com.j_spaces.kernel

Class SimpleLockStoredList<T>

java.lang.Object

com.j_spaces.kernel.AbstractStoredList<T>

com.j_spaces.kernel.SimpleLockStoredList<T>

All Implemented Interfaces:

IHashEntry<Object,IStoredList<T>>, ICollection<T>, IStoredList<T>, IObjectsList, Iterable<T>

Direct Known Subclasses:

HashedSimpleLockIStoredList

public class SimpleLockStoredList<T>
extends AbstractStoredList<T>

Read/Write Lock version of StoredList to be used with JDK 1.5+

Field Summary

Fields

Modifier and Type	Field and Description
protected ReentrantSimpleLock	lock

Fields inherited from class com.j_spaces.kernel.AbstractStoredList

m_AllOccupiedPos, m_BasicOccupied, m_Head, m_LastChunk, m_LastPos, m_Size, m_Support_Random_Scans, m_Tail, MINIMAL_NUMBER_TO_HANDLE_POSITIONS, NUMBER_OF_OCCUPIED_POS_QUOTA, SCAN_LIMIT

Constructor Summary

Constructors

Constructor and Description
SimpleLockStoredList(boolean Support_Random_Scans)
SimpleLockStoredList(boolean Support_Random_Scans, IReusableResourcePool<ReadWriteLock> locksPool) Create new stored list that will use the given ReadWriteLock for synchronization.

Method Summary

Modifier and Type	Method and Description
IObjectInfo<T>	add(T subject) store an element
IObjectInfo<T>	addUnlocked(T subject) store an element, while the SL is unlocked
boolean	contains(T obj) is this object contained in the SL ?
int	getHashCode(int id)
IObjectInfo<T>	getHead() get head of SL
Object	getKey(int id)
T	getObjectFromHead() get object from head of SL
IStoredList<T>	getValue(int id)
boolean	invalidate() Sets an indication that this StoredList is invalid.
boolean	isEmpty() Returns true if this list is empty, i.e.
protected boolean	isInvalid()
boolean	isNativeHashEntry()
protected boolean	iterate(boolean random_scan, StoredListIterator<T> res)
boolean	nextPos(StoredListIterator<T> slh)
boolean	optimizeScanForSingleObject() return true if we can save iterator creation and get a single entry
void	remove(IObjectInfo<T> oi) remove an element described by ObjectInfo
boolean	removeByObject(T obj) given an object scan the list, find it and remove it, returns true if found
void	removeUnlocked(IObjectInfo<T> oi) remove an element described by ObjectInfo, while the SL is unlocked
int	size() Returns the amount of elements in the StoredList.

Methods inherited from class com.j_spaces.kernel.AbstractStoredList

contains_impl, dump, establishListScan, freeSLHolder, isIterator, isMultiObjectCollection, iterator, iterator, next, remove_impl, removeByObject_impl, store_impl, storeBeforeCeiling_impl

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

lock

protected final ReentrantSimpleLock lock

Constructor Detail

SimpleLockStoredList

public SimpleLockStoredList(boolean Support_Random_Scans)

SimpleLockStoredList

public SimpleLockStoredList(boolean Support_Random_Scans,
                            IReusableResourcePool<ReadWriteLock> locksPool)

Create new stored list that will use the given ReadWriteLock for synchronization. This allows lock reuse between stored lists

Method Detail

size

public int size()

Description copied from interface: ICollection

Returns the amount of elements in the StoredList.

Returns:

size of the StoredList

See Also:

ICollection.isEmpty()

optimizeScanForSingleObject

public boolean optimizeScanForSingleObject()

return true if we can save iterator creation and get a single entry

Returns:

true if we can optimize

isEmpty

public boolean isEmpty()

Description copied from interface: ICollection

Returns true if this list is empty, i.e. has no elements. [Tail] - [Head]

Returns:

true if list is empty; false otherwise.

getHead

public IObjectInfo<T> getHead()

get head of SL

Returns:

the head of the list

getObjectFromHead

public T getObjectFromHead()

get object from head of SL

Returns:

the value of the head of the list

iterate

protected boolean iterate(boolean random_scan,
                          StoredListIterator<T> res)

Specified by:

iterate in class AbstractStoredList<T>

nextPos

public boolean nextPos(StoredListIterator<T> slh)

Specified by:

nextPos in class AbstractStoredList<T>

add

public IObjectInfo<T> add(T subject)

store an element

Parameters:

subject - element to store.

Returns:

an information node representing the inserted element; null if StoredList has been invalidated.

addUnlocked

public IObjectInfo<T> addUnlocked(T subject)

store an element, while the SL is unlocked

Parameters:

subject - element to store.

Returns:

an information node representing the inserted element; null if StoredList has been invalidated.

remove

public void remove(IObjectInfo<T> oi)

remove an element described by ObjectInfo

Parameters:

oi - an existing element between Tail and Head

removeUnlocked

public void removeUnlocked(IObjectInfo<T> oi)

remove an element described by ObjectInfo, while the SL is unlocked

Parameters:

oi - an existing element between Tail and Head

removeByObject

public boolean removeByObject(T obj)

given an object scan the list, find it and remove it, returns true if found

Parameters:

obj - element to remove

Returns:

true if object was removed; false otherwise (if element wasn't found)

contains

public boolean contains(T obj)

is this object contained in the SL ?

Parameters:

obj - the element to search for

Returns:

true if element exists in the StoredList; false otherwise.

invalidate

public boolean invalidate()

Sets an indication that this StoredList is invalid. if isEmpty() returns true, the indication is set; otherwise the indication remains false. Called by PersistentGC when scanning for empty StoredList that can be garbage collected.

Returns:

true if StoredList was set to invalid; false otherwise.

isInvalid

protected boolean isInvalid()

Specified by:

isInvalid in class AbstractStoredList<T>

Returns:

true if the list is invalid

getHashCode

public int getHashCode(int id)

getKey

public Object getKey(int id)

getValue

public IStoredList<T> getValue(int id)

isNativeHashEntry

public boolean isNativeHashEntry()

Returns:

true if this is a native hashmap entry