Gtid_state Class Reference

#include <rpl_gtid.h>

List of all members.

Public Member Functions
	Gtid_state (Checkable_rwlock *_sid_lock, Sid_map *_sid_map)
int	init ()
void	clear ()
bool	is_logged (const Gtid &gtid) const
my_thread_id	get_owner (const Gtid &gtid) const
enum_return_status	acquire_ownership (THD *thd, const Gtid &gtid)
enum_return_status	update_on_flush (THD *thd)
void	update_on_commit (THD *thd)
void	update_on_rollback (THD *thd)
rpl_gno	get_automatic_gno (rpl_sidno sidno) const
void	lock_sidno (rpl_sidno sidno)
	Locks a mutex for the given SIDNO.
void	unlock_sidno (rpl_sidno sidno)
	Unlocks a mutex for the given SIDNO.
void	broadcast_sidno (rpl_sidno sidno)
	Broadcasts updates for the given SIDNO.
void	assert_sidno_lock_owner (rpl_sidno sidno)
	Assert that we own the given SIDNO.
void	wait_for_gtid (THD *thd, const Gtid &gtid)
enum_return_status	ensure_sidno ()
enum_return_status	add_lost_gtids (const char *text)
const Gtid_set *	get_logged_gtids () const
	Return a pointer to the Gtid_set that contains the logged groups.
const Gtid_set *	get_lost_gtids () const
	Return a pointer to the Gtid_set that contains the logged groups.
const Owned_gtids *	get_owned_gtids () const
	Return a pointer to the Owned_gtids that contains the owned groups.
rpl_sidno	get_server_sidno () const
	Return the server's SID's SIDNO.
const rpl_sid &	get_server_sid () const
	Return the server's SID.
size_t	get_max_string_length () const
int	to_string (char *buf) const
	Debug only: Generate a string in the given buffer and return the length.
char *	to_string () const
	Debug only: return a newly allocated string, or NULL on out-of-memory.
void	print () const
	Debug only: print this Gtid_state to stdout.
void	dbug_print (const char *text="") const

---

Detailed Description

Represents the state of the group log: the set of logged groups, the set of lost groups, the set of owned groups, the owner of each owned group, and a Mutex_cond_array that protects updates to groups of each SIDNO.

Locking:

This data structure has a read-write lock that protects the number of SIDNOs, and a Mutex_cond_array that contains one mutex per SIDNO. The rwlock is always the global_sid_lock.

Access methods generally assert that the caller already holds the appropriate lock:

• before accessing any global data, hold at least the rdlock.

• before accessing a specific SIDNO in a Gtid_set or Owned_gtids (e.g., calling Gtid_set::_add_gtid(Gtid)), hold either the rdlock and the SIDNO's mutex lock; or the wrlock. If you need to hold multiple mutexes, they must be acquired in order of increasing SIDNO.

• before starting an operation that needs to access all SIDs (e.g. Gtid_set::to_string()), hold the wrlock.

The access type (read/write) does not matter; the write lock only implies that the entire data structure is locked whereas the read lock implies that everything except SID-specific data is locked.

---

Constructor & Destructor Documentation

Gtid_state::Gtid_state	(	Checkable_rwlock *	_sid_lock,
		Sid_map *	_sid_map
	)		[inline]

Constructs a new Gtid_state object.

Parameters:

_sid_lock	Read-write lock that protects updates to the number of SIDs.
_sid_map	Sid_map used by this group log.

---

Member Function Documentation

enum_return_status Gtid_state::acquire_ownership	(	THD *	thd,
		const Gtid &	gtid
	)

Acquires ownership of the given GTID, on behalf of the given thread.

The caller must lock the SIDNO before invoking this function.

Parameters:

thd	The thread that will own the GTID.
gtid	The Gtid to acquire ownership of.

Returns:

RETURN_STATUS_OK or RETURN_STATUS_REPORTED_ERROR.

enum_return_status Gtid_state::add_lost_gtids

(

const char *

text

)

Adds the given Gtid_set that contains the groups in the given string to lost_gtids and logged_gtids, since lost_gtids must be a subset of executed_gtids. Requires that the write lock on sid_locks is held.

Parameters:

text	The string to parse, see Gtid_set:add_gtid_text(const char *, bool) for format details.

Returns:

RETURN_STATUS_OK or RETURN_STATUS_REPORTED_ERROR.

void Gtid_state::clear

(

)

Reset the state after RESET MASTER: remove all logged and lost groups, but keep owned groups as they are.

The caller must hold the write lock on sid_lock before calling this function.

void Gtid_state::dbug_print

(

const char *

text = ""

)

const [inline]

Print this Gtid_state to the trace file if debug is enabled; no-op otherwise.

enum_return_status Gtid_state::ensure_sidno

(

)

Ensure that owned_gtids, logged_gtids, lost_gtids, and sid_locks have room for at least as many SIDNOs as sid_map.

This function must only be called in one place: Sid_map::add_sid().

Requires that the write lock on sid_locks is held. If any object needs to be resized, then the lock will be temporarily upgraded to a write lock and then degraded to a read lock again; there will be a short period when the lock is not held at all.

Returns:

RETURN_STATUS_OK or RETURN_STATUS_REPORTED_ERROR.

rpl_gno Gtid_state::get_automatic_gno

(

rpl_sidno

sidno

)

const

Allocates a GNO for an automatically numbered group.

Parameters:

sidno

The group's SIDNO.

Return values:

negative	the numeric value of GS_ERROR_OUT_OF_MEMORY
other	The GNO for the group.

size_t Gtid_state::get_max_string_length

(

)

const [inline]

Debug only: Returns an upper bound on the length of the string generated by to_string(), not counting '\0'. The actual length may be shorter.

my_thread_id Gtid_state::get_owner

(

const Gtid &

gtid

)

const [inline]

Returns the owner of the given GTID, or 0 if the group is not owned.

Parameters:

gtid	The Gtid to check.

Returns:

my_thread_id of the thread that owns the group, or 0 if the group is not owned.

int Gtid_state::init

(

)

Add @GLOBAL.SERVER_UUID to this binlog's Sid_map.

This can't be done in the constructor because the constructor is invoked at server startup before SERVER_UUID is initialized.

The caller must hold the read lock or write lock on sid_locks before invoking this function.

Return values:

0	Success
1	Error (out of memory or IO error).

bool Gtid_state::is_logged

(

const Gtid &

gtid

)

const [inline]

Returns true if the given GTID is logged.

Parameters:

gtid	The Gtid to check.

Return values:

true	The group is logged in the binary log.
false	The group is not logged in the binary log.

void Gtid_state::update_on_commit

(

THD *

thd

)

Remove the GTID owned by thread from owned GTIDs, stating that thd->owned_gtid was committed.

This will:

• remove owned GTID from owned_gtids;
• remove all owned GTIDS from thd->owned_gtid and thd->owned_gtid_set;

Parameters:

thd	Thread for which owned groups are updated.

enum_return_status Gtid_state::update_on_flush

(

THD *

thd

)

Update the state after the given thread has flushed cache to binlog.

This will:

• release ownership of all GTIDs owned by the THD;
• add all GTIDs in the Group_cache to logged_gtids;
• send a broadcast on the condition variable for every sidno for which we released ownership.

Parameters:

thd	Thread for which owned groups are updated.

void Gtid_state::update_on_rollback

(

THD *

thd

)

Update the state after the given thread has rollbacked.

This will:

• release ownership of all GTIDs owned by the THD;
• remove owned GTID from owned_gtids;
• remove all owned GTIDS from thd->owned_gtid and thd->owned_gtid_set;
• send a broadcast on the condition variable for every sidno for which we released ownership.

Parameters:

thd	Thread for which owned groups are updated.

void Gtid_state::wait_for_gtid	(	THD *	thd,
		const Gtid &	gtid
	)

Waits until the given GTID is not owned by any other thread.

This requires that the caller holds a read lock on sid_lock. It will release the lock before waiting; neither global_sid_lock nor the mutex lock on SIDNO will not be held when this function returns.

Parameters:

thd	THD object of the caller.
g	Gtid to wait for.

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

• rpl_gtid.h
• rpl_gtid_state.cc