MediaWiki  1.29.1
MemcLockManager Class Reference

Manage locks using memcached servers. More...

Inheritance diagram for MemcLockManager:
Collaboration diagram for MemcLockManager:

Public Member Functions

 __construct (array $config)
 Construct a new instance from configuration. More...
 
 __destruct ()
 Make sure remaining locks get cleared for sanity. More...
 
- Public Member Functions inherited from LockManager
 lock (array $paths, $type=self::LOCK_EX, $timeout=0)
 Lock the resources at the given abstract paths. More...
 
 lockByType (array $pathsByType, $timeout=0)
 Lock the resources at the given abstract paths. More...
 
 unlock (array $paths, $type=self::LOCK_EX)
 Unlock the resources at the given abstract paths. More...
 
 unlockByType (array $pathsByType)
 Unlock the resources at the given abstract paths. More...
 

Protected Member Functions

 acquireMutexes (MemcachedBagOStuff $memc, array $keys)
 
 freeLocksOnServer ( $lockSrv, array $pathsByType)
 Get a connection to a lock server and release locks on $paths. More...
 
 getCache ( $lockSrv)
 Get the MemcachedBagOStuff object for a $lockSrv. More...
 
 getLocksOnServer ( $lockSrv, array $pathsByType)
 Get a connection to a lock server and acquire locks. More...
 
 isServerUp ( $lockSrv)
 
 newLockArray ()
 
 recordKeyForPath ( $path)
 
 releaseAllLocks ()
 
 releaseMutexes (MemcachedBagOStuff $memc, array $keys)
 
 sanitizeLockArray ( $a)
 
- Protected Member Functions inherited from QuorumLockManager
 collectPledgeQuorum ( $bucket, callable $callback)
 Attempt to acquire pledges with the peers for a bucket. More...
 
 doLock (array $paths, $type)
 Lock resources with the given keys and lock type. More...
 
 doLockByType (array $pathsByType)
 
 doLockingRequestBucket ( $bucket, array $pathsByType)
 Attempt to acquire locks with the peers for a bucket. More...
 
 doUnlock (array $paths, $type)
 Unlock resources with the given keys and lock type. More...
 
 doUnlockByType (array $pathsByType)
 
 doUnlockingRequestBucket ( $bucket, array $pathsByType)
 Attempt to release locks with the peers for a bucket. More...
 
 getBucketFromPath ( $path)
 Get the bucket for resource path. More...
 
 releasePledges ( $bucket, callable $callback)
 Attempt to release pledges with the peers for a bucket. More...
 
- 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. More...
 
 sha1Base16Absolute ( $path)
 Get the base 16 SHA-1 of a string, padded to 31 digits. More...
 
 sha1Base36Absolute ( $path)
 Get the base 36 SHA-1 of a string, padded to 31 digits. More...
 

Protected Attributes

MemcachedBagOStuff[] $cacheServers = []
 Map of (server name => MemcachedBagOStuff) More...
 
array $lockTypeMap
 Mapping of lock types to the type actually used. More...
 
HashBagOStuff $statusCache
 Server status cache. More...
 
- Protected Attributes inherited from QuorumLockManager
array $degradedBuckets = []
 Map of degraded buckets. More...
 
array $srvsByBucket = []
 Map of bucket indexes to peer server lists. More...
 
- Protected Attributes inherited from LockManager
 $domain
 
array $locksHeld = []
 Map of (resource path => lock type => count) More...
 
 $lockTTL
 
array $lockTypeMap
 Mapping of lock types to the type actually used. More...
 
LoggerInterface $logger
 
string $session
 Random 32-char hex number. More...
 

Additional Inherited Members

- Public Attributes inherited from LockManager
const LOCK_EX = 3
 
const LOCK_SH = 1
 Lock types; stronger locks have higher values. More...
 
const LOCK_UW = 2
 

Detailed Description

Manage locks using memcached servers.

Version of LockManager based on using memcached servers. This is meant for multi-wiki systems that may share files. All locks are non-blocking, which avoids deadlocks.

All lock requests for a resource, identified by a hash string, will map to one bucket. Each bucket maps to one or several peer servers, each running memcached. A majority of peers must agree for a lock to be acquired.

Since
1.20

Definition at line 39 of file MemcLockManager.php.

Constructor & Destructor Documentation

◆ __construct()

MemcLockManager::__construct ( array  $config)

Construct a new instance from configuration.

Parameters
array$configParameters include:
  • lockServers : Associative array of server names to "<IP>:<port>" strings.
  • srvsByBucket : Array of 1-16 consecutive integer keys, starting from 0, each having an odd-numbered list of server names (peers) as values.
  • memcConfig : Configuration array for MemcachedBagOStuff::construct() with an additional 'class' parameter specifying which MemcachedBagOStuff subclass to use. The server names will be injected. [optional]
Exceptions
Exception

Reimplemented from LockManager.

Definition at line 64 of file MemcLockManager.php.

References $name, $params, and as.

◆ __destruct()

MemcLockManager::__destruct ( )

Make sure remaining locks get cleared for sanity.

Definition at line 348 of file MemcLockManager.php.

References $path, as, captcha-old\count, and QuorumLockManager\doUnlock().

Member Function Documentation

◆ acquireMutexes()

MemcLockManager::acquireMutexes ( MemcachedBagOStuff  $memc,
array  $keys 
)
protected
Parameters
MemcachedBagOStuff$memc
array$keysList of keys to acquire
Returns
bool

Definition at line 301 of file MemcLockManager.php.

References $keys, MemcachedBagOStuff\add(), as, captcha-old\count, releaseMutexes(), and use.

Referenced by freeLocksOnServer(), and getLocksOnServer().

◆ freeLocksOnServer()

MemcLockManager::freeLocksOnServer (   $lockSrv,
array  $pathsByType 
)
protected

Get a connection to a lock server and release locks on $paths.

Subclasses must effectively implement this or releaseAllLocks().

Parameters
string$lockSrv
array$pathsByTypeMap of LockManager::LOCK_* constants to lists of paths
Returns
StatusValue

Reimplemented from QuorumLockManager.

Definition at line 162 of file MemcLockManager.php.

References $keys, LockManager\$locksHeld, $path, $status, $type, acquireMutexes(), as, getCache(), StatusValue\newGood(), newLockArray(), recordKeyForPath(), releaseMutexes(), and sanitizeLockArray().

◆ getCache()

MemcLockManager::getCache (   $lockSrv)
protected

Get the MemcachedBagOStuff object for a $lockSrv.

Parameters
string$lockSrvServer name
Returns
MemcachedBagOStuff|null

Definition at line 250 of file MemcLockManager.php.

Referenced by freeLocksOnServer(), getLocksOnServer(), and isServerUp().

◆ getLocksOnServer()

MemcLockManager::getLocksOnServer (   $lockSrv,
array  $pathsByType 
)
protected

Get a connection to a lock server and acquire locks.

Parameters
string$lockSrv
array$pathsByTypeMap of LockManager::LOCK_* constants to lists of paths
Returns
StatusValue

Reimplemented from QuorumLockManager.

Definition at line 87 of file MemcLockManager.php.

References $keys, LockManager\$locksHeld, LockManager\$lockTTL, $path, LockManager\$session, $status, $type, acquireMutexes(), as, getCache(), StatusValue\newGood(), newLockArray(), recordKeyForPath(), releaseMutexes(), and sanitizeLockArray().

◆ isServerUp()

MemcLockManager::isServerUp (   $lockSrv)
protected
See also
QuorumLockManager::isServerUp()
Parameters
string$lockSrv
Returns
bool

Reimplemented from QuorumLockManager.

Definition at line 240 of file MemcLockManager.php.

References getCache().

◆ newLockArray()

MemcLockManager::newLockArray ( )
protected
Returns
array An empty lock structure for a key

Definition at line 278 of file MemcLockManager.php.

Referenced by freeLocksOnServer(), getLocksOnServer(), and sanitizeLockArray().

◆ recordKeyForPath()

MemcLockManager::recordKeyForPath (   $path)
protected
Parameters
string$path
Returns
string

Definition at line 271 of file MemcLockManager.php.

References $path, and LockManager\sha1Base36Absolute().

Referenced by freeLocksOnServer(), and getLocksOnServer().

◆ releaseAllLocks()

MemcLockManager::releaseAllLocks ( )
protected
See also
QuorumLockManager::releaseAllLocks()
Returns
StatusValue

Reimplemented from QuorumLockManager.

Definition at line 231 of file MemcLockManager.php.

References StatusValue\newGood().

◆ releaseMutexes()

MemcLockManager::releaseMutexes ( MemcachedBagOStuff  $memc,
array  $keys 
)
protected
Parameters
MemcachedBagOStuff$memc
array$keysList of acquired keys

Definition at line 339 of file MemcLockManager.php.

References $keys, as, and MemcachedBagOStuff\delete().

Referenced by acquireMutexes(), freeLocksOnServer(), and getLocksOnServer().

◆ sanitizeLockArray()

MemcLockManager::sanitizeLockArray (   $a)
protected
Parameters
array$a
Returns
array An empty lock structure for a key

Definition at line 286 of file MemcLockManager.php.

References newLockArray().

Referenced by freeLocksOnServer(), and getLocksOnServer().

Member Data Documentation

◆ $cacheServers

MemcachedBagOStuff [] MemcLockManager::$cacheServers = []
protected

Map of (server name => MemcachedBagOStuff)

Definition at line 48 of file MemcLockManager.php.

◆ $lockTypeMap

array MemcLockManager::$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 41 of file MemcLockManager.php.

◆ $statusCache

HashBagOStuff MemcLockManager::$statusCache
protected

Server status cache.

Definition at line 50 of file MemcLockManager.php.


The documentation for this class was generated from the following file:
LockManager\LOCK_SH
const LOCK_SH
Lock types; stronger locks have higher values.
Definition: LockManager.php:68
LockManager\LOCK_EX
const LOCK_EX
Definition: LockManager.php:70