Class OioServerSocketChannelFactory
- All Implemented Interfaces:
ChannelFactory
,ServerChannelFactory
,ServerSocketChannelFactory
,ExternalResourceReleasable
ServerSocketChannelFactory
which creates a server-side blocking
I/O based ServerSocketChannel
. It utilizes the good old blocking
I/O API which is known to yield better throughput and latency when there
are relatively small number of connections to serve.
How threads work
There are two types of threads in a OioServerSocketChannelFactory
;
one is boss thread and the other is worker thread.
Boss threads
Each bound ServerSocketChannel
has its own boss thread.
For example, if you opened two server ports such as 80 and 443, you will
have two boss threads. A boss thread accepts incoming connections until
the port is unbound. Once a connection is accepted successfully, the boss
thread passes the accepted Channel
to one of the worker
threads that the OioServerSocketChannelFactory
manages.
Worker threads
Each connected Channel
has a dedicated worker thread, just like a
traditional blocking I/O thread model.
Life cycle of threads and graceful shutdown
All threads are acquired from the Executor
s which were specified
when a OioServerSocketChannelFactory
was created. Boss threads are
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.
Both boss and worker threads are acquired lazily, and then released when there's nothing left to process. All the related resources are also released when the boss and worker threads are released. Therefore, to shut down a service gracefully, you should do the following:
- unbind all channels created by the factory,
- close all child channels accepted by the unbound channels,
(these two steps so far is usually done using
ChannelGroup.close()
) - call
releaseExternalResources()
.
RejectedExecutionException
and the related resources might not be released properly.
Limitation
A ServerSocketChannel
created by this factory and its child channels
do not support asynchronous operations. Any I/O requests such as
"write"
will be performed in a blocking manner.
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Field Summary
FieldsModifier and TypeFieldDescription(package private) final Executor
private boolean
private final ChannelSink
private final Executor
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Constructor Summary
ConstructorsConstructorDescriptionCreate a newOioServerSocketChannelFactory
with aExecutors.newCachedThreadPool()
for the boss and worker executor.OioServerSocketChannelFactory
(Executor bossExecutor, Executor workerExecutor) Creates a new instance.OioServerSocketChannelFactory
(Executor bossExecutor, Executor workerExecutor, ThreadNameDeterminer determiner) Creates a new instance. -
Method Summary
Modifier and TypeMethodDescriptionnewChannel
(ChannelPipeline pipeline) void
Releases the external resources that this factory depends on to function.void
shutdown()
Shudown the ChannelFactory and all the resource it created internal.
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Field Details
-
bossExecutor
-
workerExecutor
-
sink
-
shutdownExecutor
private boolean shutdownExecutor
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Constructor Details
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OioServerSocketChannelFactory
public OioServerSocketChannelFactory()Create a newOioServerSocketChannelFactory
with aExecutors.newCachedThreadPool()
for the boss and worker executor. SeeOioServerSocketChannelFactory(Executor, Executor)
-
OioServerSocketChannelFactory
Creates a new instance. -
OioServerSocketChannelFactory
public OioServerSocketChannelFactory(Executor bossExecutor, Executor workerExecutor, ThreadNameDeterminer determiner) Creates a new instance.- Parameters:
bossExecutor
- theExecutor
which will execute the boss threadsworkerExecutor
- theExecutor
which will execute the I/O worker threadsdeterminer
- theThreadNameDeterminer
to set the thread names.
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Method Details
-
newChannel
Description copied from interface:ChannelFactory
- Specified by:
newChannel
in interfaceChannelFactory
- Specified by:
newChannel
in interfaceServerChannelFactory
- Specified by:
newChannel
in interfaceServerSocketChannelFactory
- 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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