diff --git a/platform/platform-impl/src/com/intellij/openapi/editor/impl/DocumentImpl.java b/platform/platform-impl/src/com/intellij/openapi/editor/impl/DocumentImpl.java
index 96b46d39eb8e..39f446ac2b6b 100644
--- a/platform/platform-impl/src/com/intellij/openapi/editor/impl/DocumentImpl.java
+++ b/platform/platform-impl/src/com/intellij/openapi/editor/impl/DocumentImpl.java
@@ -54,11 +54,12 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.CopyOnWriteArrayList;
 
 public class DocumentImpl extends UserDataHolderBase implements DocumentEx {
   private static final Logger LOG = Logger.getInstance("#com.intellij.openapi.editor.impl.DocumentImpl");
 
-  private final List<DocumentListener> myDocumentListeners = ContainerUtil.createEmptyCOWList();
+  private final CopyOnWriteArrayList<DocumentListener> myDocumentListeners = ContainerUtil.createEmptyCOWList();
   private final RangeMarkerTree<RangeMarkerEx> myRangeMarkers = new RangeMarkerTree<RangeMarkerEx>(this);
   private final List<RangeMarker> myGuardedBlocks = new ArrayList<RangeMarker>();
   private ReadonlyFragmentModificationHandler myReadonlyFragmentModificationHandler;
@@ -547,8 +548,8 @@ public class DocumentImpl extends UserDataHolderBase implements DocumentEx {
 
   public void addDocumentListener(@NotNull DocumentListener listener) {
     myCachedDocumentListeners = null;
-    LOG.assertTrue(!myDocumentListeners.contains(listener), listener);
-    myDocumentListeners.add(listener);
+    boolean added = myDocumentListeners.addIfAbsent(listener);
+    LOG.assertTrue(added, listener);
   }
 
   public void addDocumentListener(@NotNull final DocumentListener listener, @NotNull Disposable parentDisposable) {
@@ -609,14 +610,16 @@ public class DocumentImpl extends UserDataHolderBase implements DocumentEx {
     return lineCount;
   }
 
+  @NotNull
   private DocumentListener[] getCachedListeners() {
-    if (myCachedDocumentListeners == null) {
+    DocumentListener[] cachedListeners = myCachedDocumentListeners;
+    if (cachedListeners == null) {
       DocumentListener[] listeners = myDocumentListeners.toArray(new DocumentListener[myDocumentListeners.size()]);
       Arrays.sort(listeners, PrioritizedDocumentListener.COMPARATOR);
-      myCachedDocumentListeners = listeners;
+      myCachedDocumentListeners = cachedListeners = listeners;
     }
 
-    return myCachedDocumentListeners;
+    return cachedListeners;
   }
 
   public void fireReadOnlyModificationAttempt() {
diff --git a/platform/testFramework/src/com/intellij/testFramework/fixtures/impl/CodeInsightTestFixtureImpl.java b/platform/testFramework/src/com/intellij/testFramework/fixtures/impl/CodeInsightTestFixtureImpl.java
index 7ac2cc1acdc6..948a00cf3765 100644
--- a/platform/testFramework/src/com/intellij/testFramework/fixtures/impl/CodeInsightTestFixtureImpl.java
+++ b/platform/testFramework/src/com/intellij/testFramework/fixtures/impl/CodeInsightTestFixtureImpl.java
@@ -503,7 +503,7 @@ public class CodeInsightTestFixtureImpl extends BaseFixture implements CodeInsig
 
   @Override
   public void launchAction(@NotNull final IntentionAction action) {
-    new WriteCommandAction(myProjectFixture.getProject()) {
+    new WriteCommandAction(getProject()) {
       @Override
       protected void run(final Result result) throws Exception {
         ShowIntentionActionsHandler.chooseActionAndInvoke(getFile(), getEditor(), action, action.getText());
@@ -604,12 +604,12 @@ public class CodeInsightTestFixtureImpl extends BaseFixture implements CodeInsig
                             final String newName,
                             final boolean searchInComments,
                             final boolean searchTextOccurrences) {
-    new WriteCommandAction.Simple(myProjectFixture.getProject()) {
+    new WriteCommandAction.Simple(getProject()) {
       @Override
       protected void run() throws Exception {
         final PsiElement substitution = RenamePsiElementProcessor.forElement(element).substituteElementToRename(element, myEditor);
         if (substitution == null) return;
-        new RenameProcessor(myProjectFixture.getProject(), substitution, newName, searchInComments, searchTextOccurrences).run();
+        new RenameProcessor(getProject(), substitution, newName, searchInComments, searchTextOccurrences).run();
       }
     }.execute().throwException();
   }
@@ -739,7 +739,7 @@ public class CodeInsightTestFixtureImpl extends BaseFixture implements CodeInsig
   @Override
   public void moveFile(@NonNls final String filePath, @NonNls final String to, final String... additionalFiles) {
     assertInitialized();
-    final Project project = myProjectFixture.getProject();
+    final Project project = getProject();
     new WriteCommandAction.Simple(project) {
       @Override
       protected void run() throws Exception {
@@ -779,7 +779,7 @@ public class CodeInsightTestFixtureImpl extends BaseFixture implements CodeInsig
   @NotNull
   public Collection<GutterIconRenderer> findAllGutters(final String filePath) {
     assertInitialized();
-    final Project project = myProjectFixture.getProject();
+    final Project project = getProject();
     final SortedMap<Integer, List<GutterIconRenderer>> result = new TreeMap<Integer, List<GutterIconRenderer>>();
     configureByFilesInner(filePath);
 
@@ -944,7 +944,7 @@ public class CodeInsightTestFixtureImpl extends BaseFixture implements CodeInsig
   @Override
   public void checkResultByFile(final String expectedFile, final boolean ignoreTrailingWhitespaces) {
     assertInitialized();
-    new WriteCommandAction.Simple(myProjectFixture.getProject()) {
+    new WriteCommandAction.Simple(getProject()) {
 
       @Override
       protected void run() throws Exception {
@@ -957,7 +957,7 @@ public class CodeInsightTestFixtureImpl extends BaseFixture implements CodeInsig
   public void checkResultByFile(final String filePath, final String expectedFile, final boolean ignoreTrailingWhitespaces) {
     assertInitialized();
 
-    new WriteCommandAction.Simple(myProjectFixture.getProject()) {
+    new WriteCommandAction.Simple(getProject()) {
 
       @Override
       protected void run() throws Exception {
@@ -1333,7 +1333,7 @@ public class CodeInsightTestFixtureImpl extends BaseFixture implements CodeInsig
   @Override
   @NotNull
   public List<HighlightInfo> doHighlighting() {
-    final Project project = myProjectFixture.getProject();
+    final Project project = getProject();
     new WriteCommandAction.Simple(project) {
       @Override
       protected void run() throws Throwable {
@@ -1538,7 +1538,7 @@ public class CodeInsightTestFixtureImpl extends BaseFixture implements CodeInsig
                            final SelectionAndCaretMarkupLoader loader,
                            String actualText) {
     assertInitialized();
-    Project project = myProjectFixture.getProject();
+    Project project = getProject();
 
     project.getComponent(PostprocessReformattingAspect.class).doPostponedFormatting();
     if (stripTrailingSpaces) {
diff --git a/platform/testFramework/src/com/intellij/testFramework/fixtures/impl/LightIdeaTestFixtureImpl.java b/platform/testFramework/src/com/intellij/testFramework/fixtures/impl/LightIdeaTestFixtureImpl.java
index 0a13e332fd28..15c3411bbb24 100644
--- a/platform/testFramework/src/com/intellij/testFramework/fixtures/impl/LightIdeaTestFixtureImpl.java
+++ b/platform/testFramework/src/com/intellij/testFramework/fixtures/impl/LightIdeaTestFixtureImpl.java
@@ -53,6 +53,16 @@ class LightIdeaTestFixtureImpl extends BaseFixture implements LightIdeaTestFixtu
     storeSettings();
   }
 
+  @Override
+  public void tearDown() throws Exception {
+    CodeStyleSettingsManager.getInstance(getProject()).dropTemporarySettings();
+    checkForSettingsDamage();
+    LightPlatformTestCase.doTearDown(getProject(), LightPlatformTestCase.getApplication(), true);
+    super.tearDown();
+    ((InjectedLanguageManagerImpl)InjectedLanguageManager.getInstance(getProject())).checkInjectorsAreDisposed();
+  }
+
+
   private class MyDataProvider implements DataProvider {
     @Override
     @Nullable
@@ -69,16 +79,6 @@ class LightIdeaTestFixtureImpl extends BaseFixture implements LightIdeaTestFixtu
     }
   }
 
-
-  @Override
-  public void tearDown() throws Exception {
-    CodeStyleSettingsManager.getInstance(getProject()).dropTemporarySettings();
-    checkForSettingsDamage();
-    LightPlatformTestCase.doTearDown(getProject(), LightPlatformTestCase.getApplication(), true);
-    super.tearDown();
-    ((InjectedLanguageManagerImpl)InjectedLanguageManager.getInstance(getProject())).checkInjectorsAreDisposed();
-  }
-
   @Override
   public Project getProject() {
     return LightPlatformTestCase.getProject();