Package org.keycloak.models.map.lock

Class MapGlobalLockProvider

java.lang.Object

org.keycloak.models.map.lock.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.

Author:

Alexander Schwartz

Nested Class Summary

Nested classes/interfaces inherited from interface org.keycloak.models.locking.GlobalLockProvider

GlobalLockProvider.Constants

Constructor Summary

Constructors

Constructor	Description
MapGlobalLockProvider(KeycloakSession session, long defaultTimeoutMilliseconds, Supplier<MapStorage<MapLockEntity,MapLockEntity>> lockStoreSupplier)

Method Summary

Modifier and Type	Method	Description
void	close()
void	forceReleaseAllLocks()	Releases all locks acquired by this GlobalLockProvider.
<V> V	withLock(String lockName, Duration timeToWaitForLock, KeycloakSessionTaskWithResult<V> task)	Acquires a new non-reentrant global lock that is visible to all Keycloak nodes.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.keycloak.models.locking.GlobalLockProvider

withLock

Constructor Detail

MapGlobalLockProvider

public MapGlobalLockProvider(KeycloakSession session,
                             long defaultTimeoutMilliseconds,
                             Supplier<MapStorage<MapLockEntity,MapLockEntity>> lockStoreSupplier)

Method Detail

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 {
         KeycloakModelUtils.runJobInTransaction(factory,
                                innerSession -> /* run code that acquires the lock *\/)

         KeycloakModelUtils.runJobInTransactionWithResult(factory, task)
     } finally {
         KeycloakModelUtils.runJobInTransaction(factory,
                                innerSession -> /* run code that releases the lock *\/)
     }
 

Specified by:

withLock in interface GlobalLockProvider

Type Parameters:

V - Type of object returned by the task

Parameters:

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

Returns:

Value returned by the task

Throws:

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