chris@1: /*
chris@1:  *   SONEWS News Server
chris@1:  *   see AUTHORS for the list of contributors
chris@1:  *
chris@1:  *   This program is free software: you can redistribute it and/or modify
chris@1:  *   it under the terms of the GNU General Public License as published by
chris@1:  *   the Free Software Foundation, either version 3 of the License, or
chris@1:  *   (at your option) any later version.
chris@1:  *
chris@1:  *   This program is distributed in the hope that it will be useful,
chris@1:  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
chris@1:  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
chris@1:  *   GNU General Public License for more details.
chris@1:  *
chris@1:  *   You should have received a copy of the GNU General Public License
chris@1:  *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
chris@1:  */
chris@1: 
chris@1: package org.sonews.daemon;
chris@1: 
chris@3: import org.sonews.config.Config;
chris@3: import org.sonews.Main;
chris@1: import org.sonews.util.Log;
chris@1: import java.io.IOException;
chris@1: import java.net.BindException;
chris@1: import java.net.InetSocketAddress;
chris@1: import java.net.ServerSocket;
chris@1: import java.nio.channels.CancelledKeyException;
chris@1: import java.nio.channels.ClosedChannelException;
chris@1: import java.nio.channels.SelectionKey;
chris@1: import java.nio.channels.Selector;
chris@1: import java.nio.channels.ServerSocketChannel;
chris@1: import java.nio.channels.SocketChannel;
chris@1: 
chris@1: /**
chris@1:  * NNTP daemon using SelectableChannels.
chris@1:  * @author Christian Lins
chris@1:  * @since sonews/0.5.0
chris@1:  */
chris@1: public final class NNTPDaemon extends AbstractDaemon
chris@1: {
chris@1: 
cli@37: 	public static final Object RegisterGate = new Object();
cli@37: 	private static NNTPDaemon instance = null;
chris@1: 
cli@37: 	public static synchronized NNTPDaemon createInstance(int port)
cli@37: 	{
cli@37: 		if (instance == null) {
cli@37: 			instance = new NNTPDaemon(port);
cli@37: 			return instance;
cli@37: 		} else {
cli@37: 			throw new RuntimeException("NNTPDaemon.createInstance() called twice");
cli@37: 		}
cli@37: 	}
cli@37: 	private int port;
chris@1: 
cli@37: 	private NNTPDaemon(final int port)
cli@37: 	{
cli@37: 		Log.get().info("Server listening on port " + port);
cli@37: 		this.port = port;
cli@37: 	}
cli@37: 
cli@37: 	@Override
cli@37: 	public void run()
cli@37: 	{
cli@37: 		try {
cli@37: 			// Create a Selector that handles the SocketChannel multiplexing
cli@37: 			final Selector readSelector = Selector.open();
cli@37: 			final Selector writeSelector = Selector.open();
cli@37: 
cli@37: 			// Start working threads
cli@37: 			final int workerThreads = Runtime.getRuntime().availableProcessors() * 4;
cli@37: 			ConnectionWorker[] cworkers = new ConnectionWorker[workerThreads];
cli@37: 			for (int n = 0; n < workerThreads; n++) {
cli@37: 				cworkers[n] = new ConnectionWorker();
cli@37: 				cworkers[n].start();
cli@37: 			}
cli@37: 
cli@37: 			ChannelWriter.getInstance().setSelector(writeSelector);
cli@37: 			ChannelReader.getInstance().setSelector(readSelector);
cli@37: 			ChannelWriter.getInstance().start();
cli@37: 			ChannelReader.getInstance().start();
cli@37: 
cli@37: 			final ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
cli@37: 			serverSocketChannel.configureBlocking(true);  // Set to blocking mode
cli@37: 
cli@37: 			// Configure ServerSocket; bind to socket...
cli@37: 			final ServerSocket serverSocket = serverSocketChannel.socket();
cli@37: 			serverSocket.bind(new InetSocketAddress(this.port));
cli@37: 
cli@37: 			while (isRunning()) {
cli@37: 				SocketChannel socketChannel;
cli@37: 
cli@37: 				try {
cli@37: 					// As we set the server socket channel to blocking mode the accept()
cli@37: 					// method will block.
cli@37: 					socketChannel = serverSocketChannel.accept();
cli@37: 					socketChannel.configureBlocking(false);
cli@37: 					assert socketChannel.isConnected();
cli@37: 					assert socketChannel.finishConnect();
cli@37: 				} catch (IOException ex) {
cli@37: 					// Under heavy load an IOException "Too many open files may
cli@37: 					// be thrown. It most cases we should slow down the connection
cli@37: 					// accepting, to give the worker threads some time to process work.
cli@37: 					Log.get().severe("IOException while accepting connection: " + ex.getMessage());
cli@37: 					Log.get().info("Connection accepting sleeping for seconds...");
cli@37: 					Thread.sleep(5000); // 5 seconds
cli@37: 					continue;
cli@37: 				}
cli@37: 
cli@37: 				final NNTPConnection conn;
cli@37: 				try {
cli@37: 					conn = new NNTPConnection(socketChannel);
cli@37: 					Connections.getInstance().add(conn);
cli@37: 				} catch (IOException ex) {
cli@37: 					Log.get().warning(ex.toString());
cli@37: 					socketChannel.close();
cli@37: 					continue;
cli@37: 				}
cli@37: 
cli@37: 				try {
cli@37: 					SelectionKey selKeyWrite =
cli@37: 						registerSelector(writeSelector, socketChannel, SelectionKey.OP_WRITE);
cli@37: 					registerSelector(readSelector, socketChannel, SelectionKey.OP_READ);
cli@37: 
cli@37: 					Log.get().info("Connected: " + socketChannel.socket().getRemoteSocketAddress());
cli@37: 
cli@37: 					// Set write selection key and send hello to client
cli@37: 					conn.setWriteSelectionKey(selKeyWrite);
cli@37: 					conn.println("200 " + Config.inst().get(Config.HOSTNAME, "localhost")
cli@37: 						+ " " + Main.VERSION + " news server ready - (posting ok).");
cli@37: 				} catch (CancelledKeyException cke) {
cli@37: 					Log.get().warning("CancelledKeyException " + cke.getMessage() + " was thrown: "
cli@37: 						+ socketChannel.socket());
cli@37: 				} catch (ClosedChannelException cce) {
cli@37: 					Log.get().warning("ClosedChannelException " + cce.getMessage() + " was thrown: "
cli@37: 						+ socketChannel.socket());
cli@37: 				}
cli@37: 			}
cli@37: 		} catch (BindException ex) {
cli@37: 			// Could not bind to socket; this is a fatal problem; so perform shutdown
cli@37: 			ex.printStackTrace();
cli@37: 			System.exit(1);
cli@37: 		} catch (IOException ex) {
cli@37: 			ex.printStackTrace();
cli@37: 		} catch (Exception ex) {
cli@37: 			ex.printStackTrace();
cli@37: 		}
cli@37: 	}
cli@37: 
cli@37: 	public static SelectionKey registerSelector(final Selector selector,
cli@37: 		final SocketChannel channel, final int op)
cli@37: 		throws CancelledKeyException, ClosedChannelException
cli@37: 	{
cli@37: 		// Register the selector at the channel, so that it will be notified
cli@37: 		// on the socket's events
cli@37: 		synchronized (RegisterGate) {
cli@37: 			// Wakeup the currently blocking reader/writer thread; we have locked
cli@37: 			// the RegisterGate to prevent the awakened thread to block again
cli@37: 			selector.wakeup();
cli@37: 
cli@37: 			// Lock the selector to prevent the waiting worker threads going into
cli@37: 			// selector.select() which would block the selector.
cli@37: 			synchronized (selector) {
cli@37: 				return channel.register(selector, op, null);
cli@37: 			}
cli@37: 		}
cli@37: 	}
chris@1: }