class PersistentDatabaseLockBackend in Drupal 9

Defines the persistent database lock backend. This backend is global for this Drupal installation.

Hierarchy

• class \Drupal\Core\Lock\LockBackendAbstract implements LockBackendInterface
  • class \Drupal\Core\Lock\DatabaseLockBackend
    • class \Drupal\Core\Lock\PersistentDatabaseLockBackend

Related topics

Locking mechanisms

Functions to coordinate long operations across requests.

1 string reference to 'PersistentDatabaseLockBackend'

core.services.yml in core/core.services.yml

core/core.services.yml

1 service uses PersistentDatabaseLockBackend

lock.persistent in core/core.services.yml

Drupal\Core\Lock\PersistentDatabaseLockBackend

File

core/lib/Drupal/Core/Lock/PersistentDatabaseLockBackend.php, line 13

Namespace

Drupal\Core\Lock

class PersistentDatabaseLockBackend extends DatabaseLockBackend {

  /**
   * Constructs a new PersistentDatabaseLockBackend.
   *
   * @param \Drupal\Core\Database\Connection $database
   *   The database connection.
   */
  public function __construct(Connection $database) {

    // Do not call the parent constructor to avoid registering a shutdown
    // function that releases all the locks at the end of a request.
    $this->database = $database;

    // Set the lockId to a fixed string to make the lock ID the same across
    // multiple requests. The lock ID is used as a page token to relate all the
    // locks set during a request to each other.
    // @see \Drupal\Core\Lock\LockBackendInterface::getLockId()
    $this->lockId = 'persistent';
  }

}

Members

Name	Modifiers	Type	Description	Overrides
DatabaseLockBackend::$database	protected	property	The database connection.
DatabaseLockBackend::acquire	public	function	Acquires a lock. Overrides LockBackendInterface::acquire
DatabaseLockBackend::catchException	protected	function	Act on an exception when semaphore might be stale.
DatabaseLockBackend::ensureTableExists	protected	function	Check if the semaphore table exists and create it if not.
DatabaseLockBackend::lockMayBeAvailable	public	function	Checks if a lock is available for acquiring. Overrides LockBackendInterface::lockMayBeAvailable
DatabaseLockBackend::normalizeName	protected	function	Normalizes a lock name in order to comply with database limitations.
DatabaseLockBackend::release	public	function	Releases the given lock. Overrides LockBackendInterface::release
DatabaseLockBackend::releaseAll	public	function	Releases all locks for the given lock token identifier. Overrides LockBackendInterface::releaseAll
DatabaseLockBackend::schemaDefinition	public	function	Defines the schema for the semaphore table.
DatabaseLockBackend::TABLE_NAME		constant	The database table name.
LockBackendAbstract::$lockId	protected	property	Current page lock token identifier.
LockBackendAbstract::$locks	protected	property	Existing locks for this page.
LockBackendAbstract::getLockId	public	function	Gets the unique page token for locks. Overrides LockBackendInterface::getLockId
LockBackendAbstract::wait	public	function	Waits a short amount of time before a second lock acquire attempt. Overrides LockBackendInterface::wait
PersistentDatabaseLockBackend::__construct	public	function	Constructs a new PersistentDatabaseLockBackend. Overrides DatabaseLockBackend::__construct