#include <sys/types.h>
#include "lex_string.h"
#include "my_inttypes.h"

Functions
bool	trans_check_state (THD *thd)
	Check if we have a condition where the transaction state must not be changed (committed or rolled back). More...

void	trans_reset_one_shot_chistics (THD *thd)
	Helper: transaction ended, SET TRANSACTION one-shot variables revert to session values. More...

void	trans_track_end_trx (THD *thd)
	Helper: Tell tracker (if any) that transaction ended. More...

bool	trans_begin (THD *thd, uint flags=0)
	Begin a new transaction. More...

bool	trans_commit (THD *thd, bool ignore_global_read_lock=false)
	Commit the current transaction, making its changes permanent. More...

bool	trans_commit_implicit (THD *thd, bool ignore_global_read_lock=false)
	Implicitly commit the current transaction. More...

bool	trans_rollback (THD *thd)
	Rollback the current transaction, canceling its changes. More...

bool	trans_rollback_implicit (THD *thd)
	Implicitly rollback the current transaction, typically after deadlock was discovered. More...

bool	trans_commit_stmt (THD *thd, bool ignore_global_read_lock=false)
	Commit the single statement transaction. More...

bool	trans_rollback_stmt (THD *thd)
	Rollback the single statement transaction. More...

bool	trans_commit_attachable (THD *thd)
	Commit the attachable transaction. More...

bool	trans_savepoint (THD *thd, LEX_STRING name)
	Set a named transaction savepoint. More...

bool	trans_rollback_to_savepoint (THD *thd, LEX_STRING name)
	Rollback a transaction to the named savepoint. More...

bool	trans_release_savepoint (THD *thd, LEX_STRING name)
	Remove the named savepoint from the set of savepoints of the current transaction. More...

Function Documentation

◆ trans_begin()

bool trans_begin	(	THD *	thd,
		uint	flags
	)

Begin a new transaction.

Note: Beginning a transaction implicitly commits any current transaction and releases existing locks.

Parameters

thd	Current thread
flags	Transaction flags

Return values

false	Success
true	Failure

◆ trans_check_state()

bool trans_check_state ( THD * thd )

Check if we have a condition where the transaction state must not be changed (committed or rolled back).

Currently we check that we are not executing a stored program and that we don't have an active XA transaction.

Returns: true if the commit/rollback cannot be executed, false otherwise.

◆ trans_commit()

bool trans_commit	(	THD *	thd,
		bool	ignore_global_read_lock
	)

Commit the current transaction, making its changes permanent.

Parameters

[in]	thd	Current thread
[in]	ignore_global_read_lock	Allow commit to complete even if a global read lock is active. This can be used to allow changes to internal tables (e.g. slave status tables, analyze table).

Return values

false	Success
true	Failure

◆ trans_commit_attachable()

bool trans_commit_attachable ( THD * thd )

Commit the attachable transaction.

Note: This is slimmed down version of trans_commit_stmt() which commits attachable transaction but skips code which is unnecessary and unsafe for them (like dealing with GTIDs).

Parameters

thd	Current thread

Return values

False	- Success
True	- Failure

◆ trans_commit_implicit()

bool trans_commit_implicit	(	THD *	thd,
		bool	ignore_global_read_lock
	)

Implicitly commit the current transaction.

Note: A implicit commit does not releases existing table locks.

Parameters

[in]	thd	Current thread
[in]	ignore_global_read_lock	Allow commit to complete even if a global read lock is active. This can be used to allow changes to internal tables (e.g. slave status tables, analyze table).

Return values

false	Success
true	Failure

◆ trans_commit_stmt()

bool trans_commit_stmt	(	THD *	thd,
		bool	ignore_global_read_lock
	)

Commit the single statement transaction.

Note: Note that if the autocommit is on, then the following call inside InnoDB will commit or rollback the whole transaction (= the statement). The autocommit mechanism built into InnoDB is based on counting locks, but if the user has used LOCK TABLES then that mechanism does not know to do the commit.

Parameters

[in]	thd	Current thread
[in]	ignore_global_read_lock	Allow commit to complete even if a global read lock is active. This can be used to allow changes to internal tables (e.g. slave status tables, analyze table).

Return values

false	Success
true	Failure

◆ trans_release_savepoint()

bool trans_release_savepoint	(	THD *	thd,
		LEX_STRING	name
	)

Remove the named savepoint from the set of savepoints of the current transaction.

Note: No commit or rollback occurs. It is an error if the savepoint does not exist.

Parameters

thd	Current thread
name	Savepoint name

Return values

false	Success
true	Failure

◆ trans_reset_one_shot_chistics()

void trans_reset_one_shot_chistics ( THD * thd )

Helper: transaction ended, SET TRANSACTION one-shot variables revert to session values.

Let the transaction state tracker know.

◆ trans_rollback()

bool trans_rollback ( THD * thd )

Rollback the current transaction, canceling its changes.

Parameters

thd	Current thread

Return values

false	Success
true	Failure

◆ trans_rollback_implicit()

bool trans_rollback_implicit ( THD * thd )

Implicitly rollback the current transaction, typically after deadlock was discovered.

Parameters

thd	Current thread

Return values

False	Success
True	Failure

Note: ha_rollback_low() which is indirectly called by this function will mark XA transaction for rollback by setting appropriate RM error status if there was transaction rollback request.

◆ trans_rollback_stmt()

bool trans_rollback_stmt ( THD * thd )

Rollback the single statement transaction.

Parameters

thd	Current thread

Return values

false	Success
true	Failure

◆ trans_rollback_to_savepoint()

bool trans_rollback_to_savepoint	(	THD *	thd,
		LEX_STRING	name
	)

Rollback a transaction to the named savepoint.

Note: Modifications that the current transaction made to rows after the savepoint was set are undone in the rollback.; Savepoints that were set at a later time than the named savepoint are deleted.

Parameters

thd	Current thread
name	Savepoint name

Return values

false	Success
true	Failure

Checking whether it is safe to release metadata locks acquired after savepoint, if rollback to savepoint is successful.

Whether it is safe to release MDL after rollback to savepoint depends on storage engines participating in transaction:

InnoDB doesn't release any row-locks on rollback to savepoint so it is probably a bad idea to release MDL as well.
Binary log implementation in some cases (e.g when non-transactional tables involved) may choose not to remove events added after savepoint from transactional cache, but instead will write them to binary log accompanied with ROLLBACK TO SAVEPOINT statement. Since the real write happens at the end of transaction releasing MDL on tables mentioned in these events (i.e. acquired after savepoint and before rollback of it) can break replication, as concurrent DROP TABLES statements will be able to drop these tables before events will get into binary log,

◆ trans_savepoint()

bool trans_savepoint	(	THD *	thd,
		LEX_STRING	name
	)

Set a named transaction savepoint.

Parameters

thd	Current thread
name	Savepoint name

Return values

false	Success
true	Failure

◆ trans_track_end_trx()

void trans_track_end_trx ( THD * thd )

Helper: Tell tracker (if any) that transaction ended.

Functions

Function Documentation

◆ trans_begin()

◆ trans_check_state()

◆ trans_commit()

◆ trans_commit_attachable()

◆ trans_commit_implicit()

◆ trans_commit_stmt()

◆ trans_release_savepoint()

◆ trans_reset_one_shot_chistics()

◆ trans_rollback()

◆ trans_rollback_implicit()

◆ trans_rollback_stmt()

◆ trans_rollback_to_savepoint()

◆ trans_savepoint()

◆ trans_track_end_trx()