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

Class NioClientSocketChannelFactory

  • All Implemented Interfaces:
    ChannelFactory, ClientSocketChannelFactory, ExternalResourceReleasable
    public class NioClientSocketChannelFactory
extends java.lang.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.

    • Constructor Detail

      • NioClientSocketChannelFactory

        public NioClientSocketChannelFactory​(java.util.concurrent.Executor bossExecutor,
                                     java.util.concurrent.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​(java.util.concurrent.Executor bossExecutor,
                                     java.util.concurrent.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​(java.util.concurrent.Executor bossExecutor,
                                     java.util.concurrent.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​(java.util.concurrent.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​(java.util.concurrent.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

    • Method Detail

      • shutdown

        public void shutdown()
        Description copied from interface: ChannelFactory
        Shudown the ChannelFactory and all the resource it created internal.
        Specified by:
        shutdown in interface ChannelFactory

      • 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, Executors 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 call ChannelFactory.shutdown() before do any action
        Specified by:
        releaseExternalResources in interface ChannelFactory
        Specified by:
        releaseExternalResources in interface ExternalResourceReleasable

      • releasePools

        private void releasePools()