Class NioClientSocketChannelFactory
- All Implemented Interfaces:
ChannelFactory
,ClientSocketChannelFactory
,ExternalResourceReleasable
ClientSocketChannelFactory
which creates a client-side NIO-based
SocketChannel
. It utilizes the non-blocking I/O mode which was
introduced with NIO to serve many number of concurrent connections
efficiently.
How threads work
There are two types of threads in a NioClientSocketChannelFactory
;
one is boss thread and the other is worker thread.
Boss thread
One NioClientSocketChannelFactory
has one boss thread. It makes
a connection attempt on request. Once a connection attempt succeeds,
the boss thread passes the connected Channel
to one of the worker
threads that the NioClientSocketChannelFactory
manages.
Worker threads
One NioClientSocketChannelFactory
can have one or more worker
threads. A worker thread performs non-blocking read and write for one or
more Channel
s in a non-blocking mode.
Life cycle of threads and graceful shutdown
All threads are acquired from the Executor
s which were specified
when a NioClientSocketChannelFactory
was created. A boss thread is
acquired from the bossExecutor
, and worker threads are acquired from
the workerExecutor
. Therefore, you should make sure the specified
Executor
s are able to lend the sufficient number of threads.
It is the best bet to specify a cached thread pool.
Both boss and worker threads are acquired lazily, and then released when
there's nothing left to process. All the related resources such as
Selector
are also released when the boss and worker threads are
released. Therefore, to shut down a service gracefully, you should do the
following:
- close all channels created by the factory usually using
ChannelGroup.close()
, and - call
releaseExternalResources()
.
RejectedExecutionException
and the related resources might not be released properly.-
Field Summary
FieldsModifier and TypeFieldDescriptionprivate final BossPool<NioClientBoss>
private static final int
private boolean
private final NioClientSocketPipelineSink
private final WorkerPool<NioWorker>
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Constructor Summary
ConstructorsConstructorDescriptionCreates a newNioClientSocketChannelFactory
which usesExecutors.newCachedThreadPool()
for the worker and boss executors.NioClientSocketChannelFactory
(Executor bossExecutor, int bossCount, WorkerPool<NioWorker> workerPool) Creates a new instance.NioClientSocketChannelFactory
(Executor bossExecutor, int bossCount, WorkerPool<NioWorker> workerPool, Timer timer) Creates a new instance.NioClientSocketChannelFactory
(Executor bossExecutor, Executor workerExecutor) Creates a new instance.NioClientSocketChannelFactory
(Executor bossExecutor, Executor workerExecutor, int workerCount) Creates a new instance.NioClientSocketChannelFactory
(Executor bossExecutor, Executor workerExecutor, int bossCount, int workerCount) Creates a new instance.NioClientSocketChannelFactory
(BossPool<NioClientBoss> bossPool, WorkerPool<NioWorker> workerPool) Creates a new instance. -
Method Summary
Modifier and TypeMethodDescriptionnewChannel
(ChannelPipeline pipeline) void
Releases the external resources that this factory depends on to function.private void
void
shutdown()
Shudown the ChannelFactory and all the resource it created internal.
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Field Details
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DEFAULT_BOSS_COUNT
private static final int DEFAULT_BOSS_COUNT- See Also:
-
bossPool
-
workerPool
-
sink
-
releasePools
private boolean releasePools
-
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Constructor Details
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NioClientSocketChannelFactory
public NioClientSocketChannelFactory()Creates a newNioClientSocketChannelFactory
which usesExecutors.newCachedThreadPool()
for the worker and boss executors. SeeNioClientSocketChannelFactory(Executor, Executor)
-
NioClientSocketChannelFactory
Creates a new instance. Calling this constructor is same with callingNioClientSocketChannelFactory(Executor, Executor, int, int)
with 1 and (2 * the number of available processors in the machine) for bossCount and workerCount respectively. The number of available processors is obtained byRuntime.availableProcessors()
. -
NioClientSocketChannelFactory
public NioClientSocketChannelFactory(Executor bossExecutor, Executor workerExecutor, int workerCount) Creates a new instance. Calling this constructor is same with callingNioClientSocketChannelFactory(Executor, Executor, int, int)
with 1 as bossCount. -
NioClientSocketChannelFactory
public NioClientSocketChannelFactory(Executor bossExecutor, Executor workerExecutor, int bossCount, int workerCount) Creates a new instance. -
NioClientSocketChannelFactory
public NioClientSocketChannelFactory(Executor bossExecutor, int bossCount, WorkerPool<NioWorker> workerPool) Creates a new instance.- Parameters:
bossExecutor
- theExecutor
which will execute the boss threadbossCount
- the maximum number of boss threadsworkerPool
- theWorkerPool
to use to do the IO
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NioClientSocketChannelFactory
public NioClientSocketChannelFactory(Executor bossExecutor, int bossCount, WorkerPool<NioWorker> workerPool, Timer timer) Creates a new instance.- Parameters:
bossExecutor
- theExecutor
which will execute the boss threadbossCount
- the maximum number of boss threadsworkerPool
- theWorkerPool
to use to do the IOtimer
- theTimer
to use to handle the connection timeouts
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NioClientSocketChannelFactory
public NioClientSocketChannelFactory(BossPool<NioClientBoss> bossPool, WorkerPool<NioWorker> workerPool) Creates a new instance.- Parameters:
bossPool
- theBossPool
to use to handle the connectsworkerPool
- theWorkerPool
to use to do the IO
-
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Method Details
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newChannel
Description copied from interface:ChannelFactory
- Specified by:
newChannel
in interfaceChannelFactory
- Specified by:
newChannel
in interfaceClientSocketChannelFactory
- Parameters:
pipeline
- theChannelPipeline
which is going to be attached to the newChannel
- Returns:
- the newly open channel
-
shutdown
public void shutdown()Description copied from interface:ChannelFactory
Shudown the ChannelFactory and all the resource it created internal.- Specified by:
shutdown
in interfaceChannelFactory
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releaseExternalResources
public void releaseExternalResources()Description copied from interface:ChannelFactory
Releases the external resources that this factory depends on to function. An external resource is a resource that this factory didn't create by itself. For example,Executor
s that you specified in the factory constructor are external resources. You can call this method to release all external resources conveniently when the resources are not used by this factory or any other part of your application. An unexpected behavior will be resulted in if the resources are released when there's an open channel which is managed by this factory. This will also callChannelFactory.shutdown()
before do any action- Specified by:
releaseExternalResources
in interfaceChannelFactory
- Specified by:
releaseExternalResources
in interfaceExternalResourceReleasable
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releasePools
private void releasePools()
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