org.jgroups.blocks

Interface LockManager

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 $

Author: Roman Rokytskyy (rrokytskyy@acm.org) Robert Schaffar-Taurok (robert@fusion.at)

Method Summary
voidlock(Object obj, Object owner, int timeout)
Obtain lock on obj for specified owner.
voidunlock(Object obj, Object owner)
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).
voidunlock(Object obj, Object owner, boolean releaseMultiLocked)
Release lock on obj owned by specified owner.

Method Detail

lock

public void lock(Object obj, Object owner, int timeout)
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. ClassCastException if obj and/or owner is not of type that implementation expects to get (for example, when distributed lock manager obtains non-serializable obj or owner). ChannelException if something bad happened to communication channel.

unlock

public void unlock(Object obj, Object owner)
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: LockOwnerMismatchException if lock is owned by another object. ClassCastException if obj and/or owner is not of type that implementation expects to get (for example, when distributed lock manager obtains non-serializable obj or owner). ChannelException if something bad happened to communication channel.

unlock

public void unlock(Object obj, Object owner, boolean releaseMultiLocked)
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: LockOwnerMismatchException if lock is owned by another object. ClassCastException if obj and/or owner is not of type that implementation expects to get (for example, when distributed lock manager obtains non-serializable obj or owner). ChannelException if something bad happened to communication channel. LockMultiLockedException if the lock was unlocked, but another node already held the lock

Copyright ? 1998-2005 Bela Ban. All Rights Reserved.