Class DistributedLockManager

public DistributedLockManager(TwoPhaseVotingAdapter channel,
                              Object id)

Constructor for the DistributedLockManager_cl object.

Parameters:

channel - instance of TwoPhaseVotingAdapter that will be used for voting purposes on the lock decrees.

id - the unique identifier of this lock manager.

public DistributedLockManager(VotingAdapter voteChannel,
                              Object id)

Create instance of this class.

Parameters:

voteChannel - instance of VotingAdapter that will be used for voting purposes on the lock decrees. voteChannel() will be wrapped by the instance of the TwoPhaseVotingAdapter.

id - the unique identifier of this lock manager.

public void abort(Object decree)
            throws VoteException

Abort phase for the lock acquisition or release.

Specified by:

abort in interface TwoPhaseVotingListener

Parameters:

decree - should be an instance LockDecree, if not, we throw VoteException to be ignored by the VoteChannel.

Throws:

VoteException - if we should be ignored during voting.

public boolean commit(Object decree)
            throws VoteException

Commit phase for the lock acquisition or release.

Specified by:

commit in interface TwoPhaseVotingListener

Parameters:

decree - should be an instance LockDecree, if not, we throw VoteException to be ignored by the VoteChannel.

Returns:

true when commiting the lock operation succeeds.

Throws:

VoteException - if we should be ignored during voting.

public void lock(Object lockId,
                 Object owner,
                 int timeout)
            throws LockNotGrantedException,
                   ChannelException

Locks an object with lockId on behalf of the specified owner.

Specified by:

lock in interface LockManager

Parameters:

lockId - Object representing the object to be locked.

owner - object that requests the lock.

timeout - time during which group members should decide whether to grant a lock or not.

Throws:

LockNotGrantedException - when the lock cannot be granted.

ChannelException - if something bad happened to underlying channel.

public boolean prepare(Object decree)
            throws VoteException

Prepare phase for the lock acquisition or release.

Specified by:

prepare in interface TwoPhaseVotingListener

Parameters:

decree - should be an instance LockDecree, if not, we throw VoteException to be ignored by the VoteChannel.

Returns:

true when preparing the lock operation succeeds.

Throws:

VoteException - if we should be ignored during voting.

public void unlock(Object lockId,
                   Object owner)
            throws LockNotReleasedException,
                   ChannelException

Unlocks an object with lockId on behalf of the specified owner.

Specified by:

unlock in interface LockManager

Parameters:

lockId - long representing the object to be unlocked.

owner - object that releases the lock.

Throws:

LockNotReleasedException - when the lock cannot be released.