net.automatalib.commons.util.concurrent

Class ScalingThreadPoolExecutor

java.lang.Object

java.util.concurrent.AbstractExecutorService

java.util.concurrent.ThreadPoolExecutor

net.automatalib.commons.util.concurrent.ScalingThreadPoolExecutor

All Implemented Interfaces:

Executor, ExecutorService

public class ScalingThreadPoolExecutor
extends ThreadPoolExecutor

A ThreadPoolExecutor that internally uses a ScalingLinkedBlockingQueue to manage scheduled tasks. This allows us to manage a dynamically sized thread pool that actually spawns new threads when the pool still allows for it.

Additionally, this implementation keeps track of the current number of active threads by using an AtomicInteger counter, rather than querying its list of worker threads.

For further information, see this blog post.

Author:

frohme

Nested Class Summary

Nested classes/interfaces inherited from class java.util.concurrent.ThreadPoolExecutor

ThreadPoolExecutor.AbortPolicy, ThreadPoolExecutor.CallerRunsPolicy, ThreadPoolExecutor.DiscardOldestPolicy, ThreadPoolExecutor.DiscardPolicy

Constructor Summary

Constructors

Constructor and Description
ScalingThreadPoolExecutor(int corePoolSize, int maximumPoolSize, long keepAliveTime, TimeUnit unit)

Method Summary

Modifier and Type	Method and Description
protected void	afterExecute(Runnable r, Throwable t)
protected void	beforeExecute(Thread t, Runnable r)
int	getActiveCount()

Methods inherited from class java.util.concurrent.ThreadPoolExecutor

allowCoreThreadTimeOut, allowsCoreThreadTimeOut, awaitTermination, execute, finalize, getCompletedTaskCount, getCorePoolSize, getKeepAliveTime, getLargestPoolSize, getMaximumPoolSize, getPoolSize, getQueue, getRejectedExecutionHandler, getTaskCount, getThreadFactory, isShutdown, isTerminated, isTerminating, prestartAllCoreThreads, prestartCoreThread, purge, remove, setCorePoolSize, setKeepAliveTime, setMaximumPoolSize, setRejectedExecutionHandler, setThreadFactory, shutdown, shutdownNow, terminated, toString

Methods inherited from class java.util.concurrent.AbstractExecutorService

invokeAll, invokeAll, invokeAny, invokeAny, newTaskFor, newTaskFor, submit, submit, submit

Methods inherited from class java.lang.Object

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

Constructor Detail

ScalingThreadPoolExecutor

public ScalingThreadPoolExecutor(int corePoolSize,
                                 int maximumPoolSize,
                                 long keepAliveTime,
                                 TimeUnit unit)

Method Detail

getActiveCount

public int getActiveCount()

Overrides:

getActiveCount in class ThreadPoolExecutor

beforeExecute

protected void beforeExecute(Thread t,
                             Runnable r)

Overrides:

beforeExecute in class ThreadPoolExecutor

afterExecute

protected void afterExecute(Runnable r,
                            Throwable t)

Overrides:

afterExecute in class ThreadPoolExecutor