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();
   }
 
```
The exact semantics of this lock implemantation are defined in LockService.LockImpl.
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

Nested Classes
Modifier and Type Class Description

protected class LockService.LockImpl
Implementation of Lock.

Field Summary

Fields
Modifier and Type Field Description

protected JChannel ch

protected Locking lock_prot

Constructor Summary

Constructors
Constructor Description

LockService()

LockService(JChannel ch)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`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()`
`void`	`unlockForce(java.lang.String lock_name)`

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()
```

unlockForce

public void unlockForce(java.lang.String lock_name)

addLockListener

public void addLockListener(LockNotification listener)

removeLockListener

public void removeLockListener(LockNotification listener)

printLocks
```
public java.lang.String printLocks()
```