diff -r 000000000000 -r 6fceb66e1ad7 org/sonews/daemon/NNTPDaemon.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/org/sonews/daemon/NNTPDaemon.java	Fri Jun 26 16:48:50 2009 +0200
@@ -0,0 +1,195 @@
+/*
+ *   SONEWS News Server
+ *   see AUTHORS for the list of contributors
+ *
+ *   This program is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.sonews.daemon;
+
+import org.sonews.util.Log;
+import java.io.IOException;
+import java.net.BindException;
+import java.net.InetSocketAddress;
+import java.net.ServerSocket;
+import java.nio.channels.CancelledKeyException;
+import java.nio.channels.ClosedChannelException;
+import java.nio.channels.SelectionKey;
+import java.nio.channels.Selector;
+import java.nio.channels.ServerSocketChannel;
+import java.nio.channels.SocketChannel;
+
+/**
+ * NNTP daemon using SelectableChannels.
+ * @author Christian Lins
+ * @since sonews/0.5.0
+ */
+public final class NNTPDaemon extends AbstractDaemon
+{
+
+  public static final Object RegisterGate = new Object();
+  
+  private static NNTPDaemon instance = null;
+  
+  public static synchronized NNTPDaemon createInstance(int port)
+  {
+    if(instance == null)
+    {
+      instance = new NNTPDaemon(port);
+      return instance;
+    }
+    else
+    {
+      throw new RuntimeException("NNTPDaemon.createInstance() called twice");
+    }
+  }
+  
+  private int port;
+  
+  private NNTPDaemon(final int port)
+  {
+    Log.msg("Server listening on port " + port, false);
+    this.port = port;
+  }
+
+  @Override
+  public void run()
+  {
+    try
+    {
+      // Create a Selector that handles the SocketChannel multiplexing
+      final Selector readSelector  = Selector.open();
+      final Selector writeSelector = Selector.open();
+      
+      // Start working threads
+      final int workerThreads = Runtime.getRuntime().availableProcessors() * 4;
+      ConnectionWorker[] cworkers = new ConnectionWorker[workerThreads];
+      for(int n = 0; n < workerThreads; n++)
+      {
+        cworkers[n] = new ConnectionWorker();
+        cworkers[n].start();
+      }
+      
+      ChannelWriter.getInstance().setSelector(writeSelector);
+      ChannelReader.getInstance().setSelector(readSelector);
+      ChannelWriter.getInstance().start();
+      ChannelReader.getInstance().start();
+      
+      final ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
+      serverSocketChannel.configureBlocking(true);  // Set to blocking mode
+      
+      // Configure ServerSocket; bind to socket...
+      final ServerSocket serverSocket = serverSocketChannel.socket();
+      serverSocket.bind(new InetSocketAddress(this.port));
+      
+      while(isRunning())
+      {
+        SocketChannel socketChannel;
+        
+        try
+        {
+          // As we set the server socket channel to blocking mode the accept()
+          // method will block.
+          socketChannel = serverSocketChannel.accept();
+          socketChannel.configureBlocking(false);
+          assert socketChannel.isConnected();
+          assert socketChannel.finishConnect();
+        }
+        catch(IOException ex)
+        {
+          // Under heavy load an IOException "Too many open files may
+          // be thrown. It most cases we should slow down the connection
+          // accepting, to give the worker threads some time to process work.
+          Log.msg("IOException while accepting connection: " + ex.getMessage(), false);
+          Log.msg("Connection accepting sleeping for seconds...", true);
+          Thread.sleep(5000); // 5 seconds
+          continue;
+        }
+        
+        final NNTPConnection conn;
+        try
+        {
+          conn = new NNTPConnection(socketChannel);
+          Connections.getInstance().add(conn);
+        }
+        catch(IOException ex)
+        {
+          Log.msg(ex.getLocalizedMessage(), false);
+          socketChannel.close();
+          continue;
+        }
+        
+        try
+        {
+          SelectionKey selKeyWrite =
+            registerSelector(writeSelector, socketChannel, SelectionKey.OP_WRITE);
+          registerSelector(readSelector, socketChannel, SelectionKey.OP_READ);
+          
+          Log.msg("Connected: " + socketChannel.socket().getRemoteSocketAddress(), true);
+
+          // Set write selection key and send hello to client
+          conn.setWriteSelectionKey(selKeyWrite);
+          conn.println("200 " + Config.getInstance().get(Config.HOSTNAME, "localhost")
+              + " " + Main.VERSION + " news server ready - (posting ok).");
+        }
+        catch(CancelledKeyException cke)
+        {
+          Log.msg("CancelledKeyException " + cke.getMessage() + " was thrown: " 
+            + socketChannel.socket(), false);
+        }
+        catch(ClosedChannelException cce)
+        {
+          Log.msg("ClosedChannelException " + cce.getMessage() + " was thrown: " 
+            + socketChannel.socket(), false);
+        }
+      }
+    }
+    catch(BindException ex)
+    {
+      // Could not bind to socket; this is a fatal problem; so perform shutdown
+      ex.printStackTrace();
+      System.exit(1);
+    }
+    catch(IOException ex)
+    {
+      ex.printStackTrace();
+    }
+    catch(Exception ex)
+    {
+      ex.printStackTrace();
+    }
+  }
+  
+  public static SelectionKey registerSelector(final Selector selector,
+    final SocketChannel channel, final int op)
+    throws CancelledKeyException, ClosedChannelException
+  {
+    // Register the selector at the channel, so that it will be notified
+    // on the socket's events
+    synchronized(RegisterGate)
+    {
+      // Wakeup the currently blocking reader/writer thread; we have locked
+      // the RegisterGate to prevent the awakened thread to block again
+      selector.wakeup();
+      
+      // Lock the selector to prevent the waiting worker threads going into
+      // selector.select() which would block the selector.
+      synchronized (selector)
+      {
+        return channel.register(selector, op, null);
+      }
+    }
+  }
+  
+}