WebLogic Server 5.1.0 API Reference

weblogic.common
Class SequenceEvent

java.lang.Object
  |
  +--java.util.EventObject
        |
        +--weblogic.common.SequenceEvent

public class SequenceEvent

extends java.util.EventObject

Is an indication of operations that take place as an out-of-order stream of objects is reordered in a sequence using the "push" flow model (Lea 1997, p. 220). Possible SequenceEvents are defined in this class by static final ints, and cover these potential operations errors and warnings:

• WINDOW_OVERFLOW error is raised when the cache becomes full while waiting for a missing item to be inserted into a Sequence.
• TIMEOUT error occurs when no more objects are being inserted into a non-empty, waiting cache.
• BACKFLOW_THRESHOLD_REACHED warning is generated for flow control purposes, to slow down the object producer. This threshold is configurable.
• DUPLICATE warning is generated when a Sequenced object arrives that has already been received.

Author:

Copyright (c) 1998 by WebLogic, Inc. All Rights Reserved., Copyright (c) 1999 by BEA WebXpress. All Rights Reserved.
Copyright © 2000 BEA Systems, Inc. All Rights Reserved.

See Also:

Sequencer, Serialized Form

Field Summary

static int	BACKFLOW_THRESHOLD_REACHED Backflow threshold has been crossed.
static int	DATA New data (in sequence) is available.
static int	DUPLICATE A duplicate has been inserted.
int	id ID of a SequenceEvent.
static int	TIMEOUT No progress has been made after tmo seconds.
static int	WINDOW_OVERFLOW Window has closed, meaning that the internal buffers are full.

Fields inherited from class java.util.EventObject

source

Constructor Summary

protected	SequenceEvent(java.lang.Object source, int id)
protected	SequenceEvent(java.lang.Object source, int id, Sequenced sequenced)

Method Summary

Sequenced	getSequenced() Returns the Sequenced object associated with a SequenceEvent.
java.lang.String	toString() Displays a representation of a SequenceEvent.

Methods inherited from class java.util.EventObject

getSource

Methods inherited from class java.lang.Object

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

Field Detail

DUPLICATE

public static final int DUPLICATE

A duplicate has been inserted.

WINDOW_OVERFLOW

public static final int WINDOW_OVERFLOW

Window has closed, meaning that the internal buffers are full.

BACKFLOW_THRESHOLD_REACHED

public static final int BACKFLOW_THRESHOLD_REACHED

Backflow threshold has been crossed.

TIMEOUT

public static final int TIMEOUT

No progress has been made after tmo seconds.

DATA

public static final int DATA

New data (in sequence) is available.

id

public int id

ID of a SequenceEvent.

Constructor Detail

SequenceEvent

protected SequenceEvent(java.lang.Object source,
                        int id)

SequenceEvent

protected SequenceEvent(java.lang.Object source,
                        int id,
                        Sequenced sequenced)

Method Detail

getSequenced

public Sequenced getSequenced()

Returns the Sequenced object associated with a SequenceEvent.

Returns:

Sequenced object

toString

public java.lang.String toString()

Displays a representation of a SequenceEvent.

Returns:

SequenceEvent info

Overrides:

toString in class java.util.EventObject