Class MapGlobalLockProvider

All Implemented Interfaces:
GlobalLockProvider, Provider

public class MapGlobalLockProvider extends Object implements GlobalLockProvider
Implementing a GlobalLockProvider based on a map storage. This requires the map store to support the entity type MapLockEntity. One of the stores which supports this is the JPA Map Store. The store needs to support the uniqueness of entries in the lock area, see lock(String) for details.
Alexander Schwartz
  • Constructor Details

  • Method Details

    • withLock

      public <V> V withLock(String lockName, Duration timeToWaitForLock, KeycloakSessionTaskWithResult<V> task) throws LockAcquiringTimeoutException
      Description copied from interface: GlobalLockProvider
      Acquires a new non-reentrant global lock that is visible to all Keycloak nodes. If the lock was successfully acquired the method runs the task in a new transaction to ensure all data modified in task is committed to the stores before releasing the lock and returning to the caller.

      If there is another global lock with the same identifier (lockName) already acquired, this method waits until the lock is released, however, not more than timeToWaitForLock duration. If the lock is not acquired after timeToWaitForLock duration, the method throws LockAcquiringTimeoutException.

      When the execution of the task finishes, the acquired lock must be released regardless of the result.

      A note to implementors of the interface:

      To make sure acquiring/releasing the lock is visible to all Keycloak nodes it may be needed to run the code that acquires/releases the lock in a separate transactions. This means together the method can use 3 separate transactions, for example:

           try {
                                      innerSession -> /* run code that acquires the lock *\/)
               KeycloakModelUtils.runJobInTransactionWithResult(factory, task)
           } finally {
                                      innerSession -> /* run code that releases the lock *\/)
      Specified by:
      withLock in interface GlobalLockProvider
      Type Parameters:
      V - Type of object returned by the task
      lockName - Identifier used for acquiring lock. Can be any non-null string.
      timeToWaitForLock - Duration this method waits until it gives up acquiring the lock. If null, each implementation should provide some default duration, for example, using a configuration option.
      task - The task that will be executed under the acquired lock
      Value returned by the task
      LockAcquiringTimeoutException - When the method waits for timeToWaitForLock duration and the lock is still not available to acquire.
    • forceReleaseAllLocks

      public void forceReleaseAllLocks()
      Description copied from interface: GlobalLockProvider
      Releases all locks acquired by this GlobalLockProvider.

      This method unlocks all existing locks acquired by this provider regardless of the thread or Keycloak instance that originally acquired them.

      Specified by:
      forceReleaseAllLocks in interface GlobalLockProvider
    • close

      public void close()
      Specified by:
      close in interface Provider