org.jasig.portal.concurrency.locking
Class ReferenceEntityLockService

java.lang.Object
  org.jasig.portal.concurrency.locking.ReferenceEntityLockService

All Implemented Interfaces:

IEntityLockService

public class ReferenceEntityLockService
extends Object
implements IEntityLockService

Version:

$Revision: 19776 $

Author:

Dan Ellentuck

Field Summary

Fields inherited from interface org.jasig.portal.concurrency.IEntityLockService

READ_LOCK, WRITE_LOCK

Constructor Summary

ReferenceEntityLockService()
ReferenceEntityLockingService constructor comment.

Method Summary

void	convert(IEntityLock lock, int newType) Attempts to change the lock's lockType to newType.
void	convert(IEntityLock lock, int newType, int newDuration) Attempts to change the lock's lockType to newType.
boolean	existsInStore(IEntityLock lock) Answer if this IEntityLock exists in the store.
boolean	isValid(IEntityLock lock) Answers if this IEntityLock represents a lock that is still good.
IEntityLock	newLock(Class entityType, String entityKey, int lockType, String owner) Returns a lock for the entity, lock type and owner if no conflicting locks exist.
IEntityLock	newLock(Class entityType, String entityKey, int lockType, String owner, int durationSecs) Returns a lock for the entity, lock type and owner if no conflicting locks exist.
IEntityLock	newLock(EntityIdentifier entityID, int lockType, String owner) Returns a lock for the entity, lock type and owner if no conflicting locks exist.
IEntityLock	newLock(EntityIdentifier entityID, int lockType, String owner, int durationSecs) Returns a lock for the entity, lock type and owner if no conflicting locks exist.
void	release(IEntityLock lock) Releases the IEntityLock.
void	renew(IEntityLock lock) Extends the expiration time of the lock by some service-defined increment.
void	renew(IEntityLock lock, int duration) Extends the expiration time of the lock by some service-defined increment.
static IEntityLockService	singleton()

Methods inherited from class java.lang.Object

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

Constructor Detail

ReferenceEntityLockService

public ReferenceEntityLockService()
                           throws LockingException

ReferenceEntityLockingService constructor comment.

Throws:

LockingException

Method Detail

convert

public void convert(IEntityLock lock,
                    int newType)
             throws LockingException

Attempts to change the lock's lockType to newType.

Specified by:

convert in interface IEntityLockService

Parameters:

lock - IEntityLock

newType - int

Throws:

LockingException

convert

public void convert(IEntityLock lock,
                    int newType,
                    int newDuration)
             throws LockingException

Attempts to change the lock's lockType to newType.

Specified by:

convert in interface IEntityLockService

Parameters:

lock - IEntityLock

newType - int

newDuration - int

Throws:

LockingException

existsInStore

public boolean existsInStore(IEntityLock lock)
                      throws LockingException

Answer if this IEntityLock exists in the store.

Specified by:

existsInStore in interface IEntityLockService

Parameters:

lock -

Returns:

boolean

Throws:

LockingException

isValid

public boolean isValid(IEntityLock lock)
                throws LockingException

Answers if this IEntityLock represents a lock that is still good. To be valid, a lock must exist in the underlying store and be unexpired.

Specified by:

isValid in interface IEntityLockService

Parameters:

lock - IEntityLock

Throws:

LockingException

newLock

public IEntityLock newLock(Class entityType,
                           String entityKey,
                           int lockType,
                           String owner)
                    throws LockingException

Returns a lock for the entity, lock type and owner if no conflicting locks exist.

Specified by:

newLock in interface IEntityLockService

Parameters:

entityType -

entityKey -

lockType -

owner -

Returns:

org.jasig.portal.groups.IEntityLock

Throws:

LockingException

newLock

public IEntityLock newLock(Class entityType,
                           String entityKey,
                           int lockType,
                           String owner,
                           int durationSecs)
                    throws LockingException

Returns a lock for the entity, lock type and owner if no conflicting locks exist.

Specified by:

newLock in interface IEntityLockService

Parameters:

entityType -

entityKey -

lockType -

owner -

durationSecs -

Returns:

org.jasig.portal.groups.IEntityLock

Throws:

LockingException - Retrieves potentially conflicting locks and checks them before adding the new lock to the store. The add of a write lock will fail if any other lock exists for the entity. The add of a read lock will fail if a write lock exists for the entity. After we add a write lock we check the store a second time and roll back if any other lock has snuck in. I think this is slightly safer than depending on the db isolation level for transactional integrity.

newLock

public IEntityLock newLock(EntityIdentifier entityID,
                           int lockType,
                           String owner)
                    throws LockingException

Returns a lock for the entity, lock type and owner if no conflicting locks exist.

Specified by:

newLock in interface IEntityLockService

Parameters:

entityID - org.jasig.portal.EntityIdentifier

lockType - int

owner - String

Returns:

org.jasig.portal.groups.IEntityLock

Throws:

LockingException

newLock

public IEntityLock newLock(EntityIdentifier entityID,
                           int lockType,
                           String owner,
                           int durationSecs)
                    throws LockingException

Returns a lock for the entity, lock type and owner if no conflicting locks exist.

Specified by:

newLock in interface IEntityLockService

Parameters:

entityID - org.jasig.portal.EntityIdentifier

lockType - int

owner - String

durationSecs - int

Returns:

org.jasig.portal.groups.IEntityLock

Throws:

LockingException

release

public void release(IEntityLock lock)
             throws LockingException

Releases the IEntityLock.

Specified by:

release in interface IEntityLockService

Parameters:

lock - IEntityLock

Throws:

LockingException

renew

public void renew(IEntityLock lock)
           throws LockingException

Extends the expiration time of the lock by some service-defined increment.

Specified by:

renew in interface IEntityLockService

Parameters:

lock - IEntityLock

Throws:

LockingException

renew

public void renew(IEntityLock lock,
                  int duration)
           throws LockingException

Extends the expiration time of the lock by some service-defined increment.

Specified by:

renew in interface IEntityLockService

Parameters:

lock - IEntityLock

Throws:

LockingException

singleton

public static IEntityLockService singleton()
                                    throws LockingException

Returns:

org.jasig.portal.concurrency.locking.ReferenceEntityLockService

Throws:

LockingException