Moved LuaReference into its own class, added ways for finalization

.classpath

@@ -5,5 +5,10 @@
 	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.6"/>
 	<classpathentry kind="con" path="org.eclipse.jdt.junit.JUNIT_CONTAINER/4"/>
 	<classpathentry kind="lib" path="lua.jar"/>
+	<classpathentry kind="lib" path="/home/dafrito/mirrors/guava-libraries/target/guava-r07-SNAPSHOT.jar" sourcepath="/home/dafrito/mirrors/guava-libraries/src">
+		<attributes>
+			<attribute name="javadoc_location" value="file:/home/dafrito/mirrors/guava-libraries/javadoc/"/>
+		</attributes>
+	</classpathentry>
 	<classpathentry kind="output" path="bin"/>
 </classpath>

src/com/dafrito/lua/script/LuaReference.java

@@ -0,0 +1,73 @@
+package com.dafrito.lua.script;
+
+import java.util.concurrent.atomic.AtomicInteger;
+
+import com.google.common.base.FinalizablePhantomReference;
+import com.google.common.base.FinalizableReferenceQueue;
+
+import lua.LuaLibrary;
+import lua.LuaLibrary.lua_State;
+
+public class LuaReference {
+	private static final FinalizableReferenceQueue queue = new FinalizableReferenceQueue();
+	private static final LuaLibrary lua = LuaLibrary.INSTANCE;
+
+	private final LuaBindings b;
+	private AtomicInteger ref;
+	private final LuaPhantomReference finalizer;
+
+	public LuaReference(LuaBindings b) {
+		this.b = b;
+		this.ref = new AtomicInteger(lua.luaL_ref(b.getState(), LuaLibrary.LUA_REGISTRYINDEX));
+		this.finalizer = new LuaPhantomReference(this, queue);
+		check();
+	}
+
+	public LuaBindings getBindings() {
+		return this.b;
+	}
+
+	public void get() {
+		check();
+		lua.lua_rawgeti(b.getState(), LuaLibrary.LUA_REGISTRYINDEX, this.ref.get());
+	}
+
+	private void check() {
+		if (this.isClosed()) {
+			throw new RuntimeException();
+		}
+	}
+
+	public boolean isClosed() {
+		return this.ref.get() == LuaLibrary.LUA_REFNIL;
+	}
+
+	public void close() {
+		this.finalizer.close();
+	}
+
+	private static class LuaPhantomReference extends FinalizablePhantomReference<LuaReference> {
+
+		private AtomicInteger ref;
+		private lua_State state;
+
+		protected LuaPhantomReference(LuaReference referent, FinalizableReferenceQueue queue) {
+			super(referent, queue);
+			this.state = referent.getBindings().getState();
+			this.ref = referent.ref;
+		}
+
+		public void close() {
+			int v = this.ref.getAndSet(LuaLibrary.LUA_REFNIL);
+			if(v != LuaLibrary.LUA_REFNIL) {
+				lua.luaL_unref(state, LuaLibrary.LUA_REGISTRYINDEX, v);	
+			}
+		}
+
+		@Override
+		public void finalizeReferent() {
+			this.close();
+		}
+	}
+
+}

test/com/dafrito/lua/script/LuaTableTest.java

@@ -54,42 +54,4 @@ public void set(Object k, Object v) {
 			lua.lua_settop(s, -2);
 		}
 	}
-
-	class LuaReference {
-		private final LuaBindings b;
-		private int ref;
-
-		public LuaReference(LuaBindings b) {
-			this.b = b;
-			this.ref = lua.luaL_ref(b.getState(), LuaLibrary.LUA_REGISTRYINDEX);
-			check();
-		}
-
-		public LuaBindings getBindings() {
-			return this.b;
-		}
-
-		public void get() {
-			check();
-			lua.lua_rawgeti(b.getState(), LuaLibrary.LUA_REGISTRYINDEX, this.ref);
-		}
-
-		private void check() {
-			if (this.isClosed()) {
-				throw new RuntimeException();
-			}
-		}
-
-		public boolean isClosed() {
-			return this.ref == LuaLibrary.LUA_REFNIL;
-		}
-
-		public void close() {
-			if (this.isClosed()) {
-				return;
-			}
-			lua.luaL_unref(b.getState(), LuaLibrary.LUA_REGISTRYINDEX, this.ref);
-			this.ref = LuaLibrary.LUA_REFNIL;
-		}
-	}
 }