Remove half-baked thread-safety mechanisms from Sheet.

Sheet is now thread-unsafe, rather than attempting to expose a dodgy thread safety model.

OpenRA.Game/Graphics/Sheet.cs

@@ -18,7 +18,6 @@ namespace OpenRA.Graphics
 {
 	public sealed class Sheet : IDisposable
 	{
-		readonly object textureLock = new object();
 		bool dirty;
 		bool releaseBufferOnCommit;
 		ITexture texture;
@@ -66,33 +65,21 @@ namespace OpenRA.Graphics
 
 		public ITexture GetTexture()
 		{
-			// This is only called from the main thread but 'dirty'
-			// is set from other threads too via CommitData().
-			GenerateTexture();
-			return texture;
-		}
-
-		void GenerateTexture()
-		{
-			lock (textureLock)
+			if (texture == null)
 			{
-				if (texture == null)
-				{
-					texture = Game.Renderer.Device.CreateTexture();
-					dirty = true;
-				}
-
-				if (data != null)
-				{
-					if (dirty)
-					{
-						texture.SetData(data, Size.Width, Size.Height);
-						dirty = false;
-						if (releaseBufferOnCommit)
-							data = null;
-					}
-				}
+				texture = Game.Renderer.Device.CreateTexture();
+				dirty = true;
 			}
+
+			if (data != null && dirty)
+			{
+				texture.SetData(data, Size.Width, Size.Height);
+				dirty = false;
+				if (releaseBufferOnCommit)
+					data = null;
+			}
+
+			return texture;
 		}
 
 		public Bitmap AsBitmap()
@@ -141,41 +128,32 @@ namespace OpenRA.Graphics
 
 		public void CreateBuffer()
 		{
-			lock (textureLock)
-			{
-				if (data != null)
-					return;
-				if (texture == null)
-					data = new byte[4 * Size.Width * Size.Height];
-				else
-					data = texture.GetData();
-				releaseBufferOnCommit = false;
-			}
+			if (data != null)
+				return;
+			if (texture == null)
+				data = new byte[4 * Size.Width * Size.Height];
+			else
+				data = texture.GetData();
+			releaseBufferOnCommit = false;
 		}
 
-		public void CommitData()
+		public void CommitBufferedData()
 		{
-			lock (textureLock)
-			{
-				if (!Buffered)
-					throw new InvalidOperationException(
-						"This sheet is unbuffered. You cannot call CommitData on an unbuffered sheet. " +
-						"If you need to completely replace the texture data you should set data into the texture directly. " +
-						"If you need to make only small changes to the texture data consider creating a buffered sheet instead.");
+			if (!Buffered)
+				throw new InvalidOperationException(
+					"This sheet is unbuffered. You cannot call CommitBufferedData on an unbuffered sheet. " +
+					"If you need to completely replace the texture data you should set data into the texture directly. " +
+					"If you need to make only small changes to the texture data consider creating a buffered sheet instead.");
 
-				dirty = true;
-			}
+			dirty = true;
 		}
 
 		public void ReleaseBuffer()
 		{
-			lock (textureLock)
-			{
-				if (!Buffered)
-					return;
-				dirty = true;
-				releaseBufferOnCommit = true;
-			}
+			if (!Buffered)
+				return;
+			dirty = true;
+			releaseBufferOnCommit = true;
 		}
 
 		public void Dispose()

OpenRA.Game/Graphics/SheetBuilder.cs

@@ -70,7 +70,7 @@ namespace OpenRA.Graphics
 
 			var rect = Allocate(size, spriteOffset);
 			Util.FastCopyIntoChannel(rect, src);
-			current.CommitData();
+			current.CommitBufferedData();
 			return rect;
 		}
 
@@ -78,7 +78,7 @@ namespace OpenRA.Graphics
 		{
 			var rect = Allocate(src.Size);
 			Util.FastCopyIntoSprite(rect, src);
-			current.CommitData();
+			current.CommitBufferedData();
 			return rect;
 		}
 

OpenRA.Game/Graphics/SpriteFont.cs

@@ -136,7 +136,7 @@ namespace OpenRA.Graphics
 					}
 				}
 
-			s.Sheet.CommitData();
+			s.Sheet.CommitBufferedData();
 
 			return g;
 		}

OpenRA.Game/Graphics/VoxelLoader.cs

@@ -86,7 +86,7 @@ namespace OpenRA.Graphics
 			var s = sheetBuilder.Allocate(new Size(su, sv));
 			Util.FastCopyIntoChannel(s, 0, colors);
 			Util.FastCopyIntoChannel(s, 1, normals);
-			s.Sheet.CommitData();
+			s.Sheet.CommitBufferedData();
 
 			var channelP = ChannelSelect[(int)s.Channel];
 			var channelC = ChannelSelect[(int)s.Channel + 1];

OpenRA.Mods.Common/Widgets/RadarWidget.cs

@@ -216,7 +216,7 @@ namespace OpenRA.Mods.Common.Widgets
 				dirtyShroudCells.Clear();
 			}
 
-			radarSheet.CommitData();
+			radarSheet.CommitBufferedData();
 
 			var o = new float2(mapRect.Location.X, mapRect.Location.Y + world.Map.Bounds.Height * previewScale * (1 - radarMinimapHeight) / 2);
 			var s = new float2(mapRect.Size.Width, mapRect.Size.Height * radarMinimapHeight);