fix refresh bugs in CallStackPad

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

@@ -3,12 +3,12 @@
 
 using System;
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using System.Linq;
 using System.Text;
 using System.Windows.Controls;
 using System.Windows.Input;
 using System.Windows.Media;
-
 using Debugger;
 using Debugger.AddIn.TreeModel;
 using ICSharpCode.Core;
@@ -147,24 +147,21 @@ internal void RefreshPad()
 				return;
 			}
 
-			List<CallStackItem> items = new List<CallStackItem>();
+			var items = new ObservableCollection<CallStackItem>();
 			using(new PrintTimes("Callstack refresh")) {
 				bool showExternalMethods = DebuggingOptions.Instance.ShowExternalMethods;
-				bool lastItemIsExternalMethod = false;
+			bool previousItemIsExternalMethod = false;
 
-				foreach (StackFrame frame in debuggedProcess.SelectedThread.GetCallstack(100)) {
-					StackFrame f = frame;
-					debuggedProcess.EnqueueWork(
+			debuggedProcess.EnqueueForEach(
 						Dispatcher,
-						delegate {
-							items.AddIfNotNull(CreateItem(f, showExternalMethods, ref lastItemIsExternalMethod));
-						});
-				}
+				debuggedProcess.SelectedThread.GetCallstack(100),
+				f => items.AddIfNotNull(CreateItem(f, showExternalMethods, ref previousItemIsExternalMethod))
+			);
 			}
 			view.ItemsSource = items;
 		}
 
-		CallStackItem CreateItem(StackFrame frame, bool showExternalMethods, ref bool lastItemIsExternalMethod)
+		CallStackItem CreateItem(StackFrame frame, bool showExternalMethods, ref bool previousItemIsExternalMethod)
 		{
 			CallStackItem item;
 
@@ -187,16 +184,16 @@ CallStackItem CreateItem(StackFrame frame, bool showExternalMethods, ref bool la
 				item = new CallStackItem() {
 					Name = GetFullName(frame), Language = "", Line = lineNumber, ModuleName = moduleName
 				};
-				lastItemIsExternalMethod = false;
+				previousItemIsExternalMethod = false;
 				item.Frame = frame;
 			} else {
 				// Show [External methods] in the list
-				if (lastItemIsExternalMethod) return null;
+				if (previousItemIsExternalMethod) return null;
 				item = new CallStackItem() {
 					Name = ResourceService.GetString("MainWindow.Windows.Debug.CallStack.ExternalMethods"),
 					Language = ""
 				};
-				lastItemIsExternalMethod = true;
+				previousItemIsExternalMethod = true;
 			}
 
 			return item;

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

@@ -2,10 +2,11 @@
 // This code is distributed under the BSD license (for details please see \src\AddIns\Debugger\Debugger.AddIn\license.txt)
 
 using System;
-using System.Collections;
+using System.Collections.Generic;
 using System.Reflection;
 using System.Windows.Forms;
 using System.Windows.Threading;
+
 using Debugger.AddIn.Pads.Controls;
 using ICSharpCode.Core;
 using ICSharpCode.NRefactory.Ast;
@@ -40,6 +41,49 @@ public static void EnqueueWork(this Process process, Dispatcher dispatcher, Acti
 				}
 			);
 		}
+
+		public static void EnqueueForEach<T>(this Process process, Dispatcher dispatcher, IList<T> items, Action<T> work)
+		{
+			DebuggeeState debuggeeStateWhenEnqueued = process.DebuggeeState;
+
+			dispatcher.BeginInvoke(
+				DispatcherPriority.Normal,
+				(Action)delegate { ProcessItems(process, dispatcher, 0, items, work, debuggeeStateWhenEnqueued); }
+			);
+		}
+
+		static void ProcessItems<T>(Process process, Dispatcher dispatcher, int startIndex, IList<T> items, Action<T> work, DebuggeeState debuggeeStateWhenEnqueued)
+		{
+			var watch = new System.Diagnostics.Stopwatch();
+			watch.Start();
+
+			for (int i = startIndex; i < items.Count; i++) {
+				int index = i;
+				if (process.IsPaused && debuggeeStateWhenEnqueued == process.DebuggeeState) {
+					try {
+						// Do the work, this may recursively enqueue more work
+						work(items[index]);
+					} catch (System.Exception ex) {
+						if (process == null || process.HasExited) {
+							// Process unexpectedly exited - silently ignore
+						} else {
+							MessageService.ShowException(ex);
+						}
+						break;
+					}
+				}
+
+				// if we are too slow move to background
+				if (watch.ElapsedMilliseconds > 100) {
+					dispatcher.BeginInvoke(
+						DispatcherPriority.Background,
+						(Action)delegate { ProcessItems(process, dispatcher, index, items, work, debuggeeStateWhenEnqueued); }
+					);
+					break;
+				}
+			}
+		}
+
 	}
 
 	public class AbortedBecauseDebuggeeResumedException: System.Exception