message was sent.

Parameters

[in] message_to_send the message to send

Returns: the xcom broadcast message error

Return values

GCS_OK	when message is transmitted successfully
GCS_NOK	when error occurred while transmitting message
GCS_MESSAGE_TOO_BIG	when message is bigger then xcom can handle

Implements Gcs_communication_interface.

◆ set_communication_protocol()

void Gcs_xcom_communication::set_communication_protocol ( enum_transport_protocol protocol )

overridevirtual

Sets the communication protocol to use.

Parameters

protocol the protocol to use

Implements Gcs_communication_interface.

◆ set_maximum_supported_protocol_version()

void Gcs_xcom_communication::set_maximum_supported_protocol_version ( Gcs_protocol_version version )

◆ set_protocol_version()

std::pair< bool, std::future< void > > Gcs_xcom_communication::set_protocol_version ( Gcs_protocol_version new_version )

overridevirtual

Modifies the GCS protocol version in use.

The method is non-blocking. It returns a future on which the caller can wait for the action to finish.

This method has the following requirements:

It must be called by all group members at the same logical instant, i.e. it is part of the replicated state machine.
It must not be called concurrently, i.e. a new protocol change may only begin after the previous one has finished.

A GCS client must ensure the requirements are met. In the case of Group Replication, these requirements are ensured by initiating a GCS protocol change as part of a GR group action.

Parameters

new_version The desired GCS protocol version

Return values

{true,future}	If successful
{false,_}	If unsuccessful because `new_version` is unsupported

Implements Gcs_communication_interface.

◆ update_members_information()

void Gcs_xcom_communication::update_members_information	(	const Gcs_member_identifier &	me,
		const Gcs_xcom_nodes &	members
	)

overridevirtual

Notify the pipeline about the new XCom membership when a state exchange begins.

Note that this method must be executed by the same thread that processes global view messages and data message in order to avoid any concurrency issue.

Parameters

me	The identifier of this server
members	The XCom membership

Implements Gcs_xcom_communication_interface.

Member Data Documentation

◆ event_listeners

std::map<int, const Gcs_communication_event_listener &> Gcs_xcom_communication::event_listeners

private

◆ m_buffered_packets

std::vector<std::pair<Gcs_packet, std::unique_ptr<Gcs_xcom_nodes> > > Gcs_xcom_communication::m_buffered_packets

private

Buffer that is used to store packets while the node is about to install a view and is running the state exchange phase.

◆ m_comms_mgmt_interface

std::unique_ptr<Network_provider_management_interface> Gcs_xcom_communication::m_comms_mgmt_interface

private

◆ m_gid_hash

unsigned int Gcs_xcom_communication::m_gid_hash

private

Hash of the group.

◆ m_msg_pipeline

Gcs_message_pipeline Gcs_xcom_communication::m_msg_pipeline

private

The pipeline of stages a message has to go through before it is delivered to the application or sent to the network.

◆ m_protocol_changer

Gcs_xcom_communication_protocol_changer Gcs_xcom_communication::m_protocol_changer

private

Protocol changer.

◆ m_view_control

Gcs_xcom_view_change_control_interface* Gcs_xcom_communication::m_view_control

private

◆ m_xcom_nodes

Gcs_xcom_nodes Gcs_xcom_communication::m_xcom_nodes

private

Most recent XCom membership known.

◆ m_xcom_proxy

Gcs_xcom_proxy* Gcs_xcom_communication::m_xcom_proxy

private

◆ stats

Gcs_xcom_statistics_updater* Gcs_xcom_communication::stats

private

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

plugin/group_replication/libmysqlgcs/src/bindings/xcom/gcs_xcom_communication_interface.h
plugin/group_replication/libmysqlgcs/src/bindings/xcom/gcs_xcom_communication_interface.cc

Public Member Functions

Private Types

Private Member Functions

Private Attributes

Member Enumeration Documentation

◆ packet_recovery_result

Constructor & Destructor Documentation

◆ Gcs_xcom_communication() [1/2]

◆ ~Gcs_xcom_communication()

◆ Gcs_xcom_communication() [2/2]

Member Function Documentation

◆ add_event_listener()

◆ buffer_incoming_packet()

◆ cleanup_buffered_packets()

◆ convert_packet_to_message()

◆ deliver_buffered_packets()

◆ deliver_user_data_packet()

◆ do_send_message()

◆ get_event_listeners()

◆ get_incoming_connections_protocol()

◆ get_maximum_supported_protocol_version()

◆ get_msg_pipeline()

◆ get_protocol_version()

◆ log_packet_recovery_failure()

◆ notify_received_message()

◆ number_buffered_packets()

◆ operator=()

◆ possible_packet_recovery_donors()

◆ process_recovered_packet()

◆ process_recovered_packets()

◆ process_user_data_packet()

◆ recover_packets()

◆ recover_packets_from_donor()

◆ remove_event_listener()

◆ send_message()

◆ set_communication_protocol()

◆ set_maximum_supported_protocol_version()

◆ set_protocol_version()

◆ update_members_information()

Member Data Documentation

◆ event_listeners

◆ m_buffered_packets

◆ m_comms_mgmt_interface

◆ m_gid_hash

◆ m_msg_pipeline

◆ m_protocol_changer

◆ m_view_control

◆ m_xcom_nodes

◆ m_xcom_proxy

◆ stats