TC_LOG Class Reference

Transaction Coordinator Log. More...

#include <tc_log.h>

Inheritance diagram for TC_LOG:

Public Types
enum	enum_result { RESULT_SUCCESS , RESULT_ABORTED , RESULT_INCONSISTENT }

Public Member Functions
bool	using_heuristic_recover ()
	Perform heuristic recovery, if –tc-heuristic-recover was used. More...
	TC_LOG ()=default
virtual	~TC_LOG ()=default
virtual int	open (const char *opt_name)=0
	Initialize and open the coordinator log. More...
virtual void	close ()=0
	Close the transaction coordinator log and free any resources. More...
virtual enum_result	commit (THD *thd, bool all)=0
	Log a commit record of the transaction to the transaction coordinator log. More...
virtual int	rollback (THD *thd, bool all)=0
	Log a rollback record of the transaction to the transaction coordinator log. More...
virtual int	prepare (THD *thd, bool all)=0
	Log a prepare record of the transaction to the storage engines. More...

Detailed Description

Transaction Coordinator Log.

A base abstract class for three different implementations of the transaction coordinator.

The server uses the transaction coordinator to order transactions correctly and there are three different implementations: one using an in-memory structure, one dummy that does not do anything, and one using the binary log for transaction coordination.

Member Enumeration Documentation

enum_result

enum TC_LOG::enum_result

Enumerator
RESULT_SUCCESS
RESULT_ABORTED
RESULT_INCONSISTENT

Constructor & Destructor Documentation

TC_LOG()

TC_LOG::TC_LOG ( )

default

~TC_LOG()

virtual TC_LOG::~TC_LOG ( )

virtualdefault

Member Function Documentation

close()

virtual void TC_LOG::close ( )

pure virtual

Close the transaction coordinator log and free any resources.

Called during server shutdown.

Implemented in MYSQL_BIN_LOG, TC_LOG_DUMMY, and TC_LOG_MMAP.

commit()

virtual enum_result TC_LOG::commit ( THD *  thd, bool  all  )

pure virtual

Log a commit record of the transaction to the transaction coordinator log.

When the function returns, the transaction commit is properly logged to the transaction coordinator log and can be committed in the storage engines.

Parameters

thd	Session to log transaction for.
all	True if this is a "real" commit, false if it is a "statement" commit.

Returns

Error code on failure, zero on success.

Implemented in MYSQL_BIN_LOG, TC_LOG_DUMMY, and TC_LOG_MMAP.

open()

virtual int TC_LOG::open ( const char *  opt_name )

pure virtual

Initialize and open the coordinator log.

Do recovery if necessary. Called during server startup.

Parameters

opt_name

Name of logfile.

Return values

0	success
1	failed

Implemented in TC_LOG_DUMMY, MYSQL_BIN_LOG, and TC_LOG_MMAP.

prepare()

virtual int TC_LOG::prepare ( THD *  thd, bool  all  )

pure virtual

Log a prepare record of the transaction to the storage engines.

Parameters

thd	Session to log transaction record for.
all	true if an explicit commit or an implicit commit for a statement, false if an internal commit of the statement.

Returns

Error code on failure, zero on success.

Implemented in MYSQL_BIN_LOG, TC_LOG_DUMMY, and TC_LOG_MMAP.

rollback()

virtual int TC_LOG::rollback ( THD *  thd, bool  all  )

pure virtual

Log a rollback record of the transaction to the transaction coordinator log.

When the function returns, the transaction have been aborted in the transaction coordinator log.

Parameters

thd	Session to log transaction record for.
all	true if an explicit commit or an implicit commit for a statement, false if an internal commit of the statement.

Returns

Error code on failure, zero on success.

Implemented in MYSQL_BIN_LOG, TC_LOG_DUMMY, and TC_LOG_MMAP.

using_heuristic_recover()

bool TC_LOG::using_heuristic_recover

(

)

Perform heuristic recovery, if –tc-heuristic-recover was used.

Note

no matter whether heuristic recovery was successful or not mysqld must exit. So, return value is the same in both cases.

Return values

false	no heuristic recovery was requested
true	heuristic recovery was performed

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

• sql/tc_log.h
• sql/tc_log.cc