Writeset_trx_dependency_tracker Class Reference

Generate logical timestamps for MTS using WRITESET in the binlog-transaction-dependency-tracking option. More...

#include <rpl_trx_tracking.h>

Public Member Functions
	Writeset_trx_dependency_tracker (ulong max_history_size)
void	get_dependency (THD *thd, int64 &sequence_number, int64 &commit_parent)
	Main function that gets the dependencies using the WRITESET tracker. More...
void	rotate (int64 start)

Public Attributes
std::atomic< ulong >	m_opt_max_history_size

Private Types
typedef std::map< uint64, int64 >	Writeset_history

Private Attributes
int64	m_writeset_history_start
Writeset_history	m_writeset_history

Detailed Description

Generate logical timestamps for MTS using WRITESET in the binlog-transaction-dependency-tracking option.

Member Typedef Documentation

Writeset_history

typedef std::map<uint64, int64> Writeset_trx_dependency_tracker::Writeset_history

private

Constructor & Destructor Documentation

Writeset_trx_dependency_tracker()

Writeset_trx_dependency_tracker::Writeset_trx_dependency_tracker ( ulong  max_history_size )

inline

Member Function Documentation

get_dependency()

void Writeset_trx_dependency_tracker::get_dependency	(	THD *	thd,
		int64 &	sequence_number,
		int64 &	commit_parent
	)

Main function that gets the dependencies using the WRITESET tracker.

Get the writeset dependencies of a transaction.

Parameters

[in]	thd	THD of the caller.
[in,out]	sequence_number	sequence_number initialized and returned.
[in,out]	commit_parent	commit_parent to be returned.

This takes the commit_parent that must be previously set using Commit_order_trx_dependency_tracker and tries to make the commit_parent as low as possible, using the writesets of each transaction. The commit_parent returned depends on how many row hashes are stored in the writeset_history, which is cleared once it reaches the user-defined maximum.

Parameters

[in]	thd	Current THD from which to extract trx context.
[in,out]	sequence_number	Sequence number of current transaction.
[in,out]	commit_parent	Commit_parent of current transaction, pre-filled with the commit_parent calculated by Commit_order_trx_dependency_tracker to use when the writeset commit_parent is not valid.

rotate()

void Writeset_trx_dependency_tracker::rotate

(

int64

start

)

Member Data Documentation

m_opt_max_history_size

std::atomic<ulong> Writeset_trx_dependency_tracker::m_opt_max_history_size

m_writeset_history

Writeset_history Writeset_trx_dependency_tracker::m_writeset_history

private

m_writeset_history_start

int64 Writeset_trx_dependency_tracker::m_writeset_history_start

private

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

• sql/rpl_trx_tracking.h
• sql/rpl_trx_tracking.cc