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: 
chris@1:   public static final Object RegisterGate = new Object();
chris@1:   
chris@1:   private static NNTPDaemon instance = null;
chris@1:   
chris@1:   public static synchronized NNTPDaemon createInstance(int port)
chris@1:   {
chris@1:     if(instance == null)
chris@1:     {
chris@1:       instance = new NNTPDaemon(port);
chris@1:       return instance;
chris@1:     }
chris@1:     else
chris@1:     {
chris@1:       throw new RuntimeException("NNTPDaemon.createInstance() called twice");
chris@1:     }
chris@1:   }
chris@1:   
chris@1:   private int port;
chris@1:   
chris@1:   private NNTPDaemon(final int port)
chris@1:   {
chris@1:     Log.msg("Server listening on port " + port, false);
chris@1:     this.port = port;
chris@1:   }
chris@1: 
chris@1:   @Override
chris@1:   public void run()
chris@1:   {
chris@1:     try
chris@1:     {
chris@1:       // Create a Selector that handles the SocketChannel multiplexing
chris@1:       final Selector readSelector  = Selector.open();
chris@1:       final Selector writeSelector = Selector.open();
chris@1:       
chris@1:       // Start working threads
chris@1:       final int workerThreads = Runtime.getRuntime().availableProcessors() * 4;
chris@1:       ConnectionWorker[] cworkers = new ConnectionWorker[workerThreads];
chris@1:       for(int n = 0; n < workerThreads; n++)
chris@1:       {
chris@1:         cworkers[n] = new ConnectionWorker();
chris@1:         cworkers[n].start();
chris@1:       }
chris@1:       
chris@1:       ChannelWriter.getInstance().setSelector(writeSelector);
chris@1:       ChannelReader.getInstance().setSelector(readSelector);
chris@1:       ChannelWriter.getInstance().start();
chris@1:       ChannelReader.getInstance().start();
chris@1:       
chris@1:       final ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
chris@1:       serverSocketChannel.configureBlocking(true);  // Set to blocking mode
chris@1:       
chris@1:       // Configure ServerSocket; bind to socket...
chris@1:       final ServerSocket serverSocket = serverSocketChannel.socket();
chris@1:       serverSocket.bind(new InetSocketAddress(this.port));
chris@1:       
chris@1:       while(isRunning())
chris@1:       {
chris@1:         SocketChannel socketChannel;
chris@1:         
chris@1:         try
chris@1:         {
chris@1:           // As we set the server socket channel to blocking mode the accept()
chris@1:           // method will block.
chris@1:           socketChannel = serverSocketChannel.accept();
chris@1:           socketChannel.configureBlocking(false);
chris@1:           assert socketChannel.isConnected();
chris@1:           assert socketChannel.finishConnect();
chris@1:         }
chris@1:         catch(IOException ex)
chris@1:         {
chris@1:           // Under heavy load an IOException "Too many open files may
chris@1:           // be thrown. It most cases we should slow down the connection
chris@1:           // accepting, to give the worker threads some time to process work.
chris@1:           Log.msg("IOException while accepting connection: " + ex.getMessage(), false);
chris@1:           Log.msg("Connection accepting sleeping for seconds...", true);
chris@1:           Thread.sleep(5000); // 5 seconds
chris@1:           continue;
chris@1:         }
chris@1:         
chris@1:         final NNTPConnection conn;
chris@1:         try
chris@1:         {
chris@1:           conn = new NNTPConnection(socketChannel);
chris@1:           Connections.getInstance().add(conn);
chris@1:         }
chris@1:         catch(IOException ex)
chris@1:         {
chris@1:           Log.msg(ex.getLocalizedMessage(), false);
chris@1:           socketChannel.close();
chris@1:           continue;
chris@1:         }
chris@1:         
chris@1:         try
chris@1:         {
chris@1:           SelectionKey selKeyWrite =
chris@1:             registerSelector(writeSelector, socketChannel, SelectionKey.OP_WRITE);
chris@1:           registerSelector(readSelector, socketChannel, SelectionKey.OP_READ);
chris@1:           
chris@1:           Log.msg("Connected: " + socketChannel.socket().getRemoteSocketAddress(), true);
chris@1: 
chris@1:           // Set write selection key and send hello to client
chris@1:           conn.setWriteSelectionKey(selKeyWrite);
chris@3:           conn.println("200 " + Config.inst().get(Config.HOSTNAME, "localhost")
chris@1:               + " " + Main.VERSION + " news server ready - (posting ok).");
chris@1:         }
chris@1:         catch(CancelledKeyException cke)
chris@1:         {
chris@1:           Log.msg("CancelledKeyException " + cke.getMessage() + " was thrown: " 
chris@1:             + socketChannel.socket(), false);
chris@1:         }
chris@1:         catch(ClosedChannelException cce)
chris@1:         {
chris@1:           Log.msg("ClosedChannelException " + cce.getMessage() + " was thrown: " 
chris@1:             + socketChannel.socket(), false);
chris@1:         }
chris@1:       }
chris@1:     }
chris@1:     catch(BindException ex)
chris@1:     {
chris@1:       // Could not bind to socket; this is a fatal problem; so perform shutdown
chris@1:       ex.printStackTrace();
chris@1:       System.exit(1);
chris@1:     }
chris@1:     catch(IOException ex)
chris@1:     {
chris@1:       ex.printStackTrace();
chris@1:     }
chris@1:     catch(Exception ex)
chris@1:     {
chris@1:       ex.printStackTrace();
chris@1:     }
chris@1:   }
chris@1:   
chris@1:   public static SelectionKey registerSelector(final Selector selector,
chris@1:     final SocketChannel channel, final int op)
chris@1:     throws CancelledKeyException, ClosedChannelException
chris@1:   {
chris@1:     // Register the selector at the channel, so that it will be notified
chris@1:     // on the socket's events
chris@1:     synchronized(RegisterGate)
chris@1:     {
chris@1:       // Wakeup the currently blocking reader/writer thread; we have locked
chris@1:       // the RegisterGate to prevent the awakened thread to block again
chris@1:       selector.wakeup();
chris@1:       
chris@1:       // Lock the selector to prevent the waiting worker threads going into
chris@1:       // selector.select() which would block the selector.
chris@1:       synchronized (selector)
chris@1:       {
chris@1:         return channel.register(selector, op, null);
chris@1:       }
chris@1:     }
chris@1:   }
chris@1:   
chris@1: }