org.jboss.netty.handler.execution

类 FairOrderedMemoryAwareThreadPoolExecutor

java.lang.Object

java.util.concurrent.AbstractExecutorService

java.util.concurrent.ThreadPoolExecutor

org.jboss.netty.handler.execution.MemoryAwareThreadPoolExecutor

org.jboss.netty.handler.execution.FairOrderedMemoryAwareThreadPoolExecutor

所有已实现的接口:

java.util.concurrent.Executor, java.util.concurrent.ExecutorService

直接已知子类:

FairOrderedDownstreamThreadPoolExecutor

public class FairOrderedMemoryAwareThreadPoolExecutor
extends MemoryAwareThreadPoolExecutor

This is a fair alternative of OrderedMemoryAwareThreadPoolExecutor .

Unfair of OrderedMemoryAwareThreadPoolExecutor

The task executed in OrderedMemoryAwareThreadPoolExecutor is unfair in some situations. For example, let's say there is only one executor thread that handle the events from the two channels, and events are submitted in sequence:

           Channel A (Event A1) , Channel B (Event B), Channel A (Event A2) , ... , Channel A (Event An)
 

Then the events maybe executed in this unfair order:

          ----------------------------------------> Timeline -------------------------------->
           Channel A (Event A1) , Channel A (Event A2) , ... , Channel A (Event An), Channel B (Event B)
 

As we see above, Channel B (Event B) maybe executed unfairly late. Even more, if there are too much events come in Channel A, and one-by-one closely, then Channel B (Event B) would be waiting for a long while and become "hungry".

Fair of FairOrderedMemoryAwareThreadPoolExecutor

In the same case above ( one executor thread and two channels ) , this implement will guarantee execution order as:

          ----------------------------------------> Timeline -------------------------------->
           Channel A (Event A1) , Channel B (Event B), Channel A (Event A2) , ... , Channel A (Event An),
 

NOTE: For convenience the case above use one single executor thread, but the fair mechanism is suitable for multiple executor threads situations.

嵌套类概要

嵌套类

限定符和类型	类和说明
protected class	FairOrderedMemoryAwareThreadPoolExecutor.EventTask

从类继承的嵌套类/接口 java.util.concurrent.ThreadPoolExecutor

java.util.concurrent.ThreadPoolExecutor.AbortPolicy, java.util.concurrent.ThreadPoolExecutor.CallerRunsPolicy, java.util.concurrent.ThreadPoolExecutor.DiscardOldestPolicy, java.util.concurrent.ThreadPoolExecutor.DiscardPolicy

字段概要

字段

限定符和类型	字段和说明
protected java.util.concurrent.ConcurrentMap<java.lang.Object,FairOrderedMemoryAwareThreadPoolExecutor.EventTask>	map

构造器概要

构造器

构造器和说明
FairOrderedMemoryAwareThreadPoolExecutor(int corePoolSize, long maxChannelMemorySize, long maxTotalMemorySize) Creates a new instance.
FairOrderedMemoryAwareThreadPoolExecutor(int corePoolSize, long maxChannelMemorySize, long maxTotalMemorySize, long keepAliveTime, java.util.concurrent.TimeUnit unit) Creates a new instance.
FairOrderedMemoryAwareThreadPoolExecutor(int corePoolSize, long maxChannelMemorySize, long maxTotalMemorySize, long keepAliveTime, java.util.concurrent.TimeUnit unit, ObjectSizeEstimator objectSizeEstimator, java.util.concurrent.ThreadFactory threadFactory) Creates a new instance.
FairOrderedMemoryAwareThreadPoolExecutor(int corePoolSize, long maxChannelMemorySize, long maxTotalMemorySize, long keepAliveTime, java.util.concurrent.TimeUnit unit, java.util.concurrent.ThreadFactory threadFactory) Creates a new instance.

方法概要

方法

限定符和类型	方法和说明
protected boolean	compareAndSetNext(FairOrderedMemoryAwareThreadPoolExecutor.EventTask eventTask, FairOrderedMemoryAwareThreadPoolExecutor.EventTask expect, FairOrderedMemoryAwareThreadPoolExecutor.EventTask update)
protected void	doExecute(java.lang.Runnable task) Executes the specified task concurrently while maintaining the event order.
protected java.lang.Object	getKey(ChannelEvent e)
protected java.util.concurrent.ConcurrentMap<java.lang.Object,FairOrderedMemoryAwareThreadPoolExecutor.EventTask>	newMap()
protected boolean	removeKey(java.lang.Object key) call removeKey(Object key) when the life cycle of the key ends, such as when the channel is closed
protected boolean	shouldCount(java.lang.Runnable task) Returns true if and only if the specified task should be counted to limit the global and per-channel memory consumption.

从类继承的方法 org.jboss.netty.handler.execution.MemoryAwareThreadPoolExecutor

beforeExecute, decreaseCounter, doUnorderedExecute, execute, getMaxChannelMemorySize, getMaxTotalMemorySize, getNotifyChannelFuturesOnShutdown, getObjectSizeEstimator, increaseCounter, remove, setMaxChannelMemorySize, setNotifyChannelFuturesOnShutdown, setObjectSizeEstimator, shutdownNow, shutdownNow, terminated

从类继承的方法 java.util.concurrent.ThreadPoolExecutor

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

从类继承的方法 java.util.concurrent.AbstractExecutorService

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

从类继承的方法 java.lang.Object

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

字段详细资料

map

protected final java.util.concurrent.ConcurrentMap<java.lang.Object,FairOrderedMemoryAwareThreadPoolExecutor.EventTask> map

构造器详细资料

FairOrderedMemoryAwareThreadPoolExecutor

public FairOrderedMemoryAwareThreadPoolExecutor(int corePoolSize,
                                        long maxChannelMemorySize,
                                        long maxTotalMemorySize)

Creates a new instance.

参数:

corePoolSize - the maximum number of active threads

maxChannelMemorySize - the maximum total size of the queued events per channel. Specify 0 to disable.

maxTotalMemorySize - the maximum total size of the queued events for this pool Specify 0 to disable.

FairOrderedMemoryAwareThreadPoolExecutor

public FairOrderedMemoryAwareThreadPoolExecutor(int corePoolSize,
                                        long maxChannelMemorySize,
                                        long maxTotalMemorySize,
                                        long keepAliveTime,
                                        java.util.concurrent.TimeUnit unit)

Creates a new instance.

参数:

corePoolSize - the maximum number of active threads

maxChannelMemorySize - the maximum total size of the queued events per channel. Specify 0 to disable.

maxTotalMemorySize - the maximum total size of the queued events for this pool Specify 0 to disable.

keepAliveTime - the amount of time for an inactive thread to shut itself down

unit - the TimeUnit of keepAliveTime

FairOrderedMemoryAwareThreadPoolExecutor

public FairOrderedMemoryAwareThreadPoolExecutor(int corePoolSize,
                                        long maxChannelMemorySize,
                                        long maxTotalMemorySize,
                                        long keepAliveTime,
                                        java.util.concurrent.TimeUnit unit,
                                        java.util.concurrent.ThreadFactory threadFactory)

Creates a new instance.

参数:

corePoolSize - the maximum number of active threads

maxChannelMemorySize - the maximum total size of the queued events per channel. Specify 0 to disable.

maxTotalMemorySize - the maximum total size of the queued events for this pool Specify 0 to disable.

keepAliveTime - the amount of time for an inactive thread to shut itself down

unit - the TimeUnit of keepAliveTime

threadFactory - the ThreadFactory of this pool

FairOrderedMemoryAwareThreadPoolExecutor

public FairOrderedMemoryAwareThreadPoolExecutor(int corePoolSize,
                                        long maxChannelMemorySize,
                                        long maxTotalMemorySize,
                                        long keepAliveTime,
                                        java.util.concurrent.TimeUnit unit,
                                        ObjectSizeEstimator objectSizeEstimator,
                                        java.util.concurrent.ThreadFactory threadFactory)

Creates a new instance.

参数:

corePoolSize - the maximum number of active threads

maxChannelMemorySize - the maximum total size of the queued events per channel. Specify 0 to disable.

maxTotalMemorySize - the maximum total size of the queued events for this pool Specify 0 to disable.

keepAliveTime - the amount of time for an inactive thread to shut itself down

unit - the TimeUnit of keepAliveTime

threadFactory - the ThreadFactory of this pool

objectSizeEstimator - the ObjectSizeEstimator of this pool

方法详细资料

newMap

protected java.util.concurrent.ConcurrentMap<java.lang.Object,FairOrderedMemoryAwareThreadPoolExecutor.EventTask> newMap()

doExecute

protected void doExecute(java.lang.Runnable task)

Executes the specified task concurrently while maintaining the event order.

覆盖:

doExecute 在类中 MemoryAwareThreadPoolExecutor

removeKey

protected boolean removeKey(java.lang.Object key)

call removeKey(Object key) when the life cycle of the key ends, such as when the channel is closed

getKey

protected java.lang.Object getKey(ChannelEvent e)

shouldCount

protected boolean shouldCount(java.lang.Runnable task)

从类复制的说明: MemoryAwareThreadPoolExecutor

Returns true if and only if the specified task should be counted to limit the global and per-channel memory consumption. To override this method, you must call super.shouldCount() to make sure important tasks are not counted.

覆盖:

shouldCount 在类中 MemoryAwareThreadPoolExecutor

compareAndSetNext

protected final boolean compareAndSetNext(FairOrderedMemoryAwareThreadPoolExecutor.EventTask eventTask,
                        FairOrderedMemoryAwareThreadPoolExecutor.EventTask expect,
                        FairOrderedMemoryAwareThreadPoolExecutor.EventTask update)