gomp-20050608-branch/libjava/classpath/gnu/java/rmi/server/UnicastServer.java

   1 /* UnicastServer.java --
   2    Copyright (c) 1996, 1997, 1998, 1999, 2002, 2004
   3    Free Software Foundation, Inc.
   4
   5 This file is part of GNU Classpath.
   6
   7 GNU Classpath is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GNU Classpath is distributed in the hope that it will be useful, but
  13 WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU Classpath; see the file COPYING.  If not, write to the
  19 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  20 02110-1301 USA.
  21
  22 Linking this library statically or dynamically with other modules is
  23 making a combined work based on this library.  Thus, the terms and
  24 conditions of the GNU General Public License cover the whole
  25 combination.
  26
  27 As a special exception, the copyright holders of this library give you
  28 permission to link this library with independent modules to produce an
  29 executable, regardless of the license terms of these independent
  30 modules, and to copy and distribute the resulting executable under
  31 terms of your choice, provided that you also meet, for each linked
  32 independent module, the terms and conditions of the license of that
  33 module.  An independent module is a module which is not derived from
  34 or based on this library.  If you modify this library, you may extend
  35 this exception to your version of the library, but you are not
  36 obligated to do so.  If you do not wish to do so, delete this
  37 exception statement from your version. */
  38
  39
  40 package gnu.java.rmi.server;
  41
  42 import gnu.java.rmi.dgc.DGCImpl;
  43
  44 import java.io.DataOutputStream;
  45 import java.io.IOException;
  46 import java.io.ObjectInputStream;
  47 import java.io.ObjectOutputStream;
  48 import java.rmi.NoSuchObjectException;
  49 import java.rmi.Remote;
  50 import java.rmi.RemoteException;
  51 import java.rmi.ServerError;
  52 import java.rmi.server.ObjID;
  53 import java.rmi.server.UID;
  54 import java.util.Collections;
  55 import java.util.Map;
  56 import java.util.Hashtable;
  57 import java.util.IdentityHashMap;
  58
  59 public class UnicastServer
  60         implements ProtocolConstants {
  61
  62 static private Hashtable objects = new Hashtable();  //mapping OBJID to server ref
  63 static private Map refcache = Collections.synchronizedMap(new IdentityHashMap()); //mapping obj itself to server ref
  64 static private DGCImpl dgc;
  65
  66 public static void exportObject(UnicastServerRef obj) {
  67         startDGC();
  68         objects.put(obj.objid, obj);
  69         refcache.put(obj.myself, obj);
  70         obj.manager.startServer();
  71 }
  72
  73 // FIX ME: I haven't handle force parameter
  74 public static boolean unexportObject(UnicastServerRef obj, boolean force) {
  75         objects.remove(obj.objid);
  76         refcache.remove(obj.myself);
  77         obj.manager.stopServer();
  78         return true;
  79 }
  80
  81 public static UnicastServerRef getExportedRef(Remote remote){
  82     return (UnicastServerRef)refcache.get(remote);
  83 }
  84
  85 private static synchronized void startDGC() {
  86         if (dgc == null) {
  87                 try {
  88                         dgc = new DGCImpl();
  89                         // Changed DGCImpl to inherit UnicastServerRef directly
  90                         //((UnicastServerRef)dgc.getRef()).exportObject(dgc);
  91                         dgc.exportObject(dgc);
  92                 }
  93                 catch (RemoteException e) {
  94                         e.printStackTrace();
  95                 }
  96         }
  97 }
  98
  99 public static void dispatch(UnicastConnection conn) throws Exception {
 100         switch (conn.getDataInputStream().readUnsignedByte()) {
 101         case MESSAGE_CALL:
 102                 incomingMessageCall(conn);
 103                 break;
 104         case MESSAGE_PING:
 105                 // jdk sends a ping before each method call -> answer it!
 106                 DataOutputStream out = conn.getDataOutputStream();
 107                 out.writeByte(MESSAGE_PING_ACK);
 108                 out.flush();
 109                 break;
 110         default:
 111                 throw new Exception("bad method type");
 112         }
 113 }
 114
 115 private static void incomingMessageCall(UnicastConnection conn) throws IOException {
 116         ObjectInputStream in = conn.startObjectInputStream();  // (re)start ObjectInputStream
 117
 118         ObjID objid = ObjID.read(in);
 119         int method = in.readInt();
 120         long hash = in.readLong();
 121
 122 //System.out.println("ObjID: " + objid + ", method: " + method + ", hash: " + hash);
 123
 124         // Use the objid to locate the relevant UnicastServerRef
 125         UnicastServerRef uref = (UnicastServerRef)objects.get(objid);
 126         Object returnval;
 127         int returncode = RETURN_ACK;
 128         // returnval is from Method.invoke(), so we must check the return class to see
 129         // if it's primitive type
 130         Class returncls = null;
 131         if (uref != null) {
 132                 try {
 133                         // Dispatch the call to it.
 134                         returnval = uref.incomingMessageCall(conn, method, hash);
 135                         returncls = uref.getMethodReturnType(method, hash);
 136                 }
 137                 catch (Exception e) {
 138                         returnval = e;
 139                         returncode = RETURN_NACK;
 140                 }
 141                 catch (Error e) {
 142                         returnval = new ServerError ("An Error is thrown while processing the invocation on the server", e);
 143                         returncode = RETURN_NACK;
 144                 }
 145         }
 146         else {
 147                 returnval = new NoSuchObjectException("");
 148                 returncode = RETURN_NACK;
 149         }
 150
 151         conn.getDataOutputStream().writeByte(MESSAGE_CALL_ACK);
 152
 153         ObjectOutputStream out = conn.startObjectOutputStream();   // (re)start ObjectOutputStream
 154
 155         out.writeByte(returncode);
 156         (new UID()).write(out);
 157
 158         //System.out.println("returnval=" + returnval + " returncls=" + returncls);
 159
 160         if(returnval != null && returncls != null)
 161             ((RMIObjectOutputStream)out).writeValue(returnval, returncls);
 162
 163         // 1.1/1.2 void return type detection:
 164         else if (!(returnval instanceof RMIVoidValue || returncls == Void.TYPE))
 165             out.writeObject(returnval);
 166
 167         out.flush();
 168 }
 169
 170 }