diff --git a/platform/vcs-impl/src/com/intellij/openapi/vcs/ex/LineStatusTracker.java b/platform/vcs-impl/src/com/intellij/openapi/vcs/ex/LineStatusTracker.java
index 165b10347f56..4223b9a1547e 100644
--- a/platform/vcs-impl/src/com/intellij/openapi/vcs/ex/LineStatusTracker.java
+++ b/platform/vcs-impl/src/com/intellij/openapi/vcs/ex/LineStatusTracker.java
@@ -20,14 +20,13 @@ import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.command.undo.UndoManager;
 import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.editor.Document;
-import com.intellij.openapi.editor.EditorFactory;
 import com.intellij.openapi.editor.event.DocumentAdapter;
 import com.intellij.openapi.editor.event.DocumentEvent;
+import com.intellij.openapi.editor.impl.DocumentImpl;
 import com.intellij.openapi.editor.markup.*;
 import com.intellij.openapi.fileEditor.FileDocumentManager;
 import com.intellij.openapi.progress.ProcessCanceledException;
 import com.intellij.openapi.project.Project;
-import com.intellij.openapi.util.Computable;
 import com.intellij.openapi.util.TextRange;
 import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.openapi.vcs.VcsBundle;
@@ -46,6 +45,7 @@ import java.util.ListIterator;
  */
 public class LineStatusTracker {
   private static final Logger LOG = Logger.getInstance("#com.intellij.openapi.vcs.ex.LineStatusTracker");
+  private final Object myLock = new Object();
   // true -> have contents
   private BaseLoadState myBaseLoaded;
 
@@ -72,36 +72,36 @@ public class LineStatusTracker {
   }
 
   public void initialize(@NotNull final String upToDateContent) {
-    ApplicationManager.getApplication().isReadAccessAllowed();
+    ApplicationManager.getApplication().assertIsDispatchThread();
     LOG.assertTrue(BaseLoadState.LOADING == myBaseLoaded);
 
-    ApplicationManager.getApplication().runWriteAction(new Runnable() {
-      public void run() {
-        try {
-          myUpToDateDocument.setReadOnly(false);
-          myUpToDateDocument.replaceString(0, myUpToDateDocument.getTextLength(), upToDateContent);
-          myUpToDateDocument.setReadOnly(true);
-          reinstallRanges();
+    synchronized (myLock) {
+      try {
+        myUpToDateDocument.setReadOnly(false);
+        myUpToDateDocument.replaceString(0, myUpToDateDocument.getTextLength(), upToDateContent);
+        myUpToDateDocument.setReadOnly(true);
+        reinstallRanges();
 
-          if (myDocumentListener == null) {
-            myDocumentListener = new MyDocumentListener();
-            myDocument.addDocumentListener(myDocumentListener);
-          }
-        }
-        finally {
-          myBaseLoaded = BaseLoadState.LOADED;
+        if (myDocumentListener == null) {
+          myDocumentListener = new MyDocumentListener();
+          myDocument.addDocumentListener(myDocumentListener);
         }
       }
-    });
+      finally {
+        myBaseLoaded = BaseLoadState.LOADED;
+      }
+    }
   }
 
   private void reinstallRanges() {
-    myApplication.assertWriteAccessAllowed();
+    myApplication.assertReadAccessAllowed();
 
-    removeHighlightersFromMarkupModel();
-    myRanges = new RangesBuilder(myDocument, myUpToDateDocument).getRanges();
-    for (final Range range : myRanges) {
-      range.setHighlighter(createHighlighter(range));
+    synchronized (myLock) {
+      removeHighlightersFromMarkupModel();
+      myRanges = new RangesBuilder(myDocument, myUpToDateDocument).getRanges();
+      for (final Range range : myRanges) {
+        range.setHighlighter(createHighlighter(range));
+      }
     }
   }
 
@@ -137,16 +137,13 @@ public class LineStatusTracker {
   }
 
   public void release() {
-    myApplication.runWriteAction(new Runnable() {
-      @Override
-      public void run() {
-        if (myDocumentListener != null) {
-          myDocument.removeDocumentListener(myDocumentListener);
-        }
-        removeHighlightersFromMarkupModel();
-        myRanges.clear();
+    synchronized (myLock) {
+      if (myDocumentListener != null) {
+        myDocument.removeDocumentListener(myDocumentListener);
       }
-    });
+      removeHighlightersFromMarkupModel();
+      myRanges.clear();
+    }
   }
 
   public Document getDocument() {
@@ -160,39 +157,38 @@ public class LineStatusTracker {
   public List<Range> getRanges() {
     myApplication.assertReadAccessAllowed();
 
-    return myRanges;
+    synchronized (myLock) {
+      return myRanges;
+    }
   }
 
   public Document getUpToDateDocument() {
+    myApplication.assertIsDispatchThread();
     return myUpToDateDocument;
   }
 
   public void startBulkUpdate() {
-    myApplication.runWriteAction(new Runnable() {
-      @Override
-      public void run() {
-        myBulkUpdate = true;
-        removeHighlightersFromMarkupModel();
-        myRanges.clear();
-      }
-    });
+    synchronized (myLock) {
+      myBulkUpdate = true;
+      removeHighlightersFromMarkupModel();
+      myRanges.clear();
+    }
   }
 
   private void removeHighlightersFromMarkupModel() {
     final MarkupModel markupModel = myDocument.getMarkupModel(myProject);
-    for (Range range : myRanges) {
-      markupModel.removeHighlighter(range.getHighlighter());
+    synchronized (myLock) {
+      for (Range range : myRanges) {
+        markupModel.removeHighlighter(range.getHighlighter());
+      }
     }
   }
 
   public void finishBulkUpdate() {
-    myApplication.runWriteAction(new Runnable() {
-      @Override
-      public void run() {
-        myBulkUpdate = false;
-        reinstallRanges();
-      }
-    });
+    synchronized (myLock) {
+      myBulkUpdate = false;
+      reinstallRanges();
+    }
   }
 
   /**
@@ -200,24 +196,18 @@ public class LineStatusTracker {
    * false -> load was already started; after contents is loaded,
    */
   public boolean resetForBaseRevisionLoad() {
-    return myApplication.runReadAction(new Computable<Boolean>() {
-      @Override
-      public Boolean compute() {
-        if (BaseLoadState.LOADING == myBaseLoaded) return false;
-        return myApplication.runWriteAction(new Computable<Boolean>() {
-          @Override
-          public Boolean compute() {
-            myUpToDateDocument.setReadOnly(false);
-            myUpToDateDocument.setText("");
-            myUpToDateDocument.setReadOnly(true);
-            removeHighlightersFromMarkupModel();
-            myRanges.clear();
-            myBaseLoaded = BaseLoadState.LOADING;
-            return true;
-          }
-        });
-      }
-    });
+    myApplication.assertReadAccessAllowed();
+
+    synchronized (myLock) {
+      if (BaseLoadState.LOADING == myBaseLoaded) return false;
+      myUpToDateDocument.setReadOnly(false);
+      myUpToDateDocument.setText("");
+      myUpToDateDocument.setReadOnly(true);
+      removeHighlightersFromMarkupModel();
+      myRanges.clear();
+      myBaseLoaded = BaseLoadState.LOADING;
+      return true;
+    }
   }
 
   private class MyDocumentListener extends DocumentAdapter {
@@ -231,39 +221,41 @@ public class LineStatusTracker {
       if (myBulkUpdate || (BaseLoadState.LOADED != myBaseLoaded)) return;
       myApplication.assertWriteAccessAllowed();
 
-      try {
-        myFirstChangedLine = myDocument.getLineNumber(e.getOffset());
-        myLastChangedLine = myDocument.getLineNumber(e.getOffset() + e.getOldLength());
-        if (StringUtil.endsWithChar(e.getOldFragment(), '\n')) myLastChangedLine++;
+      synchronized (myLock) {
+        try {
+          myFirstChangedLine = myDocument.getLineNumber(e.getOffset());
+          myLastChangedLine = myDocument.getLineNumber(e.getOffset() + e.getOldLength());
+          if (StringUtil.endsWithChar(e.getOldFragment(), '\n')) myLastChangedLine++;
 
-        myLinesBeforeChange = myDocument.getLineNumber(e.getOffset() + e.getOldLength()) - myDocument.getLineNumber(e.getOffset());
+          myLinesBeforeChange = myDocument.getLineNumber(e.getOffset() + e.getOldLength()) - myDocument.getLineNumber(e.getOffset());
 
-        Range firstChangedRange = getLastRangeBeforeLine(myFirstChangedLine);
+          Range firstChangedRange = getLastRangeBeforeLine(myFirstChangedLine);
 
-        if (firstChangedRange == null) {
-          myUpToDateFirstLine = myFirstChangedLine;
-        }
-        else if (firstChangedRange.containsLine(myFirstChangedLine)) {
-          myFirstChangedLine = firstChangedRange.getOffset1();
-          myUpToDateFirstLine = firstChangedRange.getUOffset1();
-        }
-        else {
-          myUpToDateFirstLine = firstChangedRange.getUOffset2() + (myFirstChangedLine - firstChangedRange.getOffset2());
-        }
+          if (firstChangedRange == null) {
+            myUpToDateFirstLine = myFirstChangedLine;
+          }
+          else if (firstChangedRange.containsLine(myFirstChangedLine)) {
+            myFirstChangedLine = firstChangedRange.getOffset1();
+            myUpToDateFirstLine = firstChangedRange.getUOffset1();
+          }
+          else {
+            myUpToDateFirstLine = firstChangedRange.getUOffset2() + (myFirstChangedLine - firstChangedRange.getOffset2());
+          }
 
-        Range myLastChangedRange = getLastRangeBeforeLine(myLastChangedLine);
+          Range myLastChangedRange = getLastRangeBeforeLine(myLastChangedLine);
 
-        if (myLastChangedRange == null) {
-          myUpToDateLastLine = myLastChangedLine;
+          if (myLastChangedRange == null) {
+            myUpToDateLastLine = myLastChangedLine;
+          }
+          else if (myLastChangedRange.containsLine(myLastChangedLine)) {
+            myUpToDateLastLine = myLastChangedRange.getUOffset2();
+            myLastChangedLine = myLastChangedRange.getOffset2();
+          }
+          else {
+            myUpToDateLastLine = myLastChangedRange.getUOffset2() + (myLastChangedLine - myLastChangedRange.getOffset2());
+          }
+        } catch (ProcessCanceledException ignore) {
         }
-        else if (myLastChangedRange.containsLine(myLastChangedLine)) {
-          myUpToDateLastLine = myLastChangedRange.getUOffset2();
-          myLastChangedLine = myLastChangedRange.getOffset2();
-        }
-        else {
-          myUpToDateLastLine = myLastChangedRange.getUOffset2() + (myLastChangedLine - myLastChangedRange.getOffset2());
-        }
-      } catch (ProcessCanceledException ignore) {
       }
     }
 
@@ -281,47 +273,49 @@ public class LineStatusTracker {
       if (myBulkUpdate || (BaseLoadState.LOADED != myBaseLoaded)) return;
       myApplication.assertWriteAccessAllowed();
 
-      try {
+      synchronized (myLock) {
+        try {
 
-        int line = myDocument.getLineNumber(e.getOffset() + e.getNewLength());
-        int linesAfterChange = line - myDocument.getLineNumber(e.getOffset());
-        int linesShift = linesAfterChange - myLinesBeforeChange;
+          int line = myDocument.getLineNumber(e.getOffset() + e.getNewLength());
+          int linesAfterChange = line - myDocument.getLineNumber(e.getOffset());
+          int linesShift = linesAfterChange - myLinesBeforeChange;
 
-        List<Range> rangesAfterChange = getRangesAfter(myRanges, myLastChangedLine);
-        List<Range> rangesBeforeChange = getRangesBefore(myRanges, myFirstChangedLine);
+          List<Range> rangesAfterChange = getRangesAfter(myRanges, myLastChangedLine);
+          List<Range> rangesBeforeChange = getRangesBefore(myRanges, myFirstChangedLine);
 
-        List<Range> changedRanges = getChangedRanges(myFirstChangedLine, myLastChangedLine);
+          List<Range> changedRanges = getChangedRanges(myFirstChangedLine, myLastChangedLine);
 
-        int newSize = rangesBeforeChange.size() + changedRanges.size() + rangesAfterChange.size();
-        if (myRanges.size() != newSize) {
-          LOG.info("Ranges: " + myRanges + "; first changed line: " + myFirstChangedLine + "; last changed line: " + myLastChangedLine);
-          LOG.assertTrue(false);
-        }
-
-
-        myLastChangedLine += linesShift;
-
-
-        List<Range> newChangedRanges = getNewChangedRanges();
-
-        shiftRanges(rangesAfterChange, linesShift);
-
-        if (!changedRanges.equals(newChangedRanges)) {
-          replaceRanges(changedRanges, newChangedRanges);
-
-          myRanges = new ArrayList<Range>();
-
-          myRanges.addAll(rangesBeforeChange);
-          myRanges.addAll(newChangedRanges);
-          myRanges.addAll(rangesAfterChange);
-
-          myRanges = mergeRanges(myRanges);
-
-          for (Range range : myRanges) {
-            if (!range.hasHighlighter()) range.setHighlighter(createHighlighter(range));
+          int newSize = rangesBeforeChange.size() + changedRanges.size() + rangesAfterChange.size();
+          if (myRanges.size() != newSize) {
+            LOG.info("Ranges: " + myRanges + "; first changed line: " + myFirstChangedLine + "; last changed line: " + myLastChangedLine);
+            LOG.assertTrue(false);
           }
+
+
+          myLastChangedLine += linesShift;
+
+
+          List<Range> newChangedRanges = getNewChangedRanges();
+
+          shiftRanges(rangesAfterChange, linesShift);
+
+          if (!changedRanges.equals(newChangedRanges)) {
+            replaceRanges(changedRanges, newChangedRanges);
+
+            myRanges = new ArrayList<Range>();
+
+            myRanges.addAll(rangesBeforeChange);
+            myRanges.addAll(newChangedRanges);
+            myRanges.addAll(rangesAfterChange);
+
+            myRanges = mergeRanges(myRanges);
+
+            for (Range range : myRanges) {
+              if (!range.hasHighlighter()) range.setHighlighter(createHighlighter(range));
+            }
+          }
+        } catch (ProcessCanceledException ignore) {
         }
-      } catch (ProcessCanceledException ignore) {
       }
     }
 
@@ -390,49 +384,57 @@ public class LineStatusTracker {
 
   @Nullable
   Range getNextRange(final Range range) {
-    final int index = myRanges.indexOf(range);
-    if (index == myRanges.size() - 1) return null;
-    return myRanges.get(index + 1);
+    synchronized (myLock) {
+      final int index = myRanges.indexOf(range);
+      if (index == myRanges.size() - 1) return null;
+      return myRanges.get(index + 1);
+    }
   }
 
   @Nullable
   Range getPrevRange(final Range range) {
-    final int index = myRanges.indexOf(range);
-    if (index <= 0) return null;
-    return myRanges.get(index - 1);
+    synchronized (myLock) {
+      final int index = myRanges.indexOf(range);
+      if (index <= 0) return null;
+      return myRanges.get(index - 1);
+    }
   }
 
   @Nullable
   public Range getNextRange(final int line) {
-    final Range currentRange = getRangeForLine(line);
-    if (currentRange != null) {
-      return getNextRange(currentRange);
-    }
-
-    for (final Range range : myRanges) {
-      if (line > range.getOffset1() || line > range.getOffset2()) {
-        continue;
+    synchronized (myLock) {
+      final Range currentRange = getRangeForLine(line);
+      if (currentRange != null) {
+        return getNextRange(currentRange);
       }
-      return range;
+
+      for (final Range range : myRanges) {
+        if (line > range.getOffset1() || line > range.getOffset2()) {
+          continue;
+        }
+        return range;
+      }
+      return null;
     }
-    return null;
   }
 
   @Nullable
   public Range getPrevRange(final int line) {
-    final Range currentRange = getRangeForLine(line);
-    if (currentRange != null) {
-      return getPrevRange(currentRange);
-    }
-
-    for (ListIterator<Range> iterator = myRanges.listIterator(myRanges.size()); iterator.hasPrevious();) {
-      final Range range = iterator.previous();
-      if (range.getOffset1() > line) {
-        continue;
+    synchronized (myLock) {
+      final Range currentRange = getRangeForLine(line);
+      if (currentRange != null) {
+        return getPrevRange(currentRange);
       }
-      return range;
+
+      for (ListIterator<Range> iterator = myRanges.listIterator(myRanges.size()); iterator.hasPrevious();) {
+        final Range range = iterator.previous();
+        if (range.getOffset1() > line) {
+          continue;
+        }
+        return range;
+      }
+      return null;
     }
-    return null;
   }
 
   public static List<Range> getRangesBefore(List<Range> ranges, int line) {
@@ -455,43 +457,49 @@ public class LineStatusTracker {
 
   @Nullable
   public Range getRangeForLine(final int line) {
-    for (final Range range : myRanges) {
-      if (range.getType() == Range.DELETED && line == range.getOffset1()) {
-        return range;
-      }
-      else if (line >= range.getOffset1() && line < range.getOffset2()) {
-        return range;
+    synchronized (myLock) {
+      for (final Range range : myRanges) {
+        if (range.getType() == Range.DELETED && line == range.getOffset1()) {
+          return range;
+        }
+        else if (line >= range.getOffset1() && line < range.getOffset2()) {
+          return range;
+        }
       }
+      return null;
     }
-    return null;
   }
 
   public void rollbackChanges(final Range range) {
     myApplication.assertWriteAccessAllowed();
 
-    TextRange currentTextRange = getCurrentTextRange(range);
+    synchronized (myLock) {
+      TextRange currentTextRange = getCurrentTextRange(range);
 
-    if (range.getType() == Range.INSERTED) {
-      myDocument
-        .replaceString(currentTextRange.getStartOffset(), Math.min(currentTextRange.getEndOffset() + 1, myDocument.getTextLength()), "");
-    }
-    else if (range.getType() == Range.DELETED) {
-      String upToDateContent = getUpToDateContent(range);
-      myDocument.insertString(currentTextRange.getStartOffset(), upToDateContent);
-    }
-    else {
+      if (range.getType() == Range.INSERTED) {
+        myDocument
+          .replaceString(currentTextRange.getStartOffset(), Math.min(currentTextRange.getEndOffset() + 1, myDocument.getTextLength()), "");
+      }
+      else if (range.getType() == Range.DELETED) {
+        String upToDateContent = getUpToDateContent(range);
+        myDocument.insertString(currentTextRange.getStartOffset(), upToDateContent);
+      }
+      else {
 
-      String upToDateContent = getUpToDateContent(range);
-      myDocument.replaceString(currentTextRange.getStartOffset(), Math.min(currentTextRange.getEndOffset() + 1, myDocument.getTextLength()),
-                               upToDateContent);
+        String upToDateContent = getUpToDateContent(range);
+        myDocument.replaceString(currentTextRange.getStartOffset(), Math.min(currentTextRange.getEndOffset() + 1, myDocument.getTextLength()),
+                                 upToDateContent);
+      }
     }
   }
 
   public String getUpToDateContent(Range range) {
-    TextRange textRange = getUpToDateRange(range);
-    final int startOffset = textRange.getStartOffset();
-    final int endOffset = Math.min(textRange.getEndOffset() + 1, myUpToDateDocument.getTextLength());
-    return myUpToDateDocument.getCharsSequence().subSequence(startOffset, endOffset).toString();
+    synchronized (myLock) {
+      TextRange textRange = getUpToDateRange(range);
+      final int startOffset = textRange.getStartOffset();
+      final int endOffset = Math.min(textRange.getEndOffset() + 1, myUpToDateDocument.getTextLength());
+      return myUpToDateDocument.getCharsSequence().subSequence(startOffset, endOffset).toString();
+    }
   }
 
   Project getProject() {
@@ -539,7 +547,7 @@ public class LineStatusTracker {
   }
 
   public static LineStatusTracker createOn(final Document doc, final Project project) {
-    final Document document = EditorFactory.getInstance().createDocument("");
+    final Document document = new DocumentImpl(true);
     return new LineStatusTracker(doc, document, project);
   }
 
@@ -548,8 +556,9 @@ public class LineStatusTracker {
   }
 
   public void baseRevisionLoadFailed() {
-    myApplication.assertWriteAccessAllowed();
-    myBaseLoaded = BaseLoadState.FAILED;
+    synchronized (myLock) {
+      myBaseLoaded = BaseLoadState.FAILED;
+    }
   }
 
   public static enum BaseLoadState {
diff --git a/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/LineStatusTrackerManager.java b/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/LineStatusTrackerManager.java
index 9e899d0d94e9..bee5b12b96bf 100644
--- a/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/LineStatusTrackerManager.java
+++ b/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/LineStatusTrackerManager.java
@@ -42,7 +42,6 @@ import com.intellij.openapi.editor.ex.DocumentBulkUpdateListener;
 import com.intellij.openapi.fileEditor.FileDocumentManager;
 import com.intellij.openapi.fileEditor.FileEditorManager;
 import com.intellij.openapi.project.Project;
-import com.intellij.openapi.util.Computable;
 import com.intellij.openapi.util.Condition;
 import com.intellij.openapi.util.Disposer;
 import com.intellij.openapi.util.text.StringUtil;
@@ -68,6 +67,7 @@ import java.util.Map;
 
 public class LineStatusTrackerManager implements ProjectComponent, LineStatusTrackerManagerI {
   private static final Logger LOG = Logger.getInstance("#com.intellij.openapi.vcs.impl.LineStatusTrackerManager");
+  public final Object myLock = new Object();
 
   public static LineStatusTrackerManagerI getInstance(final Project project) {
     if (System.getProperty(IGNORE_CHANGEMARKERS_KEY) != null) {
@@ -116,15 +116,17 @@ public class LineStatusTrackerManager implements ProjectComponent, LineStatusTra
     myDisposable = new Disposable() {
       @Override
       public void dispose() {
-        final Collection<LineStatusTracker> trackers = myLineStatusTrackers.values();
-        final LineStatusTracker[] lineStatusTrackers = trackers.toArray(new LineStatusTracker[trackers.size()]);
-        for (final LineStatusTracker tracker : lineStatusTrackers) {
-          releaseTracker(tracker.getDocument());
-        }
+        synchronized (myLock) {
+          final Collection<LineStatusTracker> trackers = myLineStatusTrackers.values();
+          final LineStatusTracker[] lineStatusTrackers = trackers.toArray(new LineStatusTracker[trackers.size()]);
+          for (final LineStatusTracker tracker : lineStatusTrackers) {
+            releaseTracker(tracker.getDocument());
+          }
 
-        myLineStatusTrackers.clear();
-        assert myLineStatusUpdateAlarms.isEmpty();
-        myLineStatusUpdateAlarms.clear();
+          myLineStatusTrackers.clear();
+          assert myLineStatusUpdateAlarms.isEmpty();
+          myLineStatusUpdateAlarms.clear();
+        }
       }
     };
     Disposer.register(myProject, myDisposable);
@@ -178,12 +180,15 @@ public class LineStatusTrackerManager implements ProjectComponent, LineStatusTra
   @Override
   public LineStatusTracker getLineStatusTracker(final Document document) {
     myApplication.assertReadAccessAllowed();
-
     if ((! myProject.isOpen()) || myProject.isDisposed()) return null;
-    return myLineStatusTrackers.get(document);
+
+    synchronized (myLock) {
+      return myLineStatusTrackers.get(document);
+    }
   }
 
   private void resetTracker(@NotNull final VirtualFile virtualFile) {
+    myApplication.assertReadAccessAllowed();
     if ((! myProject.isOpen()) || myProject.isDisposed()) return;
 
     final Document document = FileDocumentManager.getInstance().getCachedDocument(virtualFile);
@@ -194,49 +199,43 @@ public class LineStatusTrackerManager implements ProjectComponent, LineStatusTra
 
     log("resetting tracker for file " + virtualFile.getPath());
 
-    final LineStatusTracker tracker = myLineStatusTrackers.get(document);
     final boolean editorOpened = myFileEditorManager.isFileOpen(virtualFile);
     final boolean shouldBeInstalled = shouldBeInstalled(virtualFile) && editorOpened;
 
-    if (tracker == null && (! shouldBeInstalled)) return;
+    synchronized (myLock) {
+      final LineStatusTracker tracker = myLineStatusTrackers.get(document);
 
-    myApplication.runWriteAction(new Runnable() {
-      @Override
-      public void run() {
-        // remove ?
-        if (tracker != null) {
-          if (! shouldBeInstalled) {
-            releaseTracker(document);
-            return;
-          } else if ((LineStatusTracker.BaseLoadState.LOADING == tracker.getBaseLoaded())) {
-            return; // will be recalculated
-          } else {
-            tracker.resetForBaseRevisionLoad();
-            startAlarm(document, virtualFile);
-          }
-        } else if (shouldBeInstalled) {
-          installTracker(virtualFile, document);
+      if (tracker == null && (! shouldBeInstalled)) return;
+
+      if (tracker != null) {
+        if (! shouldBeInstalled) {
+          releaseTracker(document);
+          return;
+        } else if ((LineStatusTracker.BaseLoadState.LOADING == tracker.getBaseLoaded())) {
+          return; // will be recalculated
+        } else {
+          tracker.resetForBaseRevisionLoad();
+          startAlarm(document, virtualFile);
         }
+      } else if (shouldBeInstalled) {
+        installTracker(virtualFile, document);
       }
-    });
+    }
   }
 
   private void releaseTracker(final Document document) {
     if ((! myProject.isOpen()) || myProject.isDisposed()) return;
 
-    myApplication.runWriteAction(new Runnable() {
-      @Override
-      public void run() {
-        final Alarm alarm = myLineStatusUpdateAlarms.remove(document);
-        if (alarm != null) {
-          alarm.cancelAllRequests();
-        }
-        final LineStatusTracker tracker = myLineStatusTrackers.remove(document);
-        if (tracker != null) {
-          tracker.release();
-        }
+    synchronized (myLock) {
+      final Alarm alarm = myLineStatusUpdateAlarms.remove(document);
+      if (alarm != null) {
+        alarm.cancelAllRequests();
       }
-    });
+      final LineStatusTracker tracker = myLineStatusTrackers.remove(document);
+      if (tracker != null) {
+        tracker.release();
+      }
+    }
   }
 
   private boolean shouldBeInstalled(final VirtualFile virtualFile) {
@@ -261,25 +260,24 @@ public class LineStatusTrackerManager implements ProjectComponent, LineStatusTra
   }
 
   private void installTracker(final VirtualFile virtualFile, final Document document) {
-    myApplication.runWriteAction(new Runnable() {
-      @Override
-      public void run() {
-        if (myLineStatusTrackers.containsKey(document)) return;
-        assert !myLineStatusUpdateAlarms.containsKey(document);
+    synchronized (myLock) {
+      if (myLineStatusTrackers.containsKey(document)) return;
+      assert !myLineStatusUpdateAlarms.containsKey(document);
 
-        final LineStatusTracker tracker = LineStatusTracker.createOn(document, myProject);
-        myLineStatusTrackers.put(document, tracker);
+      final LineStatusTracker tracker = LineStatusTracker.createOn(document, myProject);
+      myLineStatusTrackers.put(document, tracker);
 
-        startAlarm(document, virtualFile);
-      }
-    });
+      startAlarm(document, virtualFile);
+    }
   }
 
   private void startAlarm(final Document document, final VirtualFile virtualFile) {
-    myApplication.assertWriteAccessAllowed();
+    myApplication.assertReadAccessAllowed();
 
     final Alarm alarm = new Alarm(Alarm.ThreadToUse.SHARED_THREAD);
-    myLineStatusUpdateAlarms.put(document, alarm);
+    synchronized (myLock) {
+      myLineStatusUpdateAlarms.put(document, alarm);
+    }
     alarm.addRequest(new BaseRevisionLoader(alarm, document, virtualFile), 10);
   }
 
@@ -297,14 +295,12 @@ public class LineStatusTrackerManager implements ProjectComponent, LineStatusTra
     @Override
     public void run() {
       myAlarm.cancelAllRequests();
-      final Boolean removed = myApplication.runReadAction(new Computable<Boolean>() {
-        @Override
-        public Boolean compute() {
-          final Alarm removed = myLineStatusUpdateAlarms.remove(myDocument);
-          return removed != null;
+      synchronized (myLock) {
+        final Alarm removed = myLineStatusUpdateAlarms.remove(myDocument);
+        if (removed == null) {
+          return;
         }
-      });
-      if (! Boolean.TRUE.equals(removed)) return;
+      }
       if ((! myProject.isOpen()) || myProject.isDisposed()) return;
 
       if (! myVirtualFile.isValid()) {
@@ -323,15 +319,13 @@ public class LineStatusTrackerManager implements ProjectComponent, LineStatusTra
       final String converted = StringUtil.convertLineSeparators(lastUpToDateContent);
       myApplication.invokeLater(new Runnable() {
         public void run() {
-          ApplicationManager.getApplication().runWriteAction(new Runnable() {
-            public void run() {
-              log("initializing tracker for file " + myVirtualFile.getPath());
-              final LineStatusTracker tracker = myLineStatusTrackers.get(myDocument);
-              if (tracker != null) {
-                tracker.initialize(converted);
-              }
+          synchronized (myLock) {
+            log("initializing tracker for file " + myVirtualFile.getPath());
+            final LineStatusTracker tracker = myLineStatusTrackers.get(myDocument);
+            if (tracker != null) {
+              tracker.initialize(converted);
             }
-          });
+          }
         }
       }, new Condition() {
         @Override
@@ -342,24 +336,13 @@ public class LineStatusTrackerManager implements ProjectComponent, LineStatusTra
     }
 
     private void reportTrackerBaseLoadFailed() {
-      myApplication.invokeLater(new Runnable() {
-        public void run() {
-          ApplicationManager.getApplication().runWriteAction(new Runnable() {
-            public void run() {
-              log("base revision load failed for file " + myVirtualFile.getPath());
-              final LineStatusTracker tracker = myLineStatusTrackers.get(myDocument);
-              if (tracker != null) {
-                tracker.baseRevisionLoadFailed();
-              }
-            }
-          });
+      synchronized (myLock) {
+        log("base revision load failed for file " + myVirtualFile.getPath());
+        final LineStatusTracker tracker = myLineStatusTrackers.get(myDocument);
+        if (tracker != null) {
+          tracker.baseRevisionLoadFailed();
         }
-      }, new Condition() {
-        @Override
-        public boolean value(final Object ignore) {
-          return (! myProject.isOpen()) || myProject.isDisposed();
-        }
-      });
+      }
     }
   }
 
@@ -369,7 +352,6 @@ public class LineStatusTrackerManager implements ProjectComponent, LineStatusTra
 
     final VirtualFile[] openFiles = myFileEditorManager.getOpenFiles();
     for(final VirtualFile openFile: openFiles) {
-      // write action inside is sufficient level
       resetTracker(openFile);
     }
   }