diff --git a/platform/platform-api/src/com/intellij/ide/util/DelegatingProgressIndicator.java b/platform/platform-api/src/com/intellij/ide/util/DelegatingProgressIndicator.java
index 20a4ba061dcc..e42df3e4d008 100644
--- a/platform/platform-api/src/com/intellij/ide/util/DelegatingProgressIndicator.java
+++ b/platform/platform-api/src/com/intellij/ide/util/DelegatingProgressIndicator.java
@@ -20,6 +20,7 @@ import com.intellij.openapi.progress.EmptyProgressIndicator;
 import com.intellij.openapi.progress.ProcessCanceledException;
 import com.intellij.openapi.progress.ProgressIndicator;
 import com.intellij.openapi.progress.ProgressManager;
+import org.jetbrains.annotations.NotNull;
 
 /**
  * @author Eugene Zhuravlev
@@ -97,6 +98,7 @@ public class DelegatingProgressIndicator implements ProgressIndicator {
     return getDelegate().isModal();
   }
 
+  @NotNull
   public ModalityState getModalityState() {
     return getDelegate().getModalityState();
   }
diff --git a/platform/platform-api/src/com/intellij/mock/MockProgressIndicator.java b/platform/platform-api/src/com/intellij/mock/MockProgressIndicator.java
index f6d09623546e..fcd265bd616a 100644
--- a/platform/platform-api/src/com/intellij/mock/MockProgressIndicator.java
+++ b/platform/platform-api/src/com/intellij/mock/MockProgressIndicator.java
@@ -17,6 +17,7 @@ package com.intellij.mock;
 
 import com.intellij.openapi.application.ModalityState;
 import com.intellij.openapi.progress.ProgressIndicator;
+import org.jetbrains.annotations.NotNull;
 
 public class MockProgressIndicator implements ProgressIndicator {
   private boolean myIsRunning = false;
@@ -80,6 +81,7 @@ public class MockProgressIndicator implements ProgressIndicator {
     return false;
   }
 
+  @NotNull
   public ModalityState getModalityState() {
     return ModalityState.NON_MODAL;
   }
@@ -96,4 +98,4 @@ public class MockProgressIndicator implements ProgressIndicator {
 
   public void checkCanceled() {
   }
-}
\ No newline at end of file
+}
diff --git a/platform/platform-api/src/com/intellij/openapi/application/Application.java b/platform/platform-api/src/com/intellij/openapi/application/Application.java
index da64669c3749..3eed0bf0ea52 100644
--- a/platform/platform-api/src/com/intellij/openapi/application/Application.java
+++ b/platform/platform-api/src/com/intellij/openapi/application/Application.java
@@ -208,6 +208,7 @@ public interface Application extends ComponentManager {
    *
    * @return the current modality state.
    */
+  @NotNull
   ModalityState getCurrentModalityState();
 
   /**
@@ -216,6 +217,7 @@ public interface Application extends ComponentManager {
    * @param c the component for which the modality state is requested.
    * @return the modality state.
    */
+  @NotNull
   ModalityState getModalityStateForComponent(@NotNull Component c);
 
   /**
@@ -224,6 +226,7 @@ public interface Application extends ComponentManager {
    *
    * @return the modality state for the current thread.
    */
+  @NotNull
   ModalityState getDefaultModalityState();
 
   /**
@@ -232,6 +235,7 @@ public interface Application extends ComponentManager {
    *
    * @return the modality state for no modal dialogs.
    */
+  @NotNull
   ModalityState getNoneModalityState();
 
   /**
diff --git a/platform/platform-api/src/com/intellij/openapi/application/ModalityState.java b/platform/platform-api/src/com/intellij/openapi/application/ModalityState.java
index 37ff7f91187c..8b3bd0cb50d8 100644
--- a/platform/platform-api/src/com/intellij/openapi/application/ModalityState.java
+++ b/platform/platform-api/src/com/intellij/openapi/application/ModalityState.java
@@ -45,17 +45,20 @@ public abstract class ModalityState {
     }
   }
 
+  @NotNull
   public static ModalityState current() {
     return ApplicationManager.getApplication().getCurrentModalityState();
   }
 
+  @NotNull
   public static ModalityState stateForComponent(Component component){
     return ApplicationManager.getApplication().getModalityStateForComponent(component);
   }
 
+  @NotNull
   public static ModalityState defaultModalityState() {
     return ApplicationManager.getApplication().getDefaultModalityState();
   }
 
-  public abstract boolean dominates(ModalityState anotherState);
+  public abstract boolean dominates(@NotNull ModalityState anotherState);
 }
diff --git a/platform/platform-api/src/com/intellij/openapi/progress/EmptyProgressIndicator.java b/platform/platform-api/src/com/intellij/openapi/progress/EmptyProgressIndicator.java
index 4d10437480ac..f8b4a114856c 100644
--- a/platform/platform-api/src/com/intellij/openapi/progress/EmptyProgressIndicator.java
+++ b/platform/platform-api/src/com/intellij/openapi/progress/EmptyProgressIndicator.java
@@ -17,6 +17,7 @@
 package com.intellij.openapi.progress;
 
 import com.intellij.openapi.application.ModalityState;
+import org.jetbrains.annotations.NotNull;
 
 public class EmptyProgressIndicator implements ProgressIndicator {
   private boolean myIsRunning = false;
@@ -80,6 +81,7 @@ public class EmptyProgressIndicator implements ProgressIndicator {
     return false;
   }
 
+  @NotNull
   public ModalityState getModalityState() {
     return ModalityState.NON_MODAL;
   }
diff --git a/platform/platform-api/src/com/intellij/openapi/progress/ProgressIndicator.java b/platform/platform-api/src/com/intellij/openapi/progress/ProgressIndicator.java
index a0efe9bad7c8..65b64a33ff71 100644
--- a/platform/platform-api/src/com/intellij/openapi/progress/ProgressIndicator.java
+++ b/platform/platform-api/src/com/intellij/openapi/progress/ProgressIndicator.java
@@ -16,6 +16,7 @@
 package com.intellij.openapi.progress;
 
 import com.intellij.openapi.application.ModalityState;
+import org.jetbrains.annotations.NotNull;
 
 public interface ProgressIndicator {
   void start();
@@ -60,6 +61,7 @@ public interface ProgressIndicator {
 
   boolean isModal();
 
+  @NotNull
   ModalityState getModalityState();
 
   void setModalityProgress(ProgressIndicator modalityProgress);
@@ -69,4 +71,4 @@ public interface ProgressIndicator {
   void setIndeterminate(boolean indeterminate);
 
   void checkCanceled() throws ProcessCanceledException;
-}
\ No newline at end of file
+}
diff --git a/platform/platform-api/src/com/intellij/util/ui/update/MergingUpdateQueue.java b/platform/platform-api/src/com/intellij/util/ui/update/MergingUpdateQueue.java
index 4e68e64ba9ca..bcb2e34055f7 100644
--- a/platform/platform-api/src/com/intellij/util/ui/update/MergingUpdateQueue.java
+++ b/platform/platform-api/src/com/intellij/util/ui/update/MergingUpdateQueue.java
@@ -23,6 +23,7 @@ import com.intellij.openapi.util.Disposer;
 import com.intellij.util.Alarm;
 import com.intellij.util.ui.UIUtil;
 import org.jetbrains.annotations.NonNls;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import javax.swing.*;
@@ -368,6 +369,7 @@ public class MergingUpdateQueue implements Runnable, Disposable, Activatable {
     return myModalityStateComponent == ANY_COMPONENT ? null : getModalityState();
   }
 
+  @NotNull
   public ModalityState getModalityState() {
     if (myModalityStateComponent == null) {
       return ModalityState.NON_MODAL;
diff --git a/platform/platform-impl/src/com/intellij/openapi/application/impl/ApplicationImpl.java b/platform/platform-impl/src/com/intellij/openapi/application/impl/ApplicationImpl.java
index f318d33732ec..7b4c1fb6ee3c 100644
--- a/platform/platform-impl/src/com/intellij/openapi/application/impl/ApplicationImpl.java
+++ b/platform/platform-impl/src/com/intellij/openapi/application/impl/ApplicationImpl.java
@@ -631,17 +631,20 @@ public class ApplicationImpl extends ComponentManagerImpl implements Application
     LaterInvocator.invokeAndWait(runnable, modalityState);
   }
 
+  @NotNull
   public ModalityState getCurrentModalityState() {
     Object[] entities = LaterInvocator.getCurrentModalEntities();
     return entities.length > 0 ? new ModalityStateEx(entities) : getNoneModalityState();
   }
 
+  @NotNull
   public ModalityState getModalityStateForComponent(@NotNull Component c) {
     Window window = c instanceof Window ? (Window)c : SwingUtilities.windowForComponent(c);
     if (window == null) return getNoneModalityState(); //?
     return LaterInvocator.modalityStateForWindow(window);
   }
 
+  @NotNull
   public ModalityState getDefaultModalityState() {
     if (EventQueue.isDispatchThread()) {
       return getCurrentModalityState();
@@ -652,6 +655,7 @@ public class ApplicationImpl extends ComponentManagerImpl implements Application
     }
   }
 
+  @NotNull
   public ModalityState getNoneModalityState() {
     return MODALITY_STATE_NONE;
   }
diff --git a/platform/platform-impl/src/com/intellij/openapi/application/impl/LaterInvocator.java b/platform/platform-impl/src/com/intellij/openapi/application/impl/LaterInvocator.java
index 70390c10d3f6..dc42c718b0ee 100644
--- a/platform/platform-impl/src/com/intellij/openapi/application/impl/LaterInvocator.java
+++ b/platform/platform-impl/src/com/intellij/openapi/application/impl/LaterInvocator.java
@@ -96,6 +96,7 @@ public class LaterInvocator {
     ourModalityStateMulticaster.removeListener(listener);
   }
 
+  @NotNull
   static ModalityStateEx modalityStateForWindow(@NotNull Window window){
     int index = ourModalEntities.indexOf(window);
     if (index < 0){
diff --git a/platform/platform-impl/src/com/intellij/openapi/application/impl/ModalityStateEx.java b/platform/platform-impl/src/com/intellij/openapi/application/impl/ModalityStateEx.java
index 533b4b22f7da..3545e1c47799 100644
--- a/platform/platform-impl/src/com/intellij/openapi/application/impl/ModalityStateEx.java
+++ b/platform/platform-impl/src/com/intellij/openapi/application/impl/ModalityStateEx.java
@@ -18,6 +18,7 @@ package com.intellij.openapi.application.impl;
 import com.intellij.openapi.application.ModalityState;
 import com.intellij.openapi.progress.ProgressIndicator;
 import org.jetbrains.annotations.NonNls;
+import org.jetbrains.annotations.NotNull;
 
 import java.lang.ref.WeakReference;
 import java.util.ArrayList;
@@ -44,11 +45,13 @@ public class ModalityStateEx extends ModalityState {
     }
   }
 
-  public ModalityState appendProgress(ProgressIndicator progress){
+  @NotNull
+  public ModalityState appendProgress(@NotNull ProgressIndicator progress){
     return appendEntity(progress);
   }
 
-  ModalityStateEx appendEntity(Object anEntity){
+  @NotNull
+  ModalityStateEx appendEntity(@NotNull Object anEntity){
     ArrayList<Object> list = new ArrayList<Object>();
     for (WeakReference modalEntity : myModalEntities) {
       Object entity = modalEntity.get();
@@ -68,7 +71,7 @@ public class ModalityStateEx extends ModalityState {
     return false;
   }
 
-  public boolean dominates(ModalityState anotherState){
+  public boolean dominates(@NotNull ModalityState anotherState){
     for (WeakReference modalEntity : myModalEntities) {
       Object entity = modalEntity.get();
       if (entity == null) continue;
@@ -93,4 +96,4 @@ public class ModalityStateEx extends ModalityState {
     }
     return buffer.toString();
   }
-}
\ No newline at end of file
+}
diff --git a/platform/platform-impl/src/com/intellij/openapi/progress/util/ProgressIndicatorBase.java b/platform/platform-impl/src/com/intellij/openapi/progress/util/ProgressIndicatorBase.java
index 97ff72231abf..948c5352a4b5 100644
--- a/platform/platform-impl/src/com/intellij/openapi/progress/util/ProgressIndicatorBase.java
+++ b/platform/platform-impl/src/com/intellij/openapi/progress/util/ProgressIndicatorBase.java
@@ -303,6 +303,7 @@ public class ProgressIndicatorBase extends UserDataHolderBase implements Progres
     return myModalityProgress != null;
   }
 
+  @NotNull
   public final ModalityState getModalityState() {
     return myModalityState;
   }
diff --git a/platform/testFramework/src/com/intellij/mock/MockApplication.java b/platform/testFramework/src/com/intellij/mock/MockApplication.java
index 269131d50774..b09414903c61 100644
--- a/platform/testFramework/src/com/intellij/mock/MockApplication.java
+++ b/platform/testFramework/src/com/intellij/mock/MockApplication.java
@@ -169,7 +169,7 @@ public class MockApplication extends MockComponentManager implements Application
   }
 
   @Override
-  public <T> T getCurrentWriteAction(@NotNull Class<T> actionClass) {
+  public <T> T getCurrentWriteAction(@Nullable Class<T> actionClass) {
     return null;
   }
 
@@ -285,21 +285,25 @@ public class MockApplication extends MockComponentManager implements Application
     return Extensions.getRootArea().getExtensionPoint(extensionPointName).getExtensions();
   }
 
+  @NotNull
   @Override
   public ModalityState getCurrentModalityState() {
-    return null;
+    throw new UnsupportedOperationException();
   }
 
+  @NotNull
   @Override
   public ModalityState getModalityStateForComponent(@NotNull Component c) {
-    return null;
+    throw new UnsupportedOperationException();
   }
 
+  @NotNull
   @Override
   public ModalityState getDefaultModalityState() {
-    return null;
+    throw new UnsupportedOperationException();
   }
 
+  @NotNull
   @Override
   public ModalityState getNoneModalityState() {
     if (MODALITY_STATE_NONE == null) {
diff --git a/plugins/cvs/cvs-core/src/com/intellij/cvsSupport2/cvsExecution/ModalityContext.java b/plugins/cvs/cvs-core/src/com/intellij/cvsSupport2/cvsExecution/ModalityContext.java
index ffe22fec545a..89f9c0fc7f1c 100644
--- a/plugins/cvs/cvs-core/src/com/intellij/cvsSupport2/cvsExecution/ModalityContext.java
+++ b/plugins/cvs/cvs-core/src/com/intellij/cvsSupport2/cvsExecution/ModalityContext.java
@@ -17,9 +17,10 @@
 package com.intellij.cvsSupport2.cvsExecution;
 
 import com.intellij.openapi.project.Project;
+import org.jetbrains.annotations.NotNull;
 
 public interface ModalityContext {
-  void runInDispatchThread(Runnable action, Project project);
+  void runInDispatchThread(@NotNull Runnable action, Project project);
 
   boolean isForTemporaryConfiguration();
 }
diff --git a/plugins/cvs/cvs-plugin/src/com/intellij/cvsSupport2/cvsExecution/ModalityContextImpl.java b/plugins/cvs/cvs-plugin/src/com/intellij/cvsSupport2/cvsExecution/ModalityContextImpl.java
index 8af0d5c34b31..85071fd427bd 100644
--- a/plugins/cvs/cvs-plugin/src/com/intellij/cvsSupport2/cvsExecution/ModalityContextImpl.java
+++ b/plugins/cvs/cvs-plugin/src/com/intellij/cvsSupport2/cvsExecution/ModalityContextImpl.java
@@ -22,6 +22,7 @@ import com.intellij.openapi.application.ModalityState;
 import com.intellij.openapi.progress.ProgressIndicator;
 import com.intellij.openapi.progress.ProgressManager;
 import com.intellij.openapi.project.Project;
+import org.jetbrains.annotations.NotNull;
 
 /**
  * author: lesya
@@ -40,7 +41,7 @@ public class ModalityContextImpl implements ModalityContext {
     myIsForTemporaryConfiguration = forTemp;
   }
 
-  public void runInDispatchThread(Runnable action, Project project) {
+  public void runInDispatchThread(@NotNull Runnable action, Project project) {
     Application application = ApplicationManager.getApplication();
     if (application.isUnitTestMode() || application.isDispatchThread()) {
       action.run();
diff --git a/plugins/cvs/cvs-plugin/src/com/intellij/cvsSupport2/cvshandlers/UpdateHandler.java b/plugins/cvs/cvs-plugin/src/com/intellij/cvsSupport2/cvshandlers/UpdateHandler.java
index 5a203d92569b..d8a95c75f452 100644
--- a/plugins/cvs/cvs-plugin/src/com/intellij/cvsSupport2/cvshandlers/UpdateHandler.java
+++ b/plugins/cvs/cvs-plugin/src/com/intellij/cvsSupport2/cvshandlers/UpdateHandler.java
@@ -56,13 +56,13 @@ public class UpdateHandler extends CommandCvsHandler implements PostCvsActivity
   private final Collection<File> myNotProcessedRepositories = new HashSet<File>();
   private double myDirectoriesToBeProcessedCount;
 
-  private final static CvsMessagePattern UPDATE_PATTERN = new CvsMessagePattern(new String[]{"cvs server: Updating ", "*"}, 2);
+  private static final CvsMessagePattern UPDATE_PATTERN = new CvsMessagePattern(new String[]{"cvs server: Updating ", "*"}, 2);
   private final Project myProject;
   private final Collection<MergedWithConflictProjectOrModuleFile> myCorruptedFiles = new ArrayList<MergedWithConflictProjectOrModuleFile>();
   private final UpdatedFiles myUpdatedFiles;
   private final UpdateSettings myUpdateSettings;
 
-  public UpdateHandler(FilePath[] files, UpdateSettings updateSettings, Project project, @NotNull UpdatedFiles updatedFiles) {
+  public UpdateHandler(FilePath[] files, UpdateSettings updateSettings, @NotNull Project project, @NotNull UpdatedFiles updatedFiles) {
     super(CvsBundle.message("operation.name.update"), new UpdateOperation(new FilePath[0], updateSettings, project),
           FileSetToBeUpdated.selectedFiles(files));
     myFiles = files;
diff --git a/plugins/svn4idea/src/org/jetbrains/idea/svn/dialogs/browserCache/RepositoryLoader.java b/plugins/svn4idea/src/org/jetbrains/idea/svn/dialogs/browserCache/RepositoryLoader.java
index 68da5c966a0a..6ea6824522c4 100644
--- a/plugins/svn4idea/src/org/jetbrains/idea/svn/dialogs/browserCache/RepositoryLoader.java
+++ b/plugins/svn4idea/src/org/jetbrains/idea/svn/dialogs/browserCache/RepositoryLoader.java
@@ -20,6 +20,7 @@ import com.intellij.openapi.application.ModalityState;
 import com.intellij.openapi.progress.EmptyProgressIndicator;
 import com.intellij.openapi.progress.ProgressManager;
 import com.intellij.openapi.util.Pair;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.idea.svn.SvnVcs;
 import org.jetbrains.idea.svn.dialogs.RepositoryTreeNode;
 import org.tmatesoft.svn.core.ISVNDirEntryHandler;
@@ -87,6 +88,7 @@ class RepositoryLoader extends Loader {
       @Override
       public void run() {
         ProgressManager.getInstance().runProcess(new LoadTask(data), new EmptyProgressIndicator() {
+          @NotNull
           @Override
           public ModalityState getModalityState() {
             return state;