implement ReaderWritelLockSlim to resolve threading issues

5 files changed, 168 insertions, 115 deletions

diff --git a/src/GraphicObjects/Docker.cs b/src/GraphicObjects/Docker.cs
index 3b66eb7e..c52c094f 100644
--- a/src/GraphicObjects/Docker.cs
+++ b/src/GraphicObjects/Docker.cs
@@ -146,14 +146,16 @@ namespace Crow
 				gr.Clip ();
 			}
 
-			lock (Children) {
-				foreach (GraphicObject g in Children) {
-					if (CurrentInterface.DragAndDropOperation?.DragSource == g)
-						continue;
-					g.Paint (ref gr);
-				}
+			childrenRWLock.EnterReadLock ();
+
+			foreach (GraphicObject g in Children) {
+				if (CurrentInterface.DragAndDropOperation?.DragSource == g)
+					continue;
+				g.Paint (ref gr);
 			}
 
+			childrenRWLock.ExitReadLock ();
+
 			if (showDockingTarget) {
 				Rectangle r;
 				if (mainStack == null)
diff --git a/src/GraphicObjects/GraphicObject.cs b/src/GraphicObjects/GraphicObject.cs
index d49cbe8f..f671239d 100644
--- a/src/GraphicObjects/GraphicObject.cs
+++ b/src/GraphicObjects/GraphicObject.cs
@@ -34,6 +34,7 @@ using System.Runtime.CompilerServices;
 using Cairo;
 using System.Diagnostics;
 using Crow.IML;
+using System.Threading;
 
 namespace Crow
 {
@@ -42,6 +43,8 @@ namespace Crow
 	/// </summary>
 	public class GraphicObject : ILayoutable, IValueChange, IDisposable
 	{
+		internal ReaderWriterLockSlim parentRWLock = new ReaderWriterLockSlim();
+
 		#region IDisposable implementation
 		protected bool disposed = false;
 
@@ -66,6 +69,7 @@ namespace Crow
 				if (IsQueueForRedraw)
 				throw new Exception("Trying to dispose an object queued for Redraw: " + this.ToString());
 				#endif
+
 				if (CurrentInterface.HoverWidget != null) {
 					if (CurrentInterface.HoverWidget.IsOrIsInside(this))
 						CurrentInterface.HoverWidget = null;
@@ -80,13 +84,15 @@ namespace Crow
 				}
 				if (!localDataSourceIsNull)
 					DataSource = null;
+
+				parentRWLock.EnterWriteLock();
 				parent = null;
+				parentRWLock.ExitWriteLock();
 			} else
 				Debug.WriteLine ("!!! Finalized by GC: {0}", this.ToString ());
 			Clipping?.Dispose ();
 			bmp?.Dispose ();
 			disposed = true;
-
 		}  
 		#endregion
 
@@ -217,7 +223,7 @@ namespace Crow
 		//TODO: we should ensure the whole parsed widget tree is the last painted
 		public Rectangle LastPaintedSlot;
 		/// <summary>Prevent requeuing multiple times the same widget</summary>
-		public bool IsQueueForRedraw = false;
+		public bool IsQueueForClipping = false;
 		/// <summary>drawing Cache, if null, a redraw is done, cached or not</summary>
 		public Surface bmp;
 		public bool IsDirty = true;
@@ -243,11 +249,12 @@ namespace Crow
 				if (parent == value)
 					return;
 				DataSourceChangeEventArgs e = new DataSourceChangeEventArgs (parent, value);
-				lock (CurrentInterface.LayoutMutex) {
-					parent = value;
-				}
-					onParentChanged (this, e);
-				
+
+				parentRWLock.EnterWriteLock();
+				parent = value;
+				parentRWLock.ExitWriteLock();
+									
+				onParentChanged (this, e);
 			}
 		}
 		[XmlIgnore]public ILayoutable LogicalParent {
@@ -774,7 +781,7 @@ namespace Crow
 		/// Seek first logical tree upward if logicalParent is set, or seek graphic tree for
 		/// a not null dataSource that will be active for all descendants having dataSource=null
 		/// </summary>
-		[XmlAttributeAttribute]//[DefaultValue(null)]
+		[XmlAttributeAttribute]
 		public virtual object DataSource {
 			set {
 				if (DataSource == value)
@@ -784,12 +791,11 @@ namespace Crow
 				dataSource = value;
 				dse.NewDataSource = DataSource;
 
-				//prevent setting null causing stack overflow in specific case
 				if (dse.NewDataSource == dse.OldDataSource)
 					return;
-				lock (CurrentInterface.LayoutMutex) {
-					OnDataSourceChanged (this, dse);
-				}
+			
+				OnDataSourceChanged (this, dse);
+
 
 				NotifyValueChanged ("DataSource", DataSource);
 			}
@@ -854,9 +860,9 @@ namespace Crow
 		/// <summary> Loads the default values from XML attributes default </summary>
 		public void loadDefaultValues()
 		{
-			#if DEBUG_LOAD
-			Debug.WriteLine ("LoadDefValues for " + this.ToString ());
-			#endif
+//			#if DEBUG_LOAD
+//			Debug.WriteLine ("LoadDefValues for " + this.ToString ());
+//			#endif
 
 			Type thisType = this.GetType ();
 
@@ -1138,13 +1144,12 @@ namespace Crow
 			#if DEBUG_UPDATE
 			Debug.WriteLine (string.Format("ClippingRegistration -> {0}", this.ToString ()));
 			#endif
-			lock(CurrentInterface.LayoutMutex){
-				IsQueueForRedraw = false;
-				if (Parent == null)
-					return;
+			parentRWLock.EnterReadLock ();
+			if (parent != null) {					
 				Parent.RegisterClip (LastPaintedSlot);
 				Parent.RegisterClip (Slot);
 			}
+			parentRWLock.ExitReadLock ();
 		}
 		/// <summary>
 		/// Add clip rectangle to this.clipping and propagate up to root
diff --git a/src/GraphicObjects/Group.cs b/src/GraphicObjects/Group.cs
index 1b5847d4..e7604842 100644
--- a/src/GraphicObjects/Group.cs
+++ b/src/GraphicObjects/Group.cs
@@ -31,12 +31,15 @@ using System.Xml.Serialization;
 using Cairo;
 using System.Diagnostics;
 using System.Reflection;
+using System.Threading;
 
 
 namespace Crow
 {
 	public class Group : GraphicObject
     {
+		protected ReaderWriterLockSlim childrenRWLock = new ReaderWriterLockSlim();
+
 		#region CTOR
 		public Group () : base() {}
 		public Group(Interface iface) : base(iface){}
@@ -62,10 +65,13 @@ namespace Crow
             set { _multiSelect = value; }
         }
 		public virtual void AddChild(GraphicObject g){
-			lock (Children) {
-				g.Parent = this;
-				Children.Add (g);
-			}
+			childrenRWLock.EnterWriteLock();
+
+			g.Parent = this;
+			Children.Add (g);
+
+			childrenRWLock.ExitWriteLock();
+
 			g.RegisteredLayoutings = LayoutingType.None;
 			g.LayoutChanged += OnChildLayoutChanges;
 			g.RegisterForLayouting (LayoutingType.Sizing | LayoutingType.ArrangeChildren);
@@ -79,8 +85,11 @@ namespace Crow
 					CurrentInterface.HoverWidget = null;
 			}
 
-			lock (Children)
-				Children.Remove(child);
+			childrenRWLock.EnterWriteLock ();
+
+			Children.Remove(child);
+
+			childrenRWLock.ExitWriteLock ();
 
 			if (child == largestChild && Width == Measure.Fit)
 				searchLargestChild ();
@@ -96,10 +105,13 @@ namespace Crow
 			child.Dispose ();
         }
 		public virtual void InsertChild (int idx, GraphicObject g) {
-			lock (Children) {
-				g.Parent = this;
-				Children.Insert (idx, g);
-			}
+			childrenRWLock.EnterWriteLock ();
+				
+			g.Parent = this;
+			Children.Insert (idx, g);
+
+			childrenRWLock.ExitWriteLock ();
+
 			g.RegisteredLayoutings = LayoutingType.None;
 			g.LayoutChanged += OnChildLayoutChanges;
 			g.RegisterForLayouting (LayoutingType.Sizing | LayoutingType.ArrangeChildren);
@@ -109,15 +121,17 @@ namespace Crow
 		}
 		public virtual void ClearChildren()
 		{
-			lock (Children) {
-				while (Children.Count > 0) {
-					GraphicObject g = Children [Children.Count - 1];
-					g.LayoutChanged -= OnChildLayoutChanges;
-					Children.RemoveAt (Children.Count - 1);
-					g.Dispose ();
-				}
+			childrenRWLock.EnterWriteLock ();
+
+			while (Children.Count > 0) {
+				GraphicObject g = Children [Children.Count - 1];
+				g.LayoutChanged -= OnChildLayoutChanges;
+				Children.RemoveAt (Children.Count - 1);
+				g.Dispose ();
 			}
 
+			childrenRWLock.ExitWriteLock ();
+
 			resetChildrenMaxSize ();
 
 			this.RegisterForLayouting (LayoutingType.Sizing);
@@ -128,20 +142,24 @@ namespace Crow
 		{
 			if (Children.Contains(w))
 			{
-				lock (Children) {
-					Children.Remove (w);
-					Children.Add (w);
-				}
+				childrenRWLock.EnterWriteLock ();
+
+				Children.Remove (w);
+				Children.Add (w);
+
+				childrenRWLock.ExitWriteLock ();
 			}
 		}
 		public void putWidgetOnBottom(GraphicObject w)
 		{
 			if (Children.Contains(w))
 			{
-				lock (Children) {
-					Children.Remove (w);
-					Children.Insert (0, w);
-				}
+				childrenRWLock.EnterWriteLock ();
+
+				Children.Remove (w);
+				Children.Insert (0, w);
+
+				childrenRWLock.ExitWriteLock ();
 			}
 		}
 
@@ -149,24 +167,31 @@ namespace Crow
 		public override void OnDataSourceChanged (object sender, DataSourceChangeEventArgs e)
 		{
 			base.OnDataSourceChanged (this, e);
-			lock (Children) {
-				foreach (GraphicObject g in children)
-					if (g.localDataSourceIsNull & g.localLogicalParentIsNull)
-						g.OnDataSourceChanged (g, e);
-			}
+
+			childrenRWLock.EnterReadLock ();
+
+			foreach (GraphicObject g in children)
+				if (g.localDataSourceIsNull & g.localLogicalParentIsNull)
+					g.OnDataSourceChanged (g, e);
+			
+			childrenRWLock.ExitReadLock ();
 		}
 		public override GraphicObject FindByName (string nameToFind)
 		{
 			if (Name == nameToFind)
 				return this;
 			GraphicObject tmp = null;
-			lock (Children) {
-				foreach (GraphicObject w in Children) {
-					tmp = w.FindByName (nameToFind);
-					if (tmp != null)
-						break;
-				}
+
+			childrenRWLock.EnterReadLock ();
+
+			foreach (GraphicObject w in Children) {
+				tmp = w.FindByName (nameToFind);
+				if (tmp != null)
+					break;
 			}
+
+			childrenRWLock.ExitReadLock ();
+
 			return tmp;
 		}
 		public override bool Contains (GraphicObject goToFind)
@@ -207,10 +232,11 @@ namespace Crow
 		{
 			base.OnLayoutChanges (layoutType);
 
+			childrenRWLock.EnterReadLock ();
 			//position smaller objects in group when group size is fit
 			switch (layoutType) {
 			case LayoutingType.Width:
-				foreach (GraphicObject c in Children){
+				foreach (GraphicObject c in Children) {
 					if (c.Width.Units == Unit.Percent)
 						c.RegisterForLayouting (LayoutingType.Width);
 					else
@@ -226,6 +252,7 @@ namespace Crow
 				}
 				break;
 			}
+			childrenRWLock.ExitReadLock ();
 		}
 		protected override void onDraw (Context gr)
 		{
@@ -239,11 +266,13 @@ namespace Crow
 				gr.Clip ();
 			}
 
-			lock (Children) {
+			childrenRWLock.EnterReadLock ();
+
 				foreach (GraphicObject g in Children) {
 					g.Paint (ref gr);
 				}
-			}
+
+			childrenRWLock.ExitReadLock ();
 			gr.Restore ();
 		}
 		protected override void UpdateCache (Context ctx)
@@ -268,16 +297,18 @@ namespace Crow
 					gr.Clip ();
 				}
 
-				lock (Children) {
-					foreach (GraphicObject c in Children) {
-						if (!c.Visible)
-							continue;
-						if (Clipping.Contains (c.Slot + ClientRectangle.Position) == RegionOverlap.Out)
-							continue;
-						c.Paint (ref gr);
-					}
+				childrenRWLock.EnterReadLock ();
+
+				foreach (GraphicObject c in Children) {
+					if (!c.Visible)
+						continue;
+					if (Clipping.Contains (c.Slot + ClientRectangle.Position) == RegionOverlap.Out)
+						continue;
+					c.Paint (ref gr);
 				}
 
+				childrenRWLock.ExitReadLock ();
+
 				#if DEBUG_CLIP_RECTANGLE
 				Clipping.stroke (gr, Color.Amaranth.AdjustAlpha (0.8));
 				#endif
diff --git a/src/GraphicObjects/TabView.cs b/src/GraphicObjects/TabView.cs
index c5292da7..abaa6ac0 100644
--- a/src/GraphicObjects/TabView.cs
+++ b/src/GraphicObjects/TabView.cs
@@ -176,17 +176,20 @@ namespace Crow
 				gr.Clip ();
 			}
 
-			lock (Children) {
-				TabItem[] tabItms = Children.Cast<TabItem> ().OrderBy (t => t.ViewIndex).ToArray ();
-				for (int i = 0; i < tabItms.Length; i++) {
-					if (tabItms [i] == Children [SelectedTab])
-						continue;
-					tabItms [i].Paint (ref gr);
-				}
+			childrenRWLock.EnterReadLock ();
 
-				if (SelectedTab < tabItms.Length && SelectedTab >= 0)
-					Children [SelectedTab].Paint (ref gr);
+			TabItem[] tabItms = Children.Cast<TabItem> ().OrderBy (t => t.ViewIndex).ToArray ();
+			for (int i = 0; i < tabItms.Length; i++) {
+				if (tabItms [i] == Children [SelectedTab])
+					continue;
+				tabItms [i].Paint (ref gr);
 			}
+
+			if (SelectedTab < tabItms.Length && SelectedTab >= 0)
+				Children [SelectedTab].Paint (ref gr);
+
+			childrenRWLock.ExitReadLock ();
+		
 			gr.Restore ();
 		}
 
diff --git a/src/GraphicObjects/Wrapper.cs b/src/GraphicObjects/Wrapper.cs
index e56d9332..4fff17ff 100644
--- a/src/GraphicObjects/Wrapper.cs
+++ b/src/GraphicObjects/Wrapper.cs
@@ -131,26 +131,32 @@ namespace Crow
 				else {
 					int dy = 0;
 					int largestChild = 0;
-					lock (Children) {
-						foreach (GraphicObject c in Children) {
-							if (!c.Visible)
-								continue;
-							if (c.Height.Units == Unit.Percent &&
-								c.RegisteredLayoutings.HasFlag (LayoutingType.Height))
-								return -1;
-							if (dy + c.Slot.Height > ClientRectangle.Height) {
-								dy = 0;
-								tmp += largestChild + Spacing;
-								largestChild = c.Slot.Width;
-							} else if (largestChild < c.Slot.Width)
-								largestChild = c.Slot.Width;
 
-							dy += c.Slot.Height + Spacing;
+					childrenRWLock.EnterReadLock();
+
+					foreach (GraphicObject c in Children) {
+						if (!c.Visible)
+							continue;
+						if (c.Height.Units == Unit.Percent &&
+						    c.RegisteredLayoutings.HasFlag (LayoutingType.Height)) {
+							childrenRWLock.ExitReadLock();
+							return -1;
 						}
-						if (dy == 0)
-							tmp -= Spacing;
-						return tmp + largestChild + 2 * Margin;
+						if (dy + c.Slot.Height > ClientRectangle.Height) {
+							dy = 0;
+							tmp += largestChild + Spacing;
+							largestChild = c.Slot.Width;
+						} else if (largestChild < c.Slot.Width)
+							largestChild = c.Slot.Width;
+
+						dy += c.Slot.Height + Spacing;
 					}
+
+					childrenRWLock.ExitReadLock ();
+
+					if (dy == 0)
+						tmp -= Spacing;
+					return tmp + largestChild + 2 * Margin;
 				}
 			} else if (Orientation == Orientation.Horizontal) {
 				Height = Measure.Stretched;
@@ -160,26 +166,32 @@ namespace Crow
 			else {
 				int dx = 0;
 				int tallestChild = 0;
-				lock (Children) {
-					foreach (GraphicObject c in Children) {
-						if (!c.Visible)
-							continue;
-						if (c.Width.Units == Unit.Percent &&
-							c.RegisteredLayoutings.HasFlag (LayoutingType.Width))
-							return -1;
-						if (dx + c.Slot.Width > ClientRectangle.Width) {
-							dx = 0;
-							tmp += tallestChild + Spacing;
-							tallestChild = c.Slot.Height;
-						} else if (tallestChild < c.Slot.Height)
-							tallestChild = c.Slot.Height;
 
-						dx += c.Slot.Width + Spacing;
+				childrenRWLock.EnterReadLock();
+
+				foreach (GraphicObject c in Children) {
+					if (!c.Visible)
+						continue;
+					if (c.Width.Units == Unit.Percent &&
+					    c.RegisteredLayoutings.HasFlag (LayoutingType.Width)) {
+						childrenRWLock.ExitReadLock();
+						return -1;
 					}
-					if (dx == 0)
-						tmp -= Spacing;
-					return tmp + tallestChild + 2 * Margin;
+					if (dx + c.Slot.Width > ClientRectangle.Width) {
+						dx = 0;
+						tmp += tallestChild + Spacing;
+						tallestChild = c.Slot.Height;
+					} else if (tallestChild < c.Slot.Height)
+						tallestChild = c.Slot.Height;
+
+					dx += c.Slot.Width + Spacing;
 				}
+
+				childrenRWLock.ExitReadLock();
+
+				if (dx == 0)
+					tmp -= Spacing;
+				return tmp + tallestChild + 2 * Margin;
 			}
 		}