old-autovect-branch/libjava/classpath/gnu/CORBA/Poa/gnuPOAManager.java

   1 /* gnuPOAManager.java --
   2    Copyright (C) 2005 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 02110-1301 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38
  39 package gnu.CORBA.Poa;
  40
  41 import org.omg.CORBA.BAD_INV_ORDER;
  42 import org.omg.CORBA.LocalObject;
  43 import org.omg.PortableInterceptor.NON_EXISTENT;
  44 import org.omg.PortableInterceptor.ObjectReferenceTemplate;
  45 import org.omg.PortableServer.POAManager;
  46 import org.omg.PortableServer.POAManagerPackage.AdapterInactive;
  47 import org.omg.PortableServer.POAManagerPackage.State;
  48
  49 import java.util.HashSet;
  50 import java.util.Iterator;
  51
  52 /**
  53  * The implementation of the POA manager. The manager is a controlled
  54  * switch that can change its states in response to the method calls
  55  * and throw exceptions if the requested change is invalid. It is possible
  56  * to check the state this switch. It does not do anything else.
  57  *
  58  * @author Audrius Meskauskas, Lithuania (AudriusA@Bioinformatics.org)
  59  */
  60 public class gnuPOAManager
  61   extends LocalObject
  62   implements POAManager
  63 {
  64   /**
  65    * Use serialVersionUID for interoperability.
  66    */
  67   private static final long serialVersionUID = 1;
  68
  69   /**
  70    * The POAs, controlled by this manager.
  71    */
  72   private HashSet POAs = new HashSet();
  73
  74   /**
  75    * The state of the manager. The newly created manager is always
  76    * in the holding state.
  77    */
  78   State state = State.HOLDING;
  79
  80   /**
  81    * Get the state of the POA manager.
  82    */
  83   public State get_state()
  84   {
  85     return state;
  86   }
  87
  88   /**
  89    * Turns the associated POAs into active state, allowing them to receive
  90    * and process requests.
  91    *
  92    * @throws if the POAs are in the inactive state. If once inactivated,
  93    * the POA cannot be activated again. This method can only be called
  94    * to leave the holding or discarding state.
  95    */
  96   public void activate()
  97                 throws AdapterInactive
  98   {
  99     if (state != State.INACTIVE)
 100       state = State.ACTIVE;
 101     else
 102       throw new AdapterInactive();
 103
 104     notifyInterceptors(state.value());
 105   }
 106
 107   /**
 108    * Turns the associated POAs into holding state. In this state, the POAs
 109    * queue incoming requests but do not process them.
 110    *
 111    * @param wait_for_completion if true, the method call suspends the current
 112    * thread till POAs complete the requests they are currently processing. If
 113    * false, the method returns immediately.
 114
 115    * @throws AdapterInactive if the POAs are in the inactive state.
 116    */
 117   public void hold_requests(boolean wait_for_completion)
 118                      throws AdapterInactive
 119   {
 120     if (state != State.INACTIVE)
 121       state = State.HOLDING;
 122     else
 123       throw new AdapterInactive();
 124
 125     notifyInterceptors(state.value());
 126
 127     if (wait_for_completion)
 128       waitForIdle();
 129   }
 130
 131   /**
 132    *
 133    * Turns the asociated POAs into inactive state. The POAs in the incative
 134    * state will reject new requests. If the POA is once inactivated, it
 135    * cannot be activated again. The operation is used when
 136    * the associated POAs are to be shut down.
 137    *
 138    * @param etherealize_objects if true, the servant managers of the
 139    * associated POAs, having RETAIN and USE_SERVANT_MANAGER policies,
 140    * will receive a call of {@link ServantActivatorOperations#etherealize}.
 141    *
 142    * @param wait_for_completion if true, the method call suspends the current
 143    * thread till POAs complete the requests they are currently processing. If
 144    * false, the method returns immediately.
 145    *
 146    * @throws AdapterInactive if the POAs are already in the inactive state.
 147    *
 148    * @see POAOperations#destroy
 149    */
 150   public void deactivate(boolean etherealize_objects,
 151                          boolean wait_for_completion
 152                         )
 153                   throws AdapterInactive
 154   {
 155     if (state == State.INACTIVE)
 156       throw new AdapterInactive("Repetetive inactivation");
 157     state = State.INACTIVE;
 158
 159     notifyInterceptors(state.value());
 160
 161     if (wait_for_completion)
 162       waitForIdle();
 163
 164     Iterator iter = POAs.iterator();
 165     while (iter.hasNext())
 166       {
 167         gnuPOA poa = (gnuPOA) iter.next();
 168
 169         // If the servant activator is non null, this means it has been
 170         // set - hence the policies are appropriate.
 171         if (poa.servant_activator != null)
 172           poa.etherealizeAll();
 173       }
 174   }
 175
 176   /**
 177    * Turns the associated POAs into discaring state. In this state, the POAs
 178    * discard the incoming requests. This mode is used in situations when
 179    * the server is flooded with requests. The client receives remote exception
 180    * ({@link org.omg.CORBA.TRANSIENT}, minor code 1).
 181    *
 182    * @param wait_for_completion if true, the method call suspends the current
 183    * thread till POAs complete the requests they are currently processing. If
 184    * false, the method returns immediately.
 185
 186    * @throws AdapterInactive if the POAs are in the inactive state.
 187    */
 188   public void discard_requests(boolean wait_for_completion)
 189                         throws AdapterInactive
 190   {
 191     if (state != State.INACTIVE)
 192       state = State.DISCARDING;
 193     else
 194       throw new AdapterInactive();
 195
 196     notifyInterceptors(state.value());
 197
 198     if (wait_for_completion)
 199       waitForIdle();
 200   }
 201
 202   /**
 203    * Suspend the current thread while at least one of the associated POA is
 204    * actively processing some requests. The method assumes that the POAs
 205    * are not accepting the <i>new</i> requests due manager state.
 206    *
 207    * @throws BAD_INV_ORDER if the POAs are in the active state.
 208    */
 209   public void waitForIdle()
 210   {
 211     if (state == State.ACTIVE)
 212       throw new BAD_INV_ORDER("The state is active");
 213
 214     gnuPOA poa;
 215     Iterator iter = POAs.iterator();
 216
 217     while (iter.hasNext())
 218       {
 219         poa = (gnuPOA) iter.next();
 220         poa.waitWhileRunning();
 221       }
 222   }
 223
 224   /**
 225    * Add the POA that will be controlled by this manager.
 226    *
 227    * @param poa the POA.
 228    */
 229   public void addPoa(gnuPOA poa)
 230   {
 231     POAs.add(poa);
 232   }
 233
 234   /**
 235    * Remove the POA, releasing it from the control of this manager.
 236    * Called in POA finaliser.
 237    *
 238    * @param poa the POA to remove.
 239    */
 240   public void removePOA(gnuPOA poa)
 241   {
 242     POAs.remove(poa);
 243   }
 244
 245   /**
 246    * This method is called when POA is destryed. The interceptors are
 247    * notified.
 248    */
 249   public void poaDestroyed(gnuPOA poa)
 250   {
 251     notifyInterceptors(NON_EXISTENT.value);
 252   }
 253
 254   /**
 255    * Notify CORBA 3.0 interceptors about the status change.
 256    */
 257   public synchronized void notifyInterceptors(int new_state)
 258   {
 259     gnuPOA poa;
 260     Iterator iter = POAs.iterator();
 261
 262     // The System.identityHashCode is also called in gnuIorInfo.
 263     while (iter.hasNext())
 264       {
 265         poa = (gnuPOA) iter.next();
 266         if (poa.m_orb.iIor != null)
 267           {
 268             poa.m_orb.iIor.adapter_manager_state_changed(
 269               System.identityHashCode(this), (short) new_state);
 270           }
 271       }
 272   }
 273 }