org.entityfs.lock
Class NoObjectDummyLock

java.lang.Object
  org.entityfs.lock.NoObjectDummyLock

All Implemented Interfaces:

Lock, EntityLock

Direct Known Subclasses:

DummyLock

public class NoObjectDummyLock
extends Object
implements EntityLock

This is a dummy EntityLock implementation that is not connected to any particular entity.

Since this object does not contain any mutable internal state, the singleton instance INSTANCE can be used instead of instantiating the class.

Since:

1.0

Author:

Karl Gustafsson

Field Summary

static NoObjectDummyLock

INSTANCE Singleton instance that may be used instead of instantiating the class.

Constructor Summary

NoObjectDummyLock()

Method Summary

int	getHoldCount() Get the hold count of the lock.
Lockable	getLocked() Get the locked object.
boolean	isDummy() Is this lock a dummy lock.
boolean	isHeldByCurrentThread() Is this lock held by the current thread? (This is implemented by ReentrantLock but not specified in the Lock interface.)
boolean	isReadLock() Returns true if this lock is a read lock.
boolean	isWriteLock() Returns true if this lock is a write lock.
void	lock()
void	lockInterruptibly()
Condition	newCondition()
boolean	tryLock()
boolean	tryLock(long timeout, TimeUnit tu)
void	unlock()

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE

public static final NoObjectDummyLock INSTANCE

Singleton instance that may be used instead of instantiating the class.

Constructor Detail

NoObjectDummyLock

public NoObjectDummyLock()

Method Detail

isReadLock

public boolean isReadLock()

Description copied from interface: EntityLock

Returns true if this lock is a read lock.

Specified by:

isReadLock in interface EntityLock

Returns:

true, always.

isWriteLock

public boolean isWriteLock()

Description copied from interface: EntityLock

Returns true if this lock is a write lock.

Specified by:

isWriteLock in interface EntityLock

Returns:

true, always.

getLocked

public Lockable getLocked()

Description copied from interface: EntityLock

Get the locked object. For locks that are not connected to any particular object (dummy locks, mostly), this method returns null.

Specified by:

getLocked in interface EntityLock

Returns:

null, always.

newCondition

public Condition newCondition()
                       throws UnsupportedOperationException

Specified by:

newCondition in interface Lock

Throws:

UnsupportedOperationException - Always.

tryLock

public boolean tryLock()

Specified by:

tryLock in interface Lock

Returns:

true, always.

tryLock

public boolean tryLock(long timeout,
                       TimeUnit tu)

Specified by:

tryLock in interface Lock

Returns:

true, always.

unlock

public void unlock()

Specified by:

unlock in interface Lock

lock

public void lock()

Specified by:

lock in interface Lock

lockInterruptibly

public void lockInterruptibly()

Specified by:

lockInterruptibly in interface Lock

getHoldCount

public int getHoldCount()

Description copied from interface: EntityLock

Get the hold count of the lock. (How many Lock.lock() has been called minus the number of times Lock.unlock() has been called by the current thread.) If the hold count is 0, the lock is unlocked. The hold count can never be less than 0.

Specified by:

getHoldCount in interface EntityLock

Returns:

0, always.

isHeldByCurrentThread

public boolean isHeldByCurrentThread()

Description copied from interface: EntityLock

Is this lock held by the current thread? (This is implemented by ReentrantLock but not specified in the Lock interface.)

Specified by:

isHeldByCurrentThread in interface EntityLock

Returns:

true, always.

isDummy

public boolean isDummy()

Description copied from interface: EntityLock

Is this lock a dummy lock. A dummy lock does not actually do any locking.

Specified by:

isDummy in interface EntityLock

Returns:

true, always.