org.jgroups.blocks.locking
Class LockService

java.lang.Object
  org.jgroups.blocks.locking.LockService

public class LockService
extends java.lang.Object

LockService is the main class for to use for distributed locking functionality. LockService needs access to a JChannel and interacts with a locking protocol (e.g. CENTRAL_LOCK) via events.

When no locking protocol is seen on the channel's stack, LockService will throw an exception at startup. An example of using LockService is:

   JChannel ch=new JChannel("/home/bela/locking.xml); // locking.xml needs to have a locking protocol towards the top
   LockService lock_service=new LockService(ch);
   ch.connect("lock-cluster");
   Lock lock=lock_service.getLock("mylock");
   lock.lock();
   try {
      // do something with the lock acquired
   }
   finally {
      lock.unlock();
   }
 

Note that, contrary to the semantics of Lock, unlock() can be called multiple times; after a lock has been released, future calls to unlock() have no effect.

Since:

2.12

Author:

Bela Ban

Nested Class Summary

protected class

LockService.LockImpl

Field Summary

protected JChannel	ch
protected Locking	lock_prot

Constructor Summary

LockService()

LockService(JChannel ch)

Method Summary

void	addLockListener(LockNotification listener)
java.util.concurrent.locks.Lock	getLock(java.lang.String lock_name)
java.lang.String	printLocks()
void	removeLockListener(LockNotification listener)
void	setChannel(JChannel ch)
void	unlockAll()

Methods inherited from class java.lang.Object

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

Field Detail

ch

protected JChannel ch

lock_prot

protected Locking lock_prot

Constructor Detail

LockService

public LockService()

LockService

public LockService(JChannel ch)

Method Detail

setChannel

public void setChannel(JChannel ch)

getLock

public java.util.concurrent.locks.Lock getLock(java.lang.String lock_name)

unlockAll

public void unlockAll()

addLockListener

public void addLockListener(LockNotification listener)

removeLockListener

public void removeLockListener(LockNotification listener)

printLocks

public java.lang.String printLocks()