alma.acs.container

Class CleaningDaemonThreadFactory

java.lang.Object

alma.acs.container.CleaningDaemonThreadFactory

All Implemented Interfaces:

java.util.concurrent.ThreadFactory

public class CleaningDaemonThreadFactory
extends java.lang.Object
implements java.util.concurrent.ThreadFactory

Thread factory that remembers all threads it creates. Method cleanUp allows killing all threads.

A ThreadGroup is used to deal with all threads at a time. Its name is that given in the constructor. Even though Josh Bloch tells us in "Effective Java", Item 53, that thread groups are almost useless, we like the UncaughtExceptionHandler which JDK 1.4 only offers through ThreadGroups. TODO: revisit this in JDK 1.5 where Thread itself has this handler.

Author:

hsommer created Mar 8, 2005 1:27:38 PM

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	LOG_THREAD_CREATION_CALLSTACK_PROPERTYNAME If this property is set to true, the creators of new threads will be identified through a INFO log showing the calling stack trace, which helps for example in finding out who created a thread but later fails to clean it up (see logs "Forcibly terminating surviving thread ...").
protected boolean	logThreadCreationCallstack Cache for value of LOG_THREAD_CREATION_CALLSTACK_PROPERTYNAME.

Constructor Summary

Constructors

Constructor and Description
CleaningDaemonThreadFactory(java.lang.String name, java.util.logging.Logger logger) Normal constructor.
CleaningDaemonThreadFactory(java.lang.String name, java.util.logging.Logger logger, java.lang.String ownerName) Special constructor, e.g.

Method Summary

Modifier and Type	Method and Description
java.util.List<java.lang.Thread>	_getAllThreadsCreated() Gets a copy of the list of all threads created by this factory up to this call.
void	cleanUp() Kills running threads via Thread.interrupt() or Thread.stop(), see code comments about the two cases.
java.lang.Thread	newThread(java.lang.Runnable command) Creates a new daemon thread that is part of the same factory thread group as all other threads created by this method.

Methods inherited from class java.lang.Object

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

Field Detail

LOG_THREAD_CREATION_CALLSTACK_PROPERTYNAME

public static final java.lang.String LOG_THREAD_CREATION_CALLSTACK_PROPERTYNAME

If this property is set to true, the creators of new threads will be identified through a INFO log showing the calling stack trace, which helps for example in finding out who created a thread but later fails to clean it up (see logs "Forcibly terminating surviving thread ...").

See Also:

Constant Field Values

logThreadCreationCallstack

protected boolean logThreadCreationCallstack

Cache for value of LOG_THREAD_CREATION_CALLSTACK_PROPERTYNAME.

Constructor Detail

CleaningDaemonThreadFactory

public CleaningDaemonThreadFactory(java.lang.String name,
                                   java.util.logging.Logger logger)

Normal constructor.

Parameters:

name - the name of the ThreadGroup to which all threads created by this factory will belong.

logger - the logger to be used by this class

CleaningDaemonThreadFactory

public CleaningDaemonThreadFactory(java.lang.String name,
                                   java.util.logging.Logger logger,
                                   java.lang.String ownerName)

Special constructor, e.g. when used internally by the container.

Parameters:

name - the name of the ThreadGroup to which all threads created by this factory will belong.

logger - the logger to be used by this class

ownerName - Can show up in log messages such as warnings by LoggingThreadGroup#uncaughtException(Thread, Throwable).

Method Detail

newThread

public java.lang.Thread newThread(java.lang.Runnable command)

Creates a new daemon thread that is part of the same factory thread group as all other threads created by this method. The thread's name will be that of the group, with an integer value appended.

Specified by:

newThread in interface java.util.concurrent.ThreadFactory

See Also:

ThreadFactory.newThread(java.lang.Runnable)

_getAllThreadsCreated

public java.util.List<java.lang.Thread> _getAllThreadsCreated()

Gets a copy of the list of all threads created by this factory up to this call. This method should only be used for testing, but not in operational code.

cleanUp

public void cleanUp()

Kills running threads via Thread.interrupt() or Thread.stop(), see code comments about the two cases. Should be called by the container or similar classes when all threads created by this factory supposedly have terminated anyway thanks to smart applications. The safety concerns which led to the deprecation of the stop method thus don't seem to apply here.