add ActionQueue, rather than leaving random variables lying around in Game.cs

OpenRA.FileFormats/OpenRA.FileFormats.csproj

@@ -75,6 +75,7 @@
     <Compile Include="PackageEntry.cs" />
     <Compile Include="Palette.cs" />
     <Compile Include="PlayerColorRemap.cs" />
+    <Compile Include="Primitives\ActionQueue.cs" />
     <Compile Include="Primitives\DisposableAction.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="Thirdparty\Random.cs" />

OpenRA.FileFormats/Primitives/ActionQueue.cs

@@ -0,0 +1,40 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2010 The OpenRA Developers (see AUTHORS)
+ * This file is part of OpenRA, which is free software. It is made 
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation. For more information,
+ * see LICENSE.
+ */
+#endregion
+
+using System;
+
+namespace OpenRA.FileFormats
+{
+	/// <summary>
+	/// A thread-safe action queue, suitable for passing units of work between threads.
+	/// </summary>
+	public class ActionQueue
+	{
+		object syncRoot = new object();
+		Action actions = () => { };
+
+		public void Add(Action a)
+		{
+			lock (syncRoot)
+				actions += a;
+		}
+
+		public void PerformActions()
+		{
+			Action a;
+			lock (syncRoot)
+			{
+				a = actions; 
+				actions = () => { };
+			}
+			a();
+		}
+	}
+}

OpenRA.Game/Game.cs

@@ -102,9 +102,9 @@ namespace OpenRA
 			return Widget.OpenWindow(widget, new Dictionary<string,object>{{ "world", world }, { "orderManager", orderManager }, { "worldRenderer", worldRenderer }});
 		}
 
-		static object syncroot = new object();
-		static Action tickActions = () => {};
-		public static void RunAfterTick(Action a) { lock(syncroot) tickActions += a; }
+		static ActionQueue afterTickActions = new ActionQueue();
+		public static void RunAfterTick(Action a) { afterTickActions.Add(a); }
+
 		static void Tick( OrderManager orderManager, Viewport viewPort )
 		{
 			if (orderManager.Connection.ConnectionState != lastConnectionState)
@@ -128,9 +128,8 @@ namespace OpenRA
 			PerfHistory.items["batches"].Tick();
 
 			MasterServerQuery.Tick();
-			Action a;
-			lock(syncroot) { a = tickActions; tickActions = () => {}; }
-			a();
+
+			afterTickActions.PerformActions();
 		}
 
 		private static void Tick( OrderManager orderManager )