diff --git a/src/github.com/cmu440/p0/server_impl.go b/src/github.com/cmu440/p0/server_impl.go
index 52792e1..0480901 100644
--- a/src/github.com/cmu440/p0/server_impl.go
+++ b/src/github.com/cmu440/p0/server_impl.go
@@ -9,11 +9,14 @@ import (
 )
 
 type multiEchoServer struct {
-    clients map[string] net.Conn
-    clientMsgs map[string] chan([] byte)
-    listener net.Listener
-    read chan []byte
-    stop bool
+    clients          map[string] net.Conn
+    clientMsgs       map[string] chan([] byte)
+    listener         net.Listener
+    readChan         chan []byte
+    closeCliChan     chan string
+    addCliChan       chan net.Conn
+    countRequestChan chan chan int
+    closeChan        chan bool
 }
 
 // New creates and returns (but does not start) a new MultiEchoServer.
@@ -21,35 +24,35 @@ func New() MultiEchoServer {
     mes := &multiEchoServer{
         clients: make(map[string] net.Conn),
         clientMsgs: make(map[string] chan([]byte)),
-        read: make(chan([]byte)),
-        stop: false,
+        readChan: make(chan([]byte)),
+        closeCliChan: make(chan string),
+        addCliChan: make(chan net.Conn),
+        countRequestChan: make(chan chan int),
+        closeChan: make(chan bool),
     }
     return MultiEchoServer(mes);
 }
 
 func (mes *multiEchoServer) Start(port int) error {
-    mes.stop = false;
     listener, e := net.Listen("tcp", fmt.Sprintf(":%d", port));
     if e != nil {
         fmt.Println("listen tcp failed");
         return e;
     }
     mes.listener = listener;
-    go mes.handleListen();
-    go mes.handleDistributeMsg();
+    go mes.handleEvent();
+    go mes.handleAccept();
     return nil;
 }
 
 func (mes *multiEchoServer) Close() {
-    mes.stop = true;
-    mes.listener.Close();
-    for _, conn := range mes.clients{
-        conn.Close();
-    }
+    mes.closeChan <- true;
 }
 
 func (mes *multiEchoServer) Count() int {
-    return len(mes.clients);
+    countChan := make(chan int);
+    mes.countRequestChan<-countChan;
+    return <-countChan;
 }
 
 // TODO: add additional methods/functions below!
@@ -59,12 +62,10 @@ func (mes *multiEchoServer) handleConn(conn net.Conn) {
     for {
         line, e := reader.ReadBytes('\n');
         if  e != nil{
-            fmt.Println("read close connetion, client : " + conn.RemoteAddr().String());
-            delete(mes.clients, conn.RemoteAddr().String());
-            conn.Close();
+            mes.closeCliChan <-conn.RemoteAddr().String();
             return;
         }
-        mes.read <- line;
+        mes.readChan <- line;
     }
 }
 
@@ -74,37 +75,53 @@ func (mes *multiEchoServer) handleWrite(conn net.Conn) {
         msg := <- msgChan;
         _, e := conn.Write(msg);
         if e != nil {
-            delete(mes.clients, conn.RemoteAddr().String());
+            mes.closeCliChan <-conn.RemoteAddr().String();
+            return;
         }
     }
 }
 
-func (mes *multiEchoServer) handleListen() {
+func (mes *multiEchoServer) handleAccept() {
     for {
         conn, e := mes.listener.Accept();
         if e != nil {
-            if mes.stop == true {
-                fmt.Println("listen stop")
-                return
-            }
-            continue;
-        }
-        if _, ok := mes.clientMsgs[conn.RemoteAddr().String()]; !ok {
-            mes.clientMsgs[conn.RemoteAddr().String()] = make(chan []byte, 100);
+            fmt.Println("listen stop")
+            return
         }
-        mes.clients[conn.RemoteAddr().String()] = conn;
-        go mes.handleConn(conn);
+        mes.addCliChan<-conn;
     }
 }
 
-func (mes *multiEchoServer) handleDistributeMsg()  {
+func (mes *multiEchoServer) handleEvent() {
     for {
-        line := <- mes.read;
-        for key, _ := range mes.clients {
-            msgChan := mes.clientMsgs[key];
-            if len(msgChan) < 100 {
-                msgChan <- line;
+        select {
+        case line := <-mes.readChan:
+            for key, _ := range mes.clients {
+                msgChan := mes.clientMsgs[key];
+                if len(msgChan) < 100 {
+                    msgChan <- line;
+                }
             }
+        case addr := <-mes.closeCliChan:
+            if conn, ok := mes.clients[addr]; ok {
+                conn.Close();
+                delete(mes.clients, addr);
+            }
+        case countChan := <-mes.countRequestChan:
+            cnt := len(mes.clients);
+            countChan<-cnt;
+        case conn := <-mes.addCliChan:
+            if _, ok := mes.clientMsgs[conn.RemoteAddr().String()]; !ok {
+                mes.clientMsgs[conn.RemoteAddr().String()] = make(chan []byte, 100);
+            }
+            mes.clients[conn.RemoteAddr().String()] = conn;
+            go mes.handleConn(conn);
+        case <-mes.closeChan:
+            mes.listener.Close();
+            for _, conn := range mes.clients {
+                conn.Close();
+            }
+            return;
         }
     }
 }
\ No newline at end of file