Index: src/main/java/org/apache/jackrabbit/core/state/LocalItemStateManager.java
===================================================================
--- src/main/java/org/apache/jackrabbit/core/state/LocalItemStateManager.java	(revision 602118)
+++ src/main/java/org/apache/jackrabbit/core/state/LocalItemStateManager.java	(working copy)
@@ -35,7 +35,7 @@
      * cache of weak references to ItemState objects issued by this
      * ItemStateManager
      */
-    private final ItemStateReferenceCache cache;
+    private final ItemStateCache cache;
 
     /**
      * Shared item state manager
@@ -69,7 +69,8 @@
      */
     public LocalItemStateManager(SharedItemStateManager sharedStateMgr,
                                  EventStateCollectionFactory factory, ItemStateCacheFactory cacheFactory) {
-        cache = new ItemStateReferenceCache(cacheFactory);
+        cache = new SynchronizedItemStateCache(
+                new ItemStateReferenceCache(cacheFactory));
         this.sharedStateMgr = sharedStateMgr;
         this.factory = factory;
 
@@ -336,8 +337,11 @@
 
         // JCR-798: copy cached item states to array
         // to avoid ConcurrentModificationException
-        ItemState[] isa = (ItemState[]) cache.values().toArray(
-                new ItemState[cache.size()]);
+        ItemState[] isa;
+        synchronized (cache) {
+            isa = (ItemState[]) cache.values().toArray(
+                            new ItemState[cache.size()]);
+        }
         for (int i = 0; i < isa.length; i++) {
             ItemState state = isa[i];
             if (state != null) {
Index: src/main/java/org/apache/jackrabbit/core/state/SynchronizedItemStateCache.java
===================================================================
--- src/main/java/org/apache/jackrabbit/core/state/SynchronizedItemStateCache.java	(revision 0)
+++ src/main/java/org/apache/jackrabbit/core/state/SynchronizedItemStateCache.java	(revision 0)
@@ -0,0 +1,189 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.jackrabbit.core.state;
+
+import org.apache.jackrabbit.core.ItemId;
+
+import java.util.Set;
+import java.util.Collection;
+import java.util.Collections;
+
+/**
+ * <code>SynchronizedItemStateCache</code> implements a wrapper for a {@link
+ * ItemStateCache} and turns it into a synchronized item state cache.
+ */
+class SynchronizedItemStateCache implements ItemStateCache {
+
+    /**
+     * The underlying item state cache (not thread-safe).
+     */
+    private final ItemStateCache cache;
+
+    /**
+     * The mutex on which to synchronize access.
+     */
+    private final Object mutex;
+
+    /**
+     * Wraps the item state <code>cache</code> and provides synchronized access
+     * to it. Access to the <code>cache</code> is synchronized on this object.
+     *
+     * @param cache the item state cache.
+     */
+    SynchronizedItemStateCache(ItemStateCache cache) {
+        this.cache = cache;
+        this.mutex = this;
+    }
+
+    /**
+     * Wraps the item state <code>cache</code> and provides synchronized access
+     * to it. Access to the <code>cache</code> is synchronized on
+     * <code>mutex</code>.
+     *
+     * @param cache the item state cache.
+     * @param mutex the object on which to synchronize access.
+     */
+    SynchronizedItemStateCache(ItemStateCache cache, Object mutex) {
+        this.cache = cache;
+        this.mutex = mutex;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public boolean isCached(ItemId id) {
+        synchronized (mutex) {
+            return cache.isCached(id);
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public ItemState retrieve(ItemId id) {
+        synchronized (mutex) {
+            return cache.retrieve(id);
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public void cache(ItemState state) {
+        synchronized (mutex) {
+            cache.cache(state);
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public void evict(ItemId id) {
+        synchronized (mutex) {
+            cache.evict(id);
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public void evictAll() {
+        synchronized (mutex) {
+            cache.evictAll();
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public boolean isEmpty() {
+        synchronized (mutex) {
+            return cache.isEmpty();
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public int size() {
+        synchronized (mutex) {
+            return cache.size();
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     * <p/>
+     * The returned Set is not synchronized. The caller must ensure that
+     * it manually synchronizes access to the Set. Example:
+     * <pre>
+     * ItemStateCache cache = new SynchronizedItemStateCache(...);
+     * synchronized (cache) {
+     *     Set keys = cache.keySet();
+     *     for (Iterator it = keys.iterator(); it.hasNext(); ) {
+     *         Object item = it.next();
+     *         // do something with item
+     *     }
+     * }
+     * </pre>
+     */
+    public Set keySet() {
+        synchronized (mutex) {
+            return cache.keySet();
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     * <p/>
+     * The returned collection is not synchronized. The caller must ensure that
+     * it manually synchronizes access to the collection. Example:
+     * <pre>
+     * ItemStateCache cache = new SynchronizedItemStateCache(...);
+     * synchronized (cache) {
+     *     Collection values = cache.values();
+     *     for (Iterator it = values.iterator(); it.hasNext(); ) {
+     *         Object item = it.next();
+     *         // do something with item
+     *     }
+     * }
+     * </pre>
+     */
+    public Collection values() {
+        synchronized (mutex) {
+            return cache.values();
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public void update(ItemId id) {
+        synchronized (mutex) {
+            cache.update(id);
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public void dispose() {
+        synchronized (mutex) {
+            cache.dispose();
+        }
+    }
+}

Property changes on: src\main\java\org\apache\jackrabbit\core\state\SynchronizedItemStateCache.java
___________________________________________________________________
Name: svn:eol-style
   + native