org.jboss.netty.channel.socket.nio.NioServerBoss Maven / Gradle / Ivy

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The Netty project is an effort to provide an asynchronous event-driven network application framework and tools for rapid development of maintainable high performance and high scalability protocol servers and clients. In other words, Netty is a NIO client server framework which enables quick and easy development of network applications such as protocol servers and clients. It greatly simplifies and streamlines network programming such as TCP and UDP socket server.
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/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package org.jboss.netty.channel.socket.nio;

import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelFuture;
import org.jboss.netty.channel.ChannelPipeline;
import org.jboss.netty.channel.ChannelSink;
import org.jboss.netty.util.ThreadNameDeterminer;
import org.jboss.netty.util.ThreadRenamingRunnable;

import java.io.IOException;
import java.net.SocketAddress;
import java.net.SocketTimeoutException;
import java.nio.channels.CancelledKeyException;
import java.nio.channels.ClosedChannelException;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.util.Iterator;
import java.util.Set;
import java.util.concurrent.Executor;

import static org.jboss.netty.channel.Channels.*;

/**
 * Boss implementation which handles accepting of new connections
 */
public final class NioServerBoss extends AbstractNioSelector implements Boss {

    NioServerBoss(Executor bossExecutor) {
        super(bossExecutor);
    }

    NioServerBoss(Executor bossExecutor, ThreadNameDeterminer determiner) {
        super(bossExecutor, determiner);
    }

    void bind(final NioServerSocketChannel channel, final ChannelFuture future,
              final SocketAddress localAddress) {
        registerTask(new RegisterTask(channel, future, localAddress));
    }

    @Override
    protected void close(SelectionKey k) {
        NioServerSocketChannel ch = (NioServerSocketChannel) k.attachment();
        close(ch, succeededFuture(ch));
    }

    void close(NioServerSocketChannel channel, ChannelFuture future) {
        boolean bound = channel.isBound();

        try {
            channel.socket.close();
            increaseCancelledKeys();

            if (channel.setClosed()) {
                future.setSuccess();

                if (bound) {
                    fireChannelUnbound(channel);
                }
                fireChannelClosed(channel);
            } else {
                future.setSuccess();
            }
        } catch (Throwable t) {
            future.setFailure(t);
            fireExceptionCaught(channel, t);
        }
    }

    @Override
    protected void process(Selector selector) {
        Set selectedKeys = selector.selectedKeys();
        if (selectedKeys.isEmpty()) {
            return;
        }
        for (Iterator i = selectedKeys.iterator(); i.hasNext();) {
            SelectionKey k = i.next();
            i.remove();
            NioServerSocketChannel channel = (NioServerSocketChannel) k.attachment();

            try {
                // accept connections in a for loop until no new connection is ready
                for (;;) {
                    SocketChannel acceptedSocket = channel.socket.accept();
                    if (acceptedSocket == null) {
                        break;
                    }
                    registerAcceptedChannel(channel, acceptedSocket, thread);
                }
            } catch (CancelledKeyException e) {
                // Raised by accept() when the server socket was closed.
                k.cancel();
                channel.close();
            } catch (SocketTimeoutException e) {
                // Thrown every second to get ClosedChannelException
                // raised.
            } catch (ClosedChannelException e) {
                // Closed as requested.
            } catch (Throwable t) {
                if (logger.isWarnEnabled()) {
                    logger.warn(
                            "Failed to accept a connection.", t);
                }

                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e1) {
                    // Ignore
                }
            }
        }
    }

    private static void registerAcceptedChannel(NioServerSocketChannel parent, SocketChannel acceptedSocket,
                                         Thread currentThread) {
        try {
            ChannelSink sink = parent.getPipeline().getSink();
            ChannelPipeline pipeline =
                    parent.getConfig().getPipelineFactory().getPipeline();
            NioWorker worker = parent.workerPool.nextWorker();
            worker.register(new NioAcceptedSocketChannel(
                    parent.getFactory(), pipeline, parent, sink
                    , acceptedSocket,
                    worker, currentThread), null);
        } catch (Exception e) {
            if (logger.isWarnEnabled()) {
                logger.warn(
                        "Failed to initialize an accepted socket.", e);
            }

            try {
                acceptedSocket.close();
            } catch (IOException e2) {
                if (logger.isWarnEnabled()) {
                    logger.warn(
                            "Failed to close a partially accepted socket.",
                            e2);
                }
            }
        }
    }

    @Override
    protected int select(Selector selector) throws IOException {
        // Just do a blocking select without any timeout
        // as this thread does not execute anything else.
        return selector.select();
    }

    @Override
    protected ThreadRenamingRunnable newThreadRenamingRunnable(int id, ThreadNameDeterminer determiner) {
        return new ThreadRenamingRunnable(this,
                "New I/O server boss #" + id, determiner);
    }

    @Override
    protected Runnable createRegisterTask(Channel channel, ChannelFuture future) {
        return new RegisterTask((NioServerSocketChannel) channel, future, null);
    }

    private final class RegisterTask implements Runnable {
        private final NioServerSocketChannel channel;
        private final ChannelFuture future;
        private final SocketAddress localAddress;

        public RegisterTask(final NioServerSocketChannel channel, final ChannelFuture future,
                            final SocketAddress localAddress) {
            this.channel = channel;
            this.future = future;
            this.localAddress = localAddress;
        }

        public void run() {
            boolean bound = false;
            boolean registered = false;
            try {
                channel.socket.socket().bind(localAddress, channel.getConfig().getBacklog());
                bound = true;

                future.setSuccess();
                fireChannelBound(channel, channel.getLocalAddress());
                channel.socket.register(selector, SelectionKey.OP_ACCEPT, channel);

                registered = true;
            } catch (Throwable t) {
                future.setFailure(t);
                fireExceptionCaught(channel, t);
            } finally {
                if (!registered && bound) {
                    close(channel, future);
                }
            }
        }
    }
}