jsr166y

类 LinkedTransferQueue.Node

java.lang.Object

jsr166y.LinkedTransferQueue.Node

封闭类:

LinkedTransferQueue<E>

static final class LinkedTransferQueue.Node
extends java.lang.Object

Queue nodes. Uses Object, not E, for items to allow forgetting them after use. Relies heavily on Unsafe mechanics to minimize unnecessary ordering constraints: Writes that are intrinsically ordered wrt other accesses or CASes use simple relaxed forms.

字段概要

字段

限定符和类型	字段和说明
(专用程序包) boolean	isData
(专用程序包) java.lang.Object	item
private static long	itemOffset
(专用程序包) LinkedTransferQueue.Node	next
private static long	nextOffset
private static long	serialVersionUID
private static sun.misc.Unsafe	UNSAFE
(专用程序包) java.lang.Thread	waiter
private static long	waiterOffset

构造器概要

构造器

构造器和说明
LinkedTransferQueue.Node(java.lang.Object item, boolean isData) Creates a new node.

方法概要

方法

限定符和类型	方法和说明
(专用程序包) boolean	cannotPrecede(boolean haveData) Returns true if a node with the given mode cannot be appended to this node because this node is unmatched and has opposite data mode.
(专用程序包) boolean	casItem(java.lang.Object cmp, java.lang.Object val)
(专用程序包) boolean	casNext(LinkedTransferQueue.Node cmp, LinkedTransferQueue.Node val)
(专用程序包) void	forgetContents() Sets item to self and waiter to null, to avoid garbage retention after matching or cancelling.
(专用程序包) void	forgetNext() Links node to itself to avoid garbage retention.
(专用程序包) boolean	isMatched() Returns true if this node has been matched, including the case of artificial matches due to cancellation.
(专用程序包) boolean	isUnmatchedRequest() Returns true if this is an unmatched request node.
(专用程序包) boolean	tryMatchData() Tries to artificially match a data node -- used by remove.

从类继承的方法 java.lang.Object

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

字段详细资料

isData

final boolean isData

item

volatile java.lang.Object item

next

volatile LinkedTransferQueue.Node next

waiter

volatile java.lang.Thread waiter

UNSAFE

private static final sun.misc.Unsafe UNSAFE

nextOffset

private static final long nextOffset

itemOffset

private static final long itemOffset

waiterOffset

private static final long waiterOffset

serialVersionUID

private static final long serialVersionUID

另请参阅:

常量字段值

构造器详细资料

LinkedTransferQueue.Node

LinkedTransferQueue.Node(java.lang.Object item,
                        boolean isData)

Creates a new node. Uses relaxed write because item can only be seen if followed by CAS.

方法详细资料

casNext

final boolean casNext(LinkedTransferQueue.Node cmp,
              LinkedTransferQueue.Node val)

casItem

final boolean casItem(java.lang.Object cmp,
              java.lang.Object val)

forgetNext

final void forgetNext()

Links node to itself to avoid garbage retention. Called only after CASing head field, so uses relaxed write.

forgetContents

final void forgetContents()

Sets item to self and waiter to null, to avoid garbage retention after matching or cancelling. Uses relaxed writes bacause order is already constrained in the only calling contexts: item is forgotten only after volatile/atomic mechanics that extract items. Similarly, clearing waiter follows either CAS or return from park (if ever parked; else we don't care).

isMatched

final boolean isMatched()

Returns true if this node has been matched, including the case of artificial matches due to cancellation.

isUnmatchedRequest

final boolean isUnmatchedRequest()

Returns true if this is an unmatched request node.

cannotPrecede

final boolean cannotPrecede(boolean haveData)

Returns true if a node with the given mode cannot be appended to this node because this node is unmatched and has opposite data mode.

tryMatchData

final boolean tryMatchData()

Tries to artificially match a data node -- used by remove.