race condition

src/github.com/cmu440/p0/server_impl.go

@@ -9,47 +9,50 @@ 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.
 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;
  }
  }
 }