net.sf.ehcache.transaction
Class ReadCommittedSoftLockImpl

java.lang.Object
  net.sf.ehcache.transaction.ReadCommittedSoftLockImpl

All Implemented Interfaces:

Serializable, SoftLock

public class ReadCommittedSoftLockImpl
extends Object
implements SoftLock

A SoftLock implementation with Read-Committed isolation level

Author:

Ludovic Orban

See Also:

Serialized Form

Method Summary

void	clearTryLock() Clear the state of the soft lock after a tryLock() call succeeded.
boolean	equals(Object object)
void	freeze() Freeze the soft lock.
Element	getElement(TransactionID currentTransactionId) Get the element the current transaction is supposed to see.
Element	getFrozenElement() Get the Element with which this soft lock should be replaced by a commit, rollback or clean up
Object	getKey() Get the key of the element this soft lock is guarding
TransactionID	getTransactionID() Get the ID of the transaction under which this soft lock is operating
int	hashCode()
boolean	isExpired() Check if the soft lock expired, ie: that the thread which locked it died
void	lock() Lock the soft lock
String	toString()
boolean	tryLock(long ms) Attempt to lock the soft lock
void	unfreeze() Unfreeze the soft lock
void	unlock() Unlock the soft lock.
Element	updateElement(Element newElement) Change the Element at the key this soft lock is guarding
boolean	wasPinned() Check if the key was pinned in the underlying store before its element was replaced by this soft lock

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

getKey

public Object getKey()

Get the key of the element this soft lock is guarding

Specified by:

getKey in interface SoftLock

Returns:

the key

getElement

public Element getElement(TransactionID currentTransactionId)

Get the element the current transaction is supposed to see.

Specified by:

getElement in interface SoftLock

Parameters:

currentTransactionId - the current transaction under which this call is executed

Returns:

the Element visible to the current transaction

updateElement

public Element updateElement(Element newElement)

Change the Element at the key this soft lock is guarding

Specified by:

updateElement in interface SoftLock

Parameters:

newElement - the new Element

Returns:

the previous Element

getTransactionID

public TransactionID getTransactionID()

Get the ID of the transaction under which this soft lock is operating

Specified by:

getTransactionID in interface SoftLock

Returns:

the TransactionID

wasPinned

public boolean wasPinned()

Check if the key was pinned in the underlying store before its element was replaced by this soft lock

Specified by:

wasPinned in interface SoftLock

Returns:

true if the key was pinned, false otherwise

lock

public void lock()

Lock the soft lock

Specified by:

lock in interface SoftLock

tryLock

public boolean tryLock(long ms)
                throws InterruptedException

Attempt to lock the soft lock

Specified by:

tryLock in interface SoftLock

Parameters:

ms - the time in milliseconds before this method gives up

Returns:

true if the soft lock was locked, false otherwise

Throws:

InterruptedException - if the thread calling this method was interrupted

clearTryLock

public void clearTryLock()

Clear the state of the soft lock after a tryLock() call succeeded.

Specified by:

clearTryLock in interface SoftLock

unlock

public void unlock()

Unlock the soft lock. Once a soft lock got unlocked, it is considered 'dead': it cannot be locked again and must be cleaned up

Specified by:

unlock in interface SoftLock

freeze

public void freeze()

Freeze the soft lock. A soft lock should only be frozen for a very short period of time as this blocks the SoftLock.getElement(TransactionID) method calls. Freeze is used to mark the start of a commit / rollback phase

Specified by:

freeze in interface SoftLock

getFrozenElement

public Element getFrozenElement()

Get the Element with which this soft lock should be replaced by a commit, rollback or clean up

Specified by:

getFrozenElement in interface SoftLock

Returns:

the Element

unfreeze

public void unfreeze()

Unfreeze the soft lock

Specified by:

unfreeze in interface SoftLock

isExpired

public boolean isExpired()

Check if the soft lock expired, ie: that the thread which locked it died

Specified by:

isExpired in interface SoftLock

Returns:

true if the soft lock is orphan and should be cleaned up, false otherwise

equals

public boolean equals(Object object)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object