cs::apply::Commit_order_queue::Node Class Reference

Queue element, holding the needed information to manage the commit ordering. More...

#include <commit_order_queue.h>

Public Member Functions
bool	freeze_commit_sequence_nr (Commit_order_queue::sequence_type expected)
	Marks the commit request sequence number this node's worker is processing as frozen iff the sequence number current value is equal to the expected parameter. More...
bool	unfreeze_commit_sequence_nr (Commit_order_queue::sequence_type previously_frozen)
	Removes the frozen mark from the commit request sequence number this node's worker is processing if it was previously frozen. More...

Public Attributes
value_type	m_worker_id {NO_WORKER}
	The identifier of the worker that maps to a queue index. More...
MDL_context *	m_mdl_context {nullptr}
	The MDL context to be used to wait on the MDL graph. More...
memory::Aligned_atomic< Commit_order_queue::enum_worker_stage >	m_stage
	Which stage is the worker on. More...

Private Member Functions
Commit_order_queue::sequence_type	reset_commit_sequence_nr ()
	Sets the commit request sequence number for this node as unassigned. More...

Private Attributes
memory::Aligned_atomic< Commit_order_queue::sequence_type >	m_commit_sequence_nr {NO_SEQUENCE_NR}
	The sequence number for the commit request this node's worker is processing. More...

Static Private Attributes
static constexpr Commit_order_queue::sequence_type	NO_SEQUENCE_NR {0}
static constexpr Commit_order_queue::sequence_type	SEQUENCE_NR_FROZEN {1}

Friends
class	Commit_order_queue

Detailed Description

Queue element, holding the needed information to manage the commit ordering.

Member Function Documentation

freeze_commit_sequence_nr()

bool cs::apply::Commit_order_queue::Node::freeze_commit_sequence_nr

(

Commit_order_queue::sequence_type

expected

)

Marks the commit request sequence number this node's worker is processing as frozen iff the sequence number current value is equal to the expected parameter.

Commit request sequence numbers are monotonically ever increasing numbers that are used by worker threads to ensure ownership of the worker commit turn unblocking operation: 1) A worker holding a sequence number N can only unblock worker with sequence number N + 1. 2) A worker with sequence number N + 1 can't be assigned a new sequence number if worker with sequence number N is executing the unblocking operation.

Parameters

expected

the commit request sequence number this node must currently hold in order for it to be frozen

Returns

true if this nodes commit request sequence number has been frozen, false otherwise.

reset_commit_sequence_nr()

cs::apply::Commit_order_queue::sequence_type cs::apply::Commit_order_queue::Node::reset_commit_sequence_nr ( )

private

Sets the commit request sequence number for this node as unassigned.

If the sequence number is currently frozen, invoking this method will make the invoking thread to spin until the sequence number is unfrozen.

Commit request sequence numbers are monotonically ever increasing numbers that are used by worker threads to ensure ownership of the worker commit turn unblocking operation: 1) A worker holding a sequence number N can only unblock worker with sequence number N + 1. 2) A worker with sequence number N + 1 can't be assigned a new sequence number if worker with sequence number N is executing the unblocking operation.

Returns

the sequence number for the commit request sequence number this node's worker is been cleared of

unfreeze_commit_sequence_nr()

bool cs::apply::Commit_order_queue::Node::unfreeze_commit_sequence_nr

(

Commit_order_queue::sequence_type

previously_frozen

)

Removes the frozen mark from the commit request sequence number this node's worker is processing if it was previously frozen.

Commit request sequence numbers are monotonically ever increasing numbers that are used by worker threads to ensure ownership of the worker commit turn unblocking operation: 1) A worker holding a sequence number N can only unblock worker with sequence number N + 1. 2) A worker with sequence number N + 1 can't be assigned a new sequence number if worker with sequence number N is executing the unblocking operation.

Parameters

previously_frozen

the sequence number value that was provided while previously freezing.

Returns

true if this nodes commit request sequence number was frozen and is now unfrozen, false otherwise.

Friends And Related Function Documentation

Commit_order_queue

friend class Commit_order_queue

friend

Member Data Documentation

m_commit_sequence_nr

memory::Aligned_atomic<Commit_order_queue::sequence_type> cs::apply::Commit_order_queue::Node::m_commit_sequence_nr {NO_SEQUENCE_NR}

private

The sequence number for the commit request this node's worker is processing.

m_mdl_context

MDL_context* cs::apply::Commit_order_queue::Node::m_mdl_context {nullptr}

The MDL context to be used to wait on the MDL graph.

m_stage

memory::Aligned_atomic<Commit_order_queue::enum_worker_stage> cs::apply::Commit_order_queue::Node::m_stage

Initial value:

{
        Commit_order_queue::enum_worker_stage::FINISHED}

Which stage is the worker on.

m_worker_id

value_type cs::apply::Commit_order_queue::Node::m_worker_id {NO_WORKER}

The identifier of the worker that maps to a queue index.

NO_SEQUENCE_NR

constexpr Commit_order_queue::sequence_type cs::apply::Commit_order_queue::Node::NO_SEQUENCE_NR {0}

staticconstexprprivate

SEQUENCE_NR_FROZEN

constexpr Commit_order_queue::sequence_type cs::apply::Commit_order_queue::Node::SEQUENCE_NR_FROZEN {1}

staticconstexprprivate

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

• sql/changestreams/apply/commit_order_queue.h
• sql/changestreams/apply/commit_order_queue.cc