com.vip.vjtools.vjkit.concurrent.threadpool

Class QueuableCachedThreadPool

java.lang.Object

java.util.concurrent.AbstractExecutorService

java.util.concurrent.ThreadPoolExecutor

com.vip.vjtools.vjkit.concurrent.threadpool.QueuableCachedThreadPool

All Implemented Interfaces:

Executor, ExecutorService

public final class QueuableCachedThreadPool
extends ThreadPoolExecutor

From Tomcat 8.5.6, 传统的FixedThreadPool有Queue但线程数量不变，而CachedThreadPool线程数可变但没有Queue Tomcat的线程池，通过控制TaskQueue，线程数，但线程数到达最大时会进入Queue中. 代码从Tomcat复制，主要修改包括： 1. 删除定期重启线程避免内存泄漏的功能， 2. TaskQueue中可能3次有锁的读取线程数量，改为只读取1次，这把锁也是这个实现里的唯一遗憾了。 https://github.com/apache/tomcat/blob/trunk/java/org/apache/tomcat/util/threads/ThreadPoolExecutor.java

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	QueuableCachedThreadPool.ControllableQueue https://github.com/apache/tomcat/blob/trunk/java/org/apache/tomcat/util/threads/TaskQueue.java

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

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

Constructor Summary

Constructors

Constructor and Description
QueuableCachedThreadPool(int corePoolSize, int maximumPoolSize, long keepAliveTime, TimeUnit unit, QueuableCachedThreadPool.ControllableQueue workQueue, ThreadFactory threadFactory, RejectedExecutionHandler handler)

Method Summary

Methods

Modifier and Type	Method and Description
protected void	afterExecute(Runnable r, Throwable t)
void	execute(Runnable command)
void	execute(Runnable command, long timeout, TimeUnit unit) Executes the given command at some time in the future.
int	getSubmittedCount()

Methods inherited from class java.util.concurrent.ThreadPoolExecutor

allowCoreThreadTimeOut, allowsCoreThreadTimeOut, awaitTermination, beforeExecute, finalize, getActiveCount, 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

QueuableCachedThreadPool

public QueuableCachedThreadPool(int corePoolSize,
                        int maximumPoolSize,
                        long keepAliveTime,
                        TimeUnit unit,
                        QueuableCachedThreadPool.ControllableQueue workQueue,
                        ThreadFactory threadFactory,
                        RejectedExecutionHandler handler)

Method Detail

afterExecute

protected void afterExecute(Runnable r,
                Throwable t)

Overrides:

afterExecute in class ThreadPoolExecutor

getSubmittedCount

public int getSubmittedCount()

execute

public void execute(Runnable command)

Specified by:

execute in interface Executor

Overrides:

execute in class ThreadPoolExecutor

execute

public void execute(Runnable command,
           long timeout,
           TimeUnit unit)

Executes the given command at some time in the future. The command may execute in a new thread, in a pooled thread, or in the calling thread, at the discretion of the Executor implementation. If no threads are available, it will be added to the work queue. If the work queue is full, the system will wait for the specified time and it throw a RejectedExecutionException if the queue is still full after that.

Parameters:

command - the runnable task

timeout - A timeout for the completion of the task

unit - The timeout time unit

Throws:

RejectedExecutionException - if this task cannot be accepted for execution - the queue is full

NullPointerException - if command or unit is null