Transaction rollback. More...

#include "mtr0mtr.h"
#include "trx0sys.h"
#include "trx0trx.h"
#include "trx0types.h"
#include "univ.i"
#include "trx0roll.ic"

Classes
struct	roll_node_t
	Rollback command node in a query graph. More...

struct	trx_named_savept_t
	A savepoint set with SQL's "SAVEPOINT savepoint_id" command. More...

Enumerations
enum	roll_node_state { ROLL_NODE_NONE = 0 , ROLL_NODE_SEND , ROLL_NODE_WAIT }
	Rollback node states. More...

Functions
bool	trx_is_recv (const trx_t *trx)
	Determines if this transaction is rolling back an incomplete transaction in crash recovery. More...

trx_savept_t	trx_savept_take (trx_t *trx)
	Returns a transaction savepoint taken at this point in time. More...

trx_undo_rec_t *	trx_roll_pop_top_rec_of_trx (trx_t trx, undo_no_t limit, roll_ptr_t roll_ptr, mem_heap_t *heap)
	Get next undo log record from redo and noredo rollback segments. More...

void	trx_rollback_or_clean_recovered (bool all)
	Rollback or clean up any incomplete transactions which were encountered in crash recovery. More...

void	trx_recovery_rollback_thread ()
	Rollback or clean up any incomplete transactions which were encountered in crash recovery. More...

roll_node_t *	roll_node_create (mem_heap_t *heap)
	Creates a rollback command node struct. More...

que_thr_t *	trx_rollback_step (que_thr_t *thr)
	Performs an execution step for a rollback command node in a query graph. More...

dberr_t	trx_rollback_for_mysql (trx_t *trx)
	Rollback a transaction used in MySQL. More...

dberr_t	trx_rollback_last_sql_stat_for_mysql (trx_t *trx)
	Rollback the latest SQL statement for MySQL. More...

dberr_t	trx_rollback_to_savepoint (trx_t trx, trx_savept_t savept)
	Rollback a transaction to a given savepoint or do a complete rollback. More...

dberr_t	trx_rollback_to_savepoint_for_mysql (trx_t trx, const char savepoint_name, int64_t *mysql_binlog_cache_pos)
	Rolls back a transaction back to a named savepoint. More...

dberr_t	trx_savepoint_for_mysql (trx_t trx, const char savepoint_name, int64_t binlog_cache_pos)
	Creates a named savepoint. More...

dberr_t	trx_release_savepoint_for_mysql (trx_t trx, const char savepoint_name)
	Releases a named savepoint. More...

void	trx_roll_savepoints_free (trx_t trx, trx_named_savept_t savep)
	Frees savepoint structs starting from savep. More...

Variables
os_event_t	recovery_lock_taken

Detailed Description

Transaction rollback.

Created 3/26/1996 Heikki Tuuri

Enumeration Type Documentation

◆ roll_node_state

enum roll_node_state

Rollback node states.

Enumerator
ROLL_NODE_NONE	Unknown state.
ROLL_NODE_SEND	about to send a rollback signal to the transaction
ROLL_NODE_WAIT	rollback signal sent to the transaction, waiting for completion

Function Documentation

◆ roll_node_create()

roll_node_t * roll_node_create ( mem_heap_t * heap )

Creates a rollback command node struct.

Returns: own: rollback node struct in: mem heap where created; own: rollback node struct

Parameters

heap	in: mem heap where created

◆ trx_is_recv()

bool trx_is_recv ( const trx_t * trx )

Determines if this transaction is rolling back an incomplete transaction in crash recovery.

Returns: true if trx is an incomplete transaction that is being rolled back in crash recovery in: transaction; true if trx is an incomplete transaction that is being rolled back in crash recovery

Parameters

trx	in: transaction

◆ trx_recovery_rollback_thread()

void trx_recovery_rollback_thread ( )

Rollback or clean up any incomplete transactions which were encountered in crash recovery.

If the transaction already was committed, then we clean up a possible insert undo log. If the transaction was not yet committed, then we roll it back. Note: this is done in a background thread.

◆ trx_release_savepoint_for_mysql()

dberr_t trx_release_savepoint_for_mysql	(	trx_t *	trx,
		const char *	savepoint_name
	)

Releases a named savepoint.

Savepoints which were set after this savepoint are deleted.

Returns: if no savepoint of the name found then DB_NO_SAVEPOINT, otherwise DB_SUCCESS in: savepoint name

Releases a named savepoint.

Savepoints which were set after this savepoint are left as is.

Returns: if no savepoint of the name found then DB_NO_SAVEPOINT, otherwise DB_SUCCESS

Parameters

trx	in: transaction handle
savepoint_name	in: savepoint name

◆ trx_roll_pop_top_rec_of_trx()

trx_undo_rec_t * trx_roll_pop_top_rec_of_trx	(	trx_t *	trx,
		undo_no_t	limit,
		roll_ptr_t *	roll_ptr,
		mem_heap_t *	heap
	)

Get next undo log record from redo and noredo rollback segments.

Returns: undo log record copied to heap, NULL if none left, or if the undo number of the top record would be less than the limit in: memory heap where copied; undo log record copied to heap, NULL if none left, or if the undo number of the top record would be less than the limit

Parameters

trx	in: transaction
limit	in: least undo number we need
roll_ptr	out: roll pointer to undo record
heap	in: memory heap where copied

◆ trx_roll_savepoints_free()

void trx_roll_savepoints_free	(	trx_t *	trx,
		trx_named_savept_t *	savep
	)

Frees savepoint structs starting from savep.

Parameters

[in]	trx	Transaction handle
[in]	savep	Free all savepoints starting with this savepoint i, if savep is nullptr free all save points

◆ trx_rollback_for_mysql()

dberr_t trx_rollback_for_mysql ( trx_t * trx )

Rollback a transaction used in MySQL.

Returns: error code or DB_SUCCESS in/out: transaction; error code or DB_SUCCESS

Parameters

trx	in/out: transaction

◆ trx_rollback_last_sql_stat_for_mysql()

dberr_t trx_rollback_last_sql_stat_for_mysql ( trx_t * trx )

Rollback the latest SQL statement for MySQL.

Returns: error code or DB_SUCCESS in/out: transaction; error code or DB_SUCCESS

Parameters

trx	in/out: transaction

◆ trx_rollback_or_clean_recovered()

void trx_rollback_or_clean_recovered ( bool all )

Rollback or clean up any incomplete transactions which were encountered in crash recovery.

If the transaction already was committed, then we clean up a possible insert undo log. If the transaction was not yet committed, then we roll it back. in: false=roll back dictionary transactions; true=roll back all non-PREPARED transactions

If the transaction already was committed, then we clean up a possible insert undo log. If the transaction was not yet committed, then we roll it back.

Parameters

all	in: false=roll back dictionary transactions; true=roll back all non-PREPARED transactions

◆ trx_rollback_step()

que_thr_t * trx_rollback_step ( que_thr_t * thr )

Performs an execution step for a rollback command node in a query graph.

Returns: query thread to run next, or NULL in: query thread; query thread to run next, or NULL

Parameters

thr	in: query thread

◆ trx_rollback_to_savepoint()

dberr_t trx_rollback_to_savepoint	(	trx_t *	trx,
		trx_savept_t *	savept
	)

Rollback a transaction to a given savepoint or do a complete rollback.

Returns: error code or DB_SUCCESS in: pointer to savepoint undo number, if partial rollback requested, or NULL for complete rollback; error code or DB_SUCCESS

Parameters

trx	in: transaction handle
savept	in: pointer to savepoint undo number, if partial rollback requested, or NULL for complete rollback

◆ trx_rollback_to_savepoint_for_mysql()

dberr_t trx_rollback_to_savepoint_for_mysql	(	trx_t *	trx,
		const char *	savepoint_name,
		int64_t *	mysql_binlog_cache_pos
	)

Rolls back a transaction back to a named savepoint.

Modifications after the savepoint are undone but InnoDB does NOT release the corresponding locks which are stored in memory. If a lock is 'implicit', that is, a new inserted row holds a lock where the lock information is carried by the trx id stored in the row, these locks are naturally released in the rollback. Savepoints which were set after this savepoint are deleted.

Returns: if no savepoint of the name found then DB_NO_SAVEPOINT, otherwise DB_SUCCESS out: the MySQL binlog cache position corresponding to this savepoint; MySQL needs this information to remove the binlog entries of the queries executed after the savepoint

Modifications after the savepoint are undone but InnoDB does NOT release the corresponding locks which are stored in memory. If a lock is 'implicit', that is, a new inserted row holds a lock where the lock information is carried by the trx id stored in the row, these locks are naturally released in the rollback. Savepoints which were set after this savepoint are deleted.

Returns: if no savepoint of the name found then DB_NO_SAVEPOINT, otherwise DB_SUCCESS

Parameters

trx	in: transaction handle
savepoint_name	in: savepoint name
mysql_binlog_cache_pos	out: the MySQL binlog cache position corresponding to this savepoint; MySQL needs this information to remove the binlog entries of the queries executed after the savepoint

◆ trx_savepoint_for_mysql()

dberr_t trx_savepoint_for_mysql	(	trx_t *	trx,
		const char *	savepoint_name,
		int64_t	binlog_cache_pos
	)

Creates a named savepoint.

If the transaction is not yet started, starts it. If there is already a savepoint of the same name, this call erases that old savepoint and replaces it with a new. Savepoints are deleted in a transaction commit or rollback.

Returns: always DB_SUCCESS in: MySQL binlog cache position corresponding to this connection at the time of the savepoint

If the transaction is not yet started, starts it. If there is already a savepoint of the same name, this call erases that old savepoint and replaces it with a new. Savepoints are deleted in a transaction commit or rollback.

Returns: always DB_SUCCESS

Parameters

trx	in: transaction handle
savepoint_name	in: savepoint name
binlog_cache_pos	in: MySQL binlog cache position corresponding to this connection at the time of the savepoint

◆ trx_savept_take()

trx_savept_t trx_savept_take ( trx_t * trx )

Returns a transaction savepoint taken at this point in time.

Returns: savepoint in: transaction; savepoint

Parameters

trx	in: transaction

Variable Documentation

◆ recovery_lock_taken

os_event_t recovery_lock_taken

extern

Classes

Enumerations

Functions

Variables

Detailed Description

Enumeration Type Documentation

◆ roll_node_state

Function Documentation

◆ roll_node_create()

◆ trx_is_recv()

◆ trx_recovery_rollback_thread()

◆ trx_release_savepoint_for_mysql()

◆ trx_roll_pop_top_rec_of_trx()

◆ trx_roll_savepoints_free()

◆ trx_rollback_for_mysql()

◆ trx_rollback_last_sql_stat_for_mysql()

◆ trx_rollback_or_clean_recovered()

◆ trx_rollback_step()

◆ trx_rollback_to_savepoint()

◆ trx_rollback_to_savepoint_for_mysql()

◆ trx_savepoint_for_mysql()

◆ trx_savept_take()

Variable Documentation

◆ recovery_lock_taken