enforce all DoEvents from pads on the main thread to avoid race conditions in debugger. Do delayed invalidate on all pads.

src/AddIns/Debugger/Debugger.AddIn/Pads/CallStackPad.xaml.cs

@@ -40,7 +40,7 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 			extMethodsItem.IsChecked = DebuggingOptions.Instance.ShowExternalMethods;
 			extMethodsItem.Click += delegate {
 				extMethodsItem.IsChecked = DebuggingOptions.Instance.ShowExternalMethods = !DebuggingOptions.Instance.ShowExternalMethods;
-				RefreshPad();
+				CallStackPad.InvalidateCallstackPad();
 			};
 			
 			MenuItem moduleItem = new MenuItem();
@@ -49,7 +49,7 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 			moduleItem.Click += delegate {
 				moduleItem.IsChecked = DebuggingOptions.Instance.ShowModuleNames = !DebuggingOptions.Instance.ShowModuleNames;
 				((GridView)view.View).Columns[0].Width = DebuggingOptions.Instance.ShowModuleNames ? 100d : 0d;
-				RefreshPad();
+				CallStackPad.InvalidateCallstackPad();
 			};
 			
 			MenuItem argNamesItem = new MenuItem();
@@ -57,7 +57,7 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 			argNamesItem.IsChecked = DebuggingOptions.Instance.ShowArgumentNames;
 			argNamesItem.Click += delegate {
 				argNamesItem.IsChecked = DebuggingOptions.Instance.ShowArgumentNames = !DebuggingOptions.Instance.ShowArgumentNames;
-				RefreshPad();
+				CallStackPad.InvalidateCallstackPad();
 			};
 			
 			MenuItem argValuesItem = new MenuItem();
@@ -65,7 +65,7 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 			argValuesItem.IsChecked = DebuggingOptions.Instance.ShowArgumentValues;
 			argValuesItem.Click += delegate {
 				argValuesItem.IsChecked = DebuggingOptions.Instance.ShowArgumentValues = !DebuggingOptions.Instance.ShowArgumentValues;
-				RefreshPad();
+				CallStackPad.InvalidateCallstackPad();
 			};
 			
 			MenuItem lineItem = new MenuItem();
@@ -74,7 +74,7 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 			lineItem.Click += delegate {
 				lineItem.IsChecked = DebuggingOptions.Instance.ShowLineNumbers = !DebuggingOptions.Instance.ShowLineNumbers;
 				((GridView)view.View).Columns[2].Width = DebuggingOptions.Instance.ShowLineNumbers ? 50d : 0d;
-				RefreshPad();
+				CallStackPad.InvalidateCallstackPad();
 			};
 			
 			return new ContextMenu() {
@@ -98,12 +98,12 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 			if (debuggedProcess != null) {
 				debuggedProcess.Paused += debuggedProcess_Paused;
 			}
-			RefreshPad();
+			CallStackPad.InvalidateCallstackPad();
 		}
 
 		void debuggedProcess_Paused(object sender, ProcessEventArgs e)
 		{
-			RefreshPad();
+			CallStackPad.InvalidateCallstackPad();
 		}
 		
 		void View_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
@@ -140,7 +140,7 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 			}
 		}
 		
-		public void RefreshPad()
+		internal void RefreshPad()
 		{
 			if (debuggedProcess == null || debuggedProcess.IsRunning || debuggedProcess.SelectedThread == null) {
 				view.ItemsSource = null;
@@ -278,6 +278,17 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 	{
 		CallStackPadContent callStackList;
 		
+		static CallStackPad instance;
+		
+		public static CallStackPad Instance {
+			get { return instance; }
+		}
+		
+		public CallStackPad()
+		{
+			instance = this;
+		}
+		
 		public override object Control {
 			get {
 				return callStackList;
@@ -294,9 +305,15 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 			callStackList.SelectProcess(process);
 		}
 		
-		public override void RefreshPad()
+		protected override void RefreshPad()
 		{
 			callStackList.RefreshPad();
 		}
+		
+		public static void InvalidateCallstackPad()
+		{
+			if (instance != null)
+				instance.InvalidatePad();
+		}
 	}
 }

src/AddIns/Debugger/Debugger.AddIn/Pads/Commands/WatchPadCommands.cs

@@ -49,7 +49,7 @@ namespace Debugger.AddIn
 						list.WatchItems.Add(text);
 				}
 				
-				pad.RefreshPad();
+				pad.InvalidatePad();
 			}
 		}
 	}
@@ -67,7 +67,7 @@ namespace Debugger.AddIn
 					return;
 				
 				list.WatchItems.Remove(node);
-				((WatchPad)this.Owner).RefreshPad();
+				((WatchPad)this.Owner).InvalidatePad();
 			}
 		}
 	}
@@ -77,7 +77,7 @@ namespace Debugger.AddIn
 		public override void Run()
 		{
 			if (this.Owner is WatchPad) {
-				((WatchPad)this.Owner).RefreshPad();
+				((WatchPad)this.Owner).InvalidatePad();
 			}
 		}
 	}

src/AddIns/Debugger/Debugger.AddIn/Pads/Controls/TreeNodeWrapper.cs

@@ -74,7 +74,7 @@ namespace Debugger.AddIn.Pads.Controls
 			if (!WatchPad.Instance.WatchList.WatchItems.Any(n => text.FullName == ((TreeNodeWrapper)n).Node.FullName))
 				WatchPad.Instance.WatchList.WatchItems.Add(node);
 			
-			WatchPad.Instance.RefreshPad();
+			WatchPad.Instance.InvalidatePad();
 		}
 	}
 }

src/AddIns/Debugger/Debugger.AddIn/Pads/Controls/WatchList.xaml.cs

@@ -60,8 +60,8 @@ namespace Debugger.AddIn.Pads.Controls
 			}
 			if (e.Key == Key.Enter || e.Key == Key.Escape) {
 				myList.UnselectAll();
-				LocalVarPad.Instance.RefreshPad();
-				WatchPad.Instance.RefreshPad();
+				LocalVarPad.Instance.InvalidatePad();
+				WatchPad.Instance.InvalidatePad();
 			}
 		}
 		
@@ -75,7 +75,7 @@ namespace Debugger.AddIn.Pads.Controls
 			SelectedNode.Node.Name = cell.CommandText;
 			myList.UnselectAll();
 			if (WatchType == WatchListType.Watch) {
-				WatchPad.Instance.RefreshPad();
+				WatchPad.Instance.InvalidatePad();
 			}
 			SelectedNode.IsEditing = false;
 		}

src/AddIns/Debugger/Debugger.AddIn/Pads/DebuggerPad.cs

@@ -28,7 +28,7 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 			
 			if (this.toolbar != null) {
 				this.toolbar.SetValue(DockPanel.DockProperty, Dock.Top);
-			
+				
 				this.panel.Children.Add(toolbar);
 			}
 			
@@ -53,8 +53,27 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 			
 		}
 		
-		public virtual void RefreshPad()
+		/// <summary>
+		/// Never call this directly. Always use InvalidatePad()
+		/// </summary>
+		protected virtual void RefreshPad()
+		{
+			
+		}
+		
+		bool invalidatePadEnqueued;
+		
+		public void InvalidatePad()
 		{
+			WorkbenchSingleton.AssertMainThread();
+			if (invalidatePadEnqueued || WorkbenchSingleton.Workbench == null)
+				return;
+			invalidatePadEnqueued = true;
+			WorkbenchSingleton.SafeThreadAsyncCall(
+				delegate {
+					invalidatePadEnqueued = false;
+					RefreshPad();
+				});
 			
 		}
 		

src/AddIns/Debugger/Debugger.AddIn/Pads/LoadedModulesPad.cs

@@ -51,7 +51,7 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 				debuggedProcess.Modules.Added += debuggedProcess_ModuleLoaded;
 				debuggedProcess.Modules.Removed += debuggedProcess_ModuleUnloaded;
 			}
-			RefreshPad();
+			InvalidatePad();
 		}
 		
 		void debuggedProcess_ModuleLoaded(object sender, CollectionItemEventArgs<Module> e)
@@ -64,7 +64,7 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 			RemoveModule(e.Item);
 		}
 		
-		public override void RefreshPad()
+		protected override void RefreshPad()
 		{
 			loadedModulesList.ItemCollection.Clear();
 			if (debuggedProcess != null) {

src/AddIns/Debugger/Debugger.AddIn/Pads/LocalVarPad.cs

@@ -46,15 +46,15 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 			if (debuggedProcess != null) {
 				debuggedProcess.Paused += debuggedProcess_Paused;
 			}
-			RefreshPad();
+			InvalidatePad();
 		}
 		
 		void debuggedProcess_Paused(object sender, ProcessEventArgs e)
 		{
-			RefreshPad();
+			InvalidatePad();
 		}
 		
-		public override void RefreshPad()
+		protected override void RefreshPad()
 		{
 			if (debuggedProcess == null || debuggedProcess.IsRunning) {
 				localVarList.WatchItems.Clear();

src/AddIns/Debugger/Debugger.AddIn/Pads/MemoryPad.cs

@@ -64,7 +64,7 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 			this.console = new ConsoleControl();
 			this.panel.Children.Add(console);
 			this.console.Encoding = Encoding.Default;
-			RefreshPad();
+			RefreshPad(); // exception
 			this.console.SetReadonly();
 			
 			DebuggerService.DebugStopped += DebuggerService_DebugStopped;

src/AddIns/Debugger/Debugger.AddIn/Pads/ObjectGraphPad.cs

@@ -37,7 +37,7 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 		}
 		
 		
-		public override void RefreshPad()
+		protected override void RefreshPad()
 		{
 			// BUG: if pad window is undocked and floats standalone, IsVisible == false (so pad won't refresh)
 			// REQUEST: need to refresh when pad becomes visible -> VisibleChanged event?
@@ -61,12 +61,12 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 			if (debuggedProcess != null) {
 				debuggedProcess.Paused += debuggedProcess_Paused;
 			}
-			RefreshPad();
+			InvalidatePad();
 		}
 		
 		void debuggedProcess_Paused(object sender, ProcessEventArgs e)
 		{
-			RefreshPad();
+			InvalidatePad();
 		}
 	}
 }

src/AddIns/Debugger/Debugger.AddIn/Pads/ParallelPad/ParallelStackPad.cs

@@ -62,10 +62,10 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 			DebuggerService.DebugStarted += OnReset;
 			DebuggerService.DebugStopped += OnReset;
 			
-			RefreshPad();
+			InvalidatePad();
 		}
 		
-		public override void RefreshPad()
+		protected override void RefreshPad()
 		{
 			if (debuggedProcess == null || debuggedProcess.IsRunning) {
 				return;
@@ -79,9 +79,7 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 				try {
 					// create all simple ThreadStacks
 					foreach (Thread thread in debuggedProcess.Threads) {
-						if (debuggedProcess.IsPaused) {
-							Utils.DoEvents(debuggedProcess);
-						}
+						Utils.DoEvents(debuggedProcess);
 						CreateThreadStack(thread);
 					}
 				}
@@ -136,7 +134,7 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 			get { return parallelStacksView; }
 			set {
 				parallelStacksView = value;
-				RefreshPad();
+				InvalidatePad();
 			}
 		}
 		
@@ -144,7 +142,7 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 			get { return isMethodView; }
 			set {
 				isMethodView = value;
-				RefreshPad();
+				InvalidatePad();
 			}
 		}
 		
@@ -168,7 +166,7 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 
 		private void OnProcessPaused(object sender, ProcessEventArgs e)
 		{
-			RefreshPad();
+			InvalidatePad();
 		}
 		
 		private void AddChildren(ThreadStack parent)
@@ -588,7 +586,7 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 			ToggleSelectedFrameBookmark(e.Location);
 			
 			if (isMethodView)
-				RefreshPad();
+				InvalidatePad();
 		}
 		
 		#endregion

src/AddIns/Debugger/Debugger.AddIn/Pads/RunningThreadsPad.Menu.cs

@@ -53,7 +53,7 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 				foreach(dynamic current in items) {
 					(current.Tag as Thread).Suspended = !suspended;
 				}
-				RefreshPad();
+				InvalidatePad();
 			};
 			
 			menu.Items.Add(freezeItem);

src/AddIns/Debugger/Debugger.AddIn/Pads/RunningThreadsPad.cs

@@ -65,12 +65,12 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 				debuggedProcess.Threads.Added        += debuggedProcess_ThreadStarted;
 			}
 			runningThreadsList.ItemCollection.Clear();
-			RefreshPad();
+			InvalidatePad();
 		}
 		
 		void debuggedProcess_Paused(object sender, ProcessEventArgs e)
 		{
-			RefreshPad();
+			InvalidatePad();
 		}
 		
 		void debuggedProcess_ThreadStarted(object sender, CollectionItemEventArgs<Thread> e)
@@ -78,7 +78,7 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 			AddThread(e.Item);
 		}
 		
-		public override void RefreshPad()
+		protected override void RefreshPad()
 		{
 			if (debuggedProcess == null || debuggedProcess.IsRunning) {
 				runningThreadsList.ItemCollection.Clear();
@@ -88,9 +88,7 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 			using(new PrintTimes("Threads refresh")) {
 				try {
 					foreach (Thread t in debuggedProcess.Threads) {
-						if (debuggedProcess.IsPaused) {
-							Utils.DoEvents(debuggedProcess);
-						}
+						Utils.DoEvents(debuggedProcess);
 						AddThread(t);
 					}
 				} catch(AbortedBecauseDebuggeeResumedException) {

src/AddIns/Debugger/Debugger.AddIn/Pads/WatchPad.cs

@@ -181,15 +181,15 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 				debuggedProcess.Paused += debuggedProcess_Paused;
 				debuggedProcess.Exited += ResetPad;
 			}
-			RefreshPad();
+			InvalidatePad();
 		}
 		
 		void debuggedProcess_Paused(object sender, ProcessEventArgs e)
 		{
-			RefreshPad();
+			InvalidatePad();
 		}
 		
-		public override void RefreshPad()
+		protected override void RefreshPad()
 		{
 			if (debuggedProcess == null || debuggedProcess.IsRunning)
 				return;

src/AddIns/Debugger/Debugger.AddIn/TreeModel/Utils.cs

@@ -10,6 +10,7 @@ using System.Windows.Threading;
 using Debugger.AddIn.Pads.Controls;
 using ICSharpCode.Core;
 using ICSharpCode.NRefactory.Ast;
+using ICSharpCode.SharpDevelop.Gui;
 using ICSharpCode.SharpDevelop.Services;
 
 namespace Debugger.AddIn.TreeModel
@@ -19,6 +20,7 @@ namespace Debugger.AddIn.TreeModel
 		/// <param name="process">Process on which to track debuggee state</param>
 		public static void DoEvents(Process process)
 		{
+			WorkbenchSingleton.AssertMainThread();
 			if (process == null) return;
 			DebuggeeState oldState = process.DebuggeeState;
 			WpfDoEvents();
@@ -31,6 +33,7 @@ namespace Debugger.AddIn.TreeModel
 		
 		public static void WpfDoEvents()
 		{
+			WorkbenchSingleton.AssertMainThread();
 			DispatcherFrame frame = new DispatcherFrame();
 			Dispatcher.CurrentDispatcher.BeginInvoke(DispatcherPriority.Background, new Action(() => frame.Continue = false));
 			Dispatcher.PushFrame(frame);