com.j_spaces.kernel.locks

Class EvictableLockObject

java.lang.Object

java.lang.Number

java.util.concurrent.atomic.AtomicInteger

com.j_spaces.kernel.locks.EvictableLockObject

All Implemented Interfaces:

IEvictableLockObject, ILockObject, Serializable

public class EvictableLockObject
extends AtomicInteger
implements IEvictableLockObject

TODO add Javadoc

Since:

6.5 a lock object stored as a representative of the original subject which is evictable

Version:

1.0

Author:

Yechiel Fefer

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
EvictableLockObject(String uid)
EvictableLockObject(String uid, boolean evictionIndicator)

Method Summary

Modifier and Type	Method and Description
boolean	decrementNumOfUsersAndIndicateEmpty() decrement the number of users using (i.e locking + waiting + finished & not released yet) of the lock object
IEvictableLockObject	getEvictableLockObject() if the lock object is an evictable lock object, return the interface (preferable to casing)
int	getNumOfUsers() get the number of users using (i.e locking + waiting + finished & not released yet) of the lock object
int	getNumOfUsersAndEmpty() atomicly get & reset the number of users of the lock object
String	getUID() get the uid for the object to lock
boolean	incrementNumOfUsersIfNotEmpty() increment the number of users using (i.e locking + waiting + finished & not released yet) of the lock object, if the lock object is not empty (zero users)
boolean	isEvictionPermissionIndicator() true if this object is an eviction indicator.
boolean	isLockSubject() returns true if the lock object is the subject itself (i.e.

Methods inherited from class java.util.concurrent.atomic.AtomicInteger

accumulateAndGet, addAndGet, compareAndSet, decrementAndGet, doubleValue, floatValue, get, getAndAccumulate, getAndAdd, getAndDecrement, getAndIncrement, getAndSet, getAndUpdate, incrementAndGet, intValue, lazySet, longValue, set, toString, updateAndGet, weakCompareAndSet

Methods inherited from class java.lang.Number

byteValue, shortValue

Methods inherited from class java.lang.Object

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

Constructor Detail

EvictableLockObject

public EvictableLockObject(String uid)

EvictableLockObject

public EvictableLockObject(String uid,
                           boolean evictionIndicator)

Method Detail

getUID

public String getUID()

get the uid for the object to lock

Specified by:

getUID in interface IEvictableLockObject

Returns:

the uid

isLockSubject

public boolean isLockSubject()

returns true if the lock object is the subject itself (i.e. entry or template) or a representing object

Specified by:

isLockSubject in interface ILockObject

Returns:

true if is the subject itself

isEvictionPermissionIndicator

public boolean isEvictionPermissionIndicator()

true if this object is an eviction indicator. regular locks will wait till eviction performed, eviction will not take place if the object is locked

Specified by:

isEvictionPermissionIndicator in interface IEvictableLockObject

Returns:

true if it is

getNumOfUsers

public int getNumOfUsers()

get the number of users using (i.e locking + waiting + finished & not released yet) of the lock object

Specified by:

getNumOfUsers in interface IEvictableLockObject

Returns:

the num of users

incrementNumOfUsersIfNotEmpty

public boolean incrementNumOfUsersIfNotEmpty()

increment the number of users using (i.e locking + waiting + finished & not released yet) of the lock object, if the lock object is not empty (zero users)

Specified by:

incrementNumOfUsersIfNotEmpty in interface IEvictableLockObject

Returns:

true if # of users incremented, false if empty

decrementNumOfUsersAndIndicateEmpty

public boolean decrementNumOfUsersAndIndicateEmpty()

decrement the number of users using (i.e locking + waiting + finished & not released yet) of the lock object

Specified by:

decrementNumOfUsersAndIndicateEmpty in interface IEvictableLockObject

Returns:

true if lock object is empty (i.e. zero users reached)

getNumOfUsersAndEmpty

public int getNumOfUsersAndEmpty()

atomicly get & reset the number of users of the lock object

Specified by:

getNumOfUsersAndEmpty in interface IEvictableLockObject

Returns:

the num of users

getEvictableLockObject

public IEvictableLockObject getEvictableLockObject()

if the lock object is an evictable lock object, return the interface (preferable to casing)

Returns:

IEvictableLockObject if implemented