centralselector.java

JAVA平台下优秀的CHART开源代码,可以实现类似EXCEL中的二维或三维的饼图/椎图功能.

/**
 * Copyright (C) 2003  Manfred Andres
 * 
 * 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 2
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

/**
 * The CentralSelector does the actual IO. All connections get Registered
 * and will be served when they are ready for action.
 * 
 * When a connection comes in, it get's registered with the CentralSelector.
 * If a connectino has content, the content will be automatically directed to
 *    one RequestReader's io-queue
 * If content must be written, the ConnectinoBuffer's write-queue attached to
 *    the connection will store it, untill the connection is ready for write-action
 */
package freecs.core;

import freecs.Server;
import freecs.util.ObjectBuffer;
import java.util.Set;
import java.util.Iterator;
import java.io.IOException;
import java.nio.channels.Selector;
import java.nio.channels.SelectionKey;
import java.nio.channels.SocketChannel;
import java.nio.channels.spi.SelectorProvider;
import java.nio.channels.ClosedChannelException;
import java.nio.channels.CancelledKeyException;

public class CentralSelector extends Thread {
   public static boolean stopped  = false;
   public static final CentralSelector cSel = new CentralSelector();
   private Selector     sel      = null;
   private long         rqLastChecked;
   public  ObjectBuffer dropKeys; 

   private CentralSelector () {
   	  dropKeys = new ObjectBuffer (1000);
      if (!initCsel ())
         Server.log ("CentralSelector.construct: unable to init Csel", Server.MSG_ERROR, Server.LVL_HALT);
   }

   private boolean initCsel () {
		if (sel == null || !sel.isOpen ()) try {
			sel = SelectorProvider.provider ().openSelector ();
		} catch (IOException ioe) {
			Server.debug ("CentralSelector.initCsel:", ioe, Server.MSG_ERROR, Server.LVL_HALT);
			return false;
		}
		if (sel != null && sel.isOpen ())
	 		return true;
		return false;
   }

	public static void startCentralSelector () {
		if (!cSel.isAlive())
			cSel.start();
		cSel.setPriority(MAX_PRIORITY);
	}

   public int keyCount () {
      Set keys = sel.keys ();
      return keys.size ();
   }
   
	public void registerSC (SocketChannel sc, int reqType) throws IOException, ClosedChannelException {
		if (sc == null) return;
		sc.configureBlocking (false);
		ConnectionBuffer cb = new ConnectionBuffer (reqType);
		synchronized (cb) {
			SelectionKey sk = sc.register (sel, SelectionKey.OP_READ, cb);
			cb.setKey (sk);
			cb.notifyAll();
		}
	}

   public void run () {
      Server.log ("CentralSelector: starting up", Server.MSG_STATE, Server.LVL_MINOR);
      int sdc = 500;
      long lastMsg = 0;
      while (Server.srv.isRunning () || sel.keys().size() > 0) try {
      	 if (!Server.srv.isRunning ()) {
      	 	sdc--;
      	 	if (sdc <= 0) break;
      	 }
      	 if ((System.currentTimeMillis () - lastMsg) > 5000) {
      	 	lastMsg=System.currentTimeMillis();
		 	Server.log ("CentralSelector.run: loop start", Server.MSG_STATE, Server.LVL_MAJOR);
      	 }
      	 synchronized (dropKeys) {
      	 	if (!dropKeys.isEmpty()) {
	   	 	 	while (!dropKeys.isEmpty()) 
	      	 		closeChannel ((SelectionKey) dropKeys.pop());
      	 	}
      	 }
         try {
			if (sel.selectNow() < 1) try {
                  Thread.sleep (33);
				  continue;
			} catch (InterruptedException ie) { }
         } catch (Exception e) {
            Server.debug ("CentralSelector.run (select):", e, Server.MSG_ERROR , Server.LVL_MAJOR);
         }
         Set keys = sel.selectedKeys();
         if (keys!=null && !keys.isEmpty()) {
			 for (Iterator i = keys.iterator (); i.hasNext (); ) {
	            SelectionKey ck = (SelectionKey) i.next ();
	            i.remove();
				try {
		            if (!ck.isValid () || !ck.channel ().isOpen ()) {
		               closeChannel (ck);
		               continue;
		            }
		            if (ck.isReadable ()) {
		               readIn (ck);
		            }/* else if (ck.isWritable()) {
			           writeOut (ck);
		            } */
		        } catch (CancelledKeyException cke) { }
			 }
        }
		try {
		   Thread.sleep (33);
		} catch (InterruptedException ie) { }
      } catch (Exception e) {
         Server.debug ("CentralSelector (outer loop): ", e, Server.MSG_ERROR, Server.LVL_MAJOR);
      }

      if (sel != null) try {
         Server.log ("CentralSelector closing down selector", Server.MSG_ERROR, Server.LVL_MAJOR);
         sel.close ();
      } catch (Exception e) {
         Server.debug ("CentralSelector shutting down: ", e, Server.MSG_ERROR, Server.LVL_MAJOR);
      }
      Server.log ("CentralSelectro suspended", Server.MSG_ERROR, Server.LVL_MINOR);
	  stopped = true;
      // cSelList.remove (this);
      // Server.log (cSelList.size () + " CentralSelectors in cSelList", Server.MSG_STATE, Server.LVL_MINOR);
   }

	private void readIn (SelectionKey sk) {
		ConnectionBuffer cb = (ConnectionBuffer) sk.attachment ();
		if (cb == null) {
			Server.log ("Key without ConnectionBuffer!", Server.MSG_ERROR, Server.LVL_MAJOR);
			closeChannel(sk);
			return;
		}
		synchronized (cb) {
			try {
				if (!sk.isValid() || !sk.channel().isOpen()) {
					closeChannel(sk);
					cb.notifyAll();
					return;
				}
				int bytesRead = ((SocketChannel) sk.channel ()).read (cb.rBuf);
				if (bytesRead < 0) {
					Server.log ("CentralSelector.readIn: droped key", Server.MSG_STATE, Server.LVL_VERY_VERBOSE);
					closeChannel (sk);
					cb.notifyAll();
					return;
				} else if (bytesRead == 0) {
					Server.log ("CentralSelector.readIn: no data from socket", Server.MSG_STATE, Server.LVL_VERBOSE);
					cb.notifyAll();
					return;
				}
				cb.updateCloseWhen();
			} catch (IOException ioe) {
				Server.debug ("CentralSelector.readIn: droped key (IOException)", ioe, Server.MSG_ERROR, Server.LVL_VERY_VERBOSE);
				closeChannel (sk);
				cb.invalidate();
				cb.logError (ioe.getMessage());
				cb.notifyAll();
				return;
			} catch (Exception e) {
				Server.debug ("CentralSelector.readIn: Exception encountered while reading: ", e, Server.MSG_ERROR, Server.LVL_MAJOR);
				cb.invalidate();
				cb.logError (e.getMessage());
				cb.notifyAll();
				return;
			}
			if (!RequestReader.processRequest(sk)) {
				closeChannel (sk);
				cb.invalidate();
				cb.logError ("No available requestreader");
				Server.log ("CentralSelector.readIn: No availabel requestreader to process request", Server.MSG_ERROR, Server.LVL_MAJOR);
				cb.notifyAll();
				return;
			}
		}
	}

	public void closeChannel (SelectionKey sk) {
		try {
			ConnectionBuffer cb = (ConnectionBuffer) sk.attachment();
			if (cb != null) {
				User u = cb.getUser();
				if (u!=null)
					u.scheduleToRemove();
			}
			sk.cancel();
			((SocketChannel) sk.channel()).close();
		} catch (Exception e) {
			Server.debug ("CentralSelector.closeChannel: ", e, Server.MSG_ERROR, Server.LVL_MAJOR);
		}
	}
	public static void dropKey (SelectionKey sk) {
		if (sk == null) return;
		ConnectionBuffer cb = (ConnectionBuffer) sk.attachment ();
		if (cb != null) {
			User u = cb.getUser ();
			if (u != null) {
				StringBuffer sb = new StringBuffer ("CentralSelector.dropKey: droped key for user ").append (u.getName ());
				Server.log (sb.toString (), Server.MSG_STATE, Server.LVL_VERBOSE);
				u.scheduleToRemove ();
			}
		}
		Responder.res.dropChannel ((SocketChannel) sk.channel());
		synchronized (cSel.dropKeys) { 
			cSel.dropKeys.put (sk);
		}
	}
	public static void dropChannel (SocketChannel sc) {
		SelectionKey sk = sc.keyFor(cSel.sel);
		if (sk == null) return;
		dropKey (sk);
	}
}