Package org.apache.cassandra.concurrent

Class ThreadPoolExecutorBase

java.lang.Object

java.util.concurrent.AbstractExecutorService

java.util.concurrent.ThreadPoolExecutor

org.apache.cassandra.concurrent.ThreadPoolExecutorBase

All Implemented Interfaces:

Executor, ExecutorService, ResizableThreadPool

Direct Known Subclasses:

ThreadPoolExecutorPlus

public class ThreadPoolExecutorBase
extends ThreadPoolExecutor
implements ResizableThreadPool

This class incorporates some Executor best practices for Cassandra. Most of the executors in the system should use or extend ThreadPoolExecutorPlus, or in rare exceptions this class. This class provides some very basic improvements:

We are configured by ThreadPoolExecutorBuilder

Tasks rejected due to overflow of the queue block the submitting thread rather than throwing RejectedExecutionException

RunnableFuture rejected due to executor shutdown will be cancelled

RunnableFuture removed by shutdownNow() will be cancelled We also provide a shutdown hook for JMX registration cleanup.

Nested Class Summary

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

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

Field Summary

Fields

Modifier and Type	Field	Description
static final RejectedExecutionHandler	blockingExecutionHandler

Constructor Summary

Constructors

Constructor	Description
ThreadPoolExecutorBase(int threads, int keepAlive, TimeUnit keepAliveUnits, BlockingQueue<Runnable> queue, NamedThreadFactory threadFactory)
ThreadPoolExecutorBase(ThreadPoolExecutorBuilder<?> builder)

Method Summary

Modifier and Type	Method	Description
int	getActiveTaskCount()	Returns the approximate number of threads that are actively executing tasks.
int	getCoreThreads()
int	getMaximumThreads()
int	getPendingTaskCount()	Returns the approximate total of tasks waiting to be executed.
NamedThreadFactory	getThreadFactory()
Runnable	onShutdown()
void	onShutdown(Runnable onShutdown)
void	setCoreThreads(int number)
void	setMaximumThreads(int number)
void	shutdown()
List<Runnable>	shutdownNow()
protected void	terminated()
String	toString()

Methods inherited from class java.util.concurrent.ThreadPoolExecutor

afterExecute, allowCoreThreadTimeOut, allowsCoreThreadTimeOut, awaitTermination, beforeExecute, execute, finalize, getActiveCount, getCompletedTaskCount, getCorePoolSize, getKeepAliveTime, getLargestPoolSize, getMaximumPoolSize, getPoolSize, getQueue, getRejectedExecutionHandler, getTaskCount, isShutdown, isTerminated, isTerminating, prestartAllCoreThreads, prestartCoreThread, purge, remove, setCorePoolSize, setKeepAliveTime, setMaximumPoolSize, setRejectedExecutionHandler, setThreadFactory

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

Methods inherited from interface org.apache.cassandra.concurrent.ResizableThreadPool

getCompletedTaskCount, getCorePoolSize, getMaximumPoolSize, getMaxTasksQueued, oldestTaskQueueTime, setCorePoolSize, setMaximumPoolSize

Field Details

blockingExecutionHandler

public static final RejectedExecutionHandler blockingExecutionHandler

Constructor Details

ThreadPoolExecutorBase

public ThreadPoolExecutorBase(ThreadPoolExecutorBuilder<?> builder)

ThreadPoolExecutorBase

public ThreadPoolExecutorBase(int threads,
 int keepAlive,
 TimeUnit keepAliveUnits,
 BlockingQueue<Runnable> queue,
 NamedThreadFactory threadFactory)

Method Details

onShutdown

public void onShutdown(Runnable onShutdown)

onShutdown

public Runnable onShutdown()

terminated

protected void terminated()

Overrides:

terminated in class ThreadPoolExecutor

shutdown

public void shutdown()

Specified by:

shutdown in interface ExecutorService

Overrides:

shutdown in class ThreadPoolExecutor

shutdownNow

public List<Runnable> shutdownNow()

Specified by:

shutdownNow in interface ExecutorService

Overrides:

shutdownNow in class ThreadPoolExecutor

getActiveTaskCount

public int getActiveTaskCount()

Description copied from interface: ResizableThreadPool

Returns the approximate number of threads that are actively executing tasks.

Specified by:

getActiveTaskCount in interface ResizableThreadPool

Returns:

the number of threads

getPendingTaskCount

public int getPendingTaskCount()

Description copied from interface: ResizableThreadPool

Returns the approximate total of tasks waiting to be executed. Because the states of tasks and threads may change dynamically during computation, the returned value is only an approximation.

Specified by:

getPendingTaskCount in interface ResizableThreadPool

Returns:

the number of tasks

getCoreThreads

public int getCoreThreads()

setCoreThreads

public void setCoreThreads(int number)

getMaximumThreads

public int getMaximumThreads()

setMaximumThreads

public void setMaximumThreads(int number)

getThreadFactory

public NamedThreadFactory getThreadFactory()

Overrides:

getThreadFactory in class ThreadPoolExecutor

toString

public String toString()

Overrides:

toString in class ThreadPoolExecutor