org.jgroups.blocks

Interface LockManager

Known Implementing Classes:
DistributedLockManager

public interface LockManager

LockManager represents generic lock manager that allows obtaining and releasing locks on objects.
Version:
$Id: LockManager.java,v 1.2 2005/06/08 15:56:54 publicnmi Exp $
Authors:
Roman Rokytskyy (rrokytskyy@acm.org)
Robert Schaffar-Taurok (robert@fusion.at)

Method Summary

void
lock(Object obj, Object owner, int timeout)
Obtain lock on obj for specified owner.
void
unlock(Object obj, Object owner)
Release lock on obj owned by specified owner.
void
unlock(Object obj, Object owner, boolean releaseMultiLocked)
Release lock on obj owned by specified owner.

Method Details

lock

public void lock(Object obj,
                 Object owner,
                 int timeout)
            throws LockNotGrantedException,
                   ClassCastException,
                   ChannelException
Obtain lock on obj for specified owner. Implementation should try to obtain lock few times within the specified timeout.
Parameters:
obj - obj to lock, usually not full object but object's ID.
owner - object identifying entity that will own the lock.
timeout - maximum time that we grant to obtain a lock.
Throws:
LockNotGrantedException - if lock is not granted within specified period.
ChannelException - if something bad happened to communication channel.

unlock

public void unlock(Object obj,
                   Object owner)
            throws LockNotReleasedException,
                   ClassCastException,
                   ChannelException
Release lock on obj owned by specified owner. since 2.2.9 this method is only a wrapper for unlock(Object lockId, Object owner, boolean releaseMultiLocked). Use that with releaseMultiLocked set to true if you want to be able to release multiple locked locks (for example after a merge)
Parameters:
obj - obj to lock, usually not full object but object's ID.
owner - object identifying entity that will own the lock.
Throws:
ChannelException - if something bad happened to communication channel.

unlock

public void unlock(Object obj,
                   Object owner,
                   boolean releaseMultiLocked)
            throws LockNotReleasedException,
                   ClassCastException,
                   ChannelException,
                   LockMultiLockedException
Release lock on obj owned by specified owner.
Parameters:
obj - obj to lock, usually not full object but object's ID.
owner - object identifying entity that will own the lock.
releaseMultiLocked - force unlocking of the lock if the local lockManager owns the lock even if another lockManager owns the same lock
Throws:
ChannelException - if something bad happened to communication channel.
LockMultiLockedException - if the lock was unlocked, but another node already held the lock

Copyright B) 1998-2005 Bela Ban. All Rights Reserved.