/** * a software bus package * * @author Yannick Jestin * @author http://www.tls.cena.fr/products/ivy/ * * (c) CENA 1998-2004 * *
 *Ivy bus = new Ivy("Dummy agent","ready",null);
 *bus.bindMsg("(.*)",myMessageListener);
 *bus.start(getDomain(null));
 *
* * CHANGELOG: * 1.2.6: * - added serial numbers for traceDebug * - changed the semantic of -b a,b:port,c:otherport if no port is * specified for a, it take the port from the next one. If none is * specified, it takes DEFAULT_PORT * - no more asynchronous sending of message ( async bind is ok though ) * because the tests are sooooo unsuccessful * - use addElement/removeElement instead of add/remove is registering * threads ( jdk1.1 backward compatibility ) * 1.2.5: * - protection of newlines * 1.2.4: * - added an accessor for doSendToSelf * - waitForMsg() and waitForClient() to make the synchronization with * other Ivy agents easier * - with the bindAsyncMsg() to subscribe and perform each callback in a * new Thread * - bindMsg(regexp,messagelistener,boolean) allow to subscribe with a * synchrone/asynch exectution * - API change, IvyException raised when \n or \0x3 are present in bus.sendMsg() * - bindListener are now handled * - removeApplicationListener can throw IvyException * - bus.start(null) now starts on getDomain(null), first the IVYBUS * property, then the DEFAULT_DOMAIN, 127:2010 * - bindMsg() now throws an IvyException if the regexp is invalid !!! * BEWARE, this can impact lots of programs ! (fixes J007) * - no more includes the "broadcasting on " in the domain(String) method * - new function sendToSelf(boolean) allow us to send messages to * ourselves * 1.2.3: * - adds a IVYBUS property to propagate the domain once set. This way, * children forked through Ivy java can inherit from the current value. * - adds synchronized flags to allow early disconnexion * 1.2.2: * added the String domains(String d) function, in order to display the * domain list * 1.2.1: * bus.start(null) now starts on DEFAULT_DOMAIN. ( correction 1.2.4 This was not true.) * added the getDomains in order to correctly display the domain list * checks if the serverThread exists before interrupting it * no has unBindMsg(String) * 1.2.0: * setSoTimeout is back on the server socket * added a regression test main() * clients is now a Hashtable. the deletion now works better * getIvyClientsByName allows the research of IvyClient by name * getDomain doesnt throw IvyException anymore * removed the close() disconnect(IvyClient c). Fixes a big badaboum bug * getDomain becomes public * adding the sendToSelf feature * fixed the printStackTrace upon closing of the ServerSocket after a close() */ package fr.dgac.ivy ; import java.net.*; import java.io.*; import java.util.*; public class Ivy implements Runnable { /** * the name of the application on the bus */ protected String appName; /** * the protocol version number */ public static final int PROTOCOLVERSION = 3 ; public static final int PROTOCOLMINIMUM = 3 ; /** * the port for the UDP rendez vous, if none is supplied */ public static final int DEFAULT_PORT = 2010 ; /** * the domain for the UDP rendez vous */ public static final String DEFAULT_DOMAIN = "127.255.255.255:"+DEFAULT_PORT; /** * the library version, useful for development purposes only, when java is * invoked with -DIVY_DEBUG */ public static final String libVersion ="1.2.6"; private boolean debug; private ServerSocket app; private Vector watchers; private volatile Thread serverThread; // to ensure quick communication of the end private Hashtable clients = new Hashtable(); private Hashtable half = new Hashtable(); private Vector ivyApplicationListenerList = new Vector(); private Vector ivyBindListenerList = new Vector(); private Vector sendThreads = new Vector(); private boolean stopped = false; protected int applicationPort; /* Application port number */ protected String ready_message = null; protected boolean doProtectNewlines = false ; private boolean doSendToSelf = false ; protected SelfIvyClient selfIvyClient ; public final static int TIMEOUTLENGTH = 3000; private static int serial=0; private int myserial=serial++; /** * Readies the structures for the software bus connexion. * * All the dirty work is done un the start() method * @see #start * @param name The name of your Ivy agent on the software bus * @param message The hellow message you will send once ready * @param appcb A callback handling the notification of connexions and * disconnections, may be null */ public Ivy( String name, String message, IvyApplicationListener appcb) { appName = name; ready_message = message; debug = (System.getProperty("IVY_DEBUG")!=null); if ( appcb != null ) ivyApplicationListenerList.addElement( appcb ); selfIvyClient=new SelfIvyClient(this,name); } /** * Waits for a message to be received * * @since 1.2.4 * @param regexp the message we're waiting for to continue the main thread. * @param timeout in millisecond, 0 if infinite * @return the IvyClient who sent the message, or null if the timeout is * reached */ public IvyClient waitForMsg(String regexp,int timeout) throws IvyException { Waiter w = new Waiter(timeout); int re = bindMsg(regexp,w); IvyClient ic=w.waitFor(); unBindMsg(re); return ic; } /** * Waits for an other IvyClient to join the bus * * @since 1.2.4 * @param name the name of the client we're waiting for to continue the main thread. * @param timeout in millisecond, 0 if infinite * @return the first IvyClient with the name or null if the timeout is * reached */ public IvyClient waitForClient(String name,int timeout) throws IvyException { IvyClient ic; if (name==null) throw new IvyException("null name given to waitForClient"); // first check if client with the same name is on the bus for (Enumeration e=clients.elements();e.hasMoreElements();) { ic = (IvyClient)e.nextElement(); if (name.compareTo(ic.getApplicationName())==0) return ic; } // if not enter the waiting loop WaiterClient w = new WaiterClient(name,timeout); int i = addApplicationListener(w); ic=w.waitForClient(); removeApplicationListener(i); return ic; } /** * connects the Ivy bus to a domain or list of domains. * *
  • One thread (IvyWatcher) for each traffic rendezvous (either UDP broadcast or TCPMulticast) *
  • One thread (serverThread/Ivy) to accept incoming connexions on server socket *
  • a thread for each IvyClient when the connexion has been done * * @param domainbus a domain of the form 10.0.0:1234, it is similar to the * netmask without the trailing .255. This will determine the meeting point * of the different applications. Right now, this is done with an UDP * broadcast. Beware of routing problems ! You can also use a comma * separated list of domains. * */ public void start(String domainbus) throws IvyException { if (domainbus==null) domainbus=getDomain(null); Properties sysProp = System.getProperties(); sysProp.put("IVYBUS",domainbus); try { app = new ServerSocket(0); app.setSoTimeout(TIMEOUTLENGTH); applicationPort = app.getLocalPort(); } catch (IOException e) { throw new IvyException("can't open TCP service socket " + e ); } traceDebug("lib: "+libVersion+" protocol: "+PROTOCOLVERSION+" TCP service open on port "+applicationPort); watchers = new Vector(); Domain[] d = parseDomains(domainbus); // readies the rendezvous : an IvyWatcher (thread) per domain bus for (int index=0;index=0;index--) { Domain dom=d[index]; if (dom.port==0) dom.port=lastport; lastport=dom.port; } return d; } /** * disconnects from the Ivy bus */ public synchronized void stop() { if (stopped) return; stopped=true; traceDebug("beginning stopping"); try { // stopping the serverThread Thread t=serverThread; serverThread=null; if (t!=null) t.interrupt(); // The serverThread might be stopped even before having been created app.close(); // stopping the IvyWatchers for (int i=0;idoesn't receive its own messages. *

    Example: *
    the Ivy agent A performs

    b.bindMsg("^Hello (*)",cb);
    *
    the Ivy agent B performs
    b2.sendMsg("Hello world");
    *
    a thread in A will uun the callback cb with its second argument set * to a array of String, with one single element, "world" * @param regexp a perl regular expression, groups are done with parenthesis * @param callback any objects implementing the IvyMessageListener * interface, on the AWT/Swing framework * @return the id of the regular expression */ public int bindMsg(String sregexp, IvyMessageListener callback ) throws IvyException { return bindMsg(sregexp,callback,false); } /** * Subscribes to a regular expression with asyncrhonous callback execution. * * Same as bindMsg, except that the callback will be executed in a separate * thread each time. * WARNING : there is no way to predict the order of execution * of the * callbacks, i.e. a message received might trigger a callback before * another one sent before * * @since 1.2.4 * @param regexp a perl compatible regular expression, groups are done with parenthesis * @param callback any objects implementing the IvyMessageListener * interface, on the AWT/Swing framework * @return the int ID of the regular expression. */ public int bindAsyncMsg(String sregexp, IvyMessageListener callback ) throws IvyException { return bindMsg(sregexp,callback,true); } /** * Subscribes to a regular expression. * * The callback will be executed with * the saved parameters of the regexp as arguments when a message will sent * by another agent. A program doesn't receive its own messages. *

    Example: *
    the Ivy agent A performs

    b.bindMsg("^Hello (*)",cb);
    *
    the Ivy agent B performs
    b2.sendMsg("Hello world");
    *
    a thread in A will uun the callback cb with its second argument set * to a array of String, with one single element, "world" * @since 1.2.4 * @param regexp a perl regular expression, groups are done with parenthesis * @param callback any objects implementing the IvyMessageListener * interface, on the AWT/Swing framework * @param async if true, each callback will be run in a separate thread, * default is false * @return the id of the regular expression */ public int bindMsg(String sregexp, IvyMessageListener callback,boolean async ) throws IvyException { // adds the regexp to our collection in selfIvyClient int key=selfIvyClient.bindMsg(sregexp,callback,async); // notifies the other clients this new regexp for (Enumeration e=clients.elements();e.hasMoreElements();) { IvyClient c = (IvyClient)e.nextElement(); c.sendRegexp(key,sregexp); } return key; } /** * unsubscribes a regular expression * * @param id the id of the regular expression, returned when it was bound */ public void unBindMsg(int id) throws IvyException { selfIvyClient.unBindMsg(id); for (Enumeration e=clients.elements();e.hasMoreElements();) ((IvyClient)e.nextElement()).delRegexp(id ); } /** * unsubscribes a regular expression * * @return a boolean, true if the regexp existed, false otherwise or * whenever an exception occured during unbinding * @param String the string for the regular expression */ public boolean unBindMsg(String re) { return selfIvyClient.unBindMsg(re); } /** * adds a bind listener to a bus * @param callback is an object implementing the IvyBindListener interface * @return the id of the bind listener, useful if you wish to remove it later * @since 1.2.4 */ public int addBindListener(IvyBindListener callback){ ivyBindListenerList.addElement(callback); return ivyBindListenerList.indexOf(callback); } /** * removes a bind listener * @param id the id of the bind listener to remove * @since 1.2.4 */ public void removeBindListener(int id) throws IvyException { try { ivyBindListenerList.removeElementAt(id); } catch (ArrayIndexOutOfBoundsException aie) { throw new IvyException(id+" is not a valid Id"); } } /** * adds an application listener to a bus * @param callback is an object implementing the IvyApplicationListener * interface * @return the id of the application listener, useful if you wish to remove * it later */ public int addApplicationListener(IvyApplicationListener callback){ ivyApplicationListenerList.addElement(callback); return ivyApplicationListenerList.indexOf( callback ); } /** * removes an application listener * @param id the id of the application listener to remove */ public void removeApplicationListener(int id) throws IvyException { try { ivyApplicationListenerList.removeElementAt(id); } catch (ArrayIndexOutOfBoundsException aie) { throw new IvyException(id+" is not a valid Id"); } } /* invokes the application listeners upon arrival of a new Ivy client */ protected void clientConnects(IvyClient client){ for ( int i = 0 ; i < ivyApplicationListenerList.size(); i++ ) { ((IvyApplicationListener)ivyApplicationListenerList.elementAt(i)).connect(client); } } /* invokes the application listeners upon the departure of an Ivy client */ protected void clientDisconnects(IvyClient client){ for ( int i = 0 ; i < ivyApplicationListenerList.size(); i++ ) { ((IvyApplicationListener)ivyApplicationListenerList.elementAt(i)).disconnect(client); } } /* invokes the bind listeners */ protected void regexpReceived(IvyClient client,int id,String sregexp){ for ( int i = 0 ; i < ivyBindListenerList.size(); i++ ) { ((IvyBindListener)ivyBindListenerList.elementAt(i)).bindPerformed(client,id,sregexp); } } /* invokes the bind listeners */ protected void regexpDeleted(IvyClient client,int id,String sregexp){ for ( int i = 0 ; i < ivyBindListenerList.size(); i++ ) { ((IvyBindListener)ivyBindListenerList.elementAt(i)).unbindPerformed(client,id,sregexp); } } /* * invokes the application listeners when we are summoned to die * then stops */ protected void dieReceived(IvyClient client, int id,String message){ for ( int i=0 ;i0; traceDebug(ic+" "+ic.toStringExt()+((shoulda)?" must leave ":" must not leave")); traceDebug(peer+" "+peer.toStringExt()+((!shoulda)?" must leave ":" must not leave")); return shoulda; } private IvyClient searchPeer(IvyClient ic) { IvyClient peer; for (Enumeration e=half.elements();e.hasMoreElements();) if ((peer=(IvyClient)e.nextElement()).equals(ic)) return peer; for (Enumeration e=clients.elements();e.hasMoreElements();) if ((peer=(IvyClient)e.nextElement()).equals(ic)) return peer; return null; } /* * the service socket thread reader main loop */ public void run() { traceDebug("service thread started"); // THREADDEBUG Thread thisThread=Thread.currentThread(); while(thisThread==serverThread){ try { Socket socket = app.accept(); if ((thisThread!=serverThread)||stopped) break; // early disconnexion new IvyClient(this,socket,0); // the peer called me } catch (InterruptedIOException ie) { if (thisThread!=serverThread) break; } catch( IOException e ) { if (serverThread==thisThread) { traceDebug("Error IvyServer exception: " + e.getMessage()); System.out.println("Ivy server socket reader caught an exception " + e.getMessage()); System.out.println("this is probably a bug in your JVM ! (e.g. blackdown jdk1.1.8 linux)"); System.exit(0); } else { traceDebug("my server socket has been closed"); } } } traceDebug("service thread stopped"); // THREADDEBUG } protected int getSerial() { return myserial ; } private void traceDebug(String s){ if (debug) System.out.println("-->Ivy["+myserial+"]<-- "+s); } // stuff to guarantee that all the treads have left synchronized void registerThread(Thread t) { sendThreads.addElement(t); } synchronized void unRegisterThread(Thread t) { sendThreads.removeElement(t); } synchronized Thread getOneThread() { if (sendThreads.size()==0) return null; return (Thread) sendThreads.firstElement(); } // a small private method for debbugging purposes private String getClientNames(Hashtable t) { String s = "("; for (Enumeration e=t.elements();e.hasMoreElements();){ s+=((IvyClient)e.nextElement()).getApplicationName()+","; } return s+")"; } public String domains(String toparse) { String s=""; Ivy.Domain[] d = parseDomains(toparse); for (int index=0;index