MySqlLockManager Class Reference

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

Inheritance diagram for MySqlLockManager:

Collaboration diagram for MySqlLockManager:

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.
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.Subclasses must effectively implement this or releaseAllLocks(). Parameters string $lockSrv array $pathsByType Map of LockManager::LOCK_* constants to lists of paths Returns StatusValue
	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.
const	CLI_LOCK_TTL = 3600
	Default lock TTL in CLI mode.
const	MAX_LOCK_TTL = 2 * 3600
	Max expected lock expiry in any context.
const	MIN_GUESSED_LOCK_TTL = 5 * 60
	The minimum lock TTL if it is guessed from max_execution_time rather than configured.
const	MIN_LOCK_TTL = 5
	Minimum lock TTL.

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.

Stability: stable

to call

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 : An array of up to 16 arrays, each containing the DB names in a bucket. Each bucket should have an odd number of servers. If omitted, all DBs will be in one bucket. (optional). 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 $keys, $path, LockManager\$session, $type, DBLockManager\getConnection(), and LockManager\sha1Base36Absolute().

initConnection()

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

protected

Do additional initialization for new lock DB connection.

Stability: stable

to override

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 118 of file MySqlLockManager.php.

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.

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

• includes/filebackend/lockmanager/MySqlLockManager.php