Package org.jboss.netty.channel.socket.nio

Class NioClientSocketChannelFactory

java.lang.Object
org.jboss.netty.channel.socket.nio.NioClientSocketChannelFactory
All Implemented Interfaces:
ChannelFactory, ClientSocketChannelFactory, ExternalResourceReleasable
public class NioClientSocketChannelFactory extends Object implements ClientSocketChannelFactory
A 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 Channels in a non-blocking mode.

Life cycle of threads and graceful shutdown

All threads are acquired from the Executors 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 Executors 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:

  1. close all channels created by the factory usually using ChannelGroup.close(), and
  2. call releaseExternalResources().
Please make sure not to shut down the executor until all channels are closed. Otherwise, you will end up with a RejectedExecutionException and the related resources might not be released properly.

  • Field Details

  • Constructor Details

    • NioClientSocketChannelFactory

      public NioClientSocketChannelFactory()
      Creates a new NioClientSocketChannelFactory which uses Executors.newCachedThreadPool() for the worker and boss executors. See NioClientSocketChannelFactory(Executor, Executor)

    • NioClientSocketChannelFactory

      public NioClientSocketChannelFactory(Executor bossExecutor, Executor workerExecutor)
      Creates a new instance. Calling this constructor is same with calling NioClientSocketChannelFactory(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 by Runtime.availableProcessors().
      Parameters:
      bossExecutor - the Executor which will execute the boss thread
      workerExecutor - the Executor which will execute the worker threads

    • NioClientSocketChannelFactory

      public NioClientSocketChannelFactory(Executor bossExecutor, Executor workerExecutor, int workerCount)
      Creates a new instance. Calling this constructor is same with calling NioClientSocketChannelFactory(Executor, Executor, int, int) with 1 as bossCount.
      Parameters:
      bossExecutor - the Executor which will execute the boss thread
      workerExecutor - the Executor which will execute the worker threads
      workerCount - the maximum number of I/O worker threads

    • NioClientSocketChannelFactory

      public NioClientSocketChannelFactory(Executor bossExecutor, Executor workerExecutor, int bossCount, int workerCount)
      Creates a new instance.
      Parameters:
      bossExecutor - the Executor which will execute the boss thread
      workerExecutor - the Executor which will execute the worker threads
      bossCount - the maximum number of boss threads
      workerCount - the maximum number of I/O worker threads

    • NioClientSocketChannelFactory

      public NioClientSocketChannelFactory(Executor bossExecutor, int bossCount, WorkerPool<NioWorker> workerPool)
      Creates a new instance.
      Parameters:
      bossExecutor - the Executor which will execute the boss thread
      bossCount - the maximum number of boss threads
      workerPool - the WorkerPool to use to do the IO

    • NioClientSocketChannelFactory

      public NioClientSocketChannelFactory(Executor bossExecutor, int bossCount, WorkerPool<NioWorker> workerPool, Timer timer)
      Creates a new instance.
      Parameters:
      bossExecutor - the Executor which will execute the boss thread
      bossCount - the maximum number of boss threads
      workerPool - the WorkerPool to use to do the IO
      timer - the Timer to use to handle the connection timeouts

    • NioClientSocketChannelFactory

      public NioClientSocketChannelFactory(BossPool<NioClientBoss> bossPool, WorkerPool<NioWorker> workerPool)
      Creates a new instance.
      Parameters:
      bossPool - the BossPool to use to handle the connects
      workerPool - the WorkerPool to use to do the IO

  • Method Details