Purge old versions. More...

#include "fil0fil.h"
#include "mtr0mtr.h"
#include "page0page.h"
#include "que0types.h"
#include "read0types.h"
#include "trx0sys.h"
#include "trx0types.h"
#include "univ.i"
#include "usr0sess.h"
#include "trx0purge.ic"

Classes
struct	purge_iter_t
	This is the purge pointer/iterator. More...

struct	undo::space_id_account
	The currently used undo space IDs for an undo space number along with a boolean showing whether the undo space number is in use. More...

struct	undo::Tablespace
	An undo::Tablespace object is used to easily convert between undo_space_id and undo_space_num and to create the automatic file_name and space name. More...

class	undo::Tablespaces
	List of undo tablespaces, each containing a list of rollback segments. More...

class	undo::Inject_failure_once
	Inject a failure in the undo truncation debug compiled code at various places so that it fails the first time it hits and succeeds after that. More...

class	undo::Truncate
	Track an UNDO tablespace marked for truncate. More...

struct	trx_purge_t
	The control structure used in the purge operation. More...

struct	TrxUndoRsegsIterator
	Choose the rollback segment with the smallest trx_no. More...

Namespaces
namespace	undo

Enumerations
enum	purge_state_t { PURGE_STATE_INIT , PURGE_STATE_RUN , PURGE_STATE_STOP , PURGE_STATE_EXIT , PURGE_STATE_DISABLED }
	Purge states. More...

Functions
static fil_addr_t	trx_purge_get_log_from_hist (fil_addr_t node_addr)
	Calculates the file address of an undo log header when we have the file address of its history list node. More...

void	trx_purge_sys_mem_create ()
	Initialize in-memory purge structures. More...

void	trx_purge_sys_initialize (uint32_t n_purge_threads, purge_pq_t *purge_queue)
	Creates the global purge system control structure and inits the history mutex. More...

void	trx_purge_sys_close (void)
	Frees the global purge system control structure. More...

void	trx_purge_add_update_undo_to_history (trx_t trx, trx_undo_ptr_t undo_ptr, page_t undo_page, bool update_rseg_history_len, ulint n_added_logs, mtr_t mtr)
	in: mtr More...

ulint	trx_purge (ulint n_purge_threads, ulint limit, bool truncate)
	This function runs a purge batch. More...

void	trx_purge_stop (void)
	Stop purge and wait for it to stop, move to PURGE_STATE_STOP. More...

void	trx_purge_run (void)
	Resume purge, move to PURGE_STATE_RUN. More...

purge_state_t	trx_purge_state (void)
	Get the purge state. More...

bool	undo::is_reserved (space_id_t space_id)
	Check if the space_id is an undo space ID in the reserved range. More...

space_id_t	undo::num2id (space_id_t space_num, size_t ndx)
	Convert an undo space number (from 1 to 127) into the undo space_id, given an index indicating which space_id from the pool assigned to that undo number. More...

space_id_t	undo::num2id (space_id_t space_num)
	Convert an undo space number (from 1 to 127) into an undo space_id. More...

space_id_t	undo::id2num (space_id_t space_id)
	Convert an undo space ID into an undo space number. More...

space_id_t	undo::id2next_id (space_id_t space_id)

void	undo::init_space_id_bank ()
	Initialize the undo tablespace space_id bank which is a lock free repository for information about the space IDs used for undo tablespaces. More...

void	undo::use_space_id (space_id_t space_id)
	Note that the undo space number for a space ID is being used. More...

space_id_t	undo::use_next_space_id (space_id_t space_num)
	Mark that the given undo space number is being used and return the next available space_id for that space number. More...

void	undo::unuse_space_id (space_id_t space_id)
	Mark an undo number associated with a given space_id as unused and available to be reused. More...

space_id_t	undo::next_space_id (space_id_t space_id, space_id_t space_num)
	Given a valid undo space_id or SPACE_UNKNOWN, return the next space_id for the given space number. More...

space_id_t	undo::next_space_id (space_id_t space_id)
	Given a valid undo space_id, return the next space_id for that space number. More...

space_id_t	undo::get_next_available_space_num ()
	Return the next available undo space ID to be used for a new explicit undo tablespaces. More...

char *	undo::make_space_name (space_id_t space_id)
	Build a standard undo tablespace name from a space_id. More...

char *	undo::make_file_name (space_id_t space_id)
	Build a standard undo tablespace file name from a space_id. More...

void	undo::inject_crash (const char *injection_point_name)
	Inject a crash if a certain SET GLOBAL DEBUG has been set. More...

dberr_t	undo::start_logging (Tablespace *undo_space)
	Create the truncate log file. More...

void	undo::done_logging (space_id_t space_num)
	Mark completion of undo truncate action by writing magic number to the log file and then removing it from the disk. More...

bool	undo::is_active_truncate_log_present (space_id_t space_num)
	Check if TRUNCATE_DDL_LOG file exist. More...

void	undo::add_space_to_construction_list (space_id_t space_id)
	Add undo tablespace to s_under_construction vector. More...

void	undo::clear_construction_list ()
	Clear the s_under_construction vector. More...

bool	undo::is_under_construction (space_id_t space_id)
	Is an undo tablespace under construction at the moment. More...

void	undo::set_active (space_id_t space_id)
	Set an undo tablespace active. More...

bool	undo::is_active (space_id_t space_id, bool get_latch=true)

Variables
trx_purge_t *	purge_sys
	The global data structure coordinating a purge. More...

const uint32_t	undo::s_magic = 76845412
	Magic Number to indicate truncate action is complete. More...

const char *const	undo::s_log_prefix = "undo_"
	Truncate Log file Prefix. More...

const char *const	undo::s_log_ext = "trunc.log"
	Truncate Log file Extension. More...

struct space_id_account *	undo::space_id_bank
	List of currently used undo space IDs for each undo space number along with a boolean showing whether the undo space number is in use. More...

ib_mutex_t	undo::ddl_mutex
	Mutex for serializing undo tablespace related DDL. More...

Tablespaces *	undo::spaces
	A global object that contains a vector of undo::Tablespace structs. More...

Space_Ids	undo::s_under_construction
	list of undo tablespaces that need header pages and rollback segments written to them at startup. More...

constexpr ulint	undo::TRUNCATE_FREQUENCY = 128

Detailed Description

Purge old versions.

Created 3/26/1996 Heikki Tuuri

Enumeration Type Documentation

◆ purge_state_t

enum purge_state_t

Purge states.

Enumerator
PURGE_STATE_INIT	Purge instance created.
PURGE_STATE_RUN	Purge should be running.
PURGE_STATE_STOP	Purge should be stopped.
PURGE_STATE_EXIT	Purge has been shutdown.
PURGE_STATE_DISABLED	Purge was never started.

Function Documentation

◆ trx_purge()

ulint trx_purge	(	ulint	n_purge_threads,
		ulint	batch_size,
		bool	truncate
	)

This function runs a purge batch.

Returns: number of undo log pages handled in the batch in: truncate history if true; number of undo log pages handled in the batch

Parameters

n_purge_threads	in: number of purge tasks to submit to the work queue
batch_size	in: the maximum number of records to purge in one batch
truncate	in: truncate history if true

◆ trx_purge_add_update_undo_to_history()

void trx_purge_add_update_undo_to_history	(	trx_t *	trx,
		trx_undo_ptr_t *	undo_ptr,
		page_t *	undo_page,
		bool	update_rseg_history_len,
		ulint	n_added_logs,
		mtr_t *	mtr
	)

in: mtr

Removes the update undo log segment from the rseg slot if it is too big for reuse.

Parameters

trx	in: transaction
undo_ptr	in/out: update undo log.
undo_page	in: update undo log header page, x-latched
update_rseg_history_len	in: if true: update rseg history len else skip updating it.
n_added_logs	in: number of logs added
mtr	in: mtr

◆ trx_purge_get_log_from_hist()

static fil_addr_t trx_purge_get_log_from_hist ( fil_addr_t node_addr )

inlinestatic

Calculates the file address of an undo log header when we have the file address of its history list node.

Returns: file address of the log in: file address of the history list node of the log

◆ trx_purge_run()

void trx_purge_run ( void )

Resume purge, move to PURGE_STATE_RUN.

◆ trx_purge_state()

purge_state_t trx_purge_state ( void )

Get the purge state.

Returns: purge state.

◆ trx_purge_stop()

void trx_purge_stop ( void )

Stop purge and wait for it to stop, move to PURGE_STATE_STOP.

◆ trx_purge_sys_close()

void trx_purge_sys_close ( void )

Frees the global purge system control structure.

◆ trx_purge_sys_initialize()

void trx_purge_sys_initialize	(	uint32_t	n_purge_threads,
		purge_pq_t *	purge_queue
	)

Creates the global purge system control structure and inits the history mutex.

Parameters

[in]	n_purge_threads	number of purge threads
[in,out]	purge_queue	UNDO log min binary heap

◆ trx_purge_sys_mem_create()

void trx_purge_sys_mem_create ( )

Initialize in-memory purge structures.

Variable Documentation

◆ purge_sys

trx_purge_t* purge_sys

extern

The global data structure coordinating a purge.

Classes

Namespaces

Enumerations

Functions

Variables

Detailed Description

Enumeration Type Documentation

◆ purge_state_t

Function Documentation

◆ trx_purge()

◆ trx_purge_add_update_undo_to_history()

◆ trx_purge_get_log_from_hist()

◆ trx_purge_run()

◆ trx_purge_state()

◆ trx_purge_stop()

◆ trx_purge_sys_close()

◆ trx_purge_sys_initialize()

◆ trx_purge_sys_mem_create()

Variable Documentation

◆ purge_sys