doc change for the new release

1 files changed, 138 insertions, 50 deletions

diff --git a/src/IvyClient.java b/src/IvyClient.java
index 18a50f2..3857631 100755
--- a/src/IvyClient.java
+++ b/src/IvyClient.java
@@ -20,8 +20,14 @@ import gnu.regexp.*;
  *
  *  CHANGELOG:
  *  1.0.12:
+ *  - introducing a Ping and Pong in the protocol, in order to detect the loss of
+ *    connection faster. Enabled through the use of -DIVY_PING variable only
+ *    the PINGTIMEOUT value in milliseconds allows me to have a status of the
+ *    socket guaranteed after this timeout
  *  - right handling of IOExceptions in sendBuffer, the Client is removed from
- *  the bus
+ *    the bus
+ *  - sendDie goes public, so does sendDie(String)
+ *  - appName visibility changed from private to protected
  *  1.0.10:
  *  - removed the timeout bug eating all the CPU resources
  */
@@ -38,10 +44,14 @@ public class IvyClient implements Runnable {
   final static int SchizoToken = 6; /* avoid race condition in concurrent connexions */
   final static int DirectMsg = 7;/* the peer sends a direct message */
   final static int Die = 8;  /* the peer wants us to quit */
+  final static int Ping = 9;  /* checks the presence of the other */
+  final static int Pong = 10;  /* checks the presence of the other */
+
   final static String MESSAGE_TERMINATOR = "\n"; /* the next protocol will use \r */
   final static String StartArg = "\u0002";/* begin of arguments */
   final static String EndArg = "\u0003"; /* end of arguments */
 
+
   private static boolean debug = (System.getProperty("IVY_DEBUG")!=null) ;
   private Ivy bus;
   private Socket socket;
@@ -49,19 +59,25 @@ public class IvyClient implements Runnable {
   private OutputStream out;
   private Hashtable regexp_in = new Hashtable();
   private Hashtable regexp_text = new Hashtable();
-  private String appName;
   private int appPort;
-  private boolean gardefou=true;
   private boolean peerCalling;
-  private Thread client;
+  private volatile Thread clientThread;// volatile to ensure the quick communication
+  private Integer clientKey ;
+  private static boolean doping = (System.getProperty("IVY_PING")!=null) ;
+  final static int PINGTIMEOUT = 5000; 
+  private PINGER pinger;
+  private volatile Thread pingerThread;
+
+  // protected variables
+  String appName;
 
-  IvyClient(Ivy bus, Socket socket,boolean peerCalling) throws IOException {
+  IvyClient(Ivy bus, Socket socket,boolean peerCalling,Integer clientKey) throws IOException {
     appName = "Unknown";
     appPort = 0;
     this.bus = bus;
     this.socket = socket;
     this.peerCalling=peerCalling;
-    // CHANGE: socket.setSoTimeout(100);
+    this.clientKey=clientKey;
     in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
     out = socket.getOutputStream();
     Hashtable regexps=bus.regexp_out;
@@ -72,14 +88,19 @@ public class IvyClient implements Runnable {
     send(SchizoToken,bus.applicationPort,bus.appName);
     // sends our regexps to the peer
     for (Enumeration e = regexps.keys(); e.hasMoreElements(); ) {
-      Integer key = (Integer)e.nextElement();
-      sendRegexp( key.intValue(),(String)regexps.get(key));
+      Integer ikey = (Integer)e.nextElement();
+      sendRegexp( ikey.intValue(),(String)regexps.get(ikey));
     }
     send( EndRegexp,0,"");
     // spawns a thread to manage the incoming traffic on this
     // socket. We should be ready to receive messages now.
-    client= new Thread(this);
-    client.start();
+    clientThread = new Thread(this);
+    clientThread .start();
+    if (doping) {
+      pinger = new PINGER();
+      pingerThread=new Thread(pinger);
+      pingerThread.start();
+    }
   }
 
   /**
@@ -87,6 +108,8 @@ public class IvyClient implements Runnable {
    */
   public String getApplicationName() { return appName ; }
 
+  Integer getClientKey() { return clientKey ; }
+
   /**
    *  allow an Ivy package class to access the list of regexps at a
    *  given time.
@@ -98,7 +121,7 @@ public class IvyClient implements Runnable {
   int getAppPort() { return appPort ; }
 
   void sendRegexp(int id,String regexp) {
-      send(AddRegexp,id,regexp); /* perhaps we should perform some checking here */
+    send(AddRegexp,id,regexp); /* perhaps we should perform some checking here */
   }
 
   public void delRegexp(int id) {send( DelRegexp,id,"");}
@@ -124,14 +147,23 @@ public class IvyClient implements Runnable {
   
   /**
    * closes the connexion to the peer.
-   * @param msg the debug information
+   * @param notify should I send Bye message ?
    * the thread managing the socket is stopped
    */
-  void close(String msg) throws IOException {
-    traceDebug("(closing) "+msg);
-    gardefou=false;
-    client.interrupt();
-    // socket.close();  // should I ?
+  void close(boolean notify) throws IOException {
+    traceDebug("closing connexion to "+appName);
+    if (doping) { pinger.stopPinging(); }
+    if (notify) sendBye("hasta la vista");
+    stopListening();
+    // bus.clientDisconnect(this);
+    socket.close();  // should I also close in and out ?
+  }
+
+  void stopListening() {
+    Thread t = clientThread;
+    if (t==null) return; // we can be summoned to quit from two path at a time
+    clientThread=null;
+    t.interrupt();
   }
 
   /**
@@ -149,31 +181,27 @@ public class IvyClient implements Runnable {
    * the code of the thread handling the incoming messages.
    */
   public void run() {
+    Thread thisThread = Thread.currentThread();
+    traceDebug("Connected from "+ socket.getInetAddress().getHostName()+ ":"+socket.getPort());
     String msg = null;
-    try {
-      traceDebug("Connected from "+ socket.getInetAddress().getHostName()+ ":"+socket.getPort());
-      while ( gardefou ) {
-	try {
-	  if ((msg=in.readLine()) != null ) {
-	    newParseMsg(msg);
-	  }
-	} catch (IvyException ie) {
-	  ie.printStackTrace();
-	} catch (InterruptedIOException ioe) {
-	  System.out.println("I have been interrupted. I'm about to leave my thread loop");
-	  if (!gardefou) break;
+    while ( clientThread==thisThread ) {
+      try {
+	if ((msg=in.readLine()) != null ) {
+	  if (doping && (pingerThread!=null)) pingerThread.interrupt();
+	  newParseMsg(msg);
 	}
+      } catch (IvyException ie) {
+	ie.printStackTrace();
+      } catch (InterruptedIOException ioe) {
+	System.out.println("I have been interrupted. I'm about to leave my thread loop");
+	if (thisThread!=clientThread) break;
+      } catch (IOException e) {
+	if (clientThread!=thisThread) break;
+	traceDebug("abnormally Disconnected from "+
+	    socket.getInetAddress().getHostName()+":"+socket.getPort());
       }
-      traceDebug("normally Disconnected from "+ socket.getInetAddress().getHostName()+":"+socket.getPort());
-      socket.close();
-      out.close();
-      in.close();
-    } catch (IOException e) {
-      traceDebug("abnormally Disconnected from "+
-        socket.getInetAddress().getHostName()+":"+socket.getPort());
-    }
-    bus.disconnect(this);
-    bus.removeClient(this);
+    } // while 
+    traceDebug("normally Disconnected from "+ appName);
   }
 
   private void sendBuffer( String buffer ) throws IvyException {
@@ -183,8 +211,12 @@ public class IvyClient implements Runnable {
       out.flush();
     } catch ( IOException e ) {
       traceDebug("I can't send my message to this client. He probably left");
+      // first, I'm not a first class IvyClient any more
+      bus.removeClient(this);
+      // invokes the die applicationListeners
+      bus.disconnectReceived(this);
       try {
-        close("IO Exception");
+        close(false);
       } catch (IOException ioe) {
 	throw new IvyException("close failed"+ioe.getMessage());
       }
@@ -258,9 +290,32 @@ public class IvyClient implements Runnable {
     }
     from=to+1;
     switch (msgType) {
+      case Die:
+	traceDebug("received die Message from " + appName);
+	// first, I'm not a first class IvyClient any more
+	bus.removeClient(this);
+	// invokes the die applicationListeners
+	bus.dieReceived(this,msgId.intValue());
+	// makes the bus die
+	bus.stop();
+	try {
+	  close(false);
+	} catch (IOException ioe) {
+	  throw new IvyException(ioe.getMessage());
+	}
+	break;
       case Bye:
-	bus.die(this,msgId.intValue());
-	gardefou=false;
+	// the peer quits
+	traceDebug("received bye Message from "+appName);
+	// first, I'm not a first class IvyClient any more
+	bus.removeClient(this);
+	// invokes the die applicationListeners
+	bus.disconnectReceived(this);
+	try {
+	  close(false);
+	} catch (IOException ioe) {
+	  throw new IvyException(ioe.getMessage());
+	}
 	break;
       case AddRegexp:
 	String regexp=s.substring(from,b.length);
@@ -305,6 +360,16 @@ public class IvyClient implements Runnable {
 	}
 	bus.callCallback(this,msgId,tab);
 	break;
+      case Pong:
+	String paramPong=s.substring(from,b.length);
+	traceDebug("Ping msg from "+appName+" : "+paramPong);
+	break;
+      case Ping:
+	// I receive a ping. I can answer a pong.
+	String param=s.substring(from,b.length);
+	traceDebug("Ping msg from "+appName+" : "+param);
+	sendPong(param);
+	break;
       case Error:
 	String error=s.substring(from,b.length);
 	traceDebug("Error msg "+msgId+" "+error);
@@ -314,7 +379,7 @@ public class IvyClient implements Runnable {
 	appPort=msgId.intValue();
 	if ( bus.checkConnected(this) ) {
 	  try  {
-	    close("Quitting Application already connected");
+	    close(false);
 	  } catch (IOException ioe) {
 	  throw new IvyException("io " + ioe.getMessage());
 	  }
@@ -325,20 +390,43 @@ public class IvyClient implements Runnable {
 	String direct=s.substring(from,b.length);
 	bus.directMessage( this, msgId.intValue(), direct );
 	break;
-      case Die:
-	gardefou=false;
-	bus.die(this,msgId.intValue());
-  	break;
       default:
         throw new IvyException("protocol error, unknown message type "+msgType);
     }
   }
 
-  private void sendDie() {send(Die,0,"");}
-  private void sendDie(String message) {send(Die,0,message);}
+  void sendPong(String s) {send(Pong,0,s);}
+  void sendPing(String s) {send(Ping,0,s);}
+
+  private void sendBye() {send(Bye,0,"");}
+  private void sendBye(String message) {send(Bye,0,message);}
+  
+  public void sendDie() { send(Die,0,""); }
+  public void sendDie(String message) {send(Die,0,message);}
+
   private InetAddress getRemoteAddress() { return socket.getInetAddress(); }
+
+  public String toString() {
+    return "IvyClient "+bus.appName+":"+appName;
+  }
   private void traceDebug(String s){
-    if (debug) System.out.println("-->IvyClient "+appName+"<-- "+s);
+    if (debug) System.out.println("-->IvyClient "+bus.appName+":"+appName+"<-- "+s);
+  }
+
+  class PINGER implements Runnable {
+    boolean isPinging = false;
+    public void run() {
+      isPinging=true;
+      while (isPinging) {
+	try {
+	  Thread.sleep(PINGTIMEOUT);
+	  sendPing("are you here ?");
+	} catch (InterruptedException ie) {
+	}
+      }
+    }
+    public void stopPinging() { isPinging=false; pingerThread.interrupt();}
   }
+
 } // class IvyClient
 /* EOF */