org.dcache.nfs.v4.nlm

Class DistributedLockManager

java.lang.Object

org.dcache.nfs.v4.nlm.AbstractLockManager

org.dcache.nfs.v4.nlm.DistributedLockManager

All Implemented Interfaces:

LockManager

public class DistributedLockManager
extends AbstractLockManager

An implementation of LockManager which uses Hazelcast's distributed MultiMap to store locks.

Example:

   HazelcastInstance hz = ...;
   LockManager lm1 = new DistributedLockManager(hz, "distributed-byte-range-lock");
   LockManager lm2 = new DistributedLockManager(hz, "distributed-byte-range-lock");
 

The lm1 and lm2 will share the same set of locks as long as they connected to the same Hazelcast cluster.

Since:

0.16

Constructor Summary

Constructors

Constructor and Description
DistributedLockManager(com.hazelcast.core.HazelcastInstance hz, String name) Create a new DistributedLockManager with a given name.

Method Summary

Modifier and Type	Method and Description
protected void	add(byte[] objId, NlmLock lock)
protected void	addAll(byte[] objId, Collection<NlmLock> locks)
protected Collection<NlmLock>	getActiveLocks(byte[] objId) Get collection of currently used active locks on the object.
protected Lock	getObjectLock(byte[] objId)
protected boolean	remove(byte[] objId, NlmLock lock)
protected void	removeAll(byte[] objId, Collection<NlmLock> locks)

Methods inherited from class org.dcache.nfs.v4.nlm.AbstractLockManager

lock, test, unlock, unlockIfExists

Methods inherited from class java.lang.Object

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

Constructor Detail

DistributedLockManager

public DistributedLockManager(com.hazelcast.core.HazelcastInstance hz,
                              String name)

Create a new DistributedLockManager with a given name. The other instances with the same name will share the same back-end store and, as a result, will see the same set of locks.

Parameters:

hz - reference to Haselcast instance.

name - name of the lock manager.

Method Detail

getObjectLock

protected Lock getObjectLock(byte[] objId)

Specified by:

getObjectLock in class AbstractLockManager

getActiveLocks

protected Collection<NlmLock> getActiveLocks(byte[] objId)

Get collection of currently used active locks on the object.

Specified by:

getActiveLocks in class AbstractLockManager

Parameters:

objId - object id.

Returns:

collection of active locks.

add

protected void add(byte[] objId,
                   NlmLock lock)

Specified by:

add in class AbstractLockManager

remove

protected boolean remove(byte[] objId,
                         NlmLock lock)

Specified by:

remove in class AbstractLockManager

addAll

protected void addAll(byte[] objId,
                      Collection<NlmLock> locks)

Specified by:

addAll in class AbstractLockManager

removeAll

protected void removeAll(byte[] objId,
                         Collection<NlmLock> locks)

Specified by:

removeAll in class AbstractLockManager