de.fhg.igd.logging
Class AbstractAsynchronousMessageDispatcher

java.lang.Object
  java.lang.Thread
      de.fhg.igd.logging.AbstractAsynchronousMessageDispatcher

All Implemented Interfaces:

Runnable

Direct Known Subclasses:

AsynchronousStreamHandler.SunMessageDispatcher, AsynchronousWriterAppender.Log4jMessageDispatcher

public abstract class AbstractAsynchronousMessageDispatcher

extends Thread

This abstract class provides the main functionality of Asynchronous Message Dispatching.

Messages handed over via dispatch() will be put into an internal FIFO (First In, First Out) buffer. As soon as the dispatcher Thread gains the monitor, it will try to deliver buffered messages via the attached Messenger.

In case the internal buffer would exceed its limit, any further calls of dispatch() will drop the oldest message until either the dispatcher was able to catch up or enough messages have been discarded. An additional notification log entry will inform about the number of lost messages.

Version:

"$Id: AbstractAsynchronousMessageDispatcher.java 1913 2007-08-08 02:41:53Z jpeters $"

Author:

Matthias Pressfreund

Field Summary

protected List	fifo_ The internal message buffer
protected boolean	finished_ This flag will be set to true as soon as finish() has been called.
protected int	lost_ Counter for discarded messages
protected int	maxbuf_ The maximum size of the internal message buffer
protected Messenger	messenger_ The actual messenger that posts messages into the underlying logging system
protected boolean	notified_ This flag will be set to true once a notification about message loss has been printed to System.out

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

AbstractAsynchronousMessageDispatcher(Messenger messenger, int maxbuf)
Create an AbstractAsynchronousMessageDispatcher daemon.

Method Summary

protected abstract Object	createLossEntry(int lost, Object ref) Create a notification log entry informing about lost messages.
void	dispatch(Object msg) Hand over a message for dispatching.
void	finish() Calling this method will stop the dispatcher as soon as all remaining messages in the buffer are written into the destination stream.
protected abstract void	printLossMessage(Object ref) Print a notification about automatic message discarding to System.out.
void	run() This is the actual dispatcher implementation.
String	toString()

Methods inherited from class java.lang.Thread

activeCount, checkAccess, countStackFrames, currentThread, destroy, dumpStack, enumerate, getContextClassLoader, getName, getPriority, getThreadGroup, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setName, setPriority, sleep, sleep, start, stop, stop, suspend, yield

Methods inherited from class java.lang.Object

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

Field Detail

fifo_

protected List fifo_

The internal message buffer

messenger_

protected Messenger messenger_

The actual messenger that posts messages into the underlying logging system

maxbuf_

protected int maxbuf_

The maximum size of the internal message buffer

lost_

protected int lost_

Counter for discarded messages

finished_

protected boolean finished_

This flag will be set to true as soon as finish() has been called.

notified_

protected boolean notified_

This flag will be set to true once a notification about message loss has been printed to System.out

Constructor Detail

AbstractAsynchronousMessageDispatcher

public AbstractAsynchronousMessageDispatcher(Messenger messenger,
                                             int maxbuf)

Create an AbstractAsynchronousMessageDispatcher daemon.

Parameters:

messenger - The messenger that actually posts log messages into the underlying logging system

maxbuf - The maximum size of the internal message buffer

Method Detail

printLossMessage

protected abstract void printLossMessage(Object ref)

Print a notification about automatic message discarding to System.out.

Parameters:

ref - The message to refer to and get information from

createLossEntry

protected abstract Object createLossEntry(int lost,
                                          Object ref)

Create a notification log entry informing about lost messages.

Parameters:

lost - The number of lost messages

ref - The message to refer to and get information from

Returns:

The notification message object

dispatch

public void dispatch(Object msg)

Hand over a message for dispatching.

Parameters:

msg - The message to be dispatched

finish

public void finish()

Calling this method will stop the dispatcher as soon as all remaining messages in the buffer are written into the destination stream.

run

public void run()

This is the actual dispatcher implementation.

toString

public String toString()