MySQL version of DBLockManager that supports shared locks. More...

Inheritance diagram for MySqlLockManager:

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Collaboration diagram for MySqlLockManager:

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Public Member Functions
	__construct (array $config)
	Construct a new instance from configuration.

Public Member Functions inherited from DBLockManager
	__destruct ()
	Make sure remaining locks get cleared for sanity.

Public Member Functions inherited from LockManager
	lock (array $paths, $type=self::LOCK_EX, $timeout=0)
	Lock the resources at the given abstract paths.

	lockByType (array $pathsByType, $timeout=0)
	Lock the resources at the given abstract paths.

	unlock (array $paths, $type=self::LOCK_EX)
	Unlock the resources at the given abstract paths.

	unlockByType (array $pathsByType)
	Unlock the resources at the given abstract paths.

Protected Member Functions
	doGetLocksOnServer ( $lockSrv, array $paths, $type)
	Get a connection to a lock DB and acquire locks on $paths.

	initConnection ( $lockDb, IDatabase $db)
	Do additional initialization for new lock DB connection.

	releaseAllLocks ()

Protected Member Functions inherited from DBLockManager
	cacheCheckFailures ( $lockDb)
	Checks if the DB has not recently had connection/query errors.

	cacheRecordFailure ( $lockDb)
	Log a lock request failure to the cache.

	freeLocksOnServer ( $lockSrv, array $pathsByType)
	Get a connection to a lock server and release locks on $paths.

	getConnection ( $lockDb)
	Get (or reuse) a connection to a lock DB.

	getLocksOnServer ( $lockSrv, array $pathsByType)

	getMissKey ( $lockDb)
	Get a cache key for recent query misses for a DB.

	isServerUp ( $lockSrv)

Protected Member Functions inherited from QuorumLockManager
	collectPledgeQuorum ( $bucket, callable $callback)
	Attempt to acquire pledges with the peers for a bucket.

	doLock (array $paths, $type)
	Lock resources with the given keys and lock type.

	doLockByType (array $pathsByType)

	doLockingRequestBucket ( $bucket, array $pathsByType)
	Attempt to acquire locks with the peers for a bucket.

	doUnlock (array $paths, $type)
	Unlock resources with the given keys and lock type.

	doUnlockByType (array $pathsByType)

	doUnlockingRequestBucket ( $bucket, array $pathsByType)
	Attempt to release locks with the peers for a bucket.

	getBucketFromPath ( $path)
	Get the bucket for resource path.

	releasePledges ( $bucket, callable $callback)
	Attempt to release pledges with the peers for a bucket.

Protected Member Functions inherited from LockManager
	normalizePathsByType (array $pathsByType)
	Normalize the $paths array by converting LOCK_UW locks into the appropriate type and removing any duplicated paths for each lock type.

	sha1Base16Absolute ( $path)
	Get the base 16 SHA-1 of a string, padded to 31 digits.

	sha1Base36Absolute ( $path)
	Get the base 36 SHA-1 of a string, padded to 31 digits.

Protected Attributes
array	$lockTypeMap
	Mapping of lock types to the type actually used.

Protected Attributes inherited from DBLockManager
IDatabase[]	$conns = []
	Map Database connections (DB name => Database)

array[] IDatabase[]	$dbServers
	Map of (DB names => server config or IDatabase)

	$lockExpiry

	$safeDelay

BagOStuff	$statusCache

Protected Attributes inherited from QuorumLockManager
array	$degradedBuckets = []
	Map of degraded buckets.

array	$srvsByBucket = []
	Map of bucket indexes to peer server lists.

Protected Attributes inherited from LockManager
	$domain

array	$locksHeld = []
	Map of (resource path => lock type => count)

	$lockTTL

array	$lockTypeMap
	Mapping of lock types to the type actually used.

LoggerInterface	$logger

string	$session
	Random 32-char hex number.

Additional Inherited Members
Public Attributes inherited from LockManager
const	LOCK_EX = 3

const	LOCK_SH = 1
	Lock types; stronger locks have higher values.

const	LOCK_UW = 2

Detailed Description

MySQL version of DBLockManager that supports shared locks.

Do NOT use this on connection handles that are also being used for anything else as the transaction isolation will be wrong and all the other changes will get rolled back when the locks release!

All lock servers must have the innodb table defined in maintenance/locking/filelocks.sql. All locks are non-blocking, which avoids deadlocks.

Definition at line 18 of file MySqlLockManager.php.

Constructor & Destructor Documentation

◆ __construct()

MySqlLockManager::__construct ( array $config )

Construct a new instance from configuration.

Parameters

array

$config

Parameters include:

dbServers : Associative array of DB names to server configuration. Configuration is an associative array that includes:
- host : DB server name
- dbname : DB name
- type : DB type (mysql,postgres,...)
- user : DB user
- password : DB user password
- tablePrefix : DB table prefix
- flags : DB flags; bitfield of IDatabase::DBO_* constants
dbsByBucket : Array of 1-16 consecutive integer keys, starting from 0, each having an odd-numbered list of DB names (peers) as values.
lockExpiry : Lock timeout (seconds) for dropped connections. [optional] This tells the DB server how long to wait before assuming connection failure and releasing all the locks for a session.
srvCache : A BagOStuff instance using APC or the like.

Reimplemented from DBLockManager.

Definition at line 26 of file MySqlLockManager.php.

Member Function Documentation

◆ doGetLocksOnServer()

MySqlLockManager::doGetLocksOnServer	(		$lockSrv,
		array	$paths,
			$type
	)

protected

Get a connection to a lock DB and acquire locks on $paths.

This does not use GET_LOCK() per https://bugs.mysql.com/bug.php?id=1118.

See also: DBLockManager::getLocksOnServer()

Parameters

string	$lockSrv
array	$paths
string	$type

Returns: StatusValue

Reimplemented from DBLockManager.

Definition at line 49 of file MySqlLockManager.php.

References $data, $keys, $path, LockManager\$session, $type, as, DBLockManager\getConnection(), and LockManager\sha1Base36Absolute().

◆ initConnection()

MySqlLockManager::initConnection	(		$lockDb,
		IDatabase	$db
	)

protected

Do additional initialization for new lock DB connection.

Parameters

string	$lockDb
IDatabase	$db

Exceptions

DBError

Reimplemented from DBLockManager.

Definition at line 32 of file MySqlLockManager.php.

References Wikimedia\Rdbms\IDatabase\query(), and Wikimedia\Rdbms\IDatabase\startAtomic().

◆ releaseAllLocks()

MySqlLockManager::releaseAllLocks ( )

protected

See also: QuorumLockManager::releaseAllLocks()

Returns: StatusValue

Reimplemented from QuorumLockManager.

Definition at line 126 of file MySqlLockManager.php.

References $e, and as.

Member Data Documentation

◆ $lockTypeMap

array MySqlLockManager::$lockTypeMap

protected

Initial value:

= [
        self::LOCK_SH => self::LOCK_SH,
        self::LOCK_UW => self::LOCK_SH,
        self::LOCK_EX => self::LOCK_EX
    ]

Mapping of lock types to the type actually used.

Definition at line 20 of file MySqlLockManager.php.

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

includes/filebackend/lockmanager/MySqlLockManager.php

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ __construct()

Member Function Documentation

◆ doGetLocksOnServer()

◆ initConnection()

◆ releaseAllLocks()

Member Data Documentation

◆ $lockTypeMap