[577319] Implement lock state prefetching as integral part of revision loading

https://bugs.eclipse.org/bugs/show_bug.cgi?id=577319

25 files changed, 490 insertions, 102 deletions

diff --git a/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/internal/common/revision/CDORevisionManagerImpl.java b/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/internal/common/revision/CDORevisionManagerImpl.java
index 1a48acad6f..83903e19d2 100644
--- a/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/internal/common/revision/CDORevisionManagerImpl.java
+++ b/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/internal/common/revision/CDORevisionManagerImpl.java
@@ -334,17 +334,6 @@ public class CDORevisionManagerImpl extends Lifecycle implements InternalCDORevi
     return (InternalCDORevision)results.get(0);
   }
 
-  // @Override
-  // public InternalCDORevision getRevision(CDOID id, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth,
-  // boolean loadOnDemand,
-  // List<CDORevision> additionalRevisions)
-  // {
-  // List<CDOID> ids = Collections.singletonList(id);
-  // List<CDORevision> results = getRevisions(ids, branchPoint, referenceChunk, prefetchDepth, loadOnDemand,
-  // synthetics);
-  // return (InternalCDORevision)results.get(0);
-  // }
-
   @Override
   public List<CDORevision> getRevisions(List<CDOID> ids, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth, boolean loadOnDemand)
   {
@@ -355,18 +344,25 @@ public class CDORevisionManagerImpl extends Lifecycle implements InternalCDORevi
   public List<CDORevision> getRevisions(List<CDOID> ids, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth, boolean loadOnDemand,
       SyntheticCDORevision[] synthetics)
   {
-    return getRevisions(ids, branchPoint, referenceChunk, prefetchDepth, loadOnDemand, synthetics, null, null);
+    return getRevisions(ids, branchPoint, referenceChunk, prefetchDepth, false, loadOnDemand, synthetics, null, null);
+  }
+
+  @Override
+  public List<CDORevision> getRevisions(List<CDOID> ids, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth, boolean prefetchLockStates,
+      boolean loadOnDemand, SyntheticCDORevision[] synthetics)
+  {
+    return getRevisions(ids, branchPoint, referenceChunk, prefetchDepth, prefetchLockStates, loadOnDemand, synthetics, null, null);
   }
 
   @Override
   public List<CDORevision> getRevisions(List<CDOID> ids, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth, boolean loadOnDemand,
       List<CDORevision> additionalRevisions)
   {
-    return getRevisions(ids, branchPoint, referenceChunk, prefetchDepth, loadOnDemand, null, additionalRevisions, null);
+    return getRevisions(ids, branchPoint, referenceChunk, prefetchDepth, false, loadOnDemand, null, additionalRevisions, null);
   }
 
-  private List<CDORevision> getRevisions(List<CDOID> ids, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth, boolean loadOnDemand,
-      SyntheticCDORevision[] synthetics, List<CDORevision> additionalRevisions, Consumer<CDORevision> consumer)
+  private List<CDORevision> getRevisions(List<CDOID> ids, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth, boolean prefetchLockStates,
+      boolean loadOnDemand, SyntheticCDORevision[] synthetics, List<CDORevision> additionalRevisions, Consumer<CDORevision> consumer)
   {
     RevisionInfo[] allInfos = new RevisionInfo[ids.size()];
 
@@ -380,7 +376,7 @@ public class CDORevisionManagerImpl extends Lifecycle implements InternalCDORevi
     if (infosToLoad != null)
     {
       // Load the requested revision infos, then process the additional revisions.
-      loadRevisions(infosToLoad, branchPoint, referenceChunk, prefetchDepth, additionalRevisions, consumer);
+      loadRevisions(infosToLoad, branchPoint, referenceChunk, prefetchDepth, prefetchLockStates, additionalRevisions, consumer);
     }
 
     List<CDORevision> primaryRevisions = processResults(allInfos, synthetics, consumer);
@@ -406,10 +402,10 @@ public class CDORevisionManagerImpl extends Lifecycle implements InternalCDORevi
    * @since 4.15
    */
   @Override
-  public void prefetchRevisions(CDOID id, CDOBranchPoint branchPoint, int prefetchDepth, Consumer<CDORevision> consumer)
+  public void prefetchRevisions(CDOID id, CDOBranchPoint branchPoint, int prefetchDepth, boolean prefetchLockStates, Consumer<CDORevision> consumer)
   {
     List<CDOID> ids = Collections.singletonList(id);
-    getRevisions(ids, branchPoint, CDORevision.UNCHUNKED, prefetchDepth, true, null, null, consumer);
+    getRevisions(ids, branchPoint, CDORevision.UNCHUNKED, prefetchDepth, prefetchLockStates, true, null, null, consumer);
   }
 
   @Override
@@ -505,14 +501,18 @@ public class CDORevisionManagerImpl extends Lifecycle implements InternalCDORevi
   /**
    * Loads the requested revision infos, then processes and returns additional revisions.
    */
-  protected void loadRevisions(List<RevisionInfo> infosToLoad, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth,
+  protected void loadRevisions(List<RevisionInfo> infosToLoad, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth, boolean prefetchLockStates,
       List<CDORevision> additionalRevisions, Consumer<CDORevision> consumer)
   {
     acquireAtomicRequestLock(loadAndAddLock);
 
     try
     {
-      List<RevisionInfo> additionalRevisionInfos = revisionLoader.loadRevisions(infosToLoad, branchPoint, referenceChunk, prefetchDepth);
+      @SuppressWarnings("deprecation")
+      List<RevisionInfo> additionalRevisionInfos = revisionLoader instanceof RevisionLoader3
+          ? ((RevisionLoader3)revisionLoader).loadRevisions(infosToLoad, branchPoint, referenceChunk, prefetchDepth, prefetchLockStates)
+          : revisionLoader.loadRevisions(infosToLoad, branchPoint, referenceChunk, prefetchDepth);
+
       if (additionalRevisionInfos != null)
       {
         for (RevisionInfo info : additionalRevisionInfos)
diff --git a/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/spi/common/protocol/CDODataInputImpl.java b/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/spi/common/protocol/CDODataInputImpl.java
index 1c9daeb4d2..4dd4d6c30d 100644
--- a/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/spi/common/protocol/CDODataInputImpl.java
+++ b/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/spi/common/protocol/CDODataInputImpl.java
@@ -386,14 +386,23 @@ public abstract class CDODataInputImpl extends ExtendedDataInput.Delegating impl
   public CDOLockState readCDOLockState() throws IOException
   {
     Object target;
-    boolean sendingBranchWithID = readBoolean();
-    if (!sendingBranchWithID)
+
+    byte type = readByte();
+    switch (type)
     {
+    case 0:
+      return null;
+
+    case 1:
       target = readCDOID();
-    }
-    else
-    {
+      break;
+
+    case 2:
       target = readCDOIDAndBranch();
+      break;
+
+    default:
+      throw new IOException("Invalid type: " + type);
     }
 
     InternalCDOLockState lockState = new CDOLockStateImpl(target);
diff --git a/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/spi/common/protocol/CDODataOutputImpl.java b/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/spi/common/protocol/CDODataOutputImpl.java
index edb746ce0d..eaa5ee9276 100644
--- a/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/spi/common/protocol/CDODataOutputImpl.java
+++ b/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/spi/common/protocol/CDODataOutputImpl.java
@@ -369,15 +369,21 @@ public class CDODataOutputImpl extends ExtendedDataOutput.Delegating implements
   @Override
   public void writeCDOLockState(CDOLockState lockState) throws IOException
   {
+    if (lockState == null)
+    {
+      writeByte(0);
+      return;
+    }
+
     Object o = lockState.getLockedObject();
     if (o instanceof CDOID)
     {
-      writeBoolean(false);
+      writeByte(1);
       writeCDOID((CDOID)o);
     }
     else if (o instanceof CDOIDAndBranch)
     {
-      writeBoolean(true);
+      writeByte(2);
       writeCDOIDAndBranch((CDOIDAndBranch)o);
     }
     else
diff --git a/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/spi/common/revision/DelegatingCDORevisionManager.java b/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/spi/common/revision/DelegatingCDORevisionManager.java
index 2597a26755..25c600aefa 100644
--- a/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/spi/common/revision/DelegatingCDORevisionManager.java
+++ b/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/spi/common/revision/DelegatingCDORevisionManager.java
@@ -205,6 +205,13 @@ public abstract class DelegatingCDORevisionManager extends Lifecycle implements
     return getDelegate().getRevisions(ids, branchPoint, referenceChunk, prefetchDepth, loadOnDemand, synthetics);
   }
 
+  @Override
+  public List<CDORevision> getRevisions(List<CDOID> ids, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth, boolean prefetchLockStates,
+      boolean loadOnDemand, SyntheticCDORevision[] synthetics)
+  {
+    return getDelegate().getRevisions(ids, branchPoint, referenceChunk, prefetchDepth, prefetchLockStates, loadOnDemand, synthetics);
+  }
+
   /**
    * @since 4.15
    */
@@ -216,9 +223,9 @@ public abstract class DelegatingCDORevisionManager extends Lifecycle implements
   }
 
   @Override
-  public void prefetchRevisions(CDOID id, CDOBranchPoint branchPoint, int prefetchDepth, Consumer<CDORevision> consumer)
+  public void prefetchRevisions(CDOID id, CDOBranchPoint branchPoint, int prefetchDepth, boolean prefetchLockStates, Consumer<CDORevision> consumer)
   {
-    getDelegate().prefetchRevisions(id, branchPoint, prefetchDepth, consumer);
+    getDelegate().prefetchRevisions(id, branchPoint, prefetchDepth, prefetchLockStates, consumer);
   }
 
   @Override
diff --git a/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/spi/common/revision/InternalCDORevisionManager.java b/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/spi/common/revision/InternalCDORevisionManager.java
index fdeaad403f..5646f16276 100644
--- a/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/spi/common/revision/InternalCDORevisionManager.java
+++ b/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/spi/common/revision/InternalCDORevisionManager.java
@@ -83,11 +83,17 @@ public interface InternalCDORevisionManager extends CDORevisionManager, CDORevis
   /**
    * @since 4.15
    */
-  public void prefetchRevisions(CDOID id, CDOBranchPoint branchPoint, int prefetchDepth, Consumer<CDORevision> consumer);
+  public void prefetchRevisions(CDOID id, CDOBranchPoint branchPoint, int prefetchDepth, boolean prefetchLockStates, Consumer<CDORevision> consumer);
 
   public List<CDORevision> getRevisions(List<CDOID> ids, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth, boolean loadOnDemand,
       SyntheticCDORevision[] synthetics);
 
+  /**
+   * @since 4.15
+   */
+  public List<CDORevision> getRevisions(List<CDOID> ids, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth, boolean prefetchLockStates,
+      boolean loadOnDemand, SyntheticCDORevision[] synthetics);
+
   public InternalCDORevision getRevision(CDOID id, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth, boolean loadOnDemand,
       SyntheticCDORevision[] synthetics);
 
@@ -119,6 +125,10 @@ public interface InternalCDORevisionManager extends CDORevisionManager, CDORevis
    */
   public interface RevisionLoader
   {
+    /**
+     * @deprecated As of 4.15 use {@link RevisionLoader3#loadRevisions(List, CDOBranchPoint, int, int, boolean)}.
+     */
+    @Deprecated
     public List<RevisionInfo> loadRevisions(List<RevisionInfo> infos, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth);
 
     public InternalCDORevision loadRevisionByVersion(CDOID id, CDOBranchVersion branchVersion, int referenceChunk);
@@ -146,6 +156,20 @@ public interface InternalCDORevisionManager extends CDORevisionManager, CDORevis
    * If the meaning of this type isn't clear, there really should be more of a description here...
    *
    * @author Eike Stepper
+   * @since 4.15
+   * @noextend This interface is not intended to be extended by clients.
+   * @noimplement This interface is not intended to be implemented by clients.
+   */
+  public interface RevisionLoader3 extends RevisionLoader2
+  {
+    public List<RevisionInfo> loadRevisions(List<RevisionInfo> infos, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth,
+        boolean prefetchLockStates);
+  }
+
+  /**
+   * If the meaning of this type isn't clear, there really should be more of a description here...
+   *
+   * @author Eike Stepper
    * @since 3.0
    */
   public interface RevisionLocker
diff --git a/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/internal/explorer/checkouts/CDOCheckoutImpl.java b/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/internal/explorer/checkouts/CDOCheckoutImpl.java
index 2ad40d0f47..94ca561044 100644
--- a/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/internal/explorer/checkouts/CDOCheckoutImpl.java
+++ b/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/internal/explorer/checkouts/CDOCheckoutImpl.java
@@ -91,6 +91,8 @@ public abstract class CDOCheckoutImpl extends AbstractElement implements CDOChec
 
   public static final String PROP_PREFETCH = "prefetch";
 
+  public static final String PROP_PREFETCH_LOCK_STATES = "prefetchLockStates";
+
   public static final String PROP_REPOSITORY = "repository";
 
   public static final String EDITOR_PROPERTIES = "editor.properties";
@@ -459,6 +461,23 @@ public abstract class CDOCheckoutImpl extends AbstractElement implements CDOChec
     }
   }
 
+  public final boolean isPrefetchLockStates()
+  {
+    Object checkoutProperty = getProperties().get(PROP_PREFETCH_LOCK_STATES);
+    if (checkoutProperty instanceof String)
+    {
+      return Boolean.parseBoolean((String)checkoutProperty);
+    }
+
+    String systemProperty = OMPlatform.INSTANCE.getProperty("org.eclipse.emf.cdo.explorer.checkouts.CDOCheckout.DISABLE_PREFETCH_LOCK_STATES");
+    if (checkoutProperty != null)
+    {
+      return !Boolean.parseBoolean(systemProperty);
+    }
+
+    return view.options().isLockNotificationEnabled();
+  }
+
   @Override
   public boolean waitUntilPrefetched()
   {
@@ -472,8 +491,10 @@ public abstract class CDOCheckoutImpl extends AbstractElement implements CDOChec
 
   private void startPrefetcherManager()
   {
+    boolean prefetchLockStates = isPrefetchLockStates();
+
     ResourceSet resourceSet = view.getResourceSet();
-    prefetcherManager = new CDOPrefetcherManager(resourceSet);
+    prefetcherManager = new CDOPrefetcherManager(resourceSet, prefetchLockStates);
     prefetcherManager.activate();
     prefetcherManager.waitUntilPrefetched();
 
diff --git a/plugins/org.eclipse.emf.cdo.net4j/src/org/eclipse/emf/cdo/internal/net4j/protocol/CDOClientProtocol.java b/plugins/org.eclipse.emf.cdo.net4j/src/org/eclipse/emf/cdo/internal/net4j/protocol/CDOClientProtocol.java
index da4292c116..1d993af3c2 100644
--- a/plugins/org.eclipse.emf.cdo.net4j/src/org/eclipse/emf/cdo/internal/net4j/protocol/CDOClientProtocol.java
+++ b/plugins/org.eclipse.emf.cdo.net4j/src/org/eclipse/emf/cdo/internal/net4j/protocol/CDOClientProtocol.java
@@ -246,10 +246,18 @@ public class CDOClientProtocol extends AuthenticatingSignalProtocol<CDOSessionIm
     return send(new LoadChunkRequest(this, revision, feature, accessIndex, fetchIndex, fromIndex, toIndex));
   }
 
+  @Deprecated
   @Override
   public List<RevisionInfo> loadRevisions(List<RevisionInfo> infos, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth)
   {
-    return send(new LoadRevisionsRequest(this, infos, branchPoint, referenceChunk, prefetchDepth));
+    throw new UnsupportedOperationException();
+  }
+
+  @Override
+  public List<RevisionInfo> loadRevisions(List<RevisionInfo> infos, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth,
+      boolean prefetchLockStates)
+  {
+    return send(new LoadRevisionsRequest(this, infos, branchPoint, referenceChunk, prefetchDepth, prefetchLockStates));
   }
 
   @Override
diff --git a/plugins/org.eclipse.emf.cdo.net4j/src/org/eclipse/emf/cdo/internal/net4j/protocol/LoadRevisionsRequest.java b/plugins/org.eclipse.emf.cdo.net4j/src/org/eclipse/emf/cdo/internal/net4j/protocol/LoadRevisionsRequest.java
index e2b77f1465..5ec6b24926 100644
--- a/plugins/org.eclipse.emf.cdo.net4j/src/org/eclipse/emf/cdo/internal/net4j/protocol/LoadRevisionsRequest.java
+++ b/plugins/org.eclipse.emf.cdo.net4j/src/org/eclipse/emf/cdo/internal/net4j/protocol/LoadRevisionsRequest.java
@@ -13,9 +13,13 @@ package org.eclipse.emf.cdo.internal.net4j.protocol;
 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.id.CDOIDUtil;
+import org.eclipse.emf.cdo.common.lock.CDOLockState;
+import org.eclipse.emf.cdo.common.lock.CDOLockUtil;
 import org.eclipse.emf.cdo.common.protocol.CDODataInput;
 import org.eclipse.emf.cdo.common.protocol.CDODataOutput;
 import org.eclipse.emf.cdo.common.protocol.CDOProtocolConstants;
+import org.eclipse.emf.cdo.common.revision.CDOIDAndBranch;
 import org.eclipse.emf.cdo.common.revision.CDORevision;
 import org.eclipse.emf.cdo.common.revision.CDORevisionKey;
 import org.eclipse.emf.cdo.common.revision.CDORevisionUtil;
@@ -27,6 +31,8 @@ import org.eclipse.emf.cdo.spi.common.revision.PointerCDORevision;
 import org.eclipse.emf.cdo.spi.common.revision.RevisionInfo;
 import org.eclipse.emf.cdo.view.CDOFetchRuleManager;
 
+import org.eclipse.emf.internal.cdo.session.CDOLockStateCache;
+
 import org.eclipse.net4j.util.io.IORuntimeException;
 
 import org.eclipse.emf.spi.cdo.InternalCDOSession;
@@ -44,26 +50,30 @@ import java.util.Map;
  */
 public class LoadRevisionsRequest extends CDOClientRequest<List<RevisionInfo>>
 {
-  private List<RevisionInfo> infos;
+  private final List<RevisionInfo> infos;
+
+  private final CDOBranchPoint branchPoint;
 
-  private CDOBranchPoint branchPoint;
+  private final int referenceChunk;
 
-  private int referenceChunk;
+  private final int prefetchDepth;
 
-  private int prefetchDepth;
+  private final boolean prefetchLockStates;
 
   /**
    * Remembers strong references to valid revisions to prevent garbage collection.
    */
   private Map<CDORevisionKey, CDORevision> rememberedRevisions;
 
-  public LoadRevisionsRequest(CDOClientProtocol protocol, List<RevisionInfo> infos, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth)
+  public LoadRevisionsRequest(CDOClientProtocol protocol, List<RevisionInfo> infos, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth,
+      boolean prefetchLockStates)
   {
     super(protocol, CDOProtocolConstants.SIGNAL_LOAD_REVISIONS);
     this.infos = infos;
     this.branchPoint = branchPoint;
     this.referenceChunk = referenceChunk;
     this.prefetchDepth = prefetchDepth;
+    this.prefetchLockStates = prefetchLockStates;
   }
 
   @Override
@@ -71,6 +81,7 @@ public class LoadRevisionsRequest extends CDOClientRequest<List<RevisionInfo>>
   {
     out.writeCDOBranchPoint(branchPoint);
     out.writeXInt(referenceChunk);
+    out.writeBoolean(prefetchLockStates);
 
     InternalCDOSession session = getSession();
     int size = infos.size();
@@ -200,6 +211,52 @@ public class LoadRevisionsRequest extends CDOClientRequest<List<RevisionInfo>>
       }
     }
 
+    if (in.readBoolean())
+    {
+      List<CDOLockState> lockStates = new ArrayList<>();
+
+      for (;;)
+      {
+        CDOLockState lockState = in.readCDOLockState();
+        if (lockState == null)
+        {
+          break;
+        }
+
+        lockStates.add(lockState);
+      }
+
+      int noLockStateKeys = in.readXInt();
+      if (noLockStateKeys != 0)
+      {
+        if (getSession().getRevisionManager().isSupportingBranches())
+        {
+          for (int i = 0; i < noLockStateKeys; i++)
+          {
+            CDOID id = in.readCDOID();
+            CDOIDAndBranch lockTarget = CDOIDUtil.createIDAndBranch(id, requestedBranch);
+            CDOLockState lockState = CDOLockUtil.createLockState(lockTarget);
+            lockStates.add(lockState);
+          }
+        }
+        else
+        {
+          for (int i = 0; i < noLockStateKeys; i++)
+          {
+            CDOID id = in.readCDOID();
+            CDOLockState lockState = CDOLockUtil.createLockState(id);
+            lockStates.add(lockState);
+          }
+        }
+      }
+
+      if (!lockStates.isEmpty())
+      {
+        CDOLockStateCache lockStateCache = getSession().getLockStateCache();
+        lockStateCache.addLockStates(requestedBranch, lockStates, null);
+      }
+    }
+
     if (rememberedRevisions != null)
     {
       rememberedRevisions.clear(); // Help the garbage collector.
@@ -211,7 +268,8 @@ public class LoadRevisionsRequest extends CDOClientRequest<List<RevisionInfo>>
   @Override
   protected String getAdditionalInfo()
   {
-    return MessageFormat.format("infos={0}, branchPoint={1}, referenceChunk={2}, prefetchDepth={3}", infos, branchPoint, referenceChunk, prefetchDepth);
+    return MessageFormat.format("infos={0}, branchPoint={1}, referenceChunk={2}, prefetchDepth={3}, prefetchLockStates={4}", //
+        infos, branchPoint, referenceChunk, prefetchDepth, prefetchLockStates);
   }
 
   /**
diff --git a/plugins/org.eclipse.emf.cdo.server.embedded/.settings/.api_filters b/plugins/org.eclipse.emf.cdo.server.embedded/.settings/.api_filters
index eb8bc080dc..8bd60e942d 100644
--- a/plugins/org.eclipse.emf.cdo.server.embedded/.settings/.api_filters
+++ b/plugins/org.eclipse.emf.cdo.server.embedded/.settings/.api_filters
@@ -29,5 +29,11 @@
                 <message_argument value="ServerRevisionLoader"/>
             </message_arguments>
         </filter>
+        <filter id="574619656">
+            <message_arguments>
+                <message_argument value="RevisionLoader3"/>
+                <message_argument value="ServerRevisionLoader"/>
+            </message_arguments>
+        </filter>
     </resource>
 </component>
diff --git a/plugins/org.eclipse.emf.cdo.server.embedded/src/org/eclipse/emf/cdo/server/internal/embedded/ClientRevisionManager.java b/plugins/org.eclipse.emf.cdo.server.embedded/src/org/eclipse/emf/cdo/server/internal/embedded/ClientRevisionManager.java
index d4fbc0c33d..f8c7d21bf7 100644
--- a/plugins/org.eclipse.emf.cdo.server.embedded/src/org/eclipse/emf/cdo/server/internal/embedded/ClientRevisionManager.java
+++ b/plugins/org.eclipse.emf.cdo.server.embedded/src/org/eclipse/emf/cdo/server/internal/embedded/ClientRevisionManager.java
@@ -232,6 +232,21 @@ public final class ClientRevisionManager extends AbstractClientManager<InternalC
   }
 
   @Override
+  public List<CDORevision> getRevisions(List<CDOID> ids, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth, boolean prefetchLockStates,
+      boolean loadOnDemand, SyntheticCDORevision[] synthetics)
+  {
+    try
+    {
+      ServerSession.set(serverSession);
+      return delegate.getRevisions(ids, branchPoint, referenceChunk, prefetchDepth, prefetchLockStates, loadOnDemand, synthetics);
+    }
+    finally
+    {
+      ServerSession.unset();
+    }
+  }
+
+  @Override
   public InternalCDORevision getRevision(CDOID id, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth, boolean loadOnDemand)
   {
     try
@@ -289,12 +304,12 @@ public final class ClientRevisionManager extends AbstractClientManager<InternalC
   }
 
   @Override
-  public void prefetchRevisions(CDOID id, CDOBranchPoint branchPoint, int prefetchDepth, Consumer<CDORevision> consumer)
+  public void prefetchRevisions(CDOID id, CDOBranchPoint branchPoint, int prefetchDepth, boolean prefetchLockStates, Consumer<CDORevision> consumer)
   {
     try
     {
       ServerSession.set(serverSession);
-      delegate.prefetchRevisions(id, branchPoint, prefetchDepth, consumer);
+      delegate.prefetchRevisions(id, branchPoint, prefetchDepth, prefetchLockStates, consumer);
     }
     finally
     {
diff --git a/plugins/org.eclipse.emf.cdo.server.embedded/src/org/eclipse/emf/cdo/server/internal/embedded/ServerRevisionLoader.java b/plugins/org.eclipse.emf.cdo.server.embedded/src/org/eclipse/emf/cdo/server/internal/embedded/ServerRevisionLoader.java
index 3aa2d3566d..6625262096 100644
--- a/plugins/org.eclipse.emf.cdo.server.embedded/src/org/eclipse/emf/cdo/server/internal/embedded/ServerRevisionLoader.java
+++ b/plugins/org.eclipse.emf.cdo.server.embedded/src/org/eclipse/emf/cdo/server/internal/embedded/ServerRevisionLoader.java
@@ -18,7 +18,7 @@ import org.eclipse.emf.cdo.common.id.CDOID;
 import org.eclipse.emf.cdo.common.revision.CDORevisionHandler;
 import org.eclipse.emf.cdo.server.StoreThreadLocal;
 import org.eclipse.emf.cdo.spi.common.revision.InternalCDORevision;
-import org.eclipse.emf.cdo.spi.common.revision.InternalCDORevisionManager.RevisionLoader2;
+import org.eclipse.emf.cdo.spi.common.revision.InternalCDORevisionManager.RevisionLoader3;
 import org.eclipse.emf.cdo.spi.common.revision.RevisionInfo;
 import org.eclipse.emf.cdo.spi.server.InternalSession;
 
@@ -29,30 +29,38 @@ import java.util.List;
 /**
  * @author Eike Stepper
  */
-public final class ServerRevisionLoader implements RevisionLoader2
+public final class ServerRevisionLoader implements RevisionLoader3
 {
-  private final RevisionLoader2 delegate;
+  private final RevisionLoader3 delegate;
 
-  public ServerRevisionLoader(RevisionLoader2 delegate)
+  public ServerRevisionLoader(RevisionLoader3 delegate)
   {
     this.delegate = delegate;
   }
 
-  public RevisionLoader2 getDelegate()
+  public RevisionLoader3 getDelegate()
   {
     return delegate;
   }
 
   @Override
+  @Deprecated
   public List<RevisionInfo> loadRevisions(List<RevisionInfo> infos, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth)
   {
+    throw new UnsupportedOperationException();
+  }
+
+  @Override
+  public List<RevisionInfo> loadRevisions(List<RevisionInfo> infos, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth,
+      boolean prefetchLockStates)
+  {
     InternalSession serverSession = ServerSession.get();
     if (serverSession != null)
     {
       try
       {
         StoreThreadLocal.setSession(serverSession);
-        return delegate.loadRevisions(infos, branchPoint, referenceChunk, prefetchDepth);
+        return delegate.loadRevisions(infos, branchPoint, referenceChunk, prefetchDepth, prefetchLockStates);
       }
       finally
       {
@@ -60,7 +68,7 @@ public final class ServerRevisionLoader implements RevisionLoader2
       }
     }
 
-    return delegate.loadRevisions(infos, branchPoint, referenceChunk, prefetchDepth);
+    return delegate.loadRevisions(infos, branchPoint, referenceChunk, prefetchDepth, prefetchLockStates);
   }
 
   @Override
diff --git a/plugins/org.eclipse.emf.cdo.server.net4j/src/org/eclipse/emf/cdo/server/internal/net4j/protocol/LoadRevisionsIndication.java b/plugins/org.eclipse.emf.cdo.server.net4j/src/org/eclipse/emf/cdo/server/internal/net4j/protocol/LoadRevisionsIndication.java
index ef299348b6..aa4d72ca19 100644
--- a/plugins/org.eclipse.emf.cdo.server.net4j/src/org/eclipse/emf/cdo/server/internal/net4j/protocol/LoadRevisionsIndication.java
+++ b/plugins/org.eclipse.emf.cdo.server.net4j/src/org/eclipse/emf/cdo/server/internal/net4j/protocol/LoadRevisionsIndication.java
@@ -14,22 +14,29 @@ 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.id.CDOIDUtil;
+import org.eclipse.emf.cdo.common.lock.CDOLockState;
+import org.eclipse.emf.cdo.common.lock.CDOLockUtil;
 import org.eclipse.emf.cdo.common.model.CDOClassInfo;
 import org.eclipse.emf.cdo.common.protocol.CDODataInput;
 import org.eclipse.emf.cdo.common.protocol.CDODataOutput;
 import org.eclipse.emf.cdo.common.protocol.CDOProtocolConstants;
+import org.eclipse.emf.cdo.common.revision.CDOIDAndBranch;
 import org.eclipse.emf.cdo.common.revision.CDORevision;
 import org.eclipse.emf.cdo.common.revision.CDORevisionKey;
 import org.eclipse.emf.cdo.common.revision.CDORevisionUtil;
 import org.eclipse.emf.cdo.common.util.CDOFetchRule;
 import org.eclipse.emf.cdo.spi.common.model.InternalCDOPackageRegistry;
+import org.eclipse.emf.cdo.spi.common.revision.DetachedCDORevision;
 import org.eclipse.emf.cdo.spi.common.revision.InternalCDORevision;
 import org.eclipse.emf.cdo.spi.common.revision.InternalCDORevisionManager;
 import org.eclipse.emf.cdo.spi.common.revision.PointerCDORevision;
 import org.eclipse.emf.cdo.spi.common.revision.RevisionInfo;
 import org.eclipse.emf.cdo.spi.common.revision.RevisionInfo.Type;
+import org.eclipse.emf.cdo.spi.server.InternalLockManager;
 import org.eclipse.emf.cdo.spi.server.InternalRepository;
+import org.eclipse.emf.cdo.spi.server.InternalSession;
 
+import org.eclipse.net4j.util.WrappedException;
 import org.eclipse.net4j.util.collection.MoveableList;
 import org.eclipse.net4j.util.om.monitor.OMMonitor;
 
@@ -54,10 +61,14 @@ public class LoadRevisionsIndication extends CDOServerReadIndication
 
   private CDOBranchPoint branchPoint;
 
+  private CDOBranch requestedBranch;
+
   private int referenceChunk;
 
   private int prefetchDepth;
 
+  private boolean prefetchLockStates;
+
   private Map<EClass, CDOFetchRule> fetchRules = new HashMap<>();
 
   private CDOID contextID = CDOID.NULL;
@@ -66,6 +77,12 @@ public class LoadRevisionsIndication extends CDOServerReadIndication
 
   private Set<CDORevisionKey> validKeys;
 
+  private InternalCDORevisionManager revisionManager;
+
+  private InternalLockManager lockingManager;
+
+  private Set<Object> lockStateKeys;
+
   public LoadRevisionsIndication(CDOServerProtocol protocol)
   {
     super(protocol, CDOProtocolConstants.SIGNAL_LOAD_REVISIONS);
@@ -74,9 +91,24 @@ public class LoadRevisionsIndication extends CDOServerReadIndication
   @Override
   protected void indicating(CDODataInput in) throws IOException
   {
+    InternalRepository repository = getRepository();
+    revisionManager = repository.getRevisionManager();
+
     branchPoint = in.readCDOBranchPoint();
+    requestedBranch = branchPoint.getBranch();
+
     referenceChunk = in.readXInt();
 
+    prefetchLockStates = in.readBoolean();
+    if (prefetchLockStates)
+    {
+      if (branchPoint.getTimeStamp() == CDOBranchPoint.UNSPECIFIED_DATE)
+      {
+        lockingManager = repository.getLockingManager();
+        lockStateKeys = new HashSet<>();
+      }
+    }
+
     int size = in.readXInt();
     if (size < 0)
     {
@@ -117,7 +149,7 @@ public class LoadRevisionsIndication extends CDOServerReadIndication
 
       contextID = in.readCDOID();
 
-      InternalCDOPackageRegistry packageRegistry = getRepository().getPackageRegistry();
+      InternalCDOPackageRegistry packageRegistry = repository.getPackageRegistry();
 
       for (int i = 0; i < fetchRulesCount; i++)
       {
@@ -140,29 +172,26 @@ public class LoadRevisionsIndication extends CDOServerReadIndication
       revisionIDs.add(info.getID());
     }
 
-    InternalRepository repository = getRepository();
-    InternalCDORevisionManager revisionManager = repository.getRevisionManager();
-
     // Need to fetch the rule first.
     Set<CDOFetchRule> visitedFetchRules = new HashSet<>();
     if (!CDOIDUtil.isNull(contextID) && fetchRules.size() > 0)
     {
-      RevisionInfo info = createRevisionInfo(revisionManager, contextID);
+      RevisionInfo info = createRevisionInfo(contextID);
       InternalCDORevision revisionContext = info.getResult();
-      collectRevisions(revisionManager, revisionContext, revisionIDs, additionalInfos, additionalRevisions, visitedFetchRules);
+      collectRevisions(revisionContext, revisionIDs, additionalInfos, additionalRevisions, visitedFetchRules);
     }
 
     InternalCDORevision[] revisions = new InternalCDORevision[size];
     for (int i = 0; i < size; i++)
     {
       RevisionInfo info = infos[i];
-      info.execute(revisionManager, referenceChunk);
+      executeRevisionInfo(info);
 
       revisions[i] = info.getResult();
 
       if (loadRevisionCollectionChunkSize > 0)
       {
-        collectRevisions(revisionManager, revisions[i], revisionIDs, additionalInfos, additionalRevisions, visitedFetchRules);
+        collectRevisions(revisions[i], revisionIDs, additionalInfos, additionalRevisions, visitedFetchRules);
       }
     }
 
@@ -172,7 +201,7 @@ public class LoadRevisionsIndication extends CDOServerReadIndication
 
       try
       {
-        prefetchRevisions(revisionManager, prefetchDepth > 0 ? prefetchDepth : Integer.MAX_VALUE, revisions, additionalInfos, additionalRevisions, monitor);
+        prefetchRevisions(prefetchDepth > 0 ? prefetchDepth : Integer.MAX_VALUE, revisions, additionalInfos, additionalRevisions, monitor);
       }
       finally
       {
@@ -182,7 +211,9 @@ public class LoadRevisionsIndication extends CDOServerReadIndication
 
     // Read access handlers may modify/replace the revisions and additionalRevisions,
     // which must be reflected in the infos and additionalInfos below!
-    repository.notifyReadAccessHandlers(getSession(), revisions, additionalRevisions);
+    InternalRepository repository = getRepository();
+    InternalSession session = getSession();
+    repository.notifyReadAccessHandlers(session, revisions, additionalRevisions);
 
     for (int i = 0; i < size; i++)
     {
@@ -193,7 +224,6 @@ public class LoadRevisionsIndication extends CDOServerReadIndication
 
     // Write keys of additional revisions that are already cached on the client.
     int additionalSize = additionalRevisions.size();
-    CDOBranch requestedBranch = branchPoint.getBranch();
     List<RevisionInfo> infosToWrite = new ArrayList<>();
 
     for (int i = 0; i < additionalSize; i++)
@@ -230,17 +260,99 @@ public class LoadRevisionsIndication extends CDOServerReadIndication
       out.writeCDOID(info.getID());
       info.writeResult(out, referenceChunk, branchPoint);
     }
+
+    if (lockingManager != null)
+    {
+      out.writeBoolean(true);
+
+      Set<Object> noLockStateKeys = new HashSet<>();
+
+      try
+      {
+        lockingManager.getLockStates(lockStateKeys, (key, lockState) -> {
+          if (lockState != null)
+          {
+            CDOLockState cdoLockState = CDOLockUtil.convertLockState(lockState);
+
+            try
+            {
+              out.writeCDOLockState(cdoLockState);
+            }
+            catch (IOException ex)
+            {
+              throw WrappedException.wrap(ex);
+            }
+          }
+          else
+          {
+            noLockStateKeys.add(key);
+          }
+        });
+      }
+      catch (WrappedException ex)
+      {
+        Exception exception = ex.exception();
+        if (exception instanceof IOException)
+        {
+          throw (IOException)exception;
+        }
+
+        throw ex;
+      }
+
+      out.writeCDOLockState(null);
+      out.writeXInt(noLockStateKeys.size());
+
+      if (revisionManager.isSupportingBranches())
+      {
+        for (Object key : noLockStateKeys)
+        {
+          out.writeCDOID(((CDOIDAndBranch)key).getID());
+        }
+      }
+      else
+      {
+        for (Object key : noLockStateKeys)
+        {
+          out.writeCDOID((CDOID)key);
+        }
+      }
+    }
+    else
+    {
+      out.writeBoolean(false);
+    }
   }
 
-  private RevisionInfo createRevisionInfo(InternalCDORevisionManager revisionManager, CDOID id)
+  private RevisionInfo createRevisionInfo(CDOID id)
   {
     RevisionInfo info = new RevisionInfo.Missing(id, branchPoint);
-    info.execute(revisionManager, referenceChunk);
+    executeRevisionInfo(info);
     return info;
   }
 
-  private void collectRevisions(InternalCDORevisionManager revisionManager, InternalCDORevision revision, Set<CDOID> revisions,
-      List<RevisionInfo> additionalInfos, List<CDORevision> additionalRevisions, Set<CDOFetchRule> visitedFetchRules)
+  private void executeRevisionInfo(RevisionInfo info)
+  {
+    info.execute(revisionManager, referenceChunk);
+
+    if (lockingManager != null)
+    {
+      CDORevision revision = info.getSynthetic();
+      if (revision == null)
+      {
+        revision = info.getResult();
+      }
+
+      if (revision != null && !(revision instanceof DetachedCDORevision))
+      {
+        Object key = lockingManager.getLockKey(revision.getID(), requestedBranch);
+        lockStateKeys.add(key);
+      }
+    }
+  }
+
+  private void collectRevisions(InternalCDORevision revision, Set<CDOID> revisions, List<RevisionInfo> additionalInfos, List<CDORevision> additionalRevisions,
+      Set<CDOFetchRule> visitedFetchRules)
   {
     if (revision == null)
     {
@@ -271,14 +383,14 @@ public class LoadRevisionsIndication extends CDOServerReadIndication
               CDOID id = (CDOID)value;
               if (!CDOIDUtil.isNull(id) && !revisions.contains(id))
               {
-                RevisionInfo info = createRevisionInfo(revisionManager, id);
+                RevisionInfo info = createRevisionInfo(id);
                 InternalCDORevision containedRevision = info.getResult();
                 if (containedRevision != null)
                 {
                   additionalInfos.add(info);
                   revisions.add(containedRevision.getID());
                   additionalRevisions.add(containedRevision);
-                  collectRevisions(revisionManager, containedRevision, revisions, additionalInfos, additionalRevisions, visitedFetchRules);
+                  collectRevisions(containedRevision, revisions, additionalInfos, additionalRevisions, visitedFetchRules);
                 }
               }
             }
@@ -293,13 +405,13 @@ public class LoadRevisionsIndication extends CDOServerReadIndication
           CDOID id = (CDOID)value;
           if (!id.isNull() && !revisions.contains(id))
           {
-            RevisionInfo info = createRevisionInfo(revisionManager, id);
+            RevisionInfo info = createRevisionInfo(id);
             InternalCDORevision containedRevision = info.getResult();
             if (containedRevision != null)
             {
               revisions.add(containedRevision.getID());
               additionalRevisions.add(containedRevision);
-              collectRevisions(revisionManager, containedRevision, revisions, additionalInfos, additionalRevisions, visitedFetchRules);
+              collectRevisions(containedRevision, revisions, additionalInfos, additionalRevisions, visitedFetchRules);
             }
           }
         }
@@ -309,8 +421,8 @@ public class LoadRevisionsIndication extends CDOServerReadIndication
     visitedFetchRules.remove(fetchRule);
   }
 
-  private void prefetchRevisions(InternalCDORevisionManager revisionManager, int depth, CDORevision[] revisions, List<RevisionInfo> additionalInfos,
-      List<CDORevision> additionalRevisions, OMMonitor monitor)
+  private void prefetchRevisions(int depth, CDORevision[] revisions, List<RevisionInfo> additionalInfos, List<CDORevision> additionalRevisions,
+      OMMonitor monitor)
   {
     Map<CDOID, CDORevision> map = CDOIDUtil.createMap();
     for (CDORevision revision : revisions)
@@ -327,12 +439,12 @@ public class LoadRevisionsIndication extends CDOServerReadIndication
 
     for (CDORevision revision : revisions)
     {
-      prefetchRevision(revisionManager, depth, (InternalCDORevision)revision, additionalInfos, additionalRevisions, map, monitor.fork());
+      prefetchRevision(depth, (InternalCDORevision)revision, additionalInfos, additionalRevisions, map, monitor.fork());
     }
   }
 
-  private void prefetchRevision(InternalCDORevisionManager revisionManager, int depth, InternalCDORevision revision, List<RevisionInfo> additionalInfos,
-      List<CDORevision> additionalRevisions, Map<CDOID, CDORevision> map, OMMonitor monitor)
+  private void prefetchRevision(int depth, InternalCDORevision revision, List<RevisionInfo> additionalInfos, List<CDORevision> additionalRevisions,
+      Map<CDOID, CDORevision> map, OMMonitor monitor)
   {
     CDOClassInfo classInfo = revision.getClassInfo();
     EStructuralFeature[] containments = classInfo.getAllPersistentContainments();
@@ -344,7 +456,7 @@ public class LoadRevisionsIndication extends CDOServerReadIndication
       if (value instanceof CDOID)
       {
         CDOID id = (CDOID)value;
-        prefetchRevisionChild(revisionManager, depth, id, additionalInfos, additionalRevisions, map, monitor.fork());
+        prefetchRevisionChild(depth, id, additionalInfos, additionalRevisions, map, monitor.fork());
       }
       else if (value instanceof Collection<?>)
       {
@@ -360,7 +472,7 @@ public class LoadRevisionsIndication extends CDOServerReadIndication
           if (e instanceof CDOID)
           {
             CDOID id = (CDOID)e;
-            prefetchRevisionChild(revisionManager, depth, id, additionalInfos, additionalRevisions, map, subMonitor.fork());
+            prefetchRevisionChild(depth, id, additionalInfos, additionalRevisions, map, subMonitor.fork());
           }
           else
           {
@@ -379,8 +491,8 @@ public class LoadRevisionsIndication extends CDOServerReadIndication
     monitor.done();
   }
 
-  private void prefetchRevisionChild(InternalCDORevisionManager revisionManager, int depth, CDOID id, List<RevisionInfo> additionalInfos,
-      List<CDORevision> additionalRevisions, Map<CDOID, CDORevision> map, OMMonitor monitor)
+  private void prefetchRevisionChild(int depth, CDOID id, List<RevisionInfo> additionalInfos, List<CDORevision> additionalRevisions,
+      Map<CDOID, CDORevision> map, OMMonitor monitor)
   {
     if (CDOIDUtil.isNull(id))
     {
@@ -390,7 +502,7 @@ public class LoadRevisionsIndication extends CDOServerReadIndication
     CDORevision child = map.get(id);
     if (child == null)
     {
-      RevisionInfo info = createRevisionInfo(revisionManager, id);
+      RevisionInfo info = createRevisionInfo(id);
       child = info.getResult();
       if (child != null)
       {
@@ -402,7 +514,7 @@ public class LoadRevisionsIndication extends CDOServerReadIndication
 
     if (child != null && depth > 0)
     {
-      prefetchRevision(revisionManager, depth - 1, (InternalCDORevision)child, additionalInfos, additionalRevisions, map, monitor);
+      prefetchRevision(depth - 1, (InternalCDORevision)child, additionalInfos, additionalRevisions, map, monitor);
     }
   }
 }
diff --git a/plugins/org.eclipse.emf.cdo.server/.settings/.api_filters b/plugins/org.eclipse.emf.cdo.server/.settings/.api_filters
index a33c0c1fb5..2d7a2c5eae 100644
--- a/plugins/org.eclipse.emf.cdo.server/.settings/.api_filters
+++ b/plugins/org.eclipse.emf.cdo.server/.settings/.api_filters
@@ -471,6 +471,12 @@
                 <message_argument value="InternalRepository"/>
             </message_arguments>
         </filter>
+        <filter id="574619656">
+            <message_arguments>
+                <message_argument value="RevisionLoader3"/>
+                <message_argument value="InternalRepository"/>
+            </message_arguments>
+        </filter>
         <filter id="574668824">
             <message_arguments>
                 <message_argument value="IRepository"/>
diff --git a/plugins/org.eclipse.emf.cdo.server/src/org/eclipse/emf/cdo/internal/server/LockingManager.java b/plugins/org.eclipse.emf.cdo.server/src/org/eclipse/emf/cdo/internal/server/LockingManager.java
index f28278d5a1..256987fcec 100644
--- a/plugins/org.eclipse.emf.cdo.server/src/org/eclipse/emf/cdo/internal/server/LockingManager.java
+++ b/plugins/org.eclipse.emf.cdo.server/src/org/eclipse/emf/cdo/internal/server/LockingManager.java
@@ -902,7 +902,7 @@ public class LockingManager extends RWOLockManager<Object, IView> implements Int
   }
 
   @Override
-  public LockGrade getLockGrade(Object key)
+  public synchronized LockGrade getLockGrade(Object key)
   {
     LockState<Object, IView> lockState = getObjectToLocksMap().get(key);
     LockGrade grade = LockGrade.NONE;
diff --git a/plugins/org.eclipse.emf.cdo.server/src/org/eclipse/emf/cdo/internal/server/Repository.java b/plugins/org.eclipse.emf.cdo.server/src/org/eclipse/emf/cdo/internal/server/Repository.java
index 5aa71298dd..2dcb2d33ac 100644
--- a/plugins/org.eclipse.emf.cdo.server/src/org/eclipse/emf/cdo/internal/server/Repository.java
+++ b/plugins/org.eclipse.emf.cdo.server/src/org/eclipse/emf/cdo/internal/server/Repository.java
@@ -763,8 +763,16 @@ public class Repository extends Container<Object> implements InternalRepository
   }
 
   @Override
+  @Deprecated
   public List<RevisionInfo> loadRevisions(List<RevisionInfo> infos, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth)
   {
+    throw new UnsupportedOperationException();
+  }
+
+  @Override
+  public List<RevisionInfo> loadRevisions(List<RevisionInfo> infos, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth,
+      boolean prefetchLockStates)
+  {
     for (RevisionInfo info : infos)
     {
       CDOID id = info.getID();
diff --git a/plugins/org.eclipse.emf.cdo.server/src/org/eclipse/emf/cdo/spi/server/InternalLockManager.java b/plugins/org.eclipse.emf.cdo.server/src/org/eclipse/emf/cdo/spi/server/InternalLockManager.java
index 86d6e9c366..80589ebc83 100644
--- a/plugins/org.eclipse.emf.cdo.server/src/org/eclipse/emf/cdo/spi/server/InternalLockManager.java
+++ b/plugins/org.eclipse.emf.cdo.server/src/org/eclipse/emf/cdo/spi/server/InternalLockManager.java
@@ -23,6 +23,7 @@ import org.eclipse.net4j.util.concurrent.RWOLockManager.LockState;
 import java.util.Collection;
 import java.util.List;
 import java.util.Map;
+import java.util.function.BiConsumer;
 
 /**
  * The type of the to-be-locked objects is either {@link CDOIDAndBranch} or {@link CDOID}, depending on whether
@@ -72,7 +73,7 @@ public interface InternalLockManager extends IRWOLockManager<Object, IView>, ILo
       long timeout) throws InterruptedException;
 
   /**
-   * Attempts to release for a given locktype, view and objects.
+   * Attempts to release for a given lock type, view and objects.
    *
    * @throws IllegalMonitorStateException
    *           Unlocking objects without lock.
@@ -131,6 +132,11 @@ public interface InternalLockManager extends IRWOLockManager<Object, IView>, ILo
   public LockState<Object, IView> getLockState(Object key);
 
   /**
+   * @since 4.15
+   */
+  public void getLockStates(Collection<Object> keys, BiConsumer<Object, LockState<Object, IView>> consumer);
+
+  /**
    * @since 4.4
    */
   public List<LockState<Object, IView>> getLockStates();
diff --git a/plugins/org.eclipse.emf.cdo.server/src/org/eclipse/emf/cdo/spi/server/InternalRepository.java b/plugins/org.eclipse.emf.cdo.server/src/org/eclipse/emf/cdo/spi/server/InternalRepository.java
index 691db41627..9c17dab4ff 100644
--- a/plugins/org.eclipse.emf.cdo.server/src/org/eclipse/emf/cdo/spi/server/InternalRepository.java
+++ b/plugins/org.eclipse.emf.cdo.server/src/org/eclipse/emf/cdo/spi/server/InternalRepository.java
@@ -41,7 +41,7 @@ import org.eclipse.emf.cdo.spi.common.model.InternalCDOPackageUnit;
 import org.eclipse.emf.cdo.spi.common.revision.CDORevisionUnchunker;
 import org.eclipse.emf.cdo.spi.common.revision.InternalCDORevision;
 import org.eclipse.emf.cdo.spi.common.revision.InternalCDORevisionManager;
-import org.eclipse.emf.cdo.spi.common.revision.InternalCDORevisionManager.RevisionLoader2;
+import org.eclipse.emf.cdo.spi.common.revision.InternalCDORevisionManager.RevisionLoader3;
 
 import org.eclipse.net4j.util.concurrent.IExecutorServiceProvider;
 import org.eclipse.net4j.util.concurrent.IRWLockManager.LockType;
@@ -77,7 +77,7 @@ public interface InternalRepository extends IRepository, //
     PackageProcessor, //
     PackageLoader, //
     BranchLoader5, //
-    RevisionLoader2, //
+    RevisionLoader3, //
     CommitInfoLoader, //
     CDORevisionUnchunker, //
     OperationAuthorizer<ISession>, //
diff --git a/plugins/org.eclipse.emf.cdo.tests/src/org/eclipse/emf/cdo/tests/bugzilla/Bugzilla_576893_Test.java b/plugins/org.eclipse.emf.cdo.tests/src/org/eclipse/emf/cdo/tests/bugzilla/Bugzilla_576893_Test.java
index 81a209d788..7c93816cff 100644
--- a/plugins/org.eclipse.emf.cdo.tests/src/org/eclipse/emf/cdo/tests/bugzilla/Bugzilla_576893_Test.java
+++ b/plugins/org.eclipse.emf.cdo.tests/src/org/eclipse/emf/cdo/tests/bugzilla/Bugzilla_576893_Test.java
@@ -10,6 +10,7 @@
  */
 package org.eclipse.emf.cdo.tests.bugzilla;
 
+import org.eclipse.emf.cdo.CDOObject;
 import org.eclipse.emf.cdo.common.CDOCommonSession.Options.PassiveUpdateMode;
 import org.eclipse.emf.cdo.common.branch.CDOBranch;
 import org.eclipse.emf.cdo.common.id.CDOID;
@@ -17,6 +18,8 @@ import org.eclipse.emf.cdo.common.revision.CDORevision;
 import org.eclipse.emf.cdo.common.revision.CDORevisionCache;
 import org.eclipse.emf.cdo.common.util.CDOCommonUtil;
 import org.eclipse.emf.cdo.eresource.CDOResource;
+import org.eclipse.emf.cdo.internal.net4j.protocol.LockStateRequest;
+import org.eclipse.emf.cdo.net4j.CDONet4jSession;
 import org.eclipse.emf.cdo.session.CDOSession;
 import org.eclipse.emf.cdo.spi.common.revision.InternalCDORevision;
 import org.eclipse.emf.cdo.spi.common.revision.InternalCDORevisionManager;
@@ -30,8 +33,12 @@ import org.eclipse.emf.cdo.view.CDOPrefetcherManager;
 import org.eclipse.emf.cdo.view.CDOPrefetcherManager.Prefetcher;
 import org.eclipse.emf.cdo.view.CDOView;
 
+import org.eclipse.net4j.signal.ISignalProtocol;
+import org.eclipse.net4j.signal.SignalCounter;
 import org.eclipse.net4j.util.io.IOUtil;
 
+import org.eclipse.emf.common.util.TreeIterator;
+import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.resource.ResourceSet;
 
 import java.util.ArrayList;
@@ -63,7 +70,7 @@ public class Bugzilla_576893_Test extends AbstractCDOTest
     CDOSession session2 = openSession();
     CDOView view = session2.openView();
 
-    TestPrefetcherManager prefetcherManager = new TestPrefetcherManager(view.getResourceSet(), rootID);
+    TestPrefetcherManager prefetcherManager = new TestPrefetcherManager(view.getResourceSet(), rootID, false);
     prefetcherManager.activate();
     waitUntilPrefetched(prefetcherManager);
 
@@ -175,6 +182,44 @@ public class Bugzilla_576893_Test extends AbstractCDOTest
     prefetcherManager.deactivate();
   }
 
+  @Requires(IRepositoryConfig.CAPABILITY_BRANCHING)
+  public void testLockStatePrefetching() throws Exception
+  {
+    Category root = getModel1Factory().createCategory();
+    createModel(root, 2, 3, 2);
+
+    CDOSession session1 = openSession();
+    CDOTransaction transaction = session1.openTransaction();
+    CDOResource resource = transaction.createResource(getResourcePath("res1"));
+    resource.getContents().add(root);
+
+    transaction.commit();
+    CDOID rootID = CDOUtil.getCDOObject(root).cdoID();
+
+    // =======================================================================================
+    IOUtil.OUT().println("Testing open view...");
+    CDOSession session2 = openSession();
+
+    ISignalProtocol<?> protocol = ((CDONet4jSession)session2).options().getNet4jProtocol();
+    SignalCounter signalCounter = new SignalCounter(protocol);
+
+    CDOView view = session2.openView();
+    TestPrefetcherManager prefetcherManager = new TestPrefetcherManager(view.getResourceSet(), rootID, true);
+    prefetcherManager.activate();
+    waitUntilPrefetched(prefetcherManager);
+
+    CDOObject object = view.getObject(rootID);
+    object.cdoLockState();
+
+    for (TreeIterator<EObject> it = object.eAllContents(); it.hasNext();)
+    {
+      EObject child = it.next();
+      CDOUtil.getCDOObject(child).cdoLockState();
+    }
+
+    assertEquals(0, signalCounter.getCountFor(LockStateRequest.class));
+  }
+
   private static void waitUntilPrefetched(TestPrefetcherManager prefetcherManager)
   {
     assertTrue(prefetcherManager.waitUntilPrefetched(DEFAULT_TIMEOUT));
@@ -247,9 +292,9 @@ public class Bugzilla_576893_Test extends AbstractCDOTest
 
     private final CDOID rootID;
 
-    public TestPrefetcherManager(ResourceSet resourceSet, CDOID rootID)
+    public TestPrefetcherManager(ResourceSet resourceSet, CDOID rootID, boolean prefetchLockStates)
     {
-      super(resourceSet);
+      super(resourceSet, prefetchLockStates);
       this.rootID = rootID;
     }
 
@@ -262,7 +307,7 @@ public class Bugzilla_576893_Test extends AbstractCDOTest
     @Override
     protected Prefetcher createPrefetcher(CDOView view)
     {
-      return new Prefetcher(view, rootID)
+      return new Prefetcher(view, rootID, isPrefetchLockStates())
       {
         @Override
         protected void prefetch()
diff --git a/plugins/org.eclipse.emf.cdo.tests/src/org/eclipse/emf/cdo/tests/util/TestRevisionManager.java b/plugins/org.eclipse.emf.cdo.tests/src/org/eclipse/emf/cdo/tests/util/TestRevisionManager.java
index eb1c17278e..fabff6d028 100644
--- a/plugins/org.eclipse.emf.cdo.tests/src/org/eclipse/emf/cdo/tests/util/TestRevisionManager.java
+++ b/plugins/org.eclipse.emf.cdo.tests/src/org/eclipse/emf/cdo/tests/util/TestRevisionManager.java
@@ -103,10 +103,10 @@ public class TestRevisionManager extends CDORevisionManagerImpl
   }
 
   @Override
-  protected void loadRevisions(List<RevisionInfo> infosToLoad, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth,
+  protected void loadRevisions(List<RevisionInfo> infosToLoad, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth, boolean prefetchLockStates,
       List<CDORevision> additionalRevisions, Consumer<CDORevision> consumer)
   {
-    super.loadRevisions(infosToLoad, branchPoint, referenceChunk, prefetchDepth, additionalRevisions, consumer);
+    super.loadRevisions(infosToLoad, branchPoint, referenceChunk, prefetchDepth, prefetchLockStates, additionalRevisions, consumer);
 
     synchronized (lock)
     {
diff --git a/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/internal/ui/CDOContentProvider.java b/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/internal/ui/CDOContentProvider.java
index 5680470da8..e7e6975495 100644
--- a/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/internal/ui/CDOContentProvider.java
+++ b/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/internal/ui/CDOContentProvider.java
@@ -15,12 +15,13 @@ import org.eclipse.emf.cdo.CDOObject;
 import org.eclipse.emf.cdo.common.id.CDOID;
 import org.eclipse.emf.cdo.common.revision.CDOList;
 import org.eclipse.emf.cdo.common.revision.CDORevision;
-import org.eclipse.emf.cdo.common.revision.CDORevisionManager;
 import org.eclipse.emf.cdo.common.security.NoPermissionException;
 import org.eclipse.emf.cdo.eresource.CDOResource;
 import org.eclipse.emf.cdo.internal.ui.bundle.OM;
 import org.eclipse.emf.cdo.spi.common.revision.InternalCDORevision;
 import org.eclipse.emf.cdo.spi.common.revision.InternalCDORevisionCache;
+import org.eclipse.emf.cdo.spi.common.revision.InternalCDORevisionManager;
+import org.eclipse.emf.cdo.spi.common.revision.SyntheticCDORevision;
 import org.eclipse.emf.cdo.util.CDOUtil;
 import org.eclipse.emf.cdo.view.CDOView;
 
@@ -339,9 +340,19 @@ public abstract class CDOContentProvider<CONTEXT> implements ITreeContentProvide
               {
                 CDOObject cdoObject = getCDOObject((EObject)finalObject);
                 view = cdoObject.cdoView();
-                CDORevisionManager revisionManager = view.getSession().getRevisionManager();
 
-                List<CDORevision> revisions = revisionManager.getRevisions(missingIDs, view, CDORevision.UNCHUNKED, CDORevision.DEPTH_NONE, true);
+                InternalCDORevisionManager revisionManager = (InternalCDORevisionManager)view.getSession().getRevisionManager();
+                boolean prefetchLockStates = view.options().isLockNotificationEnabled();
+
+                List<CDORevision> revisions = revisionManager.getRevisions( //
+                    missingIDs, //
+                    view, //
+                    CDORevision.UNCHUNKED, //
+                    CDORevision.DEPTH_NONE, //
+                    prefetchLockStates, //
+                    true, //
+                    (SyntheticCDORevision[])null);
+
                 loadedRevisions.addAll(revisions);
               }
 
diff --git a/plugins/org.eclipse.emf.cdo/.settings/.api_filters b/plugins/org.eclipse.emf.cdo/.settings/.api_filters
index 58f74f67e1..91b7e4a31f 100644
--- a/plugins/org.eclipse.emf.cdo/.settings/.api_filters
+++ b/plugins/org.eclipse.emf.cdo/.settings/.api_filters
@@ -981,6 +981,12 @@
                 <message_argument value="CDOSessionProtocol"/>
             </message_arguments>
         </filter>
+        <filter id="571473929">
+            <message_arguments>
+                <message_argument value="RevisionLoader3"/>
+                <message_argument value="CDOSessionProtocol"/>
+            </message_arguments>
+        </filter>
     </resource>
     <resource path="src/org/eclipse/emf/spi/cdo/CDOSessionProtocol.java" type="org.eclipse.emf.spi.cdo.CDOSessionProtocol$CommitTransactionResult">
         <filter id="574619656">
diff --git a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/view/CDOPrefetcherManager.java b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/view/CDOPrefetcherManager.java
index 430cc6c1be..d0304fdeb2 100644
--- a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/view/CDOPrefetcherManager.java
+++ b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/view/CDOPrefetcherManager.java
@@ -53,6 +53,8 @@ public class CDOPrefetcherManager extends CDOViewSetHandler
 
   private final ExecutorService executorService;
 
+  private final boolean prefetchLockStates;
+
   private final Map<CDOView, Prefetcher> prefetchers = Collections.synchronizedMap(new HashMap<>());
 
   @ExcludeFromDump
@@ -60,12 +62,18 @@ public class CDOPrefetcherManager extends CDOViewSetHandler
 
   private int runnables;
 
-  public CDOPrefetcherManager(ResourceSet resourceSet)
+  public CDOPrefetcherManager(ResourceSet resourceSet, boolean prefetchLockStates)
   {
     super(resourceSet);
+    this.prefetchLockStates = prefetchLockStates;
     executorService = ConcurrencyUtil.getExecutorService(getViewSet());
   }
 
+  public boolean isPrefetchLockStates()
+  {
+    return prefetchLockStates;
+  }
+
   public final Prefetcher[] getPrefetchers()
   {
     // Don't use prefetchers.size() because that wouldn't be thread-safe anymore.
@@ -169,7 +177,7 @@ public class CDOPrefetcherManager extends CDOViewSetHandler
 
   protected Prefetcher createPrefetcher(CDOView view)
   {
-    return new Prefetcher(view);
+    return new Prefetcher(view, prefetchLockStates);
   }
 
   protected void schedule(Runnable runnable)
@@ -222,6 +230,8 @@ public class CDOPrefetcherManager extends CDOViewSetHandler
 
     private final InternalCDORevisionManager revisionManager;
 
+    private final boolean prefetchLockStates;
+
     private final IListener cacheListener = new IListener()
     {
       @Override
@@ -256,11 +266,13 @@ public class CDOPrefetcherManager extends CDOViewSetHandler
 
     private volatile boolean cancelCleanup;
 
-    public Prefetcher(CDOView view, CDOID rootID)
+    public Prefetcher(CDOView view, CDOID rootID, boolean prefetchLockStates)
     {
       this.view = view;
+
       CDOSession session = view.getSession();
       this.rootID = rootID != null ? rootID : session.getRepositoryInfo().getRootResourceID();
+      this.prefetchLockStates = prefetchLockStates;
 
       revisionManager = (InternalCDORevisionManager)session.getRevisionManager();
       revisionManager.getCache().addListener(cacheListener);
@@ -268,9 +280,9 @@ public class CDOPrefetcherManager extends CDOViewSetHandler
       branchPoint = CDOBranchUtil.copyBranchPoint(view);
     }
 
-    public Prefetcher(CDOView view)
+    public Prefetcher(CDOView view, boolean prefetchLockStates)
     {
-      this(view, null);
+      this(view, null, prefetchLockStates);
     }
 
     public final CDOView getView()
@@ -440,7 +452,7 @@ public class CDOPrefetcherManager extends CDOViewSetHandler
 
       try
       {
-        revisionManager.prefetchRevisions(rootID, branchPoint, CDORevision.DEPTH_INFINITE, r -> handleValidRevision(r));
+        revisionManager.prefetchRevisions(rootID, branchPoint, CDORevision.DEPTH_INFINITE, prefetchLockStates, r -> handleValidRevision(r));
       }
       finally
       {
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 7496890d65..0492efa243 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
@@ -474,7 +474,7 @@ public class DelegatingSessionProtocol extends Lifecycle implements CDOSessionPr
   @Deprecated
   public CDOLockState[] getLockStates(int branchID, Collection<CDOID> ids)
   {
-    return getLockStates(branchID, ids, CDOLockState.DEPTH_NONE);
+    throw new UnsupportedOperationException();
   }
 
   @Override
@@ -768,14 +768,22 @@ public class DelegatingSessionProtocol extends Lifecycle implements CDOSessionPr
   }
 
   @Override
+  @Deprecated
   public List<RevisionInfo> loadRevisions(List<RevisionInfo> infos, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth)
   {
+    throw new UnsupportedOperationException();
+  }
+
+  @Override
+  public List<RevisionInfo> loadRevisions(List<RevisionInfo> infos, CDOBranchPoint branchPoint, int referenceChunk, int prefetchDepth,
+      boolean prefetchLockStates)
+  {
     int attempt = 0;
     for (;;)
     {
       try
       {
-        return delegate.loadRevisions(infos, branchPoint, referenceChunk, prefetchDepth);
+        return delegate.loadRevisions(infos, branchPoint, referenceChunk, prefetchDepth, prefetchLockStates);
       }
       catch (Exception ex)
       {
@@ -1165,7 +1173,7 @@ public class DelegatingSessionProtocol extends Lifecycle implements CDOSessionPr
   @Deprecated
   public void requestChangeCredentials()
   {
-    requestChangeServerPassword(null);
+    throw new UnsupportedOperationException();
   }
 
   @Override
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 3bad71f8bf..c180bed6b7 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
@@ -49,7 +49,7 @@ import org.eclipse.emf.cdo.spi.common.model.InternalCDOPackageUnit;
 import org.eclipse.emf.cdo.spi.common.revision.CDOIDMapper;
 import org.eclipse.emf.cdo.spi.common.revision.CDOReferenceAdjuster;
 import org.eclipse.emf.cdo.spi.common.revision.InternalCDORevision;
-import org.eclipse.emf.cdo.spi.common.revision.InternalCDORevisionManager.RevisionLoader2;
+import org.eclipse.emf.cdo.spi.common.revision.InternalCDORevisionManager.RevisionLoader3;
 import org.eclipse.emf.cdo.view.CDOView;
 
 import org.eclipse.net4j.util.CheckUtil;
@@ -87,7 +87,7 @@ import java.util.concurrent.atomic.AtomicReference;
  * @noextend This interface is not intended to be extended by clients.
  * @noimplement This interface is not intended to be implemented by clients.
  */
-public interface CDOSessionProtocol extends CDOProtocol, PackageLoader, BranchLoader5, RevisionLoader2, CommitInfoLoader
+public interface CDOSessionProtocol extends CDOProtocol, PackageLoader, BranchLoader5, RevisionLoader3, CommitInfoLoader
 {
   public RepositoryTimeResult getRepositoryTime();
 
diff --git a/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/concurrent/RWOLockManager.java b/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/concurrent/RWOLockManager.java
index 6659e0dca5..95667be118 100644
--- a/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/concurrent/RWOLockManager.java
+++ b/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/concurrent/RWOLockManager.java
@@ -27,6 +27,7 @@ import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.function.BiConsumer;
 
 /**
  * Keeps track of locks on objects. Locks are owned by contexts. A particular combination of locks and their owners, for
@@ -297,12 +298,23 @@ public class RWOLockManager<OBJECT, CONTEXT> extends Lifecycle implements IRWOLo
     return contextToLockStates;
   }
 
-  public LockState<OBJECT, CONTEXT> getLockState(OBJECT key)
+  public synchronized LockState<OBJECT, CONTEXT> getLockState(OBJECT key)
   {
     return objectToLockStateMap.get(key);
   }
 
   /**
+   * @since 3.16
+   */
+  public synchronized void getLockStates(Collection<OBJECT> keys, BiConsumer<OBJECT, LockState<OBJECT, CONTEXT>> consumer)
+  {
+    keys.forEach(key -> {
+      LockState<OBJECT, CONTEXT> lockState = objectToLockStateMap.get(key);
+      consumer.accept(key, lockState);
+    });
+  }
+
+  /**
    * @since 3.5
    */
   public synchronized List<LockState<OBJECT, CONTEXT>> getLockStates()