--- a/src/main/java/jp/ac/u_ryukyu/treevnc/MyRfbProto.java	Sat Jun 14 09:22:52 2014 +0900
+++ b/src/main/java/jp/ac/u_ryukyu/treevnc/MyRfbProto.java	Mon Jun 16 19:20:05 2014 +0900
@@ -208,7 +208,9 @@
 						writerRunning.set(2);
 						os.close();
 					} catch (IOException e1) {
+						System.out.println("root writer close faild :" + e1);
 					}
+					System.out.println("root writer faild :" + e);
 					/* if socket closed cliList.remove(newCli); */
 				}
 			}

--- a/src/main/java/jp/ac/u_ryukyu/treevnc/TreeVncCommand.java	Sat Jun 14 09:22:52 2014 +0900
+++ b/src/main/java/jp/ac/u_ryukyu/treevnc/TreeVncCommand.java	Mon Jun 16 19:20:05 2014 +0900
@@ -117,6 +117,10 @@
     private void handleLostParent(int port, String hostname) {
         rfb.viewer.fixLostParent(hostname,port);
     }
+    
+    public TreeCommand getCommand () {
+    	return command;
+    }
 
 
 }
\ No newline at end of file

--- a/src/main/java/jp/ac/u_ryukyu/treevnc/TreeVncCommandChannelListener.java	Sat Jun 14 09:22:52 2014 +0900
+++ b/src/main/java/jp/ac/u_ryukyu/treevnc/TreeVncCommandChannelListener.java	Mon Jun 16 19:20:05 2014 +0900
@@ -2,7 +2,8 @@
 import java.net.Socket;
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
-import java.util.concurrent.LinkedBlockingDeque;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.TimeUnit;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
@@ -18,7 +19,7 @@
     public MyRfbProto rfb = null;
     byte[] imageBytes;
     int port;
-    LinkedBlockingDeque<TreeVncCommand> cmdQueue = new LinkedBlockingDeque<TreeVncCommand>();
+    LinkedBlockingQueue<TreeVncCommand> cmdQueue = new LinkedBlockingQueue<TreeVncCommand>();
     private Thread acceptThread;
     protected final static String versionMsg_3_856 = "RFB 003.856\n";
     
@@ -29,16 +30,23 @@
     }
 
     public void commandMainLoop() {
-        acceptThread = new Thread(new Runnable() {
-            @Override
-            public void run() {
-                TreeVncCommand cmd;
-                do {
-                    cmd = cmdQueue.poll();
-                    cmd.handleTreeVncCommand();
-                } while (cmd!=null);
-            }
-        },"root-command-loop");
+    	acceptThread = new Thread(new Runnable() {
+    		@Override
+    		public void run() {
+    			TreeVncCommand cmd = null;
+    			do {
+    				try {
+    					cmd = cmdQueue.poll(0, TimeUnit.MILLISECONDS);
+    				} catch (InterruptedException e) {
+    					continue;
+    				}
+    				if (cmd!=null) {
+    					cmd.handleTreeVncCommand();
+    				}
+    			} while (cmd == null || cmd.getCommand() != TreeCommand.QUIT_LOOP);
+    		}
+    	},"root-command-loop");
+    	acceptThread.start();
     }
 
     public void run() {