org.infinispan.util.concurrent.locks.impl

Class InfinispanLock

java.lang.Object

org.infinispan.util.concurrent.locks.impl.InfinispanLock

public class InfinispanLock
extends Object

A special lock for Infinispan cache.

The main different with the traditional Lock is allowing to use any object as lock owner. It is possible to use a Thread as lock owner that makes similar to Lock.

In addition, it has an asynchronous interface. acquire(Object, long, TimeUnit) will not acquire the lock immediately (except if it is free) but will return a ExtendedLockPromise. This promise allow to test if the lock is acquired asynchronously and cancel the lock acquisition, without any blocking.

Since:

8.0

Author:

Pedro Ruivo

Constructor Summary

Constructors

Constructor and Description
InfinispanLock(Executor nonBlockingExecutor, TimeService timeService) Creates a new instance.
InfinispanLock(Executor nonBlockingExecutor, TimeService timeService, Runnable releaseRunnable) Creates a new instance.

Method Summary

Modifier and Type	Method and Description
ExtendedLockPromise	acquire(Object lockOwner, long time, TimeUnit timeUnit) It tries to acquire this lock.
boolean	containsLockOwner(Object lockOwner) It tests if the lock has the lock owner.
void	deadlockCheck(DeadlockChecker deadlockChecker) It forces a deadlock checking.
Object	getLockOwner()
boolean	isLocked() It checks if the lock is acquired.
void	release(Object lockOwner) It tries to release the lock held by lockOwner.
void	setTimeService(TimeService timeService) Tests purpose only!

Methods inherited from class java.lang.Object

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

Constructor Detail

InfinispanLock

public InfinispanLock(Executor nonBlockingExecutor,
                      TimeService timeService)

Creates a new instance.

Parameters:

nonBlockingExecutor - executor that is resumed upon after a lock has been acquired or times out if waiting

timeService - the TimeService to check for timeouts.

InfinispanLock

public InfinispanLock(Executor nonBlockingExecutor,
                      TimeService timeService,
                      Runnable releaseRunnable)

Creates a new instance.

Parameters:

nonBlockingExecutor - executor that is resumed upon after a lock has been acquired or times out if waiting

timeService - the TimeService to check for timeouts.

releaseRunnable - a Runnable that is invoked every time this lock is released.

Method Detail

setTimeService

public void setTimeService(TimeService timeService)

Tests purpose only!

acquire

public ExtendedLockPromise acquire(Object lockOwner,
                                   long time,
                                   TimeUnit timeUnit)

It tries to acquire this lock.

If it is invoked multiple times with the same owner, the same ExtendedLockPromise is returned until it has timed-out or release(Object) is invoked.

If the lock is free, it is immediately acquired, otherwise the lock owner is queued.

Parameters:

lockOwner - the lock owner who needs to acquire the lock.

time - the timeout value.

timeUnit - the timeout unit.

Returns:

an ExtendedLockPromise.

Throws:

NullPointerException - if lockOwner or timeUnit is null.

release

public void release(Object lockOwner)

It tries to release the lock held by lockOwner.

If the lock is not acquired (is waiting or timed out/deadlocked) by lockOwner, its ExtendedLockPromise is canceled. If lockOwner is the current lock owner, the lock is released and the next lock owner available will acquire the lock. If the lockOwner never tried to acquire the lock, this method does nothing.

Parameters:

lockOwner - the lock owner who wants to release the lock.

Throws:

NullPointerException - if lockOwner is null.

getLockOwner

public Object getLockOwner()

Returns:

the current lock owner or null if it is not acquired.

isLocked

public boolean isLocked()

It checks if the lock is acquired.

A false return value does not mean the lock is free since it may have queued lock owners.

Returns:

true if the lock is acquired.

deadlockCheck

public void deadlockCheck(DeadlockChecker deadlockChecker)

It forces a deadlock checking.

containsLockOwner

public boolean containsLockOwner(Object lockOwner)

It tests if the lock has the lock owner.

It return true if the lock owner is the current lock owner or it in the queue.

Parameters:

lockOwner - the lock owner to test.

Returns:

true if it contains the lock owner.