Package org.keycloak.models.locking

Interface GlobalLockProvider

All Superinterfaces:

Provider

All Known Implementing Classes:

DBLockGlobalLockProvider, HotRodGlobalLockProvider, MapGlobalLockProvider

public interface GlobalLockProvider
extends Provider

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	GlobalLockProvider.Constants

Method Summary

Modifier and Type	Method	Description
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.
default <V> V	withLock(String lockName, KeycloakSessionTaskWithResult<V> task)	Acquires a new non-reentrant global lock that is visible to all Keycloak nodes.

Methods inherited from interface org.keycloak.provider.Provider

close

Method Detail

withLock

default <V> V withLock(String lockName,
                       KeycloakSessionTaskWithResult<V> task)
                throws LockAcquiringTimeoutException

Acquires a new non-reentrant global lock that is visible to all Keycloak nodes. Effectively the same as withLock(lockName, null, task)

Type Parameters:

V - Type of object returned by the task

Parameters:

lockName - Identifier used for acquiring lock. Can be any non-null string.

task - The task that will be executed under the acquired lock

Returns:

Value returned by the task

Throws:

LockAcquiringTimeoutException - When acquiring the global lock times out (see Javadoc of withLock(String, Duration, KeycloakSessionTaskWithResult) for more details on how the time duration is determined)

NullPointerException - When lockName is null.

withLock

<V> V withLock(String lockName,
               Duration timeToWaitForLock,
               KeycloakSessionTaskWithResult<V> task)
        throws LockAcquiringTimeoutException

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 *\/)
     }
 

Type Parameters:

V - Type of object returned by the task

Parameters:

lockName - Identifier used for acquiring lock. Can be any non-null string.

task - The task that will be executed under the acquired lock

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.

Returns:

Value returned by the task

Throws:

LockAcquiringTimeoutException - When the method waits for timeToWaitForLock duration and the lock is still not available to acquire.

NullPointerException - When lockName is null.

forceReleaseAllLocks

void forceReleaseAllLocks()

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.