de.cismet.commons.concurrency

Class CismetConcurrency

java.lang.Object

de.cismet.commons.concurrency.CismetConcurrency

All Implemented Interfaces:

ShutdownHook

public final class CismetConcurrency
extends Object
implements ShutdownHook

Utility class that provides some concurrency tools that should be used when concurrency shall take place within cismet applications.

Version:

1.0

Author:

martin.scholl@cismet.de

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	CismetConcurrency.CismetThreadFactory Very similar to the Executors.defaultThreadFactory() implementation.
static class	CismetConcurrency.LoggingAbortPolicy An ThreadPoolExecutor.AbortPolicy that logs a warn message (using log4j) before doing the actual handling.

Method Summary

Modifier and Type	Method and Description
void	applicationFinished() This operation is called when the application is about to be unloaded.
ThreadFactory	createThreadFactory(String prefix) Calls createThreadFactory(java.lang.String, java.lang.Thread.UncaughtExceptionHandler) with a null UncaughtExceptionHandler.
ThreadFactory	createThreadFactory(String prefix, Thread.UncaughtExceptionHandler excHandler) Creates a new CismetConcurrency.CismetThreadFactory using the ThreadGroup of this CismetConcurrency instance, the given prefix and the given Thread.UncaughtExceptionHandler.
ExecutorService	getDefaultExecutor() Getter for the default ExecutorService for cismet applications.
String	getGroup() Getter for the group name that was used to retrieve this CismetConcurrency instance.
static CismetConcurrency	getInstance(String group) Creates a new CismetConcurrency instance for the given group or uses an already existing one.
ThreadGroup	getThreadGroup() The ThreadGroup that is used for the default executor as well as should be used for every thread/executor created for the application group.

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static CismetConcurrency getInstance(String group)

Creates a new CismetConcurrency instance for the given group or uses an already existing one.

Parameters:

group - the name of the group whose instance shall be returned

Returns:

an instance of CismetConcurrency for the given group or null if the group is null

getDefaultExecutor

public ExecutorService getDefaultExecutor()

Getter for the default ExecutorService for cismet applications. Note that this executor has a upper limit how many tasks can be run in parallel and how many wait for the execution. This means that an exception is thrown if the executor is fully loaded.

Returns:

the default ExecutorService

See Also:

CismetExecutors.newCachedLimitedThreadPool(int, java.util.concurrent.ThreadFactory, java.util.concurrent.RejectedExecutionHandler)

getThreadGroup

public ThreadGroup getThreadGroup()

The ThreadGroup that is used for the default executor as well as should be used for every thread/executor created for the application group.

Returns:

the ThreadGroup of this CismetConcurrency

See Also:

getInstance(java.lang.String)

getGroup

public String getGroup()

Getter for the group name that was used to retrieve this CismetConcurrency instance.

Returns:

the group name

See Also:

getInstance(java.lang.String)

createThreadFactory

public ThreadFactory createThreadFactory(String prefix)

Calls createThreadFactory(java.lang.String, java.lang.Thread.UncaughtExceptionHandler) with a null UncaughtExceptionHandler.

Parameters:

prefix - the prefix for every thread created by this factory

Returns:

a new ThreadFactory

See Also:

createThreadFactory(java.lang.String, java.lang.Thread.UncaughtExceptionHandler)

createThreadFactory

public ThreadFactory createThreadFactory(String prefix,
                                         Thread.UncaughtExceptionHandler excHandler)

Creates a new CismetConcurrency.CismetThreadFactory using the ThreadGroup of this CismetConcurrency instance, the given prefix and the given Thread.UncaughtExceptionHandler.

Parameters:

prefix - the prefix for every thread created by this factory

excHandler - an UncaughtExceptionHandler for the threads created by the new ThreadFactory

Returns:

a new ThreadFactory

See Also:

CismetConcurrency.CismetThreadFactory

applicationFinished

public void applicationFinished()

Description copied from interface: ShutdownHook

This operation is called when the application is about to be unloaded.

Specified by:

applicationFinished in interface ShutdownHook