diff --git a/platform/platform-api/src/com/intellij/lang/Language.java b/platform/platform-api/src/com/intellij/lang/Language.java
index 5a88fc98aee0..2e14d4956875 100644
--- a/platform/platform-api/src/com/intellij/lang/Language.java
+++ b/platform/platform-api/src/com/intellij/lang/Language.java
@@ -19,8 +19,10 @@ import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.fileTypes.FileType;
 import com.intellij.openapi.fileTypes.FileTypeManager;
 import com.intellij.openapi.fileTypes.LanguageFileType;
+import com.intellij.openapi.util.Key;
 import com.intellij.openapi.util.UserDataHolderBase;
 import com.intellij.util.ArrayUtil;
+import com.intellij.util.containers.ConcurrentHashMap;
 import gnu.trove.THashMap;
 import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
@@ -29,6 +31,7 @@ import org.jetbrains.annotations.Nullable;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Map;
+import java.util.concurrent.ConcurrentMap;
 
 /**
  * The base class for all programming language support implementations. Specific language implementations should inherit from this class
@@ -72,6 +75,10 @@ public abstract class Language extends UserDataHolderBase {
     }
   }
 
+  protected ConcurrentMap<Key, Object> createDataMap() {
+    return new ConcurrentHashMap<Key, Object>();
+  }
+
   /**
    * @return collection of all languages registered so far.
    */
diff --git a/platform/util/src/com/intellij/openapi/util/UserDataHolderBase.java b/platform/util/src/com/intellij/openapi/util/UserDataHolderBase.java
index 775c76af7c9f..a2e36feb613a 100644
--- a/platform/util/src/com/intellij/openapi/util/UserDataHolderBase.java
+++ b/platform/util/src/com/intellij/openapi/util/UserDataHolderBase.java
@@ -6,13 +6,14 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.Map;
+import java.util.concurrent.ConcurrentMap;
 
 public class UserDataHolderBase implements UserDataHolderEx, Cloneable {
   private static final Object MAP_LOCK = new Object();
   private static final Object COPYABLE_MAP_LOCK = new Object();
   private static final Key<Map<Key, Object>> COPYABLE_USER_MAP_KEY = Key.create("COPYABLE_USER_MAP_KEY");
 
-  private volatile LockPoolSynchronizedMap<Key, Object> myUserMap = null;
+  private volatile ConcurrentMap<Key, Object> myUserMap = null;
 
   protected Object clone() {
     try {
@@ -28,7 +29,7 @@ public class UserDataHolderBase implements UserDataHolderEx, Cloneable {
   }
 
   public String getUserDataString() {
-    final Map<Key, Object> userMap = myUserMap;
+    final ConcurrentMap<Key, Object> userMap = myUserMap;
     if (userMap == null) {
       return "";
     }
@@ -46,7 +47,7 @@ public class UserDataHolderBase implements UserDataHolderEx, Cloneable {
       other.myUserMap = null;
     }
     else {
-      LockPoolSynchronizedMap<Key, Object> fresh = createMap();
+      ConcurrentMap<Key, Object> fresh = createDataMap();
       fresh.putAll(myUserMap);
       other.myUserMap = fresh;
     }
@@ -58,7 +59,7 @@ public class UserDataHolderBase implements UserDataHolderEx, Cloneable {
   }
 
   public <T> void putUserData(Key<T> key, T value) {
-    LockPoolSynchronizedMap<Key, Object> map = getOrCreateMap();
+    Map<Key, Object> map = getOrCreateMap();
 
     if (value == null) {
       map.remove(key);
@@ -68,7 +69,7 @@ public class UserDataHolderBase implements UserDataHolderEx, Cloneable {
     }
   }
 
-  private static LockPoolSynchronizedMap<Key, Object> createMap() {
+  protected ConcurrentMap<Key, Object> createDataMap() {
     return new LockPoolSynchronizedMap<Key, Object>(2, 0.9f);
   }
 
@@ -107,11 +108,11 @@ public class UserDataHolderBase implements UserDataHolderEx, Cloneable {
   }
 
 
-  private LockPoolSynchronizedMap<Key, Object> getOrCreateMap() {
+  private ConcurrentMap<Key, Object> getOrCreateMap() {
     if (myUserMap == null) {
       synchronized (MAP_LOCK) {
         if (myUserMap == null) {
-          myUserMap = createMap();
+          myUserMap = createDataMap();
         }
       }
     }
diff --git a/platform/util/src/com/intellij/util/containers/LockPoolSynchronizedMap.java b/platform/util/src/com/intellij/util/containers/LockPoolSynchronizedMap.java
index 85102c95a31c..a0d1f1094a52 100644
--- a/platform/util/src/com/intellij/util/containers/LockPoolSynchronizedMap.java
+++ b/platform/util/src/com/intellij/util/containers/LockPoolSynchronizedMap.java
@@ -28,8 +28,9 @@ import gnu.trove.THashMap;
 import java.util.Collection;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.ConcurrentMap;
 
-public class LockPoolSynchronizedMap<K, V> extends THashMap<K, V> {
+public class LockPoolSynchronizedMap<K, V> extends THashMap<K, V> implements ConcurrentMap<K, V> {
   private static final int NUM_LOCKS = 256;
   private static final JBReentrantReadWriteLock[] ourLocks = new JBReentrantReadWriteLock[NUM_LOCKS];
   private static int ourLockAllocationCounter = 0;
@@ -211,6 +212,24 @@ public class LockPoolSynchronizedMap<K, V> extends THashMap<K, V> {
     }
   }
 
+  public V replace(K key, V newValue) {
+    w.lock();
+    try {
+      V prev = get(key);
+
+      if (newValue == null) {
+        remove(key);
+      }
+      else {
+        put(key, newValue);
+      }
+      return prev;
+    }
+    finally {
+      w.unlock();
+    }
+  }
+
   public V putIfAbsent(K key, V value) {
     w.lock();
     try {
@@ -228,4 +247,17 @@ public class LockPoolSynchronizedMap<K, V> extends THashMap<K, V> {
     }
   }
 
+  public boolean remove(Object key, Object oldValue) {
+    w.lock();
+    try {
+      if (!Comparing.equal(oldValue, get(key))) {
+        return false;
+      }
+      return super.remove(key) != null;
+    }
+    finally {
+      w.unlock();
+    }
+  }
+
 }