[353691] Add lock notifications and lock caching

https://bugs.eclipse.org/bugs/show_bug.cgi?id=353691

14 files changed, 577 insertions, 39 deletions

diff --git a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/CDOObject.java b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/CDOObject.java
index 24e65bfe08..c08fc07adf 100644
--- a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/CDOObject.java
+++ b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/CDOObject.java
@@ -13,6 +13,7 @@ package org.eclipse.emf.cdo;
 import org.eclipse.emf.cdo.common.id.CDOID;
 import org.eclipse.emf.cdo.common.id.CDOIDTemp;
 import org.eclipse.emf.cdo.common.id.CDOWithID;
+import org.eclipse.emf.cdo.common.lock.CDOLockState;
 import org.eclipse.emf.cdo.common.revision.CDORevision;
 import org.eclipse.emf.cdo.common.revision.CDORevisionManager;
 import org.eclipse.emf.cdo.eresource.CDOResource;
@@ -141,6 +142,13 @@ public interface CDOObject extends EObject, CDOWithID
   public CDOLock cdoWriteOption();
 
   /**
+   * Returns the {@link CDOLockState} of this object.
+   * 
+   * @since 4.1
+   */
+  public CDOLockState cdoLockState();
+
+  /**
    * Ensures that the revisions of the contained objects up to the given depth are in the local
    * {@link CDORevisionManager revision cache}. Subsequent access to the respective contained objects will not lead to
    * server round-trips after calling this method.
diff --git a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/view/CDOLocksChangedEvent.java b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/view/CDOLocksChangedEvent.java
new file mode 100644
index 0000000000..904dabbaaf
--- /dev/null
+++ b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/view/CDOLocksChangedEvent.java
@@ -0,0 +1,24 @@
+/**
+ * Copyright (c) 2004 - 2011 Eike Stepper (Berlin, Germany) and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ * 
+ * Contributors:
+ *    Caspar De Groot - initial API and implementation
+ */
+package org.eclipse.emf.cdo.view;
+
+import org.eclipse.emf.cdo.common.lock.CDOLockChangeInfo;
+
+/**
+ * A {@link CDOViewEvent view event} fired when lock notifications are being received from a repository.
+ * {@link CDOView.Options#setLockNotificationEnabled(boolean)} must be enabled for this event to be fired.
+ * 
+ * @author Caspar De Groot
+ * @since 4.1
+ */
+public interface CDOLocksChangedEvent extends CDOViewEvent, CDOLockChangeInfo
+{
+}
diff --git a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/view/CDOView.java b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/view/CDOView.java
index bfe7d060d3..4d74a8f3c2 100644
--- a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/view/CDOView.java
+++ b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/view/CDOView.java
@@ -21,6 +21,7 @@ import org.eclipse.emf.cdo.common.branch.CDOBranch;
 import org.eclipse.emf.cdo.common.branch.CDOBranchPoint;
 import org.eclipse.emf.cdo.common.commit.CDOChangeSetData;
 import org.eclipse.emf.cdo.common.id.CDOID;
+import org.eclipse.emf.cdo.common.lock.CDOLockState;
 import org.eclipse.emf.cdo.common.revision.CDORevision;
 import org.eclipse.emf.cdo.common.util.CDOException;
 import org.eclipse.emf.cdo.eresource.CDOResource;
@@ -34,6 +35,7 @@ import org.eclipse.emf.cdo.util.ReadOnlyException;
 import org.eclipse.net4j.util.collection.CloseableIterator;
 import org.eclipse.net4j.util.concurrent.IRWLockManager;
 import org.eclipse.net4j.util.concurrent.IRWLockManager.LockType;
+import org.eclipse.net4j.util.event.IListener;
 import org.eclipse.net4j.util.event.INotifier;
 import org.eclipse.net4j.util.options.IOptions;
 import org.eclipse.net4j.util.options.IOptionsContainer;
@@ -466,6 +468,27 @@ public interface CDOView extends CDOCommonView, CDOUpdatable, INotifier, IOption
     public void setInvalidationNotificationEnabled(boolean enabled);
 
     /**
+     * Returns <code>true</code> if this view will notify its {@link IListener listeners} about changes to the
+     * {@link CDOLockState lock states} of the objects in this view (due to lock operations in <i>other</i> views),
+     * <code>false</code> otherwise.
+     * 
+     * @see CDOLocksChangedEvent
+     * @see CDOLockState
+     * @since 4.1
+     */
+    public boolean isLockNotificationEnabled();
+
+    /**
+     * Specifies whether this view will notify its {@link IListener listeners} about changes to the {@link CDOLockState
+     * lock states} of the objects in this view (due to lock operations in <i>other</i> views), or not.
+     * 
+     * @see CDOLocksChangedEvent
+     * @see CDOLockState
+     * @since 4.1
+     */
+    public void setLockNotificationEnabled(boolean enabled);
+
+    /**
      * Returns the current set of {@link CDOAdapterPolicy change subscription policies}.
      * 
      * @return The current set of change subscription policies, never <code>null</code>.
@@ -646,6 +669,14 @@ public interface CDOView extends CDOCommonView, CDOUpdatable, INotifier, IOption
     }
 
     /**
+     * @author Caspar De Groot
+     * @since 4.1
+     */
+    public interface LockNotificationEvent extends IOptionsEvent
+    {
+    }
+
+    /**
      * An {@link IOptionsEvent options event} fired from view {@link CDOView#options() options} when the
      * {@link Options#setRevisionPrefetchingPolicy(CDORevisionPrefetchingPolicy) revision prefetching policy} option has
      * changed.
diff --git a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/CDOObjectImpl.java b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/CDOObjectImpl.java
index e2e2aa0924..ffe5f921ce 100644
--- a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/CDOObjectImpl.java
+++ b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/CDOObjectImpl.java
@@ -15,6 +15,7 @@ import org.eclipse.emf.cdo.CDOLock;
 import org.eclipse.emf.cdo.CDOObject;
 import org.eclipse.emf.cdo.CDOState;
 import org.eclipse.emf.cdo.common.id.CDOID;
+import org.eclipse.emf.cdo.common.lock.CDOLockState;
 import org.eclipse.emf.cdo.common.model.EMFUtil;
 import org.eclipse.emf.cdo.common.revision.CDORevision;
 import org.eclipse.emf.cdo.eresource.CDOResource;
@@ -63,6 +64,7 @@ import org.eclipse.emf.spi.cdo.InternalCDOObject;
 import org.eclipse.emf.spi.cdo.InternalCDOView;
 
 import java.util.Collection;
+import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 import java.util.ListIterator;
@@ -84,6 +86,8 @@ public class CDOObjectImpl extends EStoreEObjectImpl implements InternalCDOObjec
 
   private InternalCDORevision revision;
 
+  private CDOLockState lockState;
+
   /**
    * CDO uses this list instead of eSettings for transient objects. EMF uses eSettings as cache. CDO deactivates the
    * cache but EMF still used eSettings to store list wrappers. CDO needs another place to store the real list with the
@@ -184,17 +188,7 @@ public class CDOObjectImpl extends EStoreEObjectImpl implements InternalCDOObjec
    */
   public CDOLock cdoReadLock()
   {
-    if (FSMUtil.isTransient(this))
-    {
-      throw new IllegalStateException("Call CDOView.lockObjects() for transient object " + this);
-    }
-
-    if (FSMUtil.isNew(this))
-    {
-      return CDOLockImpl.NOOP;
-    }
-
-    return new CDOLockImpl(this, LockType.READ);
+    return createCDOLock(LockType.READ);
   }
 
   /**
@@ -202,6 +196,19 @@ public class CDOObjectImpl extends EStoreEObjectImpl implements InternalCDOObjec
    */
   public CDOLock cdoWriteLock()
   {
+    return createCDOLock(LockType.WRITE);
+  }
+
+  /**
+   * @since 4.1
+   */
+  public CDOLock cdoWriteOption()
+  {
+    return createCDOLock(LockType.OPTION);
+  }
+
+  private CDOLock createCDOLock(LockType type)
+  {
     if (FSMUtil.isTransient(this))
     {
       throw new IllegalStateException("Call CDOView.lockObjects() for transient object " + this);
@@ -212,25 +219,31 @@ public class CDOObjectImpl extends EStoreEObjectImpl implements InternalCDOObjec
       return CDOLockImpl.NOOP;
     }
 
-    return new CDOLockImpl(this, LockType.WRITE);
+    return new CDOLockImpl(this, type);
   }
 
   /**
    * @since 4.1
    */
-  public CDOLock cdoWriteOption()
+  public synchronized CDOLockState cdoLockState()
   {
-    if (FSMUtil.isTransient(this))
+    if (lockState == null)
     {
-      throw new IllegalStateException("Call CDOView.lockObjects() for transient object " + this);
+      if (!FSMUtil.isTransient(this) && !FSMUtil.isNew(this))
+      {
+        lockState = view.getLockStates(Collections.singletonList(id))[0];
+      }
     }
 
-    if (FSMUtil.isNew(this))
-    {
-      return CDOLockImpl.NOOP;
-    }
+    return lockState;
+  }
 
-    return new CDOLockImpl(this, LockType.OPTION);
+  /**
+   * @since 4.1
+   */
+  public synchronized void cdoInternalSetLockState(CDOLockState lockState)
+  {
+    this.lockState = lockState;
   }
 
   public void cdoInternalSetID(CDOID id)
diff --git a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/object/CDOLegacyWrapper.java b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/object/CDOLegacyWrapper.java
index 3678c01d21..e0be18394d 100644
--- a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/object/CDOLegacyWrapper.java
+++ b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/object/CDOLegacyWrapper.java
@@ -14,6 +14,7 @@ package org.eclipse.emf.internal.cdo.object;
 import org.eclipse.emf.cdo.CDOObject;
 import org.eclipse.emf.cdo.CDOState;
 import org.eclipse.emf.cdo.common.id.CDOID;
+import org.eclipse.emf.cdo.common.lock.CDOLockState;
 import org.eclipse.emf.cdo.common.model.CDOModelUtil;
 import org.eclipse.emf.cdo.common.model.CDOPackageRegistry;
 import org.eclipse.emf.cdo.common.model.CDOType;
@@ -57,6 +58,7 @@ import java.lang.reflect.Field;
 import java.lang.reflect.InvocationHandler;
 import java.lang.reflect.Method;
 import java.lang.reflect.Proxy;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -95,6 +97,8 @@ public abstract class CDOLegacyWrapper extends CDOObjectWrapper
 
   protected InternalCDORevision revision;
 
+  protected CDOLockState lockState;
+
   /**
    * It could happen that while <i>revisionToInstance()</i> is executed externally the <i>internalPostLoad()</i> method
    * will be called. This happens for example if <i>internalPostInvalidate()</i> is called. The leads to another
@@ -121,6 +125,24 @@ public abstract class CDOLegacyWrapper extends CDOObjectWrapper
     return revision;
   }
 
+  public synchronized CDOLockState cdoLockState()
+  {
+    if (lockState == null)
+    {
+      if (!FSMUtil.isTransient(this) && !FSMUtil.isNew(this))
+      {
+        lockState = view.getLockStates(Collections.singletonList(id))[0];
+      }
+    }
+
+    return lockState;
+  }
+
+  public synchronized void cdoInternalSetLockState(CDOLockState lockState)
+  {
+    this.lockState = lockState;
+  }
+
   @Override
   public CDOResourceImpl cdoResource()
   {
diff --git a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/object/CDOLockImpl.java b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/object/CDOLockImpl.java
index 851c0a10cf..d161642a22 100644
--- a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/object/CDOLockImpl.java
+++ b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/object/CDOLockImpl.java
@@ -12,6 +12,8 @@
 package org.eclipse.emf.internal.cdo.object;
 
 import org.eclipse.emf.cdo.CDOLock;
+import org.eclipse.emf.cdo.common.lock.CDOLockOwner;
+import org.eclipse.emf.cdo.common.lock.CDOLockUtil;
 import org.eclipse.emf.cdo.util.LockTimeoutException;
 
 import org.eclipse.net4j.util.WrappedException;
@@ -33,14 +35,17 @@ public class CDOLockImpl implements CDOLock
 {
   public static final CDOLock NOOP = new NOOPLockImpl();
 
-  private InternalCDOObject object;
+  private final InternalCDOObject object;
 
-  private LockType type;
+  private final LockType type;
+
+  private final CDOLockOwner owner;
 
   public CDOLockImpl(InternalCDOObject object, LockType type)
   {
     this.object = object;
     this.type = type;
+    owner = CDOLockUtil.createLockOwner(object.cdoView());
   }
 
   public LockType getType()
@@ -50,7 +55,7 @@ public class CDOLockImpl implements CDOLock
 
   public boolean isLocked()
   {
-    return object.cdoView().isObjectLocked(object, type, false);
+    return object.cdoLockState().isLocked(type, owner, false);
   }
 
   /**
@@ -58,7 +63,7 @@ public class CDOLockImpl implements CDOLock
    */
   public boolean isLockedByOthers()
   {
-    return object.cdoView().isObjectLocked(object, type, true);
+    return object.cdoLockState().isLocked(type, owner, true);
   }
 
   public void lock()
diff --git a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/session/CDOSessionImpl.java b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/session/CDOSessionImpl.java
index 4a39ec7d44..293f899465 100644
--- a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/session/CDOSessionImpl.java
+++ b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/session/CDOSessionImpl.java
@@ -27,6 +27,7 @@ import org.eclipse.emf.cdo.common.id.CDOID;
 import org.eclipse.emf.cdo.common.id.CDOIDGenerator;
 import org.eclipse.emf.cdo.common.lob.CDOLobInfo;
 import org.eclipse.emf.cdo.common.lob.CDOLobStore;
+import org.eclipse.emf.cdo.common.lock.CDOLockChangeInfo;
 import org.eclipse.emf.cdo.common.model.CDOPackageUnit;
 import org.eclipse.emf.cdo.common.model.EMFUtil;
 import org.eclipse.emf.cdo.common.protocol.CDOAuthenticator;
@@ -89,6 +90,7 @@ import org.eclipse.net4j.util.WrappedException;
 import org.eclipse.net4j.util.collection.Pair;
 import org.eclipse.net4j.util.concurrent.IRWLockManager;
 import org.eclipse.net4j.util.concurrent.IRWLockManager.LockType;
+import org.eclipse.net4j.util.concurrent.IRWOLockManager;
 import org.eclipse.net4j.util.concurrent.RWOLockManager;
 import org.eclipse.net4j.util.event.Event;
 import org.eclipse.net4j.util.event.EventUtil;
@@ -183,7 +185,7 @@ public abstract class CDOSessionImpl extends CDOTransactionContainerImpl impleme
     }
   };
 
-  private IRWLockManager<CDOSessionImpl, Object> lockManager = new RWOLockManager<CDOSessionImpl, Object>();
+  private IRWOLockManager<CDOSessionImpl, Object> lockManager = new RWOLockManager<CDOSessionImpl, Object>();
 
   @ExcludeFromDump
   private Set<CDOSessionImpl> singletonCollection = Collections.singleton(this);
@@ -715,17 +717,48 @@ public abstract class CDOSessionImpl extends CDOTransactionContainerImpl impleme
   public boolean waitForUpdate(long updateTime, long timeoutMillis)
   {
     long end = timeoutMillis == NO_TIMEOUT ? Long.MAX_VALUE : System.currentTimeMillis() + timeoutMillis;
-    for (CDOView view : getViews())
+    InternalCDOView views[] = getViews();
+    if (views.length > 0)
     {
-      long viewTimeoutMillis = timeoutMillis == NO_TIMEOUT ? NO_TIMEOUT : end - System.currentTimeMillis();
-      boolean ok = view.waitForUpdate(updateTime, viewTimeoutMillis);
-      if (!ok)
+      for (CDOView view : views)
       {
-        return false;
+        long viewTimeoutMillis = timeoutMillis == NO_TIMEOUT ? NO_TIMEOUT : end - System.currentTimeMillis();
+        boolean ok = view.waitForUpdate(updateTime, viewTimeoutMillis);
+        if (!ok)
+        {
+          return false;
+        }
       }
+
+      return true;
     }
 
-    return true;
+    // Session without views
+    for (;;)
+    {
+      synchronized (lastUpdateTimeLock)
+      {
+        if (lastUpdateTime >= updateTime)
+        {
+          return true;
+        }
+
+        long now = System.currentTimeMillis();
+        if (now >= end)
+        {
+          return false;
+        }
+
+        try
+        {
+          lastUpdateTimeLock.wait(end - now);
+        }
+        catch (InterruptedException ex)
+        {
+          throw WrappedException.wrap(ex);
+        }
+      }
+    }
   }
 
   /**
@@ -803,6 +836,14 @@ public abstract class CDOSessionImpl extends CDOTransactionContainerImpl impleme
     }
   }
 
+  public void handleLockNotification(CDOLockChangeInfo lockChangeInfo)
+  {
+    for (InternalCDOView view : getViews())
+    {
+      view.handleLockNotification(lockChangeInfo);
+    }
+  }
+
   private void registerPackageUnits(List<CDOPackageUnit> packageUnits)
   {
     InternalCDOPackageRegistry packageRegistry = getPackageRegistry();
diff --git a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/session/DelegatingSessionProtocol.java b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/session/DelegatingSessionProtocol.java
index 875a77172d..c88715ae53 100644
--- a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/session/DelegatingSessionProtocol.java
+++ b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/session/DelegatingSessionProtocol.java
@@ -24,6 +24,7 @@ import org.eclipse.emf.cdo.common.id.CDOID;
 import org.eclipse.emf.cdo.common.id.CDOIDProvider;
 import org.eclipse.emf.cdo.common.lob.CDOLob;
 import org.eclipse.emf.cdo.common.lob.CDOLobInfo;
+import org.eclipse.emf.cdo.common.lock.CDOLockState;
 import org.eclipse.emf.cdo.common.model.CDOPackageUnit;
 import org.eclipse.emf.cdo.common.revision.CDOIDAndVersion;
 import org.eclipse.emf.cdo.common.revision.CDORevisionHandler;
@@ -384,6 +385,38 @@ public class DelegatingSessionProtocol extends Lifecycle implements CDOSessionPr
     }
   }
 
+  public CDOLockState[] getLockStates(int viewID, Collection<CDOID> ids)
+  {
+    int attempt = 0;
+    for (;;)
+    {
+      try
+      {
+        return delegate.getLockStates(viewID, ids);
+      }
+      catch (Exception ex)
+      {
+        handleException(++attempt, ex);
+      }
+    }
+  }
+
+  public void enableLockNotifications(int viewID, boolean enable)
+  {
+    int attempt = 0;
+    for (;;)
+    {
+      try
+      {
+        delegate.enableLockNotifications(viewID, enable);
+      }
+      catch (Exception ex)
+      {
+        handleException(++attempt, ex);
+      }
+    }
+  }
+
   public boolean isObjectLocked(CDOView view, CDOObject object, LockType lockType, boolean byOthers)
   {
     int attempt = 0;
@@ -579,6 +612,7 @@ public class DelegatingSessionProtocol extends Lifecycle implements CDOSessionPr
     }
   }
 
+  @Deprecated
   public LockObjectsResult lockObjects(List<InternalCDORevision> viewedRevisions, int viewID, CDOBranch viewedBranch,
       LockType lockType, long timeout) throws InterruptedException
   {
@@ -596,6 +630,60 @@ public class DelegatingSessionProtocol extends Lifecycle implements CDOSessionPr
     }
   }
 
+  /**
+   * @since 4.1
+   */
+  public LockObjectsResult lockObjects2(List<CDORevisionKey> revisionKeys, int viewID, CDOBranch viewedBranch,
+      LockType lockType, long timeout) throws InterruptedException
+
+  {
+    int attempt = 0;
+    for (;;)
+    {
+      try
+      {
+        return delegate.lockObjects2(revisionKeys, viewID, viewedBranch, lockType, timeout);
+      }
+      catch (Exception ex)
+      {
+        handleException(++attempt, ex);
+      }
+    }
+  }
+
+  public LockObjectsResult delegateLockObjects(String lockAreaID, List<CDORevisionKey> revisionKeys,
+      CDOBranch viewedBranch, LockType lockType, long timeout) throws InterruptedException
+  {
+    int attempt = 0;
+    for (;;)
+    {
+      try
+      {
+        return delegate.delegateLockObjects(lockAreaID, revisionKeys, viewedBranch, lockType, timeout);
+      }
+      catch (Exception ex)
+      {
+        handleException(++attempt, ex);
+      }
+    }
+  }
+
+  public UnlockObjectsResult delegateUnlockObjects(String lockAreaID, Collection<CDOID> objectIDs, LockType lockType)
+  {
+    int attempt = 0;
+    for (;;)
+    {
+      try
+      {
+        return delegate.delegateUnlockObjects(lockAreaID, objectIDs, lockType);
+      }
+      catch (Exception ex)
+      {
+        handleException(++attempt, ex);
+      }
+    }
+  }
+
   public void query(CDOView view, AbstractQueryIterator<?> queryResult)
   {
     int attempt = 0;
@@ -665,14 +753,14 @@ public class DelegatingSessionProtocol extends Lifecycle implements CDOSessionPr
     }
   }
 
-  public void unlockObjects(CDOView view, Collection<? extends CDOObject> objects, LockType lockType)
+  public void unlockObjects(CDOView view, Collection<CDOID> objectIDs, LockType lockType)
   {
     int attempt = 0;
     for (;;)
     {
       try
       {
-        delegate.unlockObjects(view, objects, lockType);
+        delegate.unlockObjects(view, objectIDs, lockType);
         return;
       }
       catch (Exception ex)
@@ -682,6 +770,22 @@ public class DelegatingSessionProtocol extends Lifecycle implements CDOSessionPr
     }
   }
 
+  public UnlockObjectsResult unlockObjects2(CDOView view, Collection<CDOID> objectIDs, LockType lockType)
+  {
+    int attempt = 0;
+    for (;;)
+    {
+      try
+      {
+        return delegate.unlockObjects2(view, objectIDs, lockType);
+      }
+      catch (Exception ex)
+      {
+        handleException(++attempt, ex);
+      }
+    }
+  }
+
   public List<CDORemoteSession> getRemoteSessions(InternalCDORemoteSessionManager manager, boolean subscribe)
   {
     int attempt = 0;
diff --git a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/transaction/CDOTransactionImpl.java b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/transaction/CDOTransactionImpl.java
index 0968432db1..2f81f19424 100644
--- a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/transaction/CDOTransactionImpl.java
+++ b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/transaction/CDOTransactionImpl.java
@@ -34,6 +34,7 @@ import org.eclipse.emf.cdo.common.id.CDOIDTemp;
 import org.eclipse.emf.cdo.common.id.CDOIDUtil;
 import org.eclipse.emf.cdo.common.lob.CDOLob;
 import org.eclipse.emf.cdo.common.lob.CDOLobStore;
+import org.eclipse.emf.cdo.common.lock.CDOLockState;
 import org.eclipse.emf.cdo.common.model.CDOModelUtil;
 import org.eclipse.emf.cdo.common.model.CDOPackageRegistry;
 import org.eclipse.emf.cdo.common.model.CDOPackageUnit;
@@ -2625,6 +2626,12 @@ public class CDOTransactionImpl extends CDOViewImpl implements InternalCDOTransa
 
             fireEvent(new FinishedEvent(CDOTransactionFinishedEvent.Type.COMMITTED, idMappings), listeners);
           }
+
+          CDOLockState[] newLockStates = result.getNewLockStates();
+          if (newLockStates != null)
+          {
+            updateLockStates(newLockStates);
+          }
         }
         catch (RuntimeException ex)
         {
diff --git a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/view/CDOViewImpl.java b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/view/CDOViewImpl.java
index 5f4d77d889..7e69345d50 100644
--- a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/view/CDOViewImpl.java
+++ b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/view/CDOViewImpl.java
@@ -18,6 +18,11 @@ import org.eclipse.emf.cdo.CDOState;
 import org.eclipse.emf.cdo.common.branch.CDOBranch;
 import org.eclipse.emf.cdo.common.branch.CDOBranchPoint;
 import org.eclipse.emf.cdo.common.id.CDOID;
+import org.eclipse.emf.cdo.common.lock.CDOLockChangeInfo;
+import org.eclipse.emf.cdo.common.lock.CDOLockOwner;
+import org.eclipse.emf.cdo.common.lock.CDOLockState;
+import org.eclipse.emf.cdo.common.lock.CDOLockUtil;
+import org.eclipse.emf.cdo.common.revision.CDOIDAndBranch;
 import org.eclipse.emf.cdo.common.revision.CDOIDAndVersion;
 import org.eclipse.emf.cdo.common.revision.CDORevision;
 import org.eclipse.emf.cdo.common.revision.CDORevisionKey;
@@ -36,6 +41,7 @@ import org.eclipse.emf.cdo.util.StaleRevisionLockException;
 import org.eclipse.emf.cdo.view.CDOAdapterPolicy;
 import org.eclipse.emf.cdo.view.CDOFeatureAnalyzer;
 import org.eclipse.emf.cdo.view.CDOInvalidationPolicy;
+import org.eclipse.emf.cdo.view.CDOLocksChangedEvent;
 import org.eclipse.emf.cdo.view.CDORevisionPrefetchingPolicy;
 import org.eclipse.emf.cdo.view.CDOStaleReferencePolicy;
 import org.eclipse.emf.cdo.view.CDOView;
@@ -75,6 +81,7 @@ import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.InternalEObject;
 import org.eclipse.emf.spi.cdo.CDOSessionProtocol;
 import org.eclipse.emf.spi.cdo.CDOSessionProtocol.LockObjectsResult;
+import org.eclipse.emf.spi.cdo.CDOSessionProtocol.UnlockObjectsResult;
 import org.eclipse.emf.spi.cdo.FSMUtil;
 import org.eclipse.emf.spi.cdo.InternalCDOObject;
 import org.eclipse.emf.spi.cdo.InternalCDOSession;
@@ -257,18 +264,18 @@ public class CDOViewImpl extends AbstractCDOView
     checkActive();
     checkState(getTimeStamp() == CDOBranchPoint.UNSPECIFIED_DATE, "Locking not supported for historial views");
 
-    List<InternalCDORevision> revisions = new LinkedList<InternalCDORevision>();
+    List<CDORevisionKey> revisionKeys = new LinkedList<CDORevisionKey>();
     for (CDOObject object : objects)
     {
       InternalCDORevision revision = getRevision(object);
       if (revision != null)
       {
-        revisions.add(revision);
+        revisionKeys.add(revision);
       }
     }
 
     CDOSessionProtocol sessionProtocol = session.getSessionProtocol();
-    LockObjectsResult result = sessionProtocol.lockObjects(revisions, viewID, getBranch(), lockType, timeout);
+    LockObjectsResult result = sessionProtocol.lockObjects2(revisionKeys, viewID, getBranch(), lockType, timeout);
 
     if (!result.isSuccessful())
     {
@@ -286,6 +293,8 @@ public class CDOViewImpl extends AbstractCDOView
       throw new AssertionError("Unexpected lock result state");
     }
 
+    updateLockStates(result.getNewLockStates());
+
     if (result.isWaitForUpdate())
     {
       if (!getSession().options().isPassiveUpdateEnabled())
@@ -299,6 +308,29 @@ public class CDOViewImpl extends AbstractCDOView
     }
   }
 
+  protected void updateLockStates(CDOLockState[] newLockStates)
+  {
+    for (CDOLockState lockState : newLockStates)
+    {
+      Object o = lockState.getLockedObject();
+      CDOID id;
+      if (o instanceof CDOID)
+      {
+        id = (CDOID)o;
+      }
+      else
+      {
+        id = ((CDOIDAndBranch)o).getID();
+      }
+
+      InternalCDOObject obj = getObject(id, false);
+      if (obj != null)
+      {
+        obj.cdoInternalSetLockState(lockState);
+      }
+    }
+  }
+
   protected InternalCDORevision getRevision(CDOObject object)
   {
     if (object.cdoState() == CDOState.NEW)
@@ -321,8 +353,21 @@ public class CDOViewImpl extends AbstractCDOView
   public synchronized void unlockObjects(Collection<? extends CDOObject> objects, LockType lockType)
   {
     checkActive();
+
+    List<CDOID> objectIDs = null;
+    if (objects != null)
+    {
+      objectIDs = new LinkedList<CDOID>();
+      for (CDOObject obj : objects)
+      {
+        objectIDs.add(obj.cdoID());
+      }
+    }
+
     CDOSessionProtocol sessionProtocol = session.getSessionProtocol();
-    sessionProtocol.unlockObjects(this, objects, lockType);
+    UnlockObjectsResult result = sessionProtocol.unlockObjects2(this, objectIDs, lockType);
+
+    updateLockStates(result.getNewLockStates());
   }
 
   /**
@@ -439,6 +484,13 @@ public class CDOViewImpl extends AbstractCDOView
     return revisionManager.getRevision(id, branchPoint, initialChunkSize, CDORevision.DEPTH_NONE, loadOnDemand);
   }
 
+  public CDOLockState[] getLockStates(Collection<CDOID> ids)
+  {
+    CDOSessionProtocol sessionProtocol = session.getSessionProtocol();
+    CDOLockState[] lockStates = sessionProtocol.getLockStates(viewID, ids);
+    return lockStates;
+  }
+
   private CDOBranchPoint getBranchPointForID(CDOID id)
   {
     // If this view's timestamp is something other than UNSPECIFIED_DATE,
@@ -876,6 +928,38 @@ public class CDOViewImpl extends AbstractCDOView
     }
   }
 
+  public void handleLockNotification(CDOLockChangeInfo lockChangeInfo)
+  {
+    if (!options().isLockNotificationEnabled())
+    {
+      return;
+    }
+
+    // If lockChangeInfo pertains to a different view, do nothing.
+    if (!lockChangeInfo.getBranch().equals(getBranch()))
+    {
+      return;
+    }
+
+    // If lockChangeInfo represents lock changes authored by this view itself, do nothing.
+    CDOLockOwner thisView = CDOLockUtil.createLockOwner(this);
+    if (lockChangeInfo.getLockOwner().equals(thisView))
+    {
+      return;
+    }
+
+    fireLocksChangedEvent(lockChangeInfo);
+  }
+
+  private void fireLocksChangedEvent(CDOLockChangeInfo lockChangeInfo)
+  {
+    IListener[] listeners = getListeners();
+    if (listeners != null)
+    {
+      fireEvent(new LocksChangedEvent(lockChangeInfo), listeners);
+    }
+  }
+
   /**
    * @author Simon McDuff
    * @since 2.0
@@ -1304,6 +1388,47 @@ public class CDOViewImpl extends AbstractCDOView
   }
 
   /**
+   * @author Caspar De Groot
+   * @since 4.1
+   */
+  private final class LocksChangedEvent extends Event implements CDOLocksChangedEvent
+  {
+    private static final long serialVersionUID = 1L;
+
+    private CDOLockChangeInfo lockChangeInfo;
+
+    public LocksChangedEvent(CDOLockChangeInfo lockChangeInfo)
+    {
+      this.lockChangeInfo = lockChangeInfo;
+    }
+
+    public CDOBranch getBranch()
+    {
+      return lockChangeInfo.getBranch();
+    }
+
+    public long getTimeStamp()
+    {
+      return lockChangeInfo.getTimeStamp();
+    }
+
+    public CDOLockOwner getLockOwner()
+    {
+      return lockChangeInfo.getLockOwner();
+    }
+
+    public CDOLockState[] getLockStates()
+    {
+      return lockChangeInfo.getLockStates();
+    }
+
+    public Operation getOperation()
+    {
+      return lockChangeInfo.getOperation();
+    }
+  }
+
+  /**
    * @author Eike Stepper
    * @since 2.0
    */
@@ -1313,6 +1438,8 @@ public class CDOViewImpl extends AbstractCDOView
 
     private CDOInvalidationPolicy invalidationPolicy = CDOInvalidationPolicy.DEFAULT;
 
+    private boolean lockNotificationsEnabled;
+
     private CDORevisionPrefetchingPolicy revisionPrefetchingPolicy = CDOUtil
         .createRevisionPrefetchingPolicy(NO_REVISION_PREFETCHING);
 
@@ -1378,6 +1505,28 @@ public class CDOViewImpl extends AbstractCDOView
       fireEvent(event);
     }
 
+    public boolean isLockNotificationEnabled()
+    {
+      return lockNotificationsEnabled;
+    }
+
+    public void setLockNotificationEnabled(boolean enabled)
+    {
+      IEvent event = null;
+      synchronized (CDOViewImpl.this)
+      {
+        if (enabled != lockNotificationsEnabled)
+        {
+          CDOSessionProtocol protocol = getSession().getSessionProtocol();
+          protocol.enableLockNotifications(viewID, enabled);
+          lockNotificationsEnabled = enabled;
+          event = new LockNotificationEventImpl();
+        }
+      }
+    
+      fireEvent(event);
+    }
+
     public boolean hasChangeSubscriptionPolicies()
     {
       synchronized (CDOViewImpl.this)
@@ -1662,6 +1811,19 @@ public class CDOViewImpl extends AbstractCDOView
     }
 
     /**
+     * @author Caspar De Groot
+     */
+    private final class LockNotificationEventImpl extends OptionsEvent implements LockNotificationEvent
+    {
+      private static final long serialVersionUID = 1L;
+    
+      public LockNotificationEventImpl()
+      {
+        super(OptionsImpl.this);
+      }
+    }
+
+    /**
      * @author Eike Stepper
      */
     private final class RevisionPrefetchingPolicyEventImpl extends OptionsEvent implements
diff --git a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/spi/cdo/CDOSessionProtocol.java b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/spi/cdo/CDOSessionProtocol.java
index 1032720deb..fdfc9111ed 100644
--- a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/spi/cdo/CDOSessionProtocol.java
+++ b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/spi/cdo/CDOSessionProtocol.java
@@ -24,6 +24,7 @@ import org.eclipse.emf.cdo.common.id.CDOID;
 import org.eclipse.emf.cdo.common.id.CDOIDProvider;
 import org.eclipse.emf.cdo.common.lob.CDOLob;
 import org.eclipse.emf.cdo.common.lob.CDOLobInfo;
+import org.eclipse.emf.cdo.common.lock.CDOLockState;
 import org.eclipse.emf.cdo.common.model.CDOPackageUnit;
 import org.eclipse.emf.cdo.common.protocol.CDOProtocol;
 import org.eclipse.emf.cdo.common.revision.CDOIDAndVersion;
@@ -45,6 +46,7 @@ import org.eclipse.emf.cdo.spi.common.revision.InternalCDORevision;
 import org.eclipse.emf.cdo.spi.common.revision.InternalCDORevisionManager.RevisionLoader;
 import org.eclipse.emf.cdo.view.CDOView;
 
+import org.eclipse.net4j.util.CheckUtil;
 import org.eclipse.net4j.util.concurrent.IRWLockManager.LockType;
 import org.eclipse.net4j.util.om.monitor.OMMonitor;
 
@@ -131,15 +133,41 @@ public interface CDOSessionProtocol extends CDOProtocol, PackageLoader, BranchLo
   public boolean cancelQuery(int queryId);
 
   /**
+   * Use #lockObjects2 instead.
+   * 
    * @since 4.0
+   * @deprecated Not called anymore.
    */
+  @Deprecated
   public LockObjectsResult lockObjects(List<InternalCDORevision> viewedRevisions, int viewID, CDOBranch viewedBranch,
       LockType lockType, long timeout) throws InterruptedException;
 
   /**
+   * @since 4.1
+   */
+  public LockObjectsResult lockObjects2(List<CDORevisionKey> revisionKeys, int viewID, CDOBranch viewedBranch,
+      LockType lockType, long timeout) throws InterruptedException;
+
+  /**
+   * @since 4.1
+   */
+  public LockObjectsResult delegateLockObjects(String lockAreaID, List<CDORevisionKey> revisionKeys,
+      CDOBranch viewedBranch, LockType lockType, long timeout) throws InterruptedException;
+
+  /**
    * @since 3.0
    */
-  public void unlockObjects(CDOView view, Collection<? extends CDOObject> objects, LockType lockType);
+  public void unlockObjects(CDOView view, Collection<CDOID> objectIDs, LockType lockType);
+
+  /**
+   * @since 4.1
+   */
+  public UnlockObjectsResult unlockObjects2(CDOView view, Collection<CDOID> objectIDs, LockType lockType);
+
+  /**
+   * @since 4.1
+   */
+  public UnlockObjectsResult delegateUnlockObjects(String lockAreaID, Collection<CDOID> objectIDs, LockType lockType);
 
   /**
    * @since 3.0
@@ -233,6 +261,16 @@ public interface CDOSessionProtocol extends CDOProtocol, PackageLoader, BranchLo
       CDORevisionHandler handler);
 
   /**
+   * @since 4.1
+   */
+  public CDOLockState[] getLockStates(int viewID, Collection<CDOID> ids);
+
+  /**
+   * @since 4.1
+   */
+  public void enableLockNotifications(int viewID, boolean enable);
+
+  /**
    * @author Eike Stepper
    * @since 3.0
    * @noinstantiate This class is not intended to be instantiated by clients.
@@ -606,6 +644,8 @@ public interface CDOSessionProtocol extends CDOProtocol, PackageLoader, BranchLo
 
     private CDOReferenceAdjuster referenceAdjuster;
 
+    private CDOLockState[] newLockStates;
+
     /**
      * @since 4.0
      */
@@ -697,6 +737,14 @@ public interface CDOSessionProtocol extends CDOProtocol, PackageLoader, BranchLo
       idMappings.put(oldID, newID);
     }
 
+    /**
+     * @since 4.1
+     */
+    public CDOLockState[] getNewLockStates()
+    {
+      return newLockStates;
+    }
+
     protected PostCommitReferenceAdjuster createReferenceAdjuster()
     {
       return new PostCommitReferenceAdjuster(idProvider, new CDOIDMapper(idMappings));
@@ -735,6 +783,15 @@ public interface CDOSessionProtocol extends CDOProtocol, PackageLoader, BranchLo
         return idMapper.adjustReference(id, feature, index);
       }
     }
+
+    /**
+     * @since 4.1
+     */
+    public void setNewLockStates(CDOLockState[] newLockStates)
+    {
+      CheckUtil.checkArg(newLockStates, "newLockStates");
+      this.newLockStates = newLockStates;
+    }
   }
 
   /**
@@ -752,14 +809,27 @@ public interface CDOSessionProtocol extends CDOProtocol, PackageLoader, BranchLo
 
     private CDORevisionKey[] staleRevisions;
 
+    private CDOLockState[] newLockStates;
+
+    @Deprecated
     public LockObjectsResult(boolean successful, boolean timedOut, boolean waitForUpdate, long requiredTimestamp,
         CDORevisionKey[] staleRevisions)
     {
+      throw new AssertionError("Deprecated"); // TODO (CD) What to do about this??
+    }
+
+    /**
+     * @since 4.1
+     */
+    public LockObjectsResult(boolean successful, boolean timedOut, boolean waitForUpdate, long requiredTimestamp,
+        CDORevisionKey[] staleRevisions, CDOLockState[] newLockStates)
+    {
       this.successful = successful;
       this.timedOut = timedOut;
       this.waitForUpdate = waitForUpdate;
       this.requiredTimestamp = requiredTimestamp;
       this.staleRevisions = staleRevisions;
+      this.newLockStates = newLockStates;
     }
 
     public boolean isSuccessful()
@@ -786,5 +856,31 @@ public interface CDOSessionProtocol extends CDOProtocol, PackageLoader, BranchLo
     {
       return staleRevisions;
     }
+
+    /**
+     * @since 4.1
+     */
+    public CDOLockState[] getNewLockStates()
+    {
+      return newLockStates;
+    }
+  }
+
+  /**
+   * @since 4.1
+   */
+  public static final class UnlockObjectsResult
+  {
+    private CDOLockState[] newLockStates;
+
+    public UnlockObjectsResult(CDOLockState[] newLockStates)
+    {
+      this.newLockStates = newLockStates;
+    }
+
+    public CDOLockState[] getNewLockStates()
+    {
+      return newLockStates;
+    }
   }
 }
diff --git a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/spi/cdo/InternalCDOObject.java b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/spi/cdo/InternalCDOObject.java
index ee269a96a8..4329baf19c 100644
--- a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/spi/cdo/InternalCDOObject.java
+++ b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/spi/cdo/InternalCDOObject.java
@@ -7,13 +7,14 @@
  *
  * Contributors:
  *    Eike Stepper - initial API and implementation
- *    Martin Flügge - enhancements
+ *    Martin Fl�gge - enhancements
  */
 package org.eclipse.emf.spi.cdo;
 
 import org.eclipse.emf.cdo.CDOObject;
 import org.eclipse.emf.cdo.CDOState;
 import org.eclipse.emf.cdo.common.id.CDOID;
+import org.eclipse.emf.cdo.common.lock.CDOLockState;
 import org.eclipse.emf.cdo.common.model.CDOPackageTypeRegistry.CDOObjectMarker;
 import org.eclipse.emf.cdo.common.revision.CDORevision;
 import org.eclipse.emf.cdo.spi.common.revision.InternalCDORevision;
@@ -55,6 +56,11 @@ public interface InternalCDOObject extends CDOObject, InternalEObject, InternalC
 
   public CDOState cdoInternalSetState(CDOState state);
 
+  /**
+   * @since 4.1
+   */
+  public void cdoInternalSetLockState(CDOLockState lockState);
+
   public InternalEObject cdoInternalInstance();
 
   public EStructuralFeature cdoInternalDynamicFeature(int dynamicFeatureID);
diff --git a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/spi/cdo/InternalCDOSession.java b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/spi/cdo/InternalCDOSession.java
index c82f67d8ad..2f0459575c 100644
--- a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/spi/cdo/InternalCDOSession.java
+++ b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/spi/cdo/InternalCDOSession.java
@@ -17,6 +17,7 @@ import org.eclipse.emf.cdo.common.commit.CDOCommitInfo;
 import org.eclipse.emf.cdo.common.id.CDOID;
 import org.eclipse.emf.cdo.common.id.CDOIDGenerator;
 import org.eclipse.emf.cdo.common.lob.CDOLobStore;
+import org.eclipse.emf.cdo.common.lock.CDOLockChangeInfo;
 import org.eclipse.emf.cdo.common.protocol.CDOAuthenticator;
 import org.eclipse.emf.cdo.common.revision.CDORevision;
 import org.eclipse.emf.cdo.session.CDORepositoryInfo;
@@ -180,6 +181,11 @@ public interface InternalCDOSession extends CDOSession, PackageProcessor, Packag
   public void handleCommitNotification(CDOCommitInfo commitInfo);
 
   /**
+   * @since 4.1
+   */
+  public void handleLockNotification(CDOLockChangeInfo lockChangeInfo);
+
+  /**
    * @since 3.0
    */
   public void invalidate(CDOCommitInfo commitInfo, InternalCDOTransaction sender);
diff --git a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/spi/cdo/InternalCDOView.java b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/spi/cdo/InternalCDOView.java
index 345a1ae2ce..27ba5cc0b0 100644
--- a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/spi/cdo/InternalCDOView.java
+++ b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/spi/cdo/InternalCDOView.java
@@ -15,6 +15,8 @@ import org.eclipse.emf.cdo.CDOState;
 import org.eclipse.emf.cdo.common.branch.CDOBranch;
 import org.eclipse.emf.cdo.common.id.CDOID;
 import org.eclipse.emf.cdo.common.id.CDOIDProvider;
+import org.eclipse.emf.cdo.common.lock.CDOLockChangeInfo;
+import org.eclipse.emf.cdo.common.lock.CDOLockState;
 import org.eclipse.emf.cdo.common.revision.CDOIDAndVersion;
 import org.eclipse.emf.cdo.common.revision.CDORevisionKey;
 import org.eclipse.emf.cdo.eresource.impl.CDOResourceImpl;
@@ -28,6 +30,7 @@ import org.eclipse.net4j.util.lifecycle.ILifecycle;
 import org.eclipse.emf.common.notify.Adapter;
 import org.eclipse.emf.ecore.EObject;
 
+import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 
@@ -133,6 +136,16 @@ public interface InternalCDOView extends CDOView, CDOIDProvider, ILifecycle
 
   public boolean hasSubscription(CDOID id);
 
+  /**
+   * @since 4.1
+   */
+  public void handleLockNotification(CDOLockChangeInfo lockChangeInfo);
+
+  /**
+   * @since 4.1
+   */
+  public CDOLockState[] getLockStates(Collection<CDOID> ids);
+
   // /**
   // * Each time CDORevision or CDOState of an CDOObject is modified, ensure that no concurrent access is modifying it
   // at