diff --git a/core/org.eclipse.cdt.core/browser/org/eclipse/cdt/core/browser/AllTypesCache.java b/core/org.eclipse.cdt.core/browser/org/eclipse/cdt/core/browser/AllTypesCache.java
index d66340a51bd..d63bc6072f6 100644
--- a/core/org.eclipse.cdt.core/browser/org/eclipse/cdt/core/browser/AllTypesCache.java
+++ b/core/org.eclipse.cdt.core/browser/org/eclipse/cdt/core/browser/AllTypesCache.java
@@ -51,7 +51,12 @@ public class AllTypesCache {
 		
 		try {
 			index.acquireReadLock();
-			
+		} catch (InterruptedException e) {
+			Thread.currentThread().interrupt();
+			return new ITypeInfo[0];
+		}
+		
+		try {
 			long start = System.currentTimeMillis();
 			
 			IIndexBinding[] all =
@@ -80,12 +85,9 @@ public class AllTypesCache {
 			}
 			
 			return result;
-		} catch(InterruptedException ie) {
-			ie.printStackTrace();
 		} finally {
 			index.releaseReadLock();
 		}
-		return new ITypeInfo[0];
 	}
 
 	/**
diff --git a/core/org.eclipse.cdt.core/browser/org/eclipse/cdt/core/browser/IndexTypeInfo.java b/core/org.eclipse.cdt.core/browser/org/eclipse/cdt/core/browser/IndexTypeInfo.java
index 832b54fc73e..fffee8044f0 100644
--- a/core/org.eclipse.cdt.core/browser/org/eclipse/cdt/core/browser/IndexTypeInfo.java
+++ b/core/org.eclipse.cdt.core/browser/org/eclipse/cdt/core/browser/IndexTypeInfo.java
@@ -250,7 +250,11 @@ public class IndexTypeInfo implements ITypeInfo, IFunctionInfo {
 			}
 			try {
 				index.acquireReadLock();
-
+			} catch (InterruptedException ie) {
+				Thread.currentThread().interrupt();
+				return null;
+			}
+			try {
 				IIndexBinding[] ibs = findBindings();
 				if(ibs.length>0) {
 					IIndexName[] names;
@@ -267,8 +271,6 @@ public class IndexTypeInfo implements ITypeInfo, IFunctionInfo {
 				}
 			} catch(CoreException ce) {
 				CCorePlugin.log(ce);				
-			} catch (InterruptedException ie) {
-				CCorePlugin.log(ie);
 			} finally {
 				index.releaseReadLock();
 			}
@@ -319,7 +321,11 @@ public class IndexTypeInfo implements ITypeInfo, IFunctionInfo {
 	private ITypeReference createMacroReference() {
 		try {
 			index.acquireReadLock();
-
+		} catch (InterruptedException ie) {
+			Thread.currentThread().interrupt();
+			return null;
+		}
+		try {
 			IIndexMacro[] macros = index.findMacros(fqn[0].toCharArray(), IndexFilter.ALL_DECLARED, new NullProgressMonitor());
 			if(macros.length>0) {
 				for (IIndexMacro macro : macros) {
@@ -331,9 +337,7 @@ public class IndexTypeInfo implements ITypeInfo, IFunctionInfo {
 			}
 		} catch(CoreException ce) {
 			CCorePlugin.log(ce);				
-		} catch (InterruptedException ie) {
-			Thread.currentThread().interrupt();
-		} finally {
+		}  finally {
 			index.releaseReadLock();
 		}
 		return reference;
@@ -374,6 +378,11 @@ public class IndexTypeInfo implements ITypeInfo, IFunctionInfo {
 		List<IndexTypeReference> references= new ArrayList<IndexTypeReference>();
 		try {
 			index.acquireReadLock();
+		} catch (InterruptedException ie) {
+			Thread.currentThread().interrupt();
+			return new ITypeReference[0];
+		}
+		try {
 			IIndexBinding[] ibs= findBindings();
 			HashMap<IIndexFileLocation, IIndexFile> iflMap= new HashMap<IIndexFileLocation, IIndexFile>();
 			for (IIndexBinding binding : ibs) {
@@ -392,9 +401,7 @@ public class IndexTypeInfo implements ITypeInfo, IFunctionInfo {
 				}
 			}
 		} catch(CoreException ce) {
-			CCorePlugin.log(ce);				
-		} catch (InterruptedException ie) {
-			CCorePlugin.log(ie);
+			CCorePlugin.log(ce);	
 		} finally {
 			index.releaseReadLock();
 		}
@@ -406,7 +413,11 @@ public class IndexTypeInfo implements ITypeInfo, IFunctionInfo {
 		List<IndexTypeReference> references= new ArrayList<IndexTypeReference>();
 		try {
 			index.acquireReadLock();
-
+		} catch (InterruptedException e) {
+			Thread.currentThread().interrupt();
+			return new ITypeReference[0];
+		}
+		try {
 			char[] cfn= fqn[0].toCharArray();
 			IIndexMacro[] ibs = index.findMacros(cfn, IndexFilter.ALL_DECLARED, new NullProgressMonitor());
 			// in case a file is represented multiple times in the index then we take references from
@@ -424,8 +435,6 @@ public class IndexTypeInfo implements ITypeInfo, IFunctionInfo {
 			}
 		} catch(CoreException ce) {
 			CCorePlugin.log(ce);				
-		} catch (InterruptedException ie) {
-			CCorePlugin.log(ie);
 		} finally {
 			index.releaseReadLock();
 		}
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/index/provider/IndexProviderManager.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/index/provider/IndexProviderManager.java
index 734dbb1f37b..8733a42db24 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/index/provider/IndexProviderManager.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/index/provider/IndexProviderManager.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2007, 2008 Symbian Software Systems and others.
+ * Copyright (c) 2007, 2009 Symbian Software Systems and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -11,7 +11,6 @@
  *******************************************************************************/
 package org.eclipse.cdt.internal.core.index.provider;
 
-import com.ibm.icu.text.MessageFormat;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -20,6 +19,8 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
+import com.ibm.icu.text.MessageFormat;
+
 import org.eclipse.cdt.core.CCorePlugin;
 import org.eclipse.cdt.core.index.provider.IIndexProvider;
 import org.eclipse.cdt.core.index.provider.IReadOnlyPDOMProvider;
@@ -202,8 +203,8 @@ public final class IndexProviderManager implements IElementChangedListener {
 	 */
 	private void processCandidate(Map<String, IIndexFragment> id2fragment, IIndexFragment candidate) throws InterruptedException, CoreException {
 		String cid= null, csver= null, cformatID= null;
+		candidate.acquireReadLock();
 		try {
-			candidate.acquireReadLock();
 			cid= candidate.getProperty(IIndexFragment.PROPERTY_FRAGMENT_ID);
 			csver= candidate.getProperty(IIndexFragment.PROPERTY_FRAGMENT_FORMAT_VERSION);
 			cformatID= candidate.getProperty(IIndexFragment.PROPERTY_FRAGMENT_FORMAT_ID);							
@@ -218,8 +219,8 @@ public final class IndexProviderManager implements IElementChangedListener {
 		if(getCurrentlySupportedVersionRangeForFormat(cformatID).isIncluded(cver)) {
 			if(existing != null) {
 				String esver= null, eformatID= null;
+				existing.acquireReadLock();
 				try {
-					existing.acquireReadLock();
 					esver= existing.getProperty(IIndexFragment.PROPERTY_FRAGMENT_FORMAT_VERSION);
 					eformatID= existing.getProperty(IIndexFragment.PROPERTY_FRAGMENT_FORMAT_ID);
 				} finally {
diff --git a/core/org.eclipse.cdt.ui/browser/org/eclipse/cdt/internal/ui/browser/opentype/ElementSelectionDialog.java b/core/org.eclipse.cdt.ui/browser/org/eclipse/cdt/internal/ui/browser/opentype/ElementSelectionDialog.java
index 8ab1d821991..ec4013846be 100644
--- a/core/org.eclipse.cdt.ui/browser/org/eclipse/cdt/internal/ui/browser/opentype/ElementSelectionDialog.java
+++ b/core/org.eclipse.cdt.ui/browser/org/eclipse/cdt/internal/ui/browser/opentype/ElementSelectionDialog.java
@@ -302,8 +302,8 @@ public class ElementSelectionDialog extends TypeSelectionDialog {
 			};
 			try {
 				IIndex index = CCorePlugin.getIndexManager().getIndex(CoreModel.getDefault().getCModel().getCProjects());
+				index.acquireReadLock();
 				try {
-					index.acquireReadLock();
 					IIndexBinding[] bindings= index.findBindingsForPrefix(prefix, false, filter, monitor);
 					for(int i=0; i<bindings.length; i++) {
 						if (i % 0x1000 == 0 && monitor.isCanceled()) {
diff --git a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/refactoring/utils/DefinitionFinder.java b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/refactoring/utils/DefinitionFinder.java
index ef6233bcb3f..31688fab73c 100644
--- a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/refactoring/utils/DefinitionFinder.java
+++ b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/refactoring/utils/DefinitionFinder.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2008 Institute for Software, HSR Hochschule fuer Technik  
+ * Copyright (c) 2008, 2009 Institute for Software, HSR Hochschule fuer Technik  
  * Rapperswil, University of applied sciences and others
  * All rights reserved. This program and the accompanying materials 
  * are made available under the terms of the Eclipse Public License v1.0 
@@ -59,11 +59,15 @@ public class DefinitionFinder {
 
 		try {
 			index.acquireReadLock();
-			pdomref= index.findDefinitions(bind);
 		} catch (InterruptedException e) {
 			IStatus status = new Status(IStatus.WARNING, CUIPlugin.PLUGIN_ID, IStatus.OK, e.getMessage(), e);
 			CUIPlugin.log(status);
-		} finally {
+			return null;
+		} 
+		try {
+			pdomref= index.findDefinitions(bind);
+		}
+		finally {
 			index.releaseReadLock();
 		}
 
diff --git a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/refactoring/utils/TranslationUnitHelper.java b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/refactoring/utils/TranslationUnitHelper.java
index ee8e5953dfa..40bd3e66bef 100644
--- a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/refactoring/utils/TranslationUnitHelper.java
+++ b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/refactoring/utils/TranslationUnitHelper.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2008 Institute for Software, HSR Hochschule fuer Technik  
+ * Copyright (c) 2008, 2009 Institute for Software, HSR Hochschule fuer Technik  
  * Rapperswil, University of applied sciences and others
  * All rights reserved. This program and the accompanying materials 
  * are made available under the terms of the Eclipse Public License v1.0 
@@ -151,7 +151,13 @@ public class TranslationUnitHelper {
 		IIndex index;
 		ICProject[] projects= CoreModel.getDefault().getCModel().getCProjects();
 		index= CCorePlugin.getIndexManager().getIndex(projects);
-		index.acquireReadLock();
+		try {
+			index.acquireReadLock();
+		} catch (InterruptedException e) {
+			// no lock was acquired
+			index= null; 
+			throw e;
+		}
 		return index;
 	}
 	
diff --git a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/wizards/classwizard/NewClassWizardUtil.java b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/wizards/classwizard/NewClassWizardUtil.java
index c317d421e61..83fc939f8d1 100644
--- a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/wizards/classwizard/NewClassWizardUtil.java
+++ b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/wizards/classwizard/NewClassWizardUtil.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2005, 2007 QNX Software Systems and others.
+ * Copyright (c) 2005, 2009 QNX Software Systems and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -409,6 +409,8 @@ public class NewClassWizardUtil {
 			CUIPlugin.log(e);
 			return SEARCH_MATCH_ERROR;
 		} catch (InterruptedException e) {
+			Thread.currentThread().interrupt();
+			return SEARCH_MATCH_NOTFOUND;
 		}
 		if (index == null) {
 			return SEARCH_MATCH_ERROR;