MySQL  8.0.27
Source Code Documentation
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, int64Writeset_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

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]thdTHD of the caller.
[in,out]sequence_numbersequence_number initialized and returned.
[in,out]commit_parentcommit_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]thdCurrent THD from which to extract trx context.
[in,out]sequence_numberSequence number of current transaction.
[in,out]commit_parentCommit_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

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