--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/main/java/suikwasha/distributedalgorithm/framework/Selector.java	Fri Oct 19 23:48:11 2012 +0900
@@ -0,0 +1,42 @@
+package suikwasha.distributedalgorithm.framework;
+
+import java.util.LinkedList;
+import java.util.concurrent.SynchronousQueue;
+
+public class Selector
+{
+	private final SynchronousQueue<Port> queue;
+	private final LinkedList<Port> watchList;
+	
+	public Selector()
+	{
+		queue = new SynchronousQueue<Port>();
+		watchList = new LinkedList<Port>();
+	}
+	
+	public void signal(Port _p)
+	{
+		queue.offer(_p);
+	}
+	
+	public void register(Port _p)
+	{
+		watchList.add(_p);
+	}
+	
+	public Port select() throws InterruptedException
+	{
+		Port availablePort;
+		int length = watchList.size();
+		for(int i = 0;i < length;i ++){
+			availablePort = watchList.poll();
+			if(availablePort.isReady()){
+				watchList.addLast(availablePort);
+				return availablePort;
+			}
+			watchList.addLast(availablePort);
+		}
+		
+		return queue.take();
+	}
+}