IEmulator now implements IDisposable; client now disposes cores

BizHawk.Emulation/Consoles/Calculator/TI83.cs

@@ -366,8 +366,7 @@ namespace BizHawk.Emulation.Consoles.Calculator
 		}
 		public IVideoProvider VideoProvider { get { return new MyVideoProvider(this); } }
 
-
-		public ISoundProvider SoundProvider { get { return new NullEmulator(); } }
+		public ISoundProvider SoundProvider { get { return NullSound.SilenceProvider; } }
 
 		public static readonly ControllerDefinition TI83Controller =
 			new ControllerDefinition
@@ -575,5 +574,7 @@ namespace BizHawk.Emulation.Consoles.Calculator
 		{
 			return null;
 		}
+
+        public void Dispose() { }
     }
 }

BizHawk.Emulation/Consoles/Gameboy/Gameboy.cs

@@ -855,5 +855,7 @@ namespace BizHawk.Emulation.Consoles.Gameboy
 		{
 			return null;
 		}
+
+        public void Dispose() {}
     }
 }

BizHawk.Emulation/Consoles/Nintendo/NES/NES.cs

@@ -460,7 +460,9 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			bw.Flush();
 			return ms.ToArray();
 		}
-	}
+
+        public void Dispose() {}
+    }
 }
 
 //todo

BizHawk.Emulation/Consoles/PC Engine/PCEngine.cs

@@ -308,5 +308,7 @@ namespace BizHawk.Emulation.Consoles.TurboGrafx
 					return null;
 			}
 		}
+
+        public void Dispose() {}
     }
 }

BizHawk.Emulation/Consoles/Sega/Genesis/Genesis.cs

@@ -195,5 +195,7 @@ namespace BizHawk.Emulation.Consoles.Sega
 		{
 			return null;
 		}
+
+        public void Dispose() {}
     }
 }

BizHawk.Emulation/Consoles/Sega/SMS/SMS.cs

@@ -379,5 +379,7 @@ namespace BizHawk.Emulation.Consoles.Sega
                 return DisplayType == DisplayType.NTSC ? 60d : 50d;
 			return null;
 		}
+
+        public void Dispose() {}
     }
 }

BizHawk.Emulation/Interfaces/Base Implementations/NullEmulator.cs

@@ -29,9 +29,6 @@ namespace BizHawk
         public ControllerDefinition ControllerDefinition { get { return NullController; } }
         public IController Controller { get; set; }
 
-        //public string GetControllersAsMnemonic() { return "|.|.|"; }
-        //public void SetControllersAsMnemonic(string mnemonic) { return; }
-
         public int Frame { get; set; }
         public int LagCount { get { return 0; } set { return; } }
         public bool IsLagFrame { get { return false; } }
@@ -53,10 +50,18 @@ namespace BizHawk
         private IList<MemoryDomain> memoryDomains;
         public IList<MemoryDomain> MemoryDomains { get { return memoryDomains; } }
         public MemoryDomain MainMemory { get { return memoryDomains[0]; } }
-
+        public void Dispose() { }
 		public object Query(EmulatorQuery query)
 		{
 			return null;
 		}
     }
+
+    public class NullSound : ISoundProvider
+    {
+        public static readonly NullSound SilenceProvider = new NullSound();
+
+        public void GetSamples(short[] samples) { }
+        public void DiscardSamples() { }
+    }
 }

BizHawk.Emulation/Interfaces/IEmulator.cs

@@ -4,7 +4,7 @@ using System.IO;
 
 namespace BizHawk
 {
-    public interface IEmulator
+    public interface IEmulator : IDisposable
     {
         IVideoProvider VideoProvider { get; }
         ISoundProvider SoundProvider { get; }

BizHawk.MultiClient/MainForm.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Collections.Generic;
 using System.Threading;
 using System.Drawing;
 using System.Drawing.Imaging;
@@ -720,6 +719,7 @@ namespace BizHawk.MultiClient
 				}
 
 				CloseGame();
+                Global.Emulator.Dispose();
 				Global.Emulator = nextEmulator;
 				Global.Game = game;
 				SyncControls();
@@ -795,6 +795,7 @@ namespace BizHawk.MultiClient
 				writer.Write(Global.Emulator.SaveRam, 0, len);
 				writer.Close();
 			}
+            Global.Emulator.Dispose();
 			Global.Emulator = new NullEmulator();
             Global.ActiveController = Global.NullControls;
             UserMovie.StopMovie();
@@ -1151,11 +1152,10 @@ namespace BizHawk.MultiClient
                     InputLog.GetMnemonic();
 			}
 
-			if(genSound)
+			if (genSound)
 				Global.Sound.UpdateSound(Global.Emulator.SoundProvider);
 			else
-				Global.Sound.UpdateSound(new NullEmulator()); //generates silence
-
+				Global.Sound.UpdateSound(NullSound.SilenceProvider);
 		}
 
         private void MakeScreenshot(string path)