Package org.infinispan.lock.impl.lock

Class ClusteredLockImpl

java.lang.Object

org.infinispan.lock.impl.lock.ClusteredLockImpl

All Implemented Interfaces:

ClusteredLock

public class ClusteredLockImpl
extends Object
implements ClusteredLock

Implements ClusteredLock interface.

This lock implements a non reentrant where the ownership is OwnershipLevel.NODE.

Non reentrant lock, Owner Node

Originator of the requests is the Address of the EmbeddedCacheManager

When a lock is acquired by a Node, it cannot be re-acquired, even by the actual node til the lock is released.

The lock can be unlocked only by the lock owner, in this case the node

lock method does not expire til the lock is acquired, so this can cause thread starvation in the actual implementation

Partition handling

Since:

9.2

Author:

Katia Aresti, karesti@redhat.com

See Also:

• Infinispan documentation

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
class	ClusteredLockImpl.LockRequestHolder
class	ClusteredLockImpl.RequestHolder<E>
class	ClusteredLockImpl.TryLockRequestHolder

Constructor Summary

Constructors

Constructor	Description
ClusteredLockImpl(String name, ClusteredLockKey lockKey, org.infinispan.AdvancedCache<ClusteredLockKey,ClusteredLockValue> clusteredLockCache, EmbeddedClusteredLockManager clusteredLockManager)

Method Summary

Modifier and Type	Method	Description
String	getName()
Object	getOriginator()
CompletableFuture<Boolean>	isLocked()	Returns a CompletableFuture<Boolean> holding true when the lock is locked and false when the lock is released.
CompletableFuture<Boolean>	isLockedByMe()	Returns a CompletableFuture<Boolean> holding true when the lock is owned by the caller and false when the lock is owned by someone else or it's released.
CompletableFuture<Void>	lock()	Acquires the lock.
void	stop()
String	toString()
CompletableFuture<Boolean>	tryLock()	Acquires the lock only if it is free at the time of invocation.
CompletableFuture<Boolean>	tryLock(long time, TimeUnit unit)	If the lock is available this method returns immediately with the CompletableFuture holding the value true.
CompletableFuture<Void>	unlock()	Releases the lock.

Methods inherited from class java.lang.Object

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

Constructor Details

ClusteredLockImpl

public ClusteredLockImpl(String name,
 ClusteredLockKey lockKey,
 org.infinispan.AdvancedCache<ClusteredLockKey,ClusteredLockValue> clusteredLockCache,
 EmbeddedClusteredLockManager clusteredLockManager)

Method Details

stop

public void stop()

lock

public CompletableFuture<Void> lock()

Description copied from interface: ClusteredLock

Acquires the lock. If the lock is not available then the CompletableFuture waits until the lock has been acquired. Currently, there is no maximum time specified for a lock request to fail, so this could cause thread starvation.

Specified by:

lock in interface ClusteredLock

Returns:

a completed CompletableFuture when the lock is acquired

tryLock

public CompletableFuture<Boolean> tryLock()

Description copied from interface: ClusteredLock

Acquires the lock only if it is free at the time of invocation. Acquires the lock if it is available and returns immediately with with the CompletableFuture holding the value true. If the lock is not available then this method will return immediately with the CompletableFuture holding the value false.

Specified by:

tryLock in interface ClusteredLock

Returns:

CompletableFuture(true) if the lock was acquired and CompletableFuture(false) otherwise

tryLock

public CompletableFuture<Boolean> tryLock(long time,
 TimeUnit unit)

Description copied from interface: ClusteredLock

If the lock is available this method returns immediately with the CompletableFuture holding the value true. If the lock is not available then the CompletableFuture waits until :

• The lock is acquired
• The specified waiting time elapses

If the lock is acquired then the CompletableFuture will complete with the value true. If the specified waiting time elapses then the CompletableFuture will complete with the value false. If the time is less than or equal to zero, the method will not wait at all.

Specified by:

tryLock in interface ClusteredLock

Parameters:

time - , the maximum time to wait for the lock

unit - , the time unit of the time argument

Returns:

CompletableFuture(true) if the lock was acquired and CompletableFuture(false) if the waiting time elapsed before the lock was acquired

unlock

public CompletableFuture<Void> unlock()

Description copied from interface: ClusteredLock

Releases the lock. Only the holder of the lock may release the lock.

Specified by:

unlock in interface ClusteredLock

Returns:

a completed CompletableFuture when the lock is released

isLocked

public CompletableFuture<Boolean> isLocked()

Description copied from interface: ClusteredLock

Returns a CompletableFuture<Boolean> holding true when the lock is locked and false when the lock is released.

Specified by:

isLocked in interface ClusteredLock

Returns:

a CompletableFuture holding a Boolean

isLockedByMe

public CompletableFuture<Boolean> isLockedByMe()

Description copied from interface: ClusteredLock

Returns a CompletableFuture<Boolean> holding true when the lock is owned by the caller and false when the lock is owned by someone else or it's released.

Specified by:

isLockedByMe in interface ClusteredLock

Returns:

a CompletableFuture holding a Boolean

getName

public String getName()

getOriginator

public Object getOriginator()

toString

public String toString()

Overrides:

toString in class Object