### Eclipse Workspace Patch 1.0
#P org.eclipse.cdt.debug.ui
Index: src/org/eclipse/cdt/debug/internal/ui/views/executables/ExecutablesView.java
===================================================================
RCS file: /cvsroot/tools/org.eclipse.cdt/all/org.eclipse.cdt.debug.ui/src/org/eclipse/cdt/debug/internal/ui/views/executables/ExecutablesView.java,v
retrieving revision 1.7
diff -u -r1.7 ExecutablesView.java
--- src/org/eclipse/cdt/debug/internal/ui/views/executables/ExecutablesView.java	27 May 2010 15:27:41 -0000	1.7
+++ src/org/eclipse/cdt/debug/internal/ui/views/executables/ExecutablesView.java	3 Jun 2010 22:38:28 -0000
@@ -279,34 +279,15 @@
 					{
 						// update the remove action
 						removeAction.setEnabled(!newSelection.isEmpty());
-						
+
+						// just immediately do this work: the source files content provider
+						// will do the work in the background
 						final Object firstElement = ((IStructuredSelection) newSelection).getFirstElement();
-						
-						Job setectExeJob = new Job(Messages.ExecutablesView_Select_Executable) {
 
-							@Override
-							protected IStatus run(IProgressMonitor monitor) {
-								if (firstElement instanceof Executable) {
-									Executable executable = (Executable)firstElement;
-									this.setName(Messages.ExecutablesView_Finding_Sources_Job_Name + executable.getName());
-									executable.getSourceFiles(monitor);
-								}
-								// selection could be empty, so do this no matter what to update the source
-								// files viewer
-								UIJob selectExeUIJob = new UIJob(Messages.ExecutablesView_Select_Executable){
-									@Override
-									public IStatus runInUIThread(IProgressMonitor monitor) {
-										sourceFilesViewer.setInput(firstElement);
-										sourceFilesViewer.packColumns();
-										return Status.OK_STATUS;
-									}};
-								selectExeUIJob.schedule();								
-								return Status.OK_STATUS;
-							}};
-						setectExeJob.schedule();
+						sourceFilesViewer.setInput(firstElement);
+						
 						oldSelection = (IStructuredSelection) newSelection;
 					}
-					
 				}
 			}
 		});
Index: src/org/eclipse/cdt/debug/internal/ui/views/executables/Messages.java
===================================================================
RCS file: /cvsroot/tools/org.eclipse.cdt/all/org.eclipse.cdt.debug.ui/src/org/eclipse/cdt/debug/internal/ui/views/executables/Messages.java,v
retrieving revision 1.5
diff -u -r1.5 Messages.java
--- src/org/eclipse/cdt/debug/internal/ui/views/executables/Messages.java	27 May 2010 15:27:41 -0000	1.5
+++ src/org/eclipse/cdt/debug/internal/ui/views/executables/Messages.java	3 Jun 2010 22:38:28 -0000
@@ -52,6 +52,8 @@
 	public static String ExecutablesViewer_Size;
 	public static String ExecutablesViewer_Type;
 	public static String SourceFilesContentProvider_NoFilesFound;
+	public static String SourceFilesContentProvider_ReadingDebugSymbolInformationLabel;
+	public static String SourceFilesContentProvider_Refreshing;
 	public static String SourceFilesViewer_RefreshSourceFiles;
 	public static String SourceFilesViewer_Location;
 	public static String SourceFilesViewer_Modified;
Index: src/org/eclipse/cdt/debug/internal/ui/views/executables/SourceFilesContentProvider.java
===================================================================
RCS file: /cvsroot/tools/org.eclipse.cdt/all/org.eclipse.cdt.debug.ui/src/org/eclipse/cdt/debug/internal/ui/views/executables/SourceFilesContentProvider.java,v
retrieving revision 1.5
diff -u -r1.5 SourceFilesContentProvider.java
--- src/org/eclipse/cdt/debug/internal/ui/views/executables/SourceFilesContentProvider.java	3 Jun 2010 14:19:50 -0000	1.5
+++ src/org/eclipse/cdt/debug/internal/ui/views/executables/SourceFilesContentProvider.java	3 Jun 2010 22:38:28 -0000
@@ -11,27 +11,82 @@
 
 package org.eclipse.cdt.debug.internal.ui.views.executables;
 
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
 import org.eclipse.cdt.core.model.ITranslationUnit;
-import org.eclipse.cdt.debug.core.CDebugCorePlugin;
 import org.eclipse.cdt.debug.core.executables.Executable;
+import org.eclipse.cdt.debug.core.executables.ExecutablesManager;
+import org.eclipse.cdt.debug.core.executables.IExecutablesChangeListener;
+import org.eclipse.cdt.debug.internal.ui.views.executables.SourceFilesViewer.TranslationUnitInfo;
 import org.eclipse.cdt.ui.CElementContentProvider;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Status;
+import org.eclipse.core.runtime.jobs.IJobChangeEvent;
 import org.eclipse.core.runtime.jobs.Job;
+import org.eclipse.core.runtime.jobs.JobChangeAdapter;
+import org.eclipse.jface.viewers.Viewer;
+import org.eclipse.swt.widgets.Display;
+
+public class SourceFilesContentProvider extends CElementContentProvider implements IExecutablesChangeListener {
+
+	static class QuickParseJob extends Job {
+		final Executable executable;
+		ITranslationUnit[] tus;
+		
+		public QuickParseJob(Executable executable) {
+			super (Messages.SourceFilesContentProvider_ReadingDebugSymbolInformationLabel 
+					+ executable.getName());
+			this.executable = executable;
+		}
+		
+		@Override
+		protected IStatus run(IProgressMonitor monitor) {
+			tus = executable.getSourceFiles(monitor);
+			return Status.OK_STATUS;
+		}
+	}
+	
+	/** contains running jobs */ 
+	private Map<IPath, QuickParseJob> pathToJobMap = new HashMap<IPath, SourceFilesContentProvider.QuickParseJob>();
+	
+	/** those executables for which we asked the question and got a result.
+	 * NOTE: this contains a duplicate of into in Executable, because we can't
+	 * guarantee or check whether Executable still has the info itself. */
+	private Map<IPath, ITranslationUnit[]> fetchedExecutables = new HashMap<IPath, ITranslationUnit[]>();
 
-public class SourceFilesContentProvider extends CElementContentProvider {
-
+	private final SourceFilesViewer viewer;
+	
 	public SourceFilesContentProvider(SourceFilesViewer viewer) {
 		super(true, true);
+		this.viewer = viewer;
+		ExecutablesManager.getExecutablesManager().addExecutablesChangeListener(this);
 	}
 
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.ui.CElementContentProvider#dispose()
+	 */
+	@Override
+	public void dispose() {
+		ExecutablesManager.getExecutablesManager().removeExecutablesChangeListener(this);
+		synchronized (fetchedExecutables) {
+			fetchedExecutables.clear();
+		}
+		synchronized (pathToJobMap) {
+			pathToJobMap.clear();
+		}
+		super.dispose();
+	}
+	
 	@Override
 	public boolean hasChildren(Object element) {
 		if (element instanceof ITranslationUnit) {
-			IPath path = ((ITranslationUnit) element).getLocation();
-			if (path != null && !path.toFile().exists())
+			TranslationUnitInfo info = SourceFilesViewer.fetchTranslationUnitInfo(
+					(Executable) viewer.getInput(), element);
+			if (info != null && !info.exists)
 				return false;
 		}
 		return super.hasChildren(element);
@@ -40,31 +95,127 @@
 	public Object[] getElements(Object inputElement) {
 		if (inputElement instanceof Executable) {
 			final Executable executable = (Executable) inputElement;
-			final ITranslationUnit[][] resultHolder = new ITranslationUnit[1][];
-			Job quickParseJob = new Job("Reading Debug Symbol Information: " + executable.getName()) {
-
-				@Override
-				protected IStatus run(IProgressMonitor monitor) {
-					ITranslationUnit[] sourceFiles = executable.getSourceFiles(monitor);
-					resultHolder[0] = sourceFiles;
-					return Status.OK_STATUS;
+			final IPath exePath = executable.getPath();
+			
+			// look for a job that is currently fetching this info
+			QuickParseJob job;
+			synchronized (pathToJobMap) {
+				job = pathToJobMap.get(exePath);
+			}
+			if (job != null) {
+				// job is still running
+				return new String[] { Messages.SourceFilesContentProvider_Refreshing };
+			}
+			
+			// see if we already checked
+			synchronized (fetchedExecutables) {
+				if (fetchedExecutables.containsKey(exePath)) {
+					return fetchedExecutables.get(exePath);
 				}
-			};
+			}
 			
-			try {
-				quickParseJob.schedule();
-				quickParseJob.join();
-			} catch (InterruptedException e) {
-				CDebugCorePlugin.log(e);
+			// start a background job to look for the sources
+			job = new QuickParseJob(executable);
+			synchronized (pathToJobMap) {
+				pathToJobMap.put(exePath, job);
 			}
 			
-			ITranslationUnit[] sourceFiles = resultHolder[0];
-			if (sourceFiles.length == 0)
-				return new String[] { Messages.SourceFilesContentProvider_NoFilesFound + executable.getName() };
-			else
-				return sourceFiles;
+			// once the job finishes, update the viewer
+			final QuickParseJob theJob = job;
+			job.addJobChangeListener(new JobChangeAdapter() {
+				public void done(IJobChangeEvent event) {
+					if (event.getResult().isOK()) {
+						Display.getDefault().asyncExec(new Runnable() {
+							public void run() {
+								synchronized (pathToJobMap) {
+									pathToJobMap.values().remove(theJob);
+								}
+								synchronized (fetchedExecutables) {
+									fetchedExecutables.put(exePath, theJob.tus);
+								}
+								// update the viewer
+								if (!viewer.getControl().isDisposed()) {
+									viewer.getTree().setLayoutDeferred(true);
+									viewer.refresh(executable);
+									viewer.packColumns();
+									viewer.getTree().setLayoutDeferred(false);
+								}
+							}
+						});
+					}
+				}
+			});
+			
+			job.schedule();
+			
+			// while it's running...
+			return new String[] { Messages.SourceFilesContentProvider_Refreshing };
 		}
 		return new Object[] {};
 	}
 
-}
\ No newline at end of file
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.debug.core.executables.IExecutablesChangeListener#executablesListChanged()
+	 */
+	public void executablesListChanged() {
+		// Don't clear executables -- closing/opening project doesn't imply
+		// the info is different.  But cancel all the jobs in case projects
+		// were closed.  It's non-obvious how to map executables to projects,
+		// so just bail and cancel all the current parsing.  The viewer
+		// will be refreshed and re-request source lists for any executables
+		// that are still applicable.
+		cancelQuickParseJobs();
+	}
+
+
+	/**
+	 * 
+	 */
+	private void cancelQuickParseJobs() {
+		synchronized (pathToJobMap) {
+			for (QuickParseJob job : pathToJobMap.values()) {
+				job.cancel();
+			}
+			pathToJobMap.clear();
+		}
+		
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.debug.core.executables.IExecutablesChangeListener#executablesChanged(java.util.List)
+	 */
+	public void executablesChanged(List<Executable> executables) {
+		for (Executable executable : executables) {
+			IPath exePath = executable.getPath();
+			synchronized (fetchedExecutables) {
+				fetchedExecutables.remove(exePath);
+			}
+			synchronized (pathToJobMap) {
+				QuickParseJob job = pathToJobMap.get(exePath);
+				if (job != null) {
+					job.cancel();
+					pathToJobMap.remove(exePath);
+				}
+			}
+		}
+	}
+	
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.ui.CElementContentProvider#inputChanged(org.eclipse.jface.viewers.Viewer, java.lang.Object, java.lang.Object)
+	 */
+	@Override
+	public void inputChanged(Viewer viewer, Object oldInput, final Object newInput) {
+		super.inputChanged(viewer, oldInput, newInput);
+		
+		Display.getDefault().asyncExec(new Runnable() {
+			public void run() {
+				// pack because the quick parse job won't run
+				if (newInput instanceof Executable 
+						&& fetchedExecutables.containsKey(((Executable) newInput).getPath()))
+					SourceFilesContentProvider.this.viewer.packColumns();
+			}
+		});
+	}
+}
+
Index: src/org/eclipse/cdt/debug/internal/ui/views/executables/SourceFilesLabelProvider.java
===================================================================
RCS file: /cvsroot/tools/org.eclipse.cdt/all/org.eclipse.cdt.debug.ui/src/org/eclipse/cdt/debug/internal/ui/views/executables/SourceFilesLabelProvider.java,v
retrieving revision 1.4
diff -u -r1.4 SourceFilesLabelProvider.java
--- src/org/eclipse/cdt/debug/internal/ui/views/executables/SourceFilesLabelProvider.java	3 Jun 2010 14:19:50 -0000	1.4
+++ src/org/eclipse/cdt/debug/internal/ui/views/executables/SourceFilesLabelProvider.java	3 Jun 2010 22:38:29 -0000
@@ -12,23 +12,27 @@
 package org.eclipse.cdt.debug.internal.ui.views.executables;
 
 import com.ibm.icu.text.DateFormat;
+
 import java.util.Date;
+import java.util.List;
 
 import org.eclipse.cdt.core.model.ITranslationUnit;
 import org.eclipse.cdt.debug.core.executables.Executable;
+import org.eclipse.cdt.debug.core.executables.ExecutablesManager;
+import org.eclipse.cdt.debug.core.executables.IExecutablesChangeListener;
 import org.eclipse.cdt.ui.CElementLabelProvider;
-import org.eclipse.core.runtime.IPath;
-import org.eclipse.core.runtime.Path;
 import org.eclipse.jface.resource.FontDescriptor;
 import org.eclipse.jface.resource.JFaceResources;
 import org.eclipse.jface.resource.LocalResourceManager;
 import org.eclipse.jface.viewers.TreeColumnViewerLabelProvider;
 import org.eclipse.jface.viewers.ViewerCell;
 import org.eclipse.swt.SWT;
+import org.eclipse.swt.events.DisposeEvent;
+import org.eclipse.swt.events.DisposeListener;
 import org.eclipse.swt.graphics.Font;
 import org.eclipse.swt.widgets.Display;
 
-public class SourceFilesLabelProvider extends TreeColumnViewerLabelProvider {
+public class SourceFilesLabelProvider extends TreeColumnViewerLabelProvider implements IExecutablesChangeListener {
 
 	private SourceFilesViewer viewer;
 
@@ -37,28 +41,42 @@
 	public SourceFilesLabelProvider(SourceFilesViewer viewer) {
 		super(new CElementLabelProvider());
 		this.viewer = viewer;
+		
+		// brute-force clear the cache when executables change
+		ExecutablesManager.getExecutablesManager().addExecutablesChangeListener(this);
+		viewer.getControl().addDisposeListener(new DisposeListener() {
+			public void widgetDisposed(DisposeEvent e) {
+				ExecutablesManager.getExecutablesManager().removeExecutablesChangeListener(SourceFilesLabelProvider.this);
+			}
+		});
 	}
 
 	@Override
 	public void update(ViewerCell cell) {
 		super.update(cell);
 
+		SourceFilesViewer.TranslationUnitInfo tuInfo = null;
+		Object element = cell.getElement();
+		if (element instanceof ITranslationUnit) {
+			tuInfo = SourceFilesViewer.fetchTranslationUnitInfo((Executable) viewer.getInput(), element);
+		}
+		
 		int orgColumnIndex = cell.getColumnIndex();
 
 		if (orgColumnIndex == 0) {
-			if (cell.getElement() instanceof String) {
-				cell.setText((String) cell.getElement());
-				Font boldFont = resourceManager.createFont(FontDescriptor.createFrom(viewer.getTree().getFont()).setStyle(SWT.BOLD));
-				cell.setFont(boldFont);
+			if (element instanceof String) {
+				cell.setText((String) element);
+				Font italicFont = resourceManager.createFont(FontDescriptor.createFrom(viewer.getTree().getFont()).setStyle(SWT.ITALIC));
+				cell.setFont(italicFont);
+			} else {
+				cell.setFont(viewer.getTree().getFont());
 			}
 		} else if (orgColumnIndex == 1) {
 			cell.setText(null);
-			if (cell.getElement() instanceof ITranslationUnit) {
-				ITranslationUnit tu = (ITranslationUnit) cell.getElement();
-				IPath path = tu.getLocation();
-				if (path != null) {
-					cell.setText(path.toOSString());
-					if (path.toFile().exists())
+			if (tuInfo != null) {
+				if (tuInfo.location != null) {
+					cell.setText(tuInfo.location.toOSString());
+					if (tuInfo.exists)
 						cell.setForeground(Display.getDefault().getSystemColor(SWT.COLOR_BLACK));
 					else
 						cell.setForeground(Display.getDefault().getSystemColor(SWT.COLOR_GRAY));
@@ -67,11 +85,9 @@
 			cell.setImage(null);
 		} else if (orgColumnIndex == 2) {
 			cell.setText(null);
-			if (cell.getElement() instanceof ITranslationUnit) {
-				Executable executable = (Executable) viewer.getInput();
-				Path path = new Path(executable.getOriginalLocation((ITranslationUnit) cell.getElement()));
-				cell.setText(path.toOSString());
-				if (path.toFile().exists())
+			if (tuInfo != null && tuInfo.originalLocation != null) {
+				cell.setText(tuInfo.originalLocation.toOSString());
+				if (tuInfo.originalExists)
 					cell.setForeground(Display.getDefault().getSystemColor(SWT.COLOR_BLACK));
 				else
 					cell.setForeground(Display.getDefault().getSystemColor(SWT.COLOR_GRAY));
@@ -79,34 +95,27 @@
 			cell.setImage(null);
 		} else if (orgColumnIndex == 3) {
 			cell.setText(null);
-			if (cell.getElement() instanceof ITranslationUnit) {
-				ITranslationUnit tu = (ITranslationUnit) cell.getElement();
-				IPath path = tu.getLocation();
-				if (path != null && path.toFile().exists()) {
-					long fileLength = path.toFile().length();
-					cell.setText(Long.toString(fileLength));
+			if (tuInfo != null) {
+				if (tuInfo.exists) {
+					cell.setText(Long.toString(tuInfo.fileLength));
 				}
 			}
 			cell.setImage(null);
 		} else if (orgColumnIndex == 4) {
 			cell.setText(null);
-			if (cell.getElement() instanceof ITranslationUnit) {
-				ITranslationUnit tu = (ITranslationUnit) cell.getElement();
-				IPath path = tu.getLocation();
-				if (path != null && path.toFile().exists()) {
-					long modified = path.toFile().lastModified();
-					String dateTimeString = DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.SHORT).format(new Date(modified));
+			if (tuInfo != null) {
+				if (tuInfo.exists) {
+					String dateTimeString = DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.SHORT).format(
+							new Date(tuInfo.lastModified));
 					cell.setText(dateTimeString);
 				}
 			}
 			cell.setImage(null);
 		} else if (orgColumnIndex == 5) {
 			cell.setText(null);
-			if (cell.getElement() instanceof ITranslationUnit) {
-				ITranslationUnit tu = (ITranslationUnit) cell.getElement();
-				IPath path = tu.getLocation();
-				if (path != null) {
-					String fileExtension = path.getFileExtension();
+			if (tuInfo != null) {
+				if (tuInfo.location != null) {
+					String fileExtension = tuInfo.location.getFileExtension();
 					if (fileExtension != null)
 						cell.setText(fileExtension.toLowerCase());
 				}
@@ -115,4 +124,20 @@
 		}
 	}
 
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.debug.core.executables.IExecutablesChangeListener#executablesListChanged()
+	 */
+	public void executablesListChanged() {
+		SourceFilesViewer.flushTranslationUnitCache();
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.debug.core.executables.IExecutablesChangeListener#executablesChanged(java.util.List)
+	 */
+	public void executablesChanged(List<Executable> executables) {
+		// no mapping of executable -> TU maintained; just kill all for now
+		SourceFilesViewer.flushTranslationUnitCache();
+	}
+
 }
+	
\ No newline at end of file
Index: src/org/eclipse/cdt/debug/internal/ui/views/executables/SourceFilesViewer.java
===================================================================
RCS file: /cvsroot/tools/org.eclipse.cdt/all/org.eclipse.cdt.debug.ui/src/org/eclipse/cdt/debug/internal/ui/views/executables/SourceFilesViewer.java,v
retrieving revision 1.6
diff -u -r1.6 SourceFilesViewer.java
--- src/org/eclipse/cdt/debug/internal/ui/views/executables/SourceFilesViewer.java	26 Apr 2010 16:59:04 -0000	1.6
+++ src/org/eclipse/cdt/debug/internal/ui/views/executables/SourceFilesViewer.java	3 Jun 2010 22:38:29 -0000
@@ -10,6 +10,8 @@
  *******************************************************************************/
 package org.eclipse.cdt.debug.internal.ui.views.executables;
 
+import java.io.File;
+
 import org.eclipse.cdt.core.model.ICElement;
 import org.eclipse.cdt.core.model.ISourceReference;
 import org.eclipse.cdt.core.model.ITranslationUnit;
@@ -17,13 +19,12 @@
 import org.eclipse.cdt.debug.core.executables.Executable;
 import org.eclipse.cdt.debug.internal.ui.sourcelookup.CSourceNotFoundEditorInput;
 import org.eclipse.cdt.debug.ui.ICDebugUIConstants;
+import org.eclipse.cdt.internal.core.util.LRUCache;
 import org.eclipse.cdt.internal.ui.util.EditorUtility;
 import org.eclipse.cdt.ui.CUIPlugin;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IPath;
-import org.eclipse.core.runtime.IProgressMonitor;
-import org.eclipse.core.runtime.IStatus;
-import org.eclipse.core.runtime.Status;
+import org.eclipse.core.runtime.Path;
 import org.eclipse.debug.core.DebugPlugin;
 import org.eclipse.debug.core.ILaunchConfiguration;
 import org.eclipse.debug.core.ILaunchConfigurationListener;
@@ -38,12 +39,12 @@
 import org.eclipse.swt.events.DisposeEvent;
 import org.eclipse.swt.events.DisposeListener;
 import org.eclipse.swt.widgets.Composite;
+import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Tree;
 import org.eclipse.swt.widgets.TreeColumn;
 import org.eclipse.ui.IEditorPart;
 import org.eclipse.ui.IWorkbenchPage;
 import org.eclipse.ui.PartInitException;
-import org.eclipse.ui.progress.UIJob;
 
 /**
  * Displays the list of source files for the executable selected in the
@@ -51,6 +52,24 @@
  */
 public class SourceFilesViewer extends BaseViewer implements ISourceLookupParticipant, ILaunchConfigurationListener {
 
+	/** Information from an ITranslationUnit for the various displayed columns */
+	static class TranslationUnitInfo {
+		/** when do we next check these attributes?  time in ms */
+		long nextCheckTimestamp;
+		/** the source file location */
+		IPath location;
+		/** does the file exist? */
+		boolean exists;
+		/** length of actual file in bytes */
+		long fileLength;
+		/** {@link File#lastModified()} time for source file */
+		long lastModified;
+		/** the original source file location, e.g. from debug info */
+		IPath originalLocation;
+		/** does the original file exist? */
+		boolean originalExists;
+	}
+
 	private static final String P_COLUMN_ORDER_KEY_SF = "columnOrderKeySF"; //$NON-NLS-1$
 	private static final String P_SORTED_COLUMN_INDEX_KEY_SF = "sortedColumnIndexKeySF"; //$NON-NLS-1$
 	private static final String P_COLUMN_SORT_DIRECTION_KEY_SF = "columnSortDirectionKeySF"; //$NON-NLS-1$
@@ -59,6 +78,10 @@
 
 	TreeColumn originalLocationColumn;
 	private Tree sourceFilesTree;
+	/** Tradeoff expensiveness of checking filesystem against likelihood 
+	 * that files will be added/removed/changed in the given time period */
+	static final long FILE_CHECK_DELTA = 30 * 1000;
+	private static LRUCache<Object, TranslationUnitInfo> translationUnitInfoCache = new LRUCache<Object, TranslationUnitInfo>(1024);
 
 	public SourceFilesViewer(ExecutablesView view, Composite parent, int style) {
 		super(view, parent, style);
@@ -90,6 +113,8 @@
 		sourceFilesTree.addDisposeListener(new DisposeListener() {
 
 			public void widgetDisposed(DisposeEvent e) {
+				DebugPlugin.getDefault().getLaunchManager().removeLaunchConfigurationListener(SourceFilesViewer.this);
+				
 				CDebugCorePlugin.getDefault().getCommonSourceLookupDirector().removeParticipants(
 						new ISourceLookupParticipant[] { SourceFilesViewer.this });
 			}
@@ -213,19 +238,19 @@
 	}
 
 	private void refreshContent() {
-		UIJob refreshJob = new UIJob(Messages.SourceFilesViewer_RefreshSourceFiles) {
-
-			@Override
-			public IStatus runInUIThread(IProgressMonitor monitor) {
+		Display.getDefault().asyncExec(new Runnable() {
+			public void run() {
 				Object input = getInput();
 				if (input != null && input instanceof Executable) {
 					((Executable)input).setRemapSourceFiles(true);
+					
+					// TODO: be more selective; we don't know what TUs go with which executables yet
+					flushTranslationUnitCache();
+			
 					refresh(true);
 				}
-				return Status.OK_STATUS;
 			}
-		};
-		refreshJob.schedule();
+		});
 	}
 
 	@Override
@@ -280,5 +305,58 @@
 			refreshContent();
 		}
 	}
-	
+
+
+	static TranslationUnitInfo fetchTranslationUnitInfo(Executable executable, Object element) {
+		if (!(element instanceof ITranslationUnit)) {
+			return null;
+		}
+		
+		ITranslationUnit tu = (ITranslationUnit) element;
+		long now = System.currentTimeMillis();
+		TranslationUnitInfo info;
+		
+		synchronized (translationUnitInfoCache) {
+			info = (TranslationUnitInfo) translationUnitInfoCache.get(element);
+		}
+		if (info == null || info.nextCheckTimestamp <= now) {
+			if (info == null)
+				info = new TranslationUnitInfo();
+			
+			info.location = tu.getLocation();
+			if (info.location != null) {
+				File file = info.location.toFile();
+				info.exists = file.exists();
+				info.fileLength = file.length();
+				info.lastModified = file.lastModified();
+				
+				info.originalLocation = new Path(executable.getOriginalLocation(tu));
+				info.originalExists = info.originalLocation.toFile().exists();
+			} else {
+				info.exists = false;
+				info.fileLength = 0;
+				info.lastModified = 0;
+				info.originalExists = false;
+				info.originalLocation = null;
+			}
+			
+			info.nextCheckTimestamp = System.currentTimeMillis() + FILE_CHECK_DELTA;
+			
+			synchronized (translationUnitInfoCache) {
+				translationUnitInfoCache.put(element, info);
+			}
+		}
+		return info;
+	}
+
+	/**
+	 * 
+	 */
+	static void flushTranslationUnitCache() {
+		synchronized (translationUnitInfoCache) {
+			translationUnitInfoCache.flush();
+		}
+		
+	}
+
 }
\ No newline at end of file
Index: src/org/eclipse/cdt/debug/internal/ui/views/executables/messages.properties
===================================================================
RCS file: /cvsroot/tools/org.eclipse.cdt/all/org.eclipse.cdt.debug.ui/src/org/eclipse/cdt/debug/internal/ui/views/executables/messages.properties,v
retrieving revision 1.5
diff -u -r1.5 messages.properties
--- src/org/eclipse/cdt/debug/internal/ui/views/executables/messages.properties	27 May 2010 15:27:41 -0000	1.5
+++ src/org/eclipse/cdt/debug/internal/ui/views/executables/messages.properties	3 Jun 2010 22:38:29 -0000
@@ -46,6 +46,8 @@
 ExecutablesViewer_Size=Size
 ExecutablesViewer_Type=Type
 SourceFilesContentProvider_NoFilesFound=No source files found in 
+SourceFilesContentProvider_ReadingDebugSymbolInformationLabel=Reading Debug Symbol Information: 
+SourceFilesContentProvider_Refreshing=Refreshing... 
 SourceFilesViewer_RefreshSourceFiles=Refresh Source Files
 SourceFilesViewer_Location=Location
 SourceFilesViewer_Modified=Modified