org.jboss.util.collection

Class ConcurrentSkipListMap.Index<K,V>

java.lang.Object

org.jboss.util.collection.ConcurrentSkipListMap.Index<K,V>

Direct Known Subclasses:

ConcurrentSkipListMap.HeadIndex

Enclosing class:

ConcurrentSkipListMap<K,V>

static class ConcurrentSkipListMap.Index<K,V>
extends java.lang.Object

Index nodes represent the levels of the skip list. To improve search performance, keys of the underlying nodes are cached. Note that even though both Nodes and Indexes have forward-pointing fields, they have different types and are handled in different ways, that can't nicely be captured by placing field in a shared abstract class.

Field Summary

Fields

Modifier and Type	Field and Description
(package private) ConcurrentSkipListMap.Index<K,V>	down
(package private) K	key
(package private) ConcurrentSkipListMap.Node<K,V>	node
(package private) ConcurrentSkipListMap.Index<K,V>	right
(package private) static java.util.concurrent.atomic.AtomicReferenceFieldUpdater<ConcurrentSkipListMap.Index,ConcurrentSkipListMap.Index>	rightUpdater Updater for casRight

Constructor Summary

Constructors

Constructor and Description
Index(ConcurrentSkipListMap.Node<K,V> node, ConcurrentSkipListMap.Index<K,V> down, ConcurrentSkipListMap.Index<K,V> right) Creates index node with given values

Method Summary

Modifier and Type	Method and Description
(package private) boolean	casRight(ConcurrentSkipListMap.Index<K,V> cmp, ConcurrentSkipListMap.Index<K,V> val) compareAndSet right field
(package private) boolean	indexesDeletedNode() Returns true if the node this indexes has been deleted.
(package private) boolean	link(ConcurrentSkipListMap.Index<K,V> succ, ConcurrentSkipListMap.Index<K,V> newSucc) Tries to CAS newSucc as successor.
(package private) boolean	unlink(ConcurrentSkipListMap.Index<K,V> succ) Tries to CAS right field to skip over apparent successor succ.

Methods inherited from class java.lang.Object

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

Field Detail

key

final K key

node

final ConcurrentSkipListMap.Node<K,V> node

down

final ConcurrentSkipListMap.Index<K,V> down

right

volatile ConcurrentSkipListMap.Index<K,V> right

rightUpdater

static final java.util.concurrent.atomic.AtomicReferenceFieldUpdater<ConcurrentSkipListMap.Index,ConcurrentSkipListMap.Index> rightUpdater

Updater for casRight

Constructor Detail

Index

Index(ConcurrentSkipListMap.Node<K,V> node,
      ConcurrentSkipListMap.Index<K,V> down,
      ConcurrentSkipListMap.Index<K,V> right)

Creates index node with given values

Method Detail

casRight

final boolean casRight(ConcurrentSkipListMap.Index<K,V> cmp,
                       ConcurrentSkipListMap.Index<K,V> val)

compareAndSet right field

indexesDeletedNode

final boolean indexesDeletedNode()

Returns true if the node this indexes has been deleted.

Returns:

true if indexed node is known to be deleted

link

final boolean link(ConcurrentSkipListMap.Index<K,V> succ,
                   ConcurrentSkipListMap.Index<K,V> newSucc)

Tries to CAS newSucc as successor. To minimize races with unlink that may lose this index node, if the node being indexed is known to be deleted, it doesn't try to link in.

Parameters:

succ - the expected current successor

newSucc - the new successor

Returns:

true if successful

unlink

final boolean unlink(ConcurrentSkipListMap.Index<K,V> succ)

Tries to CAS right field to skip over apparent successor succ. Fails (forcing a retraversal by caller) if this node is known to be deleted.

Parameters:

succ - the expected current successor

Returns:

true if successful